Commit Graph

338 Commits

Author SHA1 Message Date
Zhangjin Wu
ded8af47c2 tools/nolibc: aarch64: shrink _start with _start_c
move most of the _start operations to _start_c(), include the
stackprotector initialization.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
61f9880721 tools/nolibc: arm: shrink _start with _start_c
move most of the _start operations to _start_c(), include the
stackprotector initialization.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
06f2a62c81 tools/nolibc: crt.h: initialize stack protector
As suggested by Thomas, It is able to move the stackprotector
initialization from the assembly _start to the beginning of the new
_start_c(). Let's call __stack_chk_init() in _start_c() as a
preparation.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/a00284a6-54b1-498c-92aa-44997fa78403@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
d7f16723d3 tools/nolibc: stackprotector.h: add empty __stack_chk_init for !_NOLIBC_STACKPROTECTOR
Let's define an empty __stack_chk_init for the !_NOLIBC_STACKPROTECTOR
branch.

This allows to remove #ifdef around every call of __stack_chk_init().

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
1733675515 tools/nolibc: add new crt.h with _start_c
As the environ and _auxv support added for nolibc, the assembly _start
function becomes more and more complex and therefore makes the porting
of nolibc to new architectures harder and harder.

To simplify portability, this C version of _start_c() is added to do
most of the assembly start operations in C, which reduces the complexity
a lot and will eventually simplify the porting of nolibc to the new
architectures.

The new _start_c() only requires a stack pointer argument, it will find
argc, argv, envp/environ and _auxv for us, and then call main(),
finally, it exit() with main's return status. With this new _start_c(),
the future new architectures only require to add very few assembly
instructions.

As suggested by Thomas, users may use a different signature of main
(e.g. void main(void)), a _nolibc_main alias is added for main to
silence the warning about potential conflicting types.

As suggested by Willy, the code is carefully polished for both smaller
size and better readability with local variables and the right types.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230715095729.GC24086@1wt.eu/
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/90fdd255-32f4-4caf-90ff-06456b53dac3@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
af93807eae tools/nolibc: remove the old sys_stat support
The statx manpage [1] shows that it has been supported from Linux 4.11
and glibc 2.28, the Linux support can be checked for all of the
architectures with this command:

    $ git grep -r statx v4.11 arch/ include/uapi/asm-generic/unistd.h \
      | grep -E "aarch64|arm|mips|s390|x86|:include/uapi"

Besides riscv and loongarch, all of the nolibc supported architectures
have added sys_statx from Linux v4.11. riscv is mainlined to v4.15,
loongarch is mainlined to v5.19, both of them use the generic unistd.h,
so, they have added sys_statx from their first mainline versions.

The current oldest stable branch is v4.14, only reserving sys_statx
still preserves compatibility with all of the supported stable branches,
So, let's remove the old arch related and dependent sys_stat support
completely.

This is friendly to the future new architecture porting.

[1]: https://man7.org/linux/man-pages/man2/statx.2.html

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
bff60150f7 tools/nolibc: fix up startup failures for -O0 under gcc < 11.1.0
As gcc doc [1] shows:

  Most optimizations are completely disabled at -O0 or if an -O level is
  not set on the command line, even if individual optimization flags are
  specified.

Test result [2] shows, gcc>=11.1.0 deviates from the above description,
but before gcc 11.1.0, "-O0" still forcely uses frame pointer in the
_start function even if the individual optimize("omit-frame-pointer")
flag is specified.

The frame pointer related operations will change the stack pointer (e.g.
In x86_64, an extra "push %rbp" will be inserted at the beginning of
_start) and make it differs from the one we expected, as a result, break
the whole startup function.

To fix up this issue, as suggested by Thomas, the individual "Os" and
"omit-frame-pointer" optimize flags are used together on _start function
to disable frame pointer completely even if the -O0 is set on the
command line.

[1]: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
[2]: https://lore.kernel.org/lkml/20230714094723.140603-1-falcon@tinylab.org/

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/34b21ba5-7b59-4b3b-9ed6-ef9a3a5e06f7@t-8ch.de/
Fixes: 7f85485896 ("tools/nolibc: make compiler and assembler agree on the section around _start")
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
2023349835 tools/nolibc: arch-*.h: add missing space after ','
Fix up such errors reported by scripts/checkpatch.pl:

    ERROR: space required after that ',' (ctx:VxV)
    #148: FILE: tools/include/nolibc/arch-aarch64.h:148:
    +void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
                             ^

    ERROR: space required after that ',' (ctx:VxV)
    #148: FILE: tools/include/nolibc/arch-aarch64.h:148:
    +void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
                                      ^

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Thomas Weißschuh
67d108e2a2 tools/nolibc: completely remove optional environ support
In commit 52e423f5b9 ("tools/nolibc: export environ as a weak symbol on i386")
and friends the asm startup logic was extended to directly populate the
"environ" array.

This makes it impossible for "environ" to be dropped by the linker.
Therefore also drop the other logic to handle non-present "environ".

Also add a testcase to validate the initialization of environ.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:40:22 +02:00
Zhangjin Wu
f4191f3d52 tools/nolibc: add rmdir() support
a reverse operation of mkdir() is meaningful, add rmdir() here.

required by nolibc-test to remove /proc while CONFIG_PROC_FS is not
enabled.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
788aca91ab tools/nolibc: types.h: add RB_ flags for reboot()
Both glibc and musl provide RB_ flags via <sys/reboot.h> for reboot(),
they don't need to include <linux/reboot.h>, let nolibc provide RB_
flags too.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
4201cfce15 tools/nolibc: clean up sbrk() routine
Fix up the error reported by scripts/checkpatch.pl:

    ERROR: do not use assignment in if condition
    #95: FILE: tools/include/nolibc/sys.h:95:
    +	if ((ret = sys_brk(0)) && (sys_brk(ret + inc) == ret + inc))

Apply the new generic __sysret() to merge the SET_ERRNO() and return
lines.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
924e9539ae tools/nolibc: clean up mmap() routine
Do several cleanups together:

- Since all supported architectures have my_syscall6() now, remove the
  #ifdef check.

- Move the mmap() related macros to tools/include/nolibc/types.h and
  reuse most of them from <linux/mman.h>

- Apply the new generic __sysret() to convert the calling of sys_map()
  to oneline code

Note, since MAP_FAILED is -1 on Linux, so we can use the generic
__sysret() which returns -1 upon error and still satisfy user land that
checks for MAP_FAILED.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230702192347.GJ16233@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
6591be4a73 tools/nolibc: __sysret: support syscalls who return a pointer
No official reference states the errno range, here aligns with musl and
glibc and uses [-MAX_ERRNO, -1] instead of all negative ones.

- musl: src/internal/syscall_ret.c
- glibc: sysdeps/unix/sysv/linux/sysdep.h

The MAX_ERRNO used by musl and glibc is 4095, just like the one nolibc
defined in tools/include/nolibc/errno.h.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/ZKKdD%2Fp4UkEavru6@1wt.eu/
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Link: https://lore.kernel.org/linux-riscv/94dd5170929f454fbc0a10a2eb3b108d@AcuMS.aculab.com/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
6d1970e1ef tools/nolibc: add missing my_syscall6() for mips
It is able to pass the 6th argument like the 5th argument via the stack
for mips, let's add a new my_syscall6() now, see [1] for details:

  The mips/o32 system call convention passes arguments 5 through 8 on
  the user stack.

Both mmap() and pselect6() require my_syscall6().

[1]: https://man7.org/linux/man-pages/man2/syscall.2.html

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
8b9bdab635 tools/nolibc: arch-mips.h: shrink with _NOLIBC_SYSCALL_CLOBBERLIST
my_syscall<N> share the same long clobber list, define a macro for them.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
2dca615ade tools/nolibc: arch-loongarch.h: shrink with _NOLIBC_SYSCALL_CLOBBERLIST
my_syscall<N> share the same long clobber list, define a macro for them.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
f09f1912e4 toolc/nolibc: arch-*.h: clean up whitespaces after __asm__
replace "__asm__  volatile" with "__asm__ volatile" and insert necessary
whitespace before "\" to make sure the lines are aligned.

    $ sed -i -e 's/__asm__  volatile ( /__asm__ volatile (  /g' tools/include/nolibc/*.h

Note, arch-s390.h uses post-tab instead of post-whitespaces, must avoid
insert whitespace just before the tabs:

    $ sed -i -e 's/__asm__  volatile (\t/__asm__ volatile (\t/g' tools/include/nolibc/arch-*.h

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
f134c7066c tools/nolibc: arch-*.h: fix up code indent errors
More than 8 whitespaces of the code indent are replaced with "tab +
whitespaces" to fix up such errors reported by scripts/checkpatch.pl:

    ERROR: code indent should use tabs where possible
    #64: FILE: tools/include/nolibc/arch-mips.h:64:
    +^I                                                                      \$

    ERROR: code indent should use tabs where possible
    #72: FILE: tools/include/nolibc/arch-mips.h:72:
    +^I          "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9"  \$

This command is used:

    $ sed -i -e '/^\t*        /{s/        /\t/g}' tools/include/nolibc/arch-*.h

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 04:38:02 +02:00
Zhangjin Wu
2d7481eb5d tools/nolibc: unistd.h: reorder the syscall macros
Tune the macros in the using order and align most of them.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
d27447bc2e tools/nolibc: sys.h: apply __sysret() helper
Use __sysret() to shrink most of the library routines to oneline code.

Removed 266 lines of duplicated code.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
c8d54fa37c tools/nolibc: unistd.h: apply __sysret() helper
Use __sysret() to shrink the whole _syscall() to oneline code.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
428905da6e tools/nolibc: sys.h: add a syscall return helper
Most of the library routines share the same syscall return logic:

  In general, a 0 return value indicates success.  A -1 return value
  indicates an error, and an error number is stored in errno. [1]

Let's add a __sysret() helper for the above logic to simplify the coding
and shrink the code lines too.

Thomas suggested to use inline function instead of macro for __sysret().

Willy suggested to make __sysret() be always inline.

