Replace literal 0 with macro PKEY_UNRESTRICTED where pkey_*() functions
are used in mm selftests for memory protection keys.
Signed-off-by: Yury Khrustalev <yury.khrustalev@arm.com>
Suggested-by: Joey Gouly <joey.gouly@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20250113170619.484698-3-yury.khrustalev@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
sys_pkey_alloc, sys_pkey_free and sys_mprotect_pkey are currently used in
protections_keys.c, while pkey_sighandler_tests.c calls the libc wrappers
directly (e.g. pkey_mprotect()). This is probably ok when using glibc
(those symbols appeared a while ago), but Musl does not currently provide
them. The logging in the helpers from pkey-helpers.h can also come in
handy.
Make things more consistent by using the sys_pkey helpers in
pkey_sighandler_tests.c too. To that end their implementation is moved to
a common .c file (pkey_util.c). This also enables calling
is_pkeys_supported() outside of protections_keys.c, since it relies on
sys_pkey_{alloc,free}.
[kevin.brodsky@arm.com: fix dependency on pkey_util.c]
Link: https://lkml.kernel.org/r/20241216092849.2140850-1-kevin.brodsky@arm.com
Link: https://lkml.kernel.org/r/20241209095019.1732120-12-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The pkey tests define a whole lot of functions and some global variables.
A few are truly global (declared in pkey-helpers.h), but the majority are
file-scoped. Make sure those are labelled static.
Some of the pkey_{access,write}_{allow,deny} helpers are not called, or
only called when building for some architectures. Mark them
__maybe_unused to suppress compiler warnings.
Link: https://lkml.kernel.org/r/20241209095019.1732120-11-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some of the functions declared in pkey-helpers.h are actually defined in
protections_keys.c, meaning they can only be called from
protections_keys.c. This is less than ideal, but it is hard to avoid as
these helpers are themselves called from inline functions in
pkey-<arch>.h. Let's at least add a comment clarifying that. We can also
remove the empty definition in pkey_sighandler_tests.c:
expected_pkey_fault() is not meant to be called from there.
Link: https://lkml.kernel.org/r/20241209095019.1732120-10-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Headers should not define non-inline functions, as this prevents them from
being included more than once in a given program. pkey-helpers.h and the
arch-specific headers it includes currently define multiple such
non-inline functions.
In most cases those functions can simply be made inline - this patch does
just that. read_ptr() is an exception as it must not be inlined. Since
it is only called from protection_keys.c, we just move it there.
Link: https://lkml.kernel.org/r/20241209095019.1732120-9-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Using #define to define types should be avoided. Use typedef instead.
Also ensure that __u* types are actually defined by including
<linux/types.h>.
Link: https://lkml.kernel.org/r/20241209095019.1732120-8-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 5f23f6d082 ("x86/pkeys: Add self-tests") introduced a
number of helpers and functions that don't seem to have ever been
used. Let's remove them.
Link: https://lkml.kernel.org/r/20241209095019.1732120-7-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 6e182dc9f2 ("selftests/mm: Use generic pkey register
manipulation") makes use of PKEY_UNRESTRICTED in
pkey_sighandler_tests. The macro has been proposed for addition to
uapi headers [1], but the patch hasn't landed yet.
Define PKEY_UNRESTRICTED in pkey-helpers.h for the time being to fix
the build.
[1] https://lore.kernel.org/all/20241028090715.509527-2-yury.khrustalev@arm.com/
Fixes: 6e182dc9f2 ("selftests/mm: Use generic pkey register manipulation")
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20241107131640.650703-1-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
- Make LAM enablement safe vs. kernel threads using a process mm
temporarily as switching back to the process would not update CR3 and
therefore not enable LAM causing faults in user space when using tagged
pointers. Cure it by synchronizing LAM enablement via IPIs to all CPUs
which use the related mm.
- Cure a LAM harmless inconsistency between CR3 and the state during
context switch. It's both confusing and prone to lead to real bugs
- Handle alt stack handling for threads which run with a non-zero
protection key. The non-zero key prevents the kernel to access the
alternate stack. Cure it by temporarily enabling all protection keys for
the alternate stack setup/restore operations.
- Provide a EFI config table identity mapping for kexec kernel to prevent
kexec fails because the new kernel cannot access the config table array
- Use GB pages only when a full GB is mapped in the identity map as
otherwise the CPU can speculate into reserved areas after the end of
memory which causes malfunction on UV systems.