[1]: https://man7.org/linux/man-pages/man2/syscall.2.html

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/linux-riscv/ZH1+hkhiA2+ItSvX@1wt.eu/
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/ea4e7442-7223-4211-ba29-70821e907888@t-8ch.de/
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
2f98aca8aa tools/nolibc: fix up undeclared syscall macros with #ifdef and -ENOSYS
Compiling nolibc for rv32 got such errors:

    nolibc/sysroot/riscv/include/sys.h: In function ‘sys_gettimeofday’:
    nolibc/sysroot/riscv/include/sys.h:557:21: error: ‘__NR_gettimeofday’ undeclared (first use in this function); did you mean ‘sys_gettimeofday’?
      557 |  return my_syscall2(__NR_gettimeofday, tv, tz);
          |                     ^~~~~~~~~~~~~~~~~
    nolibc/sysroot/riscv/include/sys.h: In function ‘sys_lseek’:
    nolibc/sysroot/riscv/include/sys.h:675:21: error: ‘__NR_lseek’ undeclared (first use in this function)
      675 |  return my_syscall3(__NR_lseek, fd, offset, whence);
          |                     ^~~~~~~~~~
    nolibc/sysroot/riscv/include/sys.h: In function ‘sys_wait4’:
    nolibc/sysroot/riscv/include/sys.h:1341:21: error: ‘__NR_wait4’ undeclared (first use in this function)
     1341 |  return my_syscall4(__NR_wait4, pid, status, options, rusage);

If a syscall macro is not supported by a target platform, wrap it with
'#ifdef' and 'return -ENOSYS' for the '#else' branch, which lets the
other syscalls work as-is and allows developers to fix up the test
failures reported by nolibc-test one by one later.

This wraps all of the failed syscall macros with '#ifdef' and 'return
-ENOSYS' for the '#else' branch, so, all of the undeclared failures are
fixed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/5e7d2adf-e96f-41ca-a4c6-5c87a25d4c9c@app.fastmail.com/
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
ca50df3098 tools/nolibc: fix up #error compile failures with -ENOSYS
Compiling nolibc for rv32 got such errors:

    In file included from nolibc/sysroot/riscv/include/nolibc.h:99,
                     from nolibc/sysroot/riscv/include/errno.h:26,
                     from nolibc/sysroot/riscv/include/stdio.h:14,
                     from tools/testing/selftests/nolibc/nolibc-test.c:12:
    nolibc/sysroot/riscv/include/sys.h:946:2: error: #error Neither __NR_ppoll nor __NR_poll defined, cannot implement sys_poll()
      946 | #error Neither __NR_ppoll nor __NR_poll defined, cannot implement sys_poll()
          |  ^~~~~
    nolibc/sysroot/riscv/include/sys.h:1062:2: error: #error None of __NR_select, __NR_pselect6, nor __NR__newselect defined, cannot implement sys_select()
     1062 | #error None of __NR_select, __NR_pselect6, nor __NR__newselect defined, cannot implement sys_select()

If a syscall is not supported by a target platform, 'return -ENOSYS' is
better than '#error', which lets the other syscalls work as-is and
allows developers to fix up the test failures reported by nolibc-test
one by one later.

This converts all of the '#error' to 'return -ENOSYS', so, all of the
'#error' failures are fixed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/5e7d2adf-e96f-41ca-a4c6-5c87a25d4c9c@app.fastmail.com/
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-06 12:27:53 +02:00
Zhangjin Wu
f62ec079d0 tools/nolibc: open: fix up compile warning for arm
In function ‘open’:
    nolibc/sysroot/arm/include/sys.h:919:23: warning: ‘mode_t’ {aka ‘short unsigned int’} is promoted to ‘int’ when passed through ‘...’
      919 |   mode = va_arg(args, mode_t);
          |                       ^
    nolibc/sysroot/arm/include/sys.h:919:23: note: (so you should pass ‘int’ not ‘mode_t’ {aka ‘short unsigned int’} to ‘va_arg’)
    nolibc/sysroot/arm/include/sys.h:919:23: note: if this code is reached, the program will abort

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:10 -07:00
Zhangjin Wu
646ff7c7ed tools/nolibc: arm: add missing my_syscall6
This is required by the coming removal of the oldselect and newselect
support.

pselect6/pselect6_time64 will be used unconditionally, they have 6
arguments.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/bf3e07c1-75f5-425b-9124-f3f2b230e63a@app.fastmail.com/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Zhangjin Wu
bd27fef329 selftests/nolibc: not include limits.h for nolibc
When compile nolibc-test.c with 2.31 glibc, we got such error:

    In file included from /usr/riscv64-linux-gnu/include/sys/cdefs.h:452,
                     from /usr/riscv64-linux-gnu/include/features.h:461,
                     from /usr/riscv64-linux-gnu/include/bits/libc-header-start.h:33,
                     from /usr/riscv64-linux-gnu/include/limits.h:26,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/limits.h:194,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/syslimits.h:7,
                     from /usr/lib/gcc-cross/riscv64-linux-gnu/9/include/limits.h:34,
                     from /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/nolibc-test.c:6:
    /usr/riscv64-linux-gnu/include/bits/wordsize.h:28:3: error: #error "rv32i-based targets are not supported"
       28 | # error "rv32i-based targets are not supported"

Glibc (>= 2.33) commit 5b6113d62efa ("RISC-V: Support the 32-bit ABI
implementation") fixed up above error.

As suggested by Thomas, defining INT_MIN/INT_MAX for nolibc can remove
the including of limits.h, and therefore no above error. of course, the
other libcs still require limits.h, move it to the right place.

The LONG_MIN/LONG_MAX are also defined too.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/09d60dc2-e298-4c22-8e2f-8375861bd9be@t-8ch.de/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Thomas Weißschuh
f9bf5944d3 tools/nolibc: ensure fast64 integer types have 64 bits
On 32bit platforms size_t is not enough to represent [u]int_fast64_t.

Fixes: 3e9fd4e9a1 ("tools/nolibc: add integer types and integer limit macros")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Zhangjin Wu
0dd2fdbfa5 tools/nolibc: ppoll/ppoll_time64: add a missing argument
The ppoll and ppoll_time64 syscalls have 5 arguments, but we only
provide 4, align with kernel and add the missing sigsetsize argument.

Because the sigmask is NULL, the last sigsetsize argument is ignored,
keep it as 0 here is safe enough.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Thomas Weißschuh
87b9fa66af tools/nolibc: support nanoseconds in stat()
Keep backwards compatibility through unions.

The compatibility macros like

 #define st_atime st_atim.tv_sec

as documented in stat(3type) don't work for nolibc because it would
break with other stat-like structures that contain the field st_atime.

The stx_atime, stx_mtime, stx_ctime are in type of 'struct
statx_timestamp', which is incompatible with 'struct timespec', should
be converted explicitly.

    /* include/uapi/linux/stat.h */

    struct statx_timestamp {
    	__s64	tv_sec;
    	__u32	tv_nsec;
    	__s32	__reserved;
    };

    /* include/uapi/linux/time.h */
    struct timespec {
    	__kernel_old_time_t	tv_sec;		/* seconds */
    	long			tv_nsec;	/* nanoseconds */
    };

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/3a3edd48-1ace-4c89-89e8-9c594dd1b3c9@t-8ch.de/
Co-authored-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
[wt: squashed Zhangjin & Thomas' patches into one to preserve "bisectability"]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Thomas Weißschuh
208aa9d94c tools/nolibc: add support for prctl()
It will be used to disable core dumps from the child spawned to validate
the stack protector functionality.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Thomas Weißschuh
79d8d4cad2 tools/nolibc: s390: disable stackprotector in _start
s390 does not support the "global" stack protector mode that is
implemented in nolibc.

Now that nolibc detects if stack protectors are enabled at runtime it
could happen that a future compiler does indeed use global mode on
and nolibc would compile but segfault at runtime.

To avoid this hypothetic case and to align s390 with the other
architectures disable stack protectors when compiling _start().

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:09 -07:00
Thomas Weißschuh
e76b70dec9 tools/nolibc: fix segfaults on compilers without attribute no_stack_protector
Not all compilers, notably GCC < 10, have support for
__attribute__((no_stack_protector)).
Fall back to a mechanism that also works there.

Tested with GCC 9.5.0 from kernel.org crosstools.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
818924d129 tools/nolibc: add autodetection for stackprotector support
The stackprotector support in nolibc should be enabled iff it is also
enabled in the compiler.
Use the preprocessor defines added by gcc and clang if stackprotector
support is enable to automatically do so in nolibc.

This completely removes the need for any user-visible API.

To avoid inlining the lengthy preprocessor check into every user
introduce a new header compiler.h that abstracts the logic away.

As the define NOLIBC_STACKPROTECTOR is now not user-relevant anymore
prefix it with an underscore.

Suggested-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/lkml/20230520133237.GA27501@1wt.eu/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
e21a2eef74 tools/nolibc: reformat list of headers to be installed
This makes it easier to add and remove more entries in the future
without creating spurious diff hunks.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
88fc7eb54e tools/nolibc: ensure stack protector guard is never zero
The all-zero pattern is one of the more probable out-of-bound writes so
add a special case to not accidentally accept it.

Also it enables the reliable detection of stack protector initialization
during testing.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
7a9b234520 tools/nolibc: x86_64: disable stack protector for _start
This was forgotten in the original submission.

It is unknown why it worked for x86_64 on some compiler without this
attribute.

Reported-by: Willy Tarreau <w@1wt.eu>
Closes: https://lore.kernel.org/lkml/20230520133237.GA27501@1wt.eu/
Fixes: 0d8c461adb ("tools/nolibc: x86_64: add stackprotector support")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
659ee30f33 tools/nolibc: fix typo pint -> point
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
56d294a50c tools/nolibc: riscv: add stackprotector support
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
3da0de377b tools/nolibc: mips: add stackprotector support
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
ca2d043714 tools/nolibc: loongarch: add stackprotector support
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
ed6c0d89bb tools/nolibc: arm: add stackprotector support
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
c1e30f7d38 tools/nolibc: aarch64: add stackprotector support
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:08 -07:00
Thomas Weißschuh
53fcfafa8c tools/nolibc/unistd: add syscall()
syscall() is used by "normal" libcs to allow users to directly call
syscalls.
By having the same syntax inside nolibc users can more easily write code
that works with different libcs.

The macro logic is adapted from systemtaps STAP_PROBEV() macro that is
released in the public domain / CC0.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Zhangjin Wu
c22c7c81af tools/nolibc: riscv: Fix up load/store instructions for rv32
When compile nolibc application for rv32, we got such errors:
  nolibc/sysroot/riscv/include/arch.h:190: Error: unrecognized opcode `ld a4,0(a3)'
  nolibc/sysroot/riscv/include/arch.h:194: Error: unrecognized opcode `sd a3,%lo(_auxv)(a4)'
  nolibc/sysroot/riscv/include/arch.h:196: Error: unrecognized opcode `sd a2,%lo(environ)(a3)'

Refer to arch/riscv/include/asm/asm.h and add REG_L/REG_S macros here to let
rv32 uses its own lw/sw instructions.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Thomas Weißschuh
72ffbc6784 tools/nolibc: remove LINUX_REBOOT_ constants
The same constants and some more have been exposed to userspace via
linux/reboot.h for a long time.

To avoid conflicts and trim down nolibc a bit drop the custom
definitions.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Thomas Weißschuh
404fa87c0e tools/nolibc: s390: provide custom implementation for sys_fork
On s390 the first two arguments to the clone() syscall are swapped,
as documented in clone(2).

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Thomas Weißschuh
fddc8f81f1 tools/nolibc: use C89 comment syntax
Most of nolibc is already using C89 comments.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Thomas Weißschuh
0738c2d7bf tools/nolibc: use __inline__ syntax
When building in strict C89 mode the "inline" keyword is unknown.
While "__inline__" is non-standard it is used by the kernel headers
themselves.
So the used compilers would have to support it or the users shim it with
a #define.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Thomas Weißschuh
7f291cfa90 tools/nolibc: use standard __asm__ statements
Most of the code was migrated to C99-conformant __asm__ statements
before. It seems string.h was missed.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:46:07 -07:00
Mark Brown
3a8039e289 tools/nolibc: Fix build of stdio.h due to header ordering
When we added fd based file streams we created references to STx_FILENO in
stdio.h but these constants are declared in unistd.h which is the last file
included by the top level nolibc.h meaning those constants are not defined
when we try to build stdio.h. This causes programs using nolibc.h to fail
to build.

Reorder the headers to avoid this issue.

Fixes: d449546c957f ("tools/nolibc: implement fd-based FILE streams")
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:45:34 -07:00
Thomas Weißschuh
5df28c153d tools/nolibc: implement fd-based FILE streams
This enables the usage of the stream APIs with arbitrary filedescriptors.

It will be used by a future testcase.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:33:05 -07:00
Thomas Weißschuh
e8842cf04e tools/nolibc: add wrapper for memfd_create
This is useful for users and will also be used by a future testcase.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-06-09 11:33:05 -07:00
Linus Torvalds
0f50767d7e linux-kselftest-next-6.4-rc1
linux-kselftest-next-6.4-rc1
 
 This Kselftest update for Linux 6.4-rc1 consists of:
 
 - several patches to enhance and fix resctrl test
 - nolibc support for kselftest with an addition to vprintf() to
   tools/nolibc/stdio and related test changes
 - Refactor 'peeksiginfo' ptrace test part
 - add 'malloc' failures checks in cgroup test_memcontrol
 - a new prctl test
 - enhancements sched test with additional ore schedule prctl calls
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Merge tag 'linux-kselftest-next-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:

 - several patches to enhance and fix resctrl test

 - nolibc support for kselftest with an addition to vprintf() to
   tools/nolibc/stdio and related test changes

 - Refactor 'peeksiginfo' ptrace test part

 - add 'malloc' failures checks in cgroup test_memcontrol

 - a new prctl test

 - enhancements sched test with additional ore schedule prctl calls

* tag 'linux-kselftest-next-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
  selftests/resctrl: Fix incorrect error return on test complete
  selftests/resctrl: Remove duplicate codes that clear each test result file
  selftests/resctrl: Commonize the signal handler register/unregister for all tests
  selftests/resctrl: Cleanup properly when an error occurs in CAT test
  selftests/resctrl: Flush stdout file buffer before executing fork()
  selftests/resctrl: Return MBA check result and make it to output message
  selftests/resctrl: Fix set up schemata with 100% allocation on first run in MBM test
  selftests/resctrl: Use correct exit code when tests fail
  kselftest/arm64: Convert za-fork to use kselftest.h
  kselftest: Support nolibc
  tools/nolibc/stdio: Implement vprintf()
  selftests/resctrl: Correct get_llc_perf() param in function comment
  selftests/resctrl: Use remount_resctrlfs() consistently with boolean
  selftests/resctrl: Change name from CBM_MASK_PATH to INFO_PATH
  selftests/resctrl: Change initialize_llc_perf() return type to void
  selftests/resctrl: Replace obsolete memalign() with posix_memalign()
  selftests/resctrl: Check for return value after write_schemata()
  selftests/resctrl: Allow ->setup() to return errors
  selftests/resctrl: Move ->setup() call outside of test specific branches
  selftests/resctrl: Return NULL if malloc_and_init_memory() did not alloc mem
  ...
2023-04-24 12:28:34 -07:00
Mark Brown
322759f983 tools/nolibc/stdio: Implement vprintf()
vprintf() is equivalent to vfprintf() to stdout so implement it as a simple
wrapper for the existing vfprintf(), allowing us to build kselftest.h.

Suggested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-04-11 14:10:42 -06:00
Thomas Weißschuh
0d8c461adb tools/nolibc: x86_64: add stackprotector support
Enable the new stackprotector support for x86_64.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-27 16:26:10 -07:00
Thomas Weißschuh
ff221a6d9a tools/nolibc: i386: add stackprotector support
Enable the new stackprotector support for i386.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-27 16:26:10 -07:00
Thomas Weißschuh
7188d4637e tools/nolibc: add support for stack protector
This is useful when using nolibc for security-critical tools.
Using nolibc has the advantage that the code is easily auditable and
sandboxable with seccomp as no unexpected syscalls are used.
Using compiler-assistent stack protection provides another security
mechanism.

For this to work the compiler and libc have to collaborate.

This patch adds the following parts to nolibc that are required by the
compiler:

* __stack_chk_guard: random sentinel value
* __stack_chk_fail: handler for detected stack smashes

In addition an initialization function is added that randomizes the
sentinel value.

Only support for global guards is implemented.
Register guards are useful in multi-threaded context which nolibc does
not provide support for.

Link: https://lwn.net/Articles/584225/

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-27 16:26:10 -07:00
Thomas Weißschuh
8c934d4822 tools/nolibc: add helpers for wait() signal exits
These are useful for users and will also be used in an upcoming
testcase.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-27 16:26:10 -07:00
Thomas Weißschuh
00b7262896 tools/nolibc: add definitions for standard fds
These are useful for users and will also be used in an upcoming
testcase.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-27 16:26:10 -07:00
Feiyang Chen
73f12c6da7 tools/nolibc: Add support for LoongArch
Add support for LoongArch (32 and 64 bit) to nolibc.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:22 -07:00
Feiyang Chen
b551cb7dc3 tools/nolibc: Add statx() and make stat() rely on statx() if necessary
LoongArch and RISC-V 32-bit only have statx(). ARC, Hexagon, Nios2 and
OpenRISC have statx() and stat64() but not stat() or newstat(). Add
statx() and make stat() rely on statx() if necessary to make them happy.
We may just use statx() for all architectures in the future.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:22 -07:00
Feiyang Chen
a438e528b6 tools/nolibc: Include linux/fcntl.h and remove duplicate code
Include linux/fcntl.h for O_* and AT_*. asm/fcntl.h is included
by linux/fcntl.h, so it can be safely removed.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:22 -07:00
Willy Tarreau
1c3a4c10cc tools/nolibc: check for S_I* macros before defining them
Defining S_I* flags in types.h can cause some build failures if
linux/stat.h is included prior to it. But if not defined, some toolchains
that include some glibc parts will in turn fail because linux/stat.h
already takes care of avoiding these definitions when glibc is present.

Let's preserve the macros here but first include linux/stat.h and check
for their definition before doing so. We also define the previously
missing permission macros so that we don't get a different behavior
depending on the first include found.

Cc: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:22 -07:00
Willy Tarreau
919d0532d4 tools/nolibc: add getuid() and geteuid()
This can be useful to avoid attempting some privileged operations,
starting from the nolibc-test tool that gets two failures when not
privileged.

We call getuid32() and geteuid32() when they are defined, and fall
back to getuid() and geteuid() otherwise.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:22 -07:00
Vincent Dagonneau
3e9fd4e9a1 tools/nolibc: add integer types and integer limit macros
This commit adds some of the missing integer types to stdint.h and adds
limit macros (e.g. INTN_{MIN,MAX}).

The reference used for adding these types is
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/stdint.h.html.

We rely on the compiler-defined __LONG_MAX__ to get the right limits for
size_t, intptr_t, uintptr_t and ptrdiff_t. This compiler constant seem
to have been defined at least since GCC 4.1.2 and clang
3.0.0 on x86_64. It is also defined on ARM (32&64), mips and RISC-V.

Note that the maximum size of size_t is implementation-defined (>65535),
in this case I chose to go with unsigned long on all platforms since
unsigned long == unsigned int on all the platforms we care about. Note
that the kernel uses either unsigned int or unsigned long in
linux/include/uapi/asm-generic/posix_types.h. These should be equivalent
for the plaforms we are targeting.

Also note that the 'fast*' flavor of the types have been chosen to be
always 1 byte for '*fast8*' and always long (a.k.a. intptr_t/uintptr_t) for
the other variants. I have never seen the 'fast*' types in use in the wild
but that seems to be what glibc does.

Signed-off-by: Vincent Dagonneau <v@vda.io>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:21 -07:00
Vincent Dagonneau
c34da317e0 tools/nolibc: add stdint.h
Nolibc works fine for small and limited program however most program
expect integer types to be defined in stdint.h rather than std.h.

This is a quick fix that moves the existing integer definitions in std.h
to stdint.h.

Signed-off-by: Vincent Dagonneau <v@vda.io>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-03-20 08:45:21 -07:00
Paul E. McKenney
d548e9ae07 tools/nolibc: Add gitignore to avoid git complaints about sysroot
Testing of nolibc can produce a tools/include/nolibc/sysroot file, which
is not known to git.  Because it is automatically generated, there is no
reason for it to be known to git.  Therefore, add a .gitignore to remove
it from git's field of view.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
2023-03-20 08:45:21 -07:00
Ammar Faizi
7efd762e97 nolibc/sys: Implement getpagesize(2) function
This function returns the page size used by the running kernel. The
page size value is taken from the auxiliary vector at 'AT_PAGESZ' key.