- Remove the noisy and pointless SRAT table dump during boot
- Use is_ioremap_addr() for iounmap() address range checks instead of
high_memory. is_ioremap_addr() is more precise.
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Merge tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 memory management updates from Thomas Gleixner:
- Make LAM enablement safe vs. kernel threads using a process mm
temporarily as switching back to the process would not update CR3 and
therefore not enable LAM causing faults in user space when using
tagged pointers. Cure it by synchronizing LAM enablement via IPIs to
all CPUs which use the related mm.
- Cure a LAM harmless inconsistency between CR3 and the state during
context switch. It's both confusing and prone to lead to real bugs
- Handle alt stack handling for threads which run with a non-zero
protection key. The non-zero key prevents the kernel to access the
alternate stack. Cure it by temporarily enabling all protection keys
for the alternate stack setup/restore operations.
- Provide a EFI config table identity mapping for kexec kernel to
prevent kexec fails because the new kernel cannot access the config
table array
- Use GB pages only when a full GB is mapped in the identity map as
otherwise the CPU can speculate into reserved areas after the end of
memory which causes malfunction on UV systems.
- Remove the noisy and pointless SRAT table dump during boot
- Use is_ioremap_addr() for iounmap() address range checks instead of
high_memory. is_ioremap_addr() is more precise.
* tag 'x86-mm-2024-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioremap: Improve iounmap() address range checks
x86/mm: Remove duplicate check from build_cr3()
x86/mm: Remove unused NX related declarations
x86/mm: Remove unused CR3_HW_ASID_BITS
x86/mm: Don't print out SRAT table information
x86/mm/ident_map: Use gbpages only where full GB page should be mapped.
x86/kexec: Add EFI config table identity mapping for kexec kernel
selftests/mm: Add new testcases for pkeys
x86/pkeys: Restore altstack access in sigreturn()
x86/pkeys: Update PKRU to enable all pkeys before XSAVE
x86/pkeys: Add helper functions to update PKRU on the sigframe
x86/pkeys: Add PKRU as a parameter in signal handling functions
x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking
x86/mm: Fix LAM inconsistency during context switch
x86/mm: Use IPIs to synchronize LAM enablement
The encoding of the pkey register differs on arm64, than on x86/ppc. On those
platforms, a bit in the register is used to disable permissions, for arm64, a
bit enabled in the register indicates that the permission is allowed.
This drops two asserts of the form:
assert(read_pkey_reg() <= orig_pkey_reg);
Because on arm64 this doesn't hold, due to the encoding.
The pkey must be reset to both access allow and write allow in the signal
handler. pkey_access_allow() works currently for PowerPC as the
PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE have overlapping bits set.
Access to the uc_mcontext is abstracted, as arm64 has a different structure.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20240822151113.1479789-27-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Add a few new tests to exercise the signal handler flow, especially with
PKEY 0 disabled:
- Verify that the SIGSEGV handler is invoked when pkey 0 is disabled.
- Verify that a thread which disables PKEY 0 segfaults with PKUERR when
accessing the stack.
- Verify that the SIGSEGV handler that uses an alternate signal stack is
correctly invoked when the thread disabled PKEY 0
- Verify that the PKRU value set by the application is correctly restored
upon return from signal handling.
- Verify that sigreturn() is able to restore the altstack even if the
thread had PKEY 0 disabled
[ Aruna: Adapted to upstream ]
[ tglx: Made it actually compile. Restored protection_keys compile. Added
useful info to the changelog instead of bare function names. ]
Signed-off-by: Keith Lucas <keith.lucas@oracle.com>
Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240802061318.2140081-6-aruna.ramakrishna@oracle.com
Compiling mm selftest after adding a __printf() attribute to
ksft_print_msg() exposes -Wformat warning in remap_region().
Fix the wrong format specifier causing the warning.
The mm selftest uses the printf attribute in its full form. Since the
header file that uses it also includes kselftests.h it can use the macro
defined there.
Use __printf() included with kselftests.h instead of the full attribute.
Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Rename selftets/vm to selftests/mm for being more consistent with the
code, documentation, and tools directories, and won't be confused with
virtual machines.
[sj@kernel.org: convert missing vm->mm changes]
Link: https://lkml.kernel.org/r/20230107230643.252273-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230103180754.129637-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