'getpagesize(2)' is assumed as a syscall becuase the manpage placement
of this function is in entry 2 ('man 2 getpagesize') despite there is
no real 'getpagesize(2)' syscall in the Linux syscall table. Define
this function in 'sys.h'.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Ammar Faizi
c61a078015 nolibc/stdlib: Implement getauxval(3) function
Previous commits save the address of the auxiliary vector into a global
variable @_auxv. This commit creates a new function 'getauxval()' as a
helper function to get the auxv value based on the given key.

The behavior of this function is identic with the function documented
in 'man 3 getauxval'. This function is also needed to implement
'getpagesize()' function that we will wire up in the next patches.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Sven Schnelle
241c4b4e02 tools/nolibc: add auxiliary vector retrieval for s390
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
d01869cf1e tools/nolibc: add auxiliary vector retrieval for mips
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
041fa97cb3 tools/nolibc: add auxiliary vector retrieval for riscv
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.
It was tested on riscv64 only.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
59ea187624 tools/nolibc: add auxiliary vector retrieval for arm
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Willy Tarreau <w@1wt.eu>

It was tested in arm, thumb1 and thumb2 modes.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
2a39a53245 tools/nolibc: add auxiliary vector retrieval for arm64
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
1cce162ab4 tools/nolibc: add auxiliary vector retrieval for x86_64
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
2ab4aa487b tools/nolibc: add auxiliary vector retrieval for i386
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Sven Schnelle
9e5bdc613d tools/nolibc: export environ as a weak symbol on s390
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested on s390 both with environ inherited from
_start and extracted from envp.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
758f333795 tools/nolibc: export environ as a weak symbol on riscv
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested on riscv64 both with environ inherited from
_start and extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
8f7fafebd1 tools/nolibc: export environ as a weak symbol on mips
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested with mips24kc (BE) both with environ inherited
from _start and extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
a6f29a2c41 tools/nolibc: export environ as a weak symbol on arm
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested in arm and thumb1 and thumb2 modes, and for each
mode, both with environ inherited from _start and extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
9b8688c6ea tools/nolibc: export environ as a weak symbol on arm64
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested both with environ inherited from _start and
extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:56 -08:00
Willy Tarreau
52e423f5b9 tools/nolibc: export environ as a weak symbol on i386
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested both with environ inherited from _start and
extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
89dc50921c tools/nolibc: export environ as a weak symbol on x86_64
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested both with environ inherited from _start and
extracted from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
1caa1154c3 tools/nolibc: make errno a weak symbol instead of a static one
Till now errno was declared static so that it could be eliminated if
unused. While the goal is commendable for tiny executables as it allows
to eliminate any data and bss segments when not used, this comes with
some limitations, one of which being that the errno symbol seen in
different units are not the same. Even though this has never been a
real issue given the nature of the programs involved till now, it
happens that referencing the same symbol from multiple units can also
be achieved using weak symbols, with a difference being that only one
of them will be used for all of them. Compared to weak symbols, static
basically have no benefit for regular programs since there are always
at least a few variables in most of these, so the bss segment cannot
be eliminated. E.g:

  $ size nolibc-test-static-errno
     text    data     bss     dec     hex filename
    11531       0      48   11579    2d3b nolibc-test-static-errno

Furthermore, the weak symbol doesn't use bss storage at all, resulting
in a slightly section:

  $ size nolibc-test-weak-errno
     text    data     bss     dec     hex filename
    11531       0      40   11571    2d33 nolibc-test-weak-errno

This patch thus converts errno from static to weak.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
d5b48f958b tools/nolibc: remove local definitions of O_* flags for open/fcntl
The historic nolibc code did not include asm/fcntl.h and had to define
the various O_RDWR etc macros in each arch-specific file (since such
values differ between certain archs). This was found at least once to
induce bugs due to wrong definitions. Let's get rid of all of them and
include asm/nolibc.h from sys.h instead. This was verified to work
properly on all supported architectures.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
5a51b6de59 tools/nolibc: support thumb mode with frame pointers on ARM
In Thumb mode, register r7 is normally used to store the frame pointer.
By default when optimizing at -Os there's no frame pointer so this works
fine. But if no optimization is set, then build errors occur, indicating
that r7 cannot not be used. It's difficult to cheat because it's the
compiler that is complaining, not the assembler, so it's not even possible
to report that the register was clobbered. The solution consists in saving
and restoring r7 around the syscall, but this slightly inflates the code.
The syscall number is passed via r6 which is never used by syscalls.

The current patch adds a few macroes which do that only in Thumb mode,
and which continue to directly assign the syscall number to register r7
in ARM mode. Now this always builds and works for all modes (tested on
Arm, Thumbv1, Thumbv2 modes, at -Os, -O0, -O0 -fomit-frame-pointer).
The code is very slightly inflated in thumb-mode without frame-pointers
compared to previously (e.g. 7928 vs 7864 bytes for nolibc-test) but at
least it's always operational. And it's possible to disable this mechanism
by setting NOLIBC_OMIT_FRAME_POINTER.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
20470dfd65 tools/nolibc: enable support for thumb1 mode for ARM
Passing -mthumb to the kernel.org arm toolchain failed to build because it
defaults to armv5 hence thumb1, which has a fairly limited instruction set
compared to thumb2 enabled with armv7 that is much more complete. It's not
very difficult to adjust the instructions to also build on thumb1, it only
adds a total of 3 instructions, so it's worth doing it at least to ease use
by casual testers. It was verified that the adjusted code now builds and
works fine for armv5, thumb1, armv7 and thumb2, as long as frame pointers
are not used.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Willy Tarreau
7f85485896 tools/nolibc: make compiler and assembler agree on the section around _start
The out-of-block asm() statement carrying _start does not allow the
compiler to know what section the assembly code is being emitted to,
and there's no easy way to push/pop the current section and restore
it. It sometimes causes issues depending on the include files ordering
and compiler optimizations. For example if a variable is declared
immediately before the asm() block and another one after, the compiler
assumes that the current section is still .bss and doesn't re-emit it,
making the second variable appear inside the .text section instead.
Forcing .bss at the end of the _start block doesn't work either because
at certain optimizations the compiler may reorder blocks and will make
some real code appear just after this block.

A significant number of solutions were attempted, but many of them were
still sensitive to section reordering. In the end, the best way to make
sure the compiler and assembler agree on the current section is to place
this code inside a function. Here the function is directly called _start
and configured not to emit a frame-pointer, hence to have no prologue.
If some future architectures would still emit some prologue, another
working approach consists in naming the function differently and placing
the _start label inside the asm statement. But the current solution is
simpler.

It was tested with nolibc-test at -O,-O0,-O2,-O3,-Os for arm,arm64,i386,
mips,riscv,s390 and x86_64.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-10 13:33:55 -08:00
Sven Schnelle
18a5a09d90 nolibc: add support for s390
Use arch-x86_64 as a template. Not really different, but
we have our own mmap syscall which takes a structure instead
of discrete arguments.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Willy Tarreau
00b18da408 tools/nolibc: fix the O_* fcntl/open macro definitions for riscv
When RISCV port was imported in 5.2, the O_* macros were taken with
their octal value and written as-is in hex, resulting in the getdents64()
to fail in nolibc-test.

Fixes: 582e84f7b7 ("tool headers nolibc: add RISCV support") #5.2
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Willy Tarreau
1bfbe1f3e9 tools/nolibc: prevent gcc from making memset() loop over itself
When building on ARM in thumb mode with gcc-11.3 at -O2 or -O3,
nolibc-test segfaults during the select() tests. It turns out that at
this level, gcc recognizes an opportunity for using memset() to zero
the fd_set, but it miscompiles it because it also recognizes a memset
pattern as well, and decides to call memset() from the memset() code:

  000122bc <memset>:
     122bc:       b510            push    {r4, lr}
     122be:       0004            movs    r4, r0
     122c0:       2a00            cmp     r2, #0
     122c2:       d003            beq.n   122cc <memset+0x10>
     122c4:       23ff            movs    r3, #255        ; 0xff
     122c6:       4019            ands    r1, r3
     122c8:       f7ff fff8       bl      122bc <memset>
     122cc:       0020            movs    r0, r4
     122ce:       bd10            pop     {r4, pc}

Simply placing an empty asm() statement inside the loop suffices to
avoid this.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Willy Tarreau
55abdd1f5e tools/nolibc: fix missing includes causing build issues at -O0
After the nolibc includes were split to facilitate portability from
standard libcs, programs that include only what they need may miss
some symbols which are needed by libgcc. This is the case for raise()
which is needed by the divide by zero code in some architectures for
example.

Regardless, being able to include only the apparently needed files is
convenient.

Instead of trying to move all exported definitions to a single file,
since this can change over time, this patch takes another approach
consisting in including the nolibc header at the end of all standard
include files. This way their types and functions are already known
at the moment of inclusion, and including any single one of them is
sufficient to bring all the required ones.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Willy Tarreau
184177c3d6 tools/nolibc: restore mips branch ordering in the _start block
Depending on the compiler used and the optimization options, the sbrk()
test was crashing, both on real hardware (mips-24kc) and in qemu. One
such example is kernel.org toolchain in version 11.3 optimizing at -Os.

Inspecting the sys_brk() call shows the following code:

  0040047c <sys_brk>:
    40047c:       24020fcd        li      v0,4045
    400480:       27bdffe0        addiu   sp,sp,-32
    400484:       0000000c        syscall
    400488:       27bd0020        addiu   sp,sp,32
    40048c:       10e00001        beqz    a3,400494 <sys_brk+0x18>
    400490:       00021023        negu    v0,v0
    400494:       03e00008        jr      ra

It is obviously wrong, the "negu" instruction is placed in beqz's
delayed slot, and worse, there's no nop nor instruction after the
return, so the next function's first instruction (addiu sip,sip,-32)
will also be executed as part of the delayed slot that follows the
return.

This is caused by the ".set noreorder" directive in the _start block,
that applies to the whole program. The compiler emits code without the
delayed slots and relies on the compiler to swap instructions when this
option is not set. Removing the option would require to change the
startup code in a way that wouldn't make it look like the resulting
code, which would not be easy to debug. Instead let's just save the
default ordering before changing it, and restore it at the end of the
_start block. Now the code is correct:

  0040047c <sys_brk>:
    40047c:       24020fcd        li      v0,4045
    400480:       27bdffe0        addiu   sp,sp,-32
    400484:       0000000c        syscall
    400488:       10e00002        beqz    a3,400494 <sys_brk+0x18>
    40048c:       27bd0020        addiu   sp,sp,32
    400490:       00021023        negu    v0,v0
    400494:       03e00008        jr      ra
    400498:       00000000        nop

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc") #5.0
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Warner Losh
16f5cea741 tools/nolibc: Fix S_ISxxx macros
The mode field has the type encoded as an value in a field, not as a bit
mask. Mask the mode with S_IFMT instead of each type to test. Otherwise,
false positives are possible: eg S_ISDIR will return true for block
devices because S_IFDIR = 0040000 and S_IFBLK = 0060000 since mode is
masked with S_IFDIR instead of S_IFMT. These macros now match the
similar definitions in tools/include/uapi/linux/stat.h.

Signed-off-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Sven Schnelle
feaf756587 nolibc: fix fd_set type
The kernel uses unsigned long for the fd_set bitmap,
but nolibc use u32. This works fine on little endian
machines, but fails on big endian. Convert to unsigned
long to fix this.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-01-09 09:36:05 -08:00
Rasmus Villemoes
b3f4f51ea6 tools/nolibc/string: Fix memcmp() implementation
The C standard says that memcmp() must treat the buffers as consisting
of "unsigned chars". If char happens to be unsigned, the casts are ok,
but then obviously the c1 variable can never contain a negative
value. And when char is signed, the casts are wrong, and there's still
a problem with using an 8-bit quantity to hold the difference, because
that can range from -255 to +255.

For example, assuming char is signed, comparing two 1-byte buffers,
one containing 0x00 and another 0x80, the current implementation would
return -128 for both memcmp(a, b, 1) and memcmp(b, a, 1), whereas one
of those should of course return something positive.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-10-28 15:07:02 -07:00
Willy Tarreau
bfc3b0f056 tools/nolibc: Fix missing strlen() definition and infinite loop with gcc-12
When built at -Os, gcc-12 recognizes an strlen() pattern in nolibc_strlen()
and replaces it with a jump to strlen(), which is not defined as a symbol
and breaks compilation. Worse, when the function is called strlen(), the
function is simply replaced with a jump to itself, hence becomes an
infinite loop.

One way to avoid this is to always set -ffreestanding, but the calling
code doesn't know this and there's no way (either via attributes or
pragmas) to globally enable it from include files, effectively leaving
a painful situation for the caller.

Alexey suggested to place an empty asm() statement inside the loop to
stop gcc from recognizing a well-known pattern, which happens to work
pretty fine. At least it allows us to make sure our local definition
is not replaced with a self jump.

The function only needs to be renamed back to strlen() so that the symbol
exists, which implies that nolibc_strlen() which is used on variable
strings has to be declared as a macro that points back to it before the
strlen() macro is redifined.

It was verified to produce valid code with gcc 3.4 to 12.1 at different
optimization levels, and both with constant and variable strings.

In case this problem surfaces again in the future, an alternate approach
consisting in adding an optimize("no-tree-loop-distribute-patterns")
function attribute for gcc>=12 worked as well but is less pretty.

Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/r/202210081618.754a77db-yujie.liu@intel.com
Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Fixes: 96980b833a ("tools/nolibc/string: do not use __builtin_strlen() at -O0")
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-10-28 15:07:02 -07:00
Willy Tarreau
364702f755 tools/nolibc: make sys_mmap() automatically use the right __NR_mmap definition
__NR_mmap2 was used for i386 but it's also needed for other archs such
as RISCV32 or ARM. Let's decide to use it based on the __NR_mmap2
definition as it's not defined on other archs.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:43 -07:00
Willy Tarreau
8b53e83b08 tools/nolibc: fix build warning in sys_mmap() when my_syscall6 is not defined
We return -ENOSYS when there's no syscall6() operation, but we must cast
it to void* to avoid a warning.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:43 -07:00
Willy Tarreau
a30d551f34 tools/nolibc: make argc 32-bit in riscv startup code
The "ld a0, 0(sp)" instruction doesn't build on RISCV32 because that
would load a 64-bit value into a 32-bit register. But argc 32-bit,
not 64, so we ought to use "lw" here. Tested on both RISCV32 and
RISCV64.

Cc: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-08-31 05:17:43 -07:00
Willy Tarreau
4f8126f3a6 tools/nolibc: add a help target to list supported targets
The "help" target simply presents the list of supported targets
and the current set of variables being used to build the sysroot.

Since the help in tools/ suggests to use "install", which is
supported by most tools while such a target is not really relevant
here, an "install" target was also added, redirecting to "help".

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20 09:43:19 -07:00
Willy Tarreau
fe20cad47e tools/nolibc: make the default target build the headers
The help in "make -C tools" enumerates nolibc as a valid target so we
must at least make it do something. Let's make it do the equivalent
of "make headers" in that it will prepare a sysroot with the arch's
headers, but will not install the kernel's headers. This is the
minimum some tools will need when built with a full-blown toolchain
anyway.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20 09:43:19 -07:00
Willy Tarreau
6a3ad243b2 tools/nolibc: fix the makefile to also work as "make -C tools ..."
As reported by Linus, the nolibc's makefile is currently broken when
invoked as per the documented method (make -C tools nolibc_<target>),
because it now relies on the ARCH and OUTPUT variables that are not
set in this case.

This patch addresses this by sourcing subarch.include, and by
presetting OUTPUT to the current directory if not set. This is
sufficient to make the commands work both as a standalone target
and as a tools/ sub-target.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20 09:43:19 -07:00
Alviro Iskandar Setiawan
4f2c9703a1 tools/nolibc/stdio: Add format attribute to enable printf warnings
When we use printf and fprintf functions from the nolibc, we don't
get any warning from the compiler if we have the wrong arguments.
For example, the following calls will compile silently:
```
  printf("%s %s\n", "aaa");
  fprintf(stdout, "%s %s\n", "xxx", 1);
```
(Note the wrong arguments).

Those calls are undefined behavior. The compiler can help us warn
about the above mistakes by adding a `printf` format attribute to
those functions declaration. This patch adds it, and now it yields
these warnings for those mistakes:
```
  warning: format `%s` expects a matching `char *` argument [-Wformat=]
  warning: format `%s` expects argument of type `char *`, but argument 4 has type `int` [-Wformat=]
```

  [ ammarfaizi2: Simplify the attribute placement. ]

Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20 09:43:19 -07:00
Ammar Faizi
1ef150cf40 tools/nolibc/stdlib: Support overflow checking for older compiler versions
Previously, we used __builtin_mul_overflow() to check for overflow in
the multiplication operation in the calloc() function. However, older
compiler versions don't support this built-in. This patch changes the
overflow checking mechanism to make it work on any compiler version
by using a division method to check for overflow. No functional change
intended. While in there, remove the unused variable `void *orig`.

Link: https://lore.kernel.org/lkml/20220330024114.GA18892@1wt.eu
Suggested-by: Willy Tarreau <w@1wt.eu>
Cc: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-06-20 09:43:19 -07:00
Ammar Faizi
11dbdaeff4 tools/nolibc/string: Implement strdup() and strndup()
These functions are currently only available on architectures that have
my_syscall6() macro implemented. Since these functions use malloc(),
malloc() uses mmap(), mmap() depends on my_syscall6() macro.

On architectures that don't support my_syscall6(), these function will
always return NULL with errno set to ENOSYS.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
b26823c19a tools/nolibc/string: Implement strnlen()
size_t strnlen(const char *str, size_t maxlen);

The strnlen() function returns the number of bytes in the string
pointed to by sstr, excluding the terminating null byte ('\0'), but at
most maxlen. In doing this, strnlen() looks only at the first maxlen
characters in the string pointed to by str and never beyond str[maxlen-1].

The first use case of this function is for determining the memory
allocation size in the strndup() function.

Link: https://lore.kernel.org/lkml/CAOG64qMpEMh+EkOfjNdAoueC+uQyT2Uv3689_sOr37-JxdJf4g@mail.gmail.com
Suggested-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
0e0ff63840 tools/nolibc/stdlib: Implement malloc(), calloc(), realloc() and free()
Implement basic dynamic allocator functions. These functions are
currently only available on architectures that have nolibc mmap()
syscall implemented. These are not a super-fast memory allocator,
but at least they can satisfy basic needs for having heap without
libc.

Cc: David Laight <David.Laight@ACULAB.COM>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
5a18d07ce3 tools/nolibc/types: Implement offsetof() and container_of() macro
Implement `offsetof()` and `container_of()` macro. The first use case
of these macros is for `malloc()`, `realloc()` and `free()`.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
544fa1a2d3 tools/nolibc/sys: Implement mmap() and munmap()
Implement mmap() and munmap(). Currently, they are only available for
architecures that have my_syscall6 macro. For architectures that don't
have, this function will return -1 with errno set to ENOSYS (Function
not implemented).

This has been tested on x86 and i386.

Notes for i386:
 1) The common mmap() syscall implementation uses __NR_mmap2 instead
    of __NR_mmap.

 2) The offset must be shifted-right by 12-bit.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
f4738ff74c tools/nolibc: i386: Implement syscall with 6 arguments
On i386, the 6th argument of syscall goes in %ebp. However, both Clang
and GCC cannot use %ebp in the clobber list and in the "r" constraint
without using -fomit-frame-pointer. To make it always available for
any kind of compilation, the below workaround is implemented.

  1) Push the 6-th argument.
  2) Push %ebp.
  3) Load the 6-th argument from 4(%esp) to %ebp.
  4) Do the syscall (int $0x80).
  5) Pop %ebp (restore the old value of %ebp).
  6) Add %esp by 4 (undo the stack pointer).

Cc: x86@kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/lkml/2e335ac54db44f1d8496583d97f9dab0@AcuMS.aculab.com
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
1590c59836 tools/nolibc: Remove .global _start from the entry point code
Building with clang yields the following error:
```
  <inline asm>:3:1: error: _start changed binding to STB_GLOBAL
  .global _start
  ^
  1 error generated.
```
Make sure only specify one between `.global _start` and `.weak _start`.
Remove `.global _start`.

Cc: llvm@lists.linux.dev
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
37d62758e7 tools/nolibc: Replace asm with __asm__
Replace `asm` with `__asm__` to support compilation with -std flag.
Using `asm` with -std flag makes GCC think `asm()` is a function call
instead of an inline assembly.

GCC doc says:

  For the C language, the `asm` keyword is a GNU extension. When
  writing C code that can be compiled with `-ansi` and the `-std`
  options that select C dialects without GNU extensions, use
  `__asm__` instead of `asm`.

Link: https://gcc.gnu.org/onlinedocs/gcc/Basic-Asm.html
Reported-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Ammar Faizi
5312aaa5d5 tools/nolibc: x86-64: Update System V ABI document link
The old link no longer works, update it.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Willy Tarreau
2475d37ac3 tools/nolibc/stdlib: only reference the external environ when inlined
When building with gcc at -O0 we're seeing link errors due to the
"environ" variable being referenced by getenv(). The problem is that
at -O0 gcc will not inline getenv() and will not drop the external
reference. One solution would be to locally declare the variable as
weak, but then it would appear in all programs even those not using
it, and would be confusing to users of getenv() who would forget to
set environ to envp.

An alternate approach used in this patch consists in always inlining
the outer part of getenv() that references this extern so that it's
always dropped when not used. The biggest part of the function was
now moved to a new function called _getenv() that's still not inlined
by default.

Reported-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Tested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Willy Tarreau
96980b833a tools/nolibc/string: do not use __builtin_strlen() at -O0
clang wants to use strlen() for __builtin_strlen() at -O0. We don't
really care about -O0 but it at least ought to build, so let's make
sure we don't choke on this, by dropping the optimizationn for
constant strings in this case.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Willy Tarreau
2432616468 tools/nolibc: add a makefile to install headers
This provides a target "headers_standalone" which installs the nolibc's
arch-specific headers with "arch.h" taken from the current arch (or a
concatenation of both i386 and x86_64 for arch=x86), then installs
kernel headers. This creates a convenient sysroot which is directly
usable by a bare-metal compiler to create any executable.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:46 -07:00
Willy Tarreau
96d2a1313f tools/nolibc/types: add poll() and waitpid() flag definitions
- POLLIN etc were missing, so poll() could only be used with timeouts.
- WNOHANG was not defined and is convenient to check if a child is still
  running

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
54abe3590f tools/nolibc/sys: add syscall definition for getppid()
This is essentially for completeness as it's not the most often used
in regtests.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
0e7b492943 tools/nolibc/string: add strcmp() and strncmp()
We need these functions all the time, including when checking environment
variables and parsing command-line arguments. These implementations were
optimized to show optimal code size on a wide range of compilers (22 bytes
return included for strcmp(), 33 for strncmp()).

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
bd845a193a tools/nolibc/stdio: add support for '%p' to vfprintf()
%p remains quite useful in test code, and the code path can easily be
merged with the existing "%x" thus only adds ~50 bytes, thus let's
add it.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
077d0a3924 tools/nolibc/stdlib: add a simple getenv() implementation
This implementation relies on an extern definition of the environ
variable, that the caller must declare and initialize from envp.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
170b230d22 tools/nolibc/stdio: make printf(%s) accept NULL
It's often convenient to support this, especially in test programs where
a NULL may correspond to an allocation error or a non-existing value.
Let's make printf("%s") support being passed a NULL. In this case it
prints "(null)" like glibc's printf().

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
f0f04f28d5 tools/nolibc/stdlib: implement abort()
libgcc uses it for certain divide functions, so it must be exported. Like
for memset() we do that in its own section so that the linker can strip
it when not needed.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
c4486e9728 tools/nolibc: also mention how to build by just setting the include path
Now that a few basic include files are provided, some simple portable
programs may build, which will save them from having to surround their
includes with #ifndef NOLIBC. This patch mentions how to proceed, and
enumerates the list of files that are covered.

A comprehensive list of required include files is available here:

  https://en.cppreference.com/w/c/header

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
cec1505321 tools/nolibc/time: create time.h with time()
The time() syscall is used by a few simple applications, and is trivial
to implement based on gettimeofday() that we already have. Let's create
the file to ease porting and provide the function. It never returns any
error, though it may segfault in case of invalid pointer, like other
implementations relying on gettimeofday().

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
99cb50ab94 tools/nolibc/signal: move raise() to signal.h
This function is normally found in signal.h, and providing the file
eases porting of existing programs. Let's move it there.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
180a9797b0 tools/nolibc/unistd: add usleep()
This call is trivial to implement based on select() to complete sleep()
and msleep(), let's add it.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
4619de3446 tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.h
These functions are normally provided by unistd.h. For ease of porting,
let's create the file and move them there.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
45a794bf7c tools/nolibc/errno: extract errno.h from sys.h
This allows us to provide a minimal errno.h to ease porting applications
that use it.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
8d304a3740 tools/nolibc/string: export memset() and memmove()
"clang -Os" and "gcc -Ofast" without -ffreestanding may ignore memset()
and memmove(), hoping to provide their builtin equivalents, and finally
not find them. Thus we must export these functions for these rare cases.
Note that as they're set in their own sections, they will be eliminated
by the linker if not used. In addition, they do not prevent gcc from
identifying them and replacing them with the shorter "rep movsb" or
"rep stosb" when relevant.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
023033fe34 tools/nolibc/types: define PATH_MAX and MAXPATHLEN
These ones are often used and commonly set by applications to fallback
values. Let's fix them both to agree on PATH_MAX=4096 by default, as is
already present in linux/limits.h.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
dffeb81af5 tools/nolibc/arch: mark the _start symbol as weak
By doing so we can link together multiple C files that have been compiled
with nolibc and which each have a _start symbol.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
07f47ea06f tools/nolibc: move exported functions to their own section
Some functions like raise() and memcpy() are permanently exported because
they're needed by libgcc on certain platforms. However most of the time
they are not needed and needlessly take space.

Let's move them to their own sub-section, called .text.nolibc_<function>.
This allows ld to get rid of them if unused when passed --gc-sections.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:45 -07:00
Willy Tarreau
d9390de638 tools/nolibc/string: add tiny versions of strncat() and strlcat()
While these functions are often dangerous, forcing the user to work
around their absence is often much worse. Let's provide small versions
of each of them. The respective sizes in bytes on a few architectures
are:

  strncat(): x86:0x33 mips:0x68 arm:0x3c
  strlcat(): x86:0x25 mips:0x4c arm:0x2c

The two are quite different, and strncat() is even different from
strncpy() in that it limits the amount of data it copies and will always
terminate the output by one zero, while strlcat() will always limit the
total output to the specified size and will put a zero if possible.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
b312eb0b87 tools/nolibc/string: add strncpy() and strlcpy()
These are minimal variants. strncpy() always fills the destination for
<size> chars, while strlcpy() copies no more than <size> including the
zero and returns the source's length. The respective sizes on various
archs are:

  strncpy(): x86:0x1f mips:0x30 arm:0x20
  strlcpy(): x86:0x17 mips:0x34 arm:0x1a

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
d76232ff8b tools/nolibc/string: slightly simplify memmove()
The direction test inside the loop was not always completely optimized,
resulting in a larger than necessary function. This change adds a
direction variable that is set out of the loop. Now the function is down
to 48 bytes on x86, 32 on ARM and 68 on mips. It's worth noting that other
approaches were attempted (including relying on the up and down functions)
but they were only slightly beneficial on x86 and cost more on others.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
d8dcc2d8d9 tools/nolibc/string: use unidirectional variants for memcpy()
Till now memcpy() relies on memmove(), but it's always included for libgcc,
so we have a larger than needed function. Let's implement two unidirectional
variants to copy from bottom to top and from top to bottom, and use the
former for memcpy(). The variants are optimized to be compact, and at the
same time the compiler is sometimes able to detect the loop and to replace
it with a "rep movsb". The new function is 24 bytes instead of 52 on x86_64.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
830acd088e tools/nolibc/sys: make getpgrp(), getpid(), gettid() not set errno
These syscalls never fail so there is no need to extract and set errno
for them.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
6e277371a5 tools/nolibc/stdlib: make raise() use the lower level syscalls only
raise() doesn't set errno, so there's no point calling kill(), better
call sys_kill(), which also reduces the function's size.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
ac90226d53 tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()
The build of printf() on mips requires libgcc for functions __ashldi3 and
__lshrdi3 due to 64-bit shifts when scanning the input number. These are
not really needed in fact since we scan the number 4 bits at a time. Let's
arrange the loop to perform two 32-bit shifts instead on 32-bit platforms.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
a7604ba149 tools/nolibc/sys: make open() take a vararg on the 3rd argument
Let's pass a vararg to open() so that it remains compatible with existing
code. The arg is only dereferenced when flags contain O_CREAT. The function
is generally not inlined anymore, causing an extra call (total 16 extra
bytes) but it's still optimized for constant propagation, limiting the
excess to no more than 16 bytes in practice when open() is called without
O_CREAT, and ~40 with O_CREAT, which remains reasonable.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
acab7bcdb1 tools/nolibc/stdio: add perror() to report the errno value
It doesn't contain the text for the error codes, but instead displays
"errno=" followed by the errno value. Just like the regular errno, if
a non-empty message is passed, it's placed followed with ": " on the
output before the errno code. The message is emitted on stderr.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
51469d5ab3 tools/nolibc/types: define EXIT_SUCCESS and EXIT_FAILURE
These ones are found in some examples found in man pages and ease
portability tests.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
7e4346f4a3 tools/nolibc/stdio: add a minimal [vf]printf() implementation
This adds a minimal vfprintf() implementation as well as the commonly
used fprintf() and printf() that rely on it.

For now the function supports:
  - formats: %s, %c, %u, %d, %x
  - modifiers: %l and %ll
  - unknown chars are considered as modifiers and are ignored

It is designed to remain minimalist, despite this printf() is 549 bytes
on x86_64. It would be wise not to add too many formats.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
e3e19052d5 tools/nolibc/stdio: add fwrite() to stdio
We'll use it to write substrings. It relies on a simpler _fwrite() that
only takes one size. fputs() was also modified to rely on it.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
99b037cbd5 tools/nolibc/stdio: add stdin/stdout/stderr and fget*/fput* functions
The standard puts() function always emits the trailing LF which makes it
unconvenient for small string concatenation. fputs() ought to be used
instead but it requires a FILE*.

This adds 3 dummy FILE* values (stdin, stdout, stderr) which are in fact
pointers to struct FILE of one byte. We reserve 3 pointer values for them,
-3, -2 and -1, so that they are ordered, easing the tests and mapping to
integer.

>From this, fgetc(), fputc(), fgets() and fputs() were implemented, and
the previous putchar() and getchar() now remap to these. The standard
getc() and putc() macros were also implemented as pointing to these
ones.

There is absolutely no buffering, fgetc() and fgets() read one byte at
a time, fputc() writes one byte at a time, and only fputs() which knows
the string's length writes all of it at once.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
4e383a66ac tools/nolibc/stdio: add a minimal set of stdio functions
This only provides getchar(), putchar(), and puts().

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
5f493178ef tools/nolibc/stdlib: add utoh() and u64toh()
This adds a pair of functions to emit hex values.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
b1c21e7d99 tools/nolibc/stdlib: add i64toa() and u64toa()
These are 64-bit variants of the itoa() and utoa() functions. They also
support reentrant ones, and use the same itoa_buffer. The functions are
a bit larger than the previous ones in 32-bit mode (86 and 98 bytes on
x86_64 and armv7 respectively), which is why we continue to provide them
as separate functions.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:44 -07:00
Willy Tarreau
66c397c4d2 tools/nolibc/stdlib: replace the ltoa() function with more efficient ones
The original ltoa() function and the reentrant one ltoa_r() present a
number of drawbacks. The divide by 10 generates calls to external code
from libgcc_s, and the number does not necessarily start at the beginning
of the buffer.

Let's rewrite these functions so that they do not involve a divide and
only use loops on powers of 10, and implement both signed and unsigned
variants, always starting from the buffer's first character. Instead of
using a static buffer for each function, we're now using a common one.

In order to avoid confusion with the ltoa() name, the new functions are
called itoa_r() and utoa_r() to distinguish the signed and unsigned
versions, and for convenience for their callers, these functions now
reutrn the number of characters emitted. The ltoa_r() function is just
an inline mapping to the signed one and which returns the buffer.

The functions are quite small (86 bytes on x86_64, 68 on armv7) and
do not depend anymore on external code.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
56d68a3c1f tools/nolibc/stdlib: move ltoa() to stdlib.h
This function is not standard and performs the opposite of atol(). Let's
move it with atol(). It's been split between a reentrant function and one
using a static buffer.

There's no more definition in nolibc.h anymore now.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
eba6d00d38 tools/nolibc/types: move makedev to types.h and make it a macro
The makedev() man page says it's supposed to be a macro and that some
OSes have it with the other ones in sys/types.h so it now makes sense
to move it to types.h as a macro. Let's also define major() and
minor() that perform the reverse operation.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
306c9fd4c6 tools/nolibc/types: make FD_SETSIZE configurable
The macro was hard-coded to 256 but it's common to see it redefined.
Let's support this and make sure we always allocate enough entries for
the cases where it wouldn't be multiple of 32.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
8cb98b3fce tools/nolibc/types: move the FD_* functions to macros in types.h
FD_SET, FD_CLR, FD_ISSET, FD_ZERO are often expected to be macros and
not functions. In addition we already have a file dedicated to such
macros and types used by syscalls, it's types.h, so let's move them
there and turn them to macros. FD_CLR() and FD_ISSET() were missing,
so they were added. FD_ZERO() now deals with its own loop so that it
doesn't rely on memset() that sets one byte at a time.

Cc: David Laight <David.Laight@aculab.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
50850c38b2 tools/nolibc/ctype: add the missing is* functions
There was only isdigit, this commit adds the other ones.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
62a2af0774 tools/nolibc/ctype: split the is* functions to ctype.h
In fact there's only isdigit() for now. More should definitely be added.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
c91eb03389 tools/nolibc/string: split the string functions into string.h
The string manipulation functions (mem*, str*) are now found in
string.h. The file depends on almost nothing and will be
usable from other includes if needed. Maybe more functions could
be added.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
06fdba53e0 tools/nolibc/stdlib: extract the stdlib-specific functions to their own file
The new file stdlib.h contains the definitions of functions that
are usually found in stdlib.h. Many more could certainly be added.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
bd8c8fbb86 tools/nolibc/sys: split the syscall definitions into their own file
The syscall definitions were moved to sys.h. They were arranged
in a more easily maintainable order, whereby the sys_xxx() and xxx()
functions were grouped together, which also enlights the occasional
mappings such as wait relying on wait4().

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
271661c1cd tools/nolibc/arch: split arch-specific code into individual files
In order to ease maintenance, this splits the arch-specific code into
one file per architecture. A common file "arch.h" is used to include the
right file among arch-* based on the detected architecture. Projects
which are already split per architecture could simply rename these
files to $arch/arch.h and get rid of the common arch.h. For this
reason, include guards were placed into each arch-specific file.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
cc7a492ad0 tools/nolibc/types: split syscall-specific definitions into their own files
The macros and type definitions used by a number of syscalls were moved
to types.h where they will be easier to maintain. A few of them
are arch-specific and must not be moved there (e.g. O_*, sys_stat_struct).
A warning about them was placed at the top of the file.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:43 -07:00
Willy Tarreau
967cce191f tools/nolibc/std: move the standard type definitions to std.h
The ordering of includes and definitions for now is a bit of a mess, as
for example asm/signal.h is included after int definitions, but plenty of
structures are defined later as they rely on other includes.

Let's move the standard type definitions to a dedicated file that is
included first. We also move NULL there. This way all other includes
are aware of it, and we can bring asm/signal.h back to the top of the
file.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-20 17:05:33 -07:00
Willy Tarreau
930c4acc06 tools/nolibc: guard the main file against multiple inclusion
Including nolibc.h multiple times results in build errors due to multiple
definitions. Let's add a guard against multiple inclusions.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-11 17:14:33 -07:00
Willy Tarreau
9c2970fbb4 tools/nolibc: use pselect6 on RISCV
This arch doesn't provide the old-style select() syscall, we have to
use pselect6().

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-04-11 17:14:33 -07:00
Mark Brown
b0fe9dec66 tools/nolibc: Implement gettid()
Allow test programs to determine their thread ID.

Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Ammar Faizi
7bdc0e7a39 tools/nolibc: x86-64: Use mov $60,%eax instead of mov $60,%rax
Note that mov to 32-bit register will zero extend to 64-bit register.
Thus `mov $60,%eax` has the same effect with `mov $60,%rax`. Use the
shorter opcode to achieve the same thing.
```
  b8 3c 00 00 00       	mov    $60,%eax (5 bytes) [1]
  48 c7 c0 3c 00 00 00 	mov    $60,%rax (7 bytes) [2]
```
Currently, we use [2]. Change it to [1] for shorter code.

Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Ammar Faizi
bf91666959 tools/nolibc: x86: Remove r8, r9 and r10 from the clobber list
Linux x86-64 syscall only clobbers rax, rcx and r11 (and "memory").

  - rax for the return value.
  - rcx to save the return address.
  - r11 to save the rflags.

Other registers are preserved.

Having r8, r9 and r10 in the syscall clobber list is harmless, but this
results in a missed-optimization.

As the syscall doesn't clobber r8-r10, GCC should be allowed to reuse
their value after the syscall returns to userspace. But since they are
in the clobber list, GCC will always miss this opportunity.

Remove them from the x86-64 syscall clobber list to help GCC generate
better code and fix the comment.

See also the x86-64 ABI, section A.2 AMD64 Linux Kernel Conventions,
A.2.1 Calling Conventions [1].

Extra note:
Some people may think it does not really give a benefit to remove r8,
r9 and r10 from the syscall clobber list because the impression of
syscall is a C function call, and function call always clobbers those 3.

However, that is not the case for nolibc.h, because we have a potential
to inline the "syscall" instruction (which its opcode is "0f 05") to the
user functions.

All syscalls in the nolibc.h are written as a static function with inline
ASM and are likely always inline if we use optimization flag, so this is
a profit not to have r8, r9 and r10 in the clobber list.

Here is the example where this matters.

Consider the following C code:
```
  #include "tools/include/nolibc/nolibc.h"
  #define read_abc(a, b, c) __asm__ volatile("nop"::"r"(a),"r"(b),"r"(c))

  int main(void)
  {
  	int a = 0xaa;
  	int b = 0xbb;
  	int c = 0xcc;

  	read_abc(a, b, c);
  	write(1, "test\n", 5);
  	read_abc(a, b, c);

  	return 0;
  }
```

Compile with:
    gcc -Os test.c -o test -nostdlib

With r8, r9, r10 in the clobber list, GCC generates this:

0000000000001000 <main>:
    1000:	f3 0f 1e fa          	endbr64
    1004:	41 54                	push   %r12
    1006:	41 bc cc 00 00 00    	mov    $0xcc,%r12d
    100c:	55                   	push   %rbp
    100d:	bd bb 00 00 00       	mov    $0xbb,%ebp
    1012:	53                   	push   %rbx
    1013:	bb aa 00 00 00       	mov    $0xaa,%ebx
    1018:	90                   	nop
    1019:	b8 01 00 00 00       	mov    $0x1,%eax
    101e:	bf 01 00 00 00       	mov    $0x1,%edi
    1023:	ba 05 00 00 00       	mov    $0x5,%edx
    1028:	48 8d 35 d1 0f 00 00 	lea    0xfd1(%rip),%rsi
    102f:	0f 05                	syscall
    1031:	90                   	nop
    1032:	31 c0                	xor    %eax,%eax
    1034:	5b                   	pop    %rbx
    1035:	5d                   	pop    %rbp
    1036:	41 5c                	pop    %r12
    1038:	c3                   	ret

GCC thinks that syscall will clobber r8, r9, r10. So it spills 0xaa,
0xbb and 0xcc to callee saved registers (r12, rbp and rbx). This is
clearly extra memory access and extra stack size for preserving them.

But syscall does not actually clobber them, so this is a missed
optimization.

Now without r8, r9, r10 in the clobber list, GCC generates better code:

0000000000001000 <main>:
    1000:	f3 0f 1e fa          	endbr64
    1004:	41 b8 aa 00 00 00    	mov    $0xaa,%r8d
    100a:	41 b9 bb 00 00 00    	mov    $0xbb,%r9d
    1010:	41 ba cc 00 00 00    	mov    $0xcc,%r10d
    1016:	90                   	nop
    1017:	b8 01 00 00 00       	mov    $0x1,%eax
    101c:	bf 01 00 00 00       	mov    $0x1,%edi
    1021:	ba 05 00 00 00       	mov    $0x5,%edx
    1026:	48 8d 35 d3 0f 00 00 	lea    0xfd3(%rip),%rsi
    102d:	0f 05                	syscall
    102f:	90                   	nop
    1030:	31 c0                	xor    %eax,%eax
    1032:	c3                   	ret

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Link: https://gitlab.com/x86-psABIs/x86-64-ABI/-/wikis/x86-64-psABI [1]
Link: https://lore.kernel.org/lkml/20211011040344.437264-1-ammar.faizi@students.amikom.ac.id/
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Willy Tarreau
de0244ae40 tools/nolibc: fix incorrect truncation of exit code
Ammar Faizi reported that our exit code handling is wrong. We truncate
it to the lowest 8 bits but the syscall itself is expected to take a
regular 32-bit signed integer, not an unsigned char. It's the kernel
that later truncates it to the lowest 8 bits. The difference is visible
in strace, where the program below used to show exit(255) instead of
exit(-1):

  int main(void)
  {
        return -1;
  }

This patch applies the fix to all archs. x86_64, i386, arm64, armv7 and
mips were all tested and confirmed to work fine now. Risc-v was not
tested but the change is trivial and exactly the same as for other archs.

Reported-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Willy Tarreau
ebbe0d8a44 tools/nolibc: i386: fix initial stack alignment
After re-checking in the spec and comparing stack offsets with glibc,
The last pushed argument must be 16-byte aligned (i.e. aligned before the
call) so that in the callee esp+4 is multiple of 16, so the principle is
the 32-bit equivalent to what Ammar fixed for x86_64. It's possible that
32-bit code using SSE2 or MMX could have been affected. In addition the
frame pointer ought to be zero at the deepest level.

Link: https://gitlab.com/x86-psABIs/i386-ABI/-/wikis/Intel386-psABI
Cc: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Ammar Faizi
937ed91c71 tools/nolibc: x86-64: Fix startup code bug
Before this patch, the `_start` function looks like this:
```
0000000000001170 <_start>:
    1170:	pop    %rdi
    1171:	mov    %rsp,%rsi
    1174:	lea    0x8(%rsi,%rdi,8),%rdx
    1179:	and    $0xfffffffffffffff0,%rsp
    117d:	sub    $0x8,%rsp
    1181:	call   1000 <main>
    1186:	movzbq %al,%rdi
    118a:	mov    $0x3c,%rax
    1191:	syscall
    1193:	hlt
    1194:	data16 cs nopw 0x0(%rax,%rax,1)
    119f:	nop
```
Note the "and" to %rsp with $-16, it makes the %rsp be 16-byte aligned,
but then there is a "sub" with $0x8 which makes the %rsp no longer
16-byte aligned, then it calls main. That's the bug!

What actually the x86-64 System V ABI mandates is that right before the
"call", the %rsp must be 16-byte aligned, not after the "call". So the
"sub" with $0x8 here breaks the alignment. Remove it.

An example where this rule matters is when the callee needs to align
its stack at 16-byte for aligned move instruction, like `movdqa` and
`movaps`. If the callee can't align its stack properly, it will result
in segmentation fault.

x86-64 System V ABI also mandates the deepest stack frame should be
zero. Just to be safe, let's zero the %rbp on startup as the content
of %rbp may be unspecified when the program starts. Now it looks like
this:
```
0000000000001170 <_start>:
    1170:	pop    %rdi
    1171:	mov    %rsp,%rsi
    1174:	lea    0x8(%rsi,%rdi,8),%rdx
    1179:	xor    %ebp,%ebp                # zero the %rbp
    117b:	and    $0xfffffffffffffff0,%rsp # align the %rsp
    117f:	call   1000 <main>
    1184:	movzbq %al,%rdi
    1188:	mov    $0x3c,%rax
    118f:	syscall
    1191:	hlt
    1192:	data16 cs nopw 0x0(%rax,%rax,1)
    119d:	nopl   (%rax)
```

Cc: Bedirhan KURT <windowz414@gnuweeb.org>
Cc: Louvian Lyndal <louvianlyndal@gmail.com>
Reported-by: Peter Cordes <peter@cordes.ca>
Signed-off-by: Ammar Faizi <ammar.faizi@students.amikom.ac.id>
[wt: I did this on purpose due to a misunderstanding of the spec, other
     archs will thus have to be rechecked, particularly i386]
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:26:42 -08:00
Mark Brown
f916d77eed tools/nolibc: Implement msleep()
Allow users to implement shorter delays than a full second by implementing
msleep().

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-07-20 13:42:26 -07:00
Bhaskar Chowdhury
9a83f9aea7 tools: include: nolibc: Fix a typo occured to occurred in the file nolibc.h
s/occured/occurred/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-07-20 13:42:26 -07:00
Willy Tarreau
3c6ce7a536 tools/nolibc: Fix position of -lgcc in the documented example
The documentation header in the nolibc.h file provides an example command
line, but it places the -lgcc argument before the source files, which
can fail with libgcc.a (e.g. on ARM when uidiv is needed). This commit
therefore moves the -lgcc to the end of the command line, hopefully
before this example leaks into makefiles.  This is a port of nolibc's
upstream commit b5e282089223 to the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:45 -08:00
Willy Tarreau
35635d7fa6 tools/nolibc: Emit detailed error for missing alternate syscall number definitions
Some syscalls can be implemented from different __NR_* variants. For
example, sys_dup2() can be implemented based on __NR_dup3 or __NR_dup2.
In this case it is useful to mention both alternatives in error messages
when neither are detected. This information will help the user search for
the right one (e.g __NR_dup3) instead of just the fallback (__NR_dup2)
which might not exist on the platform.

This is a port of nolibc's upstream commit a21080d2ba41 to the Linux
kernel.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/lkml/20210120145447.GC77728@C02TD0UTHF1T.local/
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:45 -08:00
Willy Tarreau
f65d711778 tools/nolibc: Remove incorrect definitions of __ARCH_WANT_*
The __ARCH_WANT_* definitions were added in order to support aarch64
when it was missing some syscall definitions (including __NR_dup2,
__NR_fork, and __NR_getpgrp), but these __ARCH_WANT_* definitions were
actually wrong because these syscalls do not exist on this platform.
Defining these resulted in exposing invalid definitions, resulting in
failures on aarch64.

The missing syscalls were since implemented based on the newer ones
(__NR_dup3,  __NR_clone, __NR_getpgid) so these incorrect __ARCH_WANT_*
definitions are no longer needed.

Thanks to Mark Rutland for spotting this incorrect analysis and
explaining why it was wrong.

This is a port of nolibc's upstream commit 00b1b0d9b2a4 to the Linux
kernel.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/lkml/20210119153147.GA5083@paulmck-ThinkPad-P72
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:45 -08:00
Willy Tarreau
70ca7aea50 tools/nolibc: Get timeval, timespec and timezone from linux/time.h
The definitions of timeval(), timespec() and timezone() conflict with
linux/time.h when building, so this commit takes them directly from
linux/time.h. This is a port of nolibc's upstream commit dc45f5426b0c
to the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:45 -08:00
Willy Tarreau
5b1c827ca3 tools/nolibc: Implement poll() based on ppoll()
Some architectures like arm64 do not implement poll() and have to use
ppoll() instead. This commit therefore makes poll() use ppoll() when
available. This is a port of nolibc's upstream commit 800f75c13ede to
the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:44 -08:00
Willy Tarreau
be60ca41fb tools/nolibc: Implement fork() based on clone()
Some archs such as arm64 do not have fork() and have to use clone()
instead.  This commit therefore makes fork() use clone() when
available. This requires including signal.h to get the definition of
SIGCHLD.  This is a port of nolibc's upstream commit d2dc42fd6149 to
the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:44 -08:00
Willy Tarreau
c0c7c10375 tools/nolibc: Make getpgrp() fall back to getpgid(0)
The getpgrp() syscall is not implemented on arm64, so this commit instead
uses getpgid(0) when getpgrp() is not available.  This is a port of
nolibc's upstream commit 2379f25073f9 to the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:44 -08:00
Willy Tarreau
79f220e56d tools/nolibc: Make dup2() rely on dup3() when available
A recent boot failure on 5.4-rc3 on arm64 revealed that sys_dup2()
is not available and that only sys_dup3() is implemented.  This commit
detects this and falls back to sys_dup3() when available.  This is a
port of nolibc's upstream commit fd5272ec2c66 to the Linux kernel.

Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:44 -08:00
Willy Tarreau
c261145abd tools/nolibc: Add the definition for dup()
This commit adds the dup() function, which was omitted when sys_dup()
was defined.  This is a port of nolibc's upstream commit 47cc42a79c92
to the Linux kernel.

Fixes: 66b6f755ad ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-21 10:06:44 -08:00
Bhaskar Chowdhury
06dc8d4591 tools/nolibc: Fix a spelling error in a comment
Fix a spelling in the comment line.

s/memry/memory/p

This is on linux-next.

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:58 -08:00
Samuel Hernandez
6c5b9de2c6 rcutorture/nolibc: Fix a typo in header file
This fixes a typo. Before this, the AT_FDCWD macro would be defined
regardless of whether or not it's been defined before.

Signed-off-by: Samuel Hernandez <sam.hernandez.amador@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:13:57 -08:00
Pranith Kumar
582e84f7b7 tool headers nolibc: add RISCV support
This adds support for the RISCV architecture (32 and 64 bit) to the
nolibc header file.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
[willy: minimal rewording of the commit message]
Signed-off-by: Willy Tarreau <w@1wt.eu>
2019-05-08 15:48:43 +02:00
Willy Tarreau
30ca20517a tools headers: Move the nolibc header from rcutorture to tools/include/nolibc/
As suggested by Ingo, this header file might benefit other tools than
just rcutorture. For now it's quite limited, but is easy to extend, so
exposing it into tools/include/nolibc/ will make it much easier to
adopt by other tools.

The mkinitrd.sh script in rcutorture was updated to use this new location.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-01-25 15:37:13 -08:00