mirror_ubuntu-kernels/include/asm-generic
Kees Cook 564c9cc84e locking/refcounts, x86/asm: Use unique .text section for refcount exceptions
Using .text.unlikely for refcount exceptions isn't safe because gcc may
move entire functions into .text.unlikely (e.g. in6_dev_dev()), which
would cause any uses of a protected refcount_t function to stay inline
with the function, triggering the protection unconditionally:

        .section        .text.unlikely,"ax",@progbits
        .type   in6_dev_get, @function
in6_dev_getx:
.LFB4673:
        .loc 2 4128 0
        .cfi_startproc
...
        lock; incl 480(%rbx)
        js 111f
        .pushsection .text.unlikely
111:    lea 480(%rbx), %rcx
112:    .byte 0x0f, 0xff
.popsection
113:

This creates a unique .text..refcount section and adds an additional
test to the exception handler to WARN in the case of having none of OF,
SF, nor ZF set so we can see things like this more easily in the future.

The double dot for the section name keeps it out of the TEXT_MAIN macro
namespace, to avoid collisions and so it can be put at the end with
text.unlikely to keep the cold code together.

See commit:

  cb87481ee8 ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured")

... which matches C names: [a-zA-Z0-9_] but not ".".

Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Elena <elena.reshetova@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch <linux-arch@vger.kernel.org>
Fixes: 7a46ec0e2f ("locking/refcounts, x86/asm: Implement fast refcount overflow protection")
Link: http://lkml.kernel.org/r/1504382986-49301-2-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-28 09:45:05 +02:00
..
bitops bitops: Do not default to __clear_bit() for __clear_bit_unlock() 2016-03-21 10:50:48 +01:00
4level-fixup.h asm-generic: introduce 5level-fixup.h 2017-03-09 11:48:47 -08:00
5level-fixup.h asm-generic: introduce 5level-fixup.h 2017-03-09 11:48:47 -08:00
asm-offsets.h asm-generic: Add common asm-offsets.h 2015-06-23 13:35:49 +09:00
asm-prototypes.h asm-prototypes: Clear any CPP defines before declaring the functions 2017-01-05 12:57:42 +01:00
atomic64.h locking/atomic: Fix atomic_set_release() for 'funny' architectures 2017-08-10 12:28:54 +02:00
atomic-long.h locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API 2016-07-07 09:16:20 +02:00
atomic.h openrisc: add optimized atomic operations 2017-02-25 04:14:06 +09:00
audit_change_attr.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h audit: Modify a set of system calls in audit class definitions 2014-01-17 17:01:46 -05:00
barrier.h locking/spinlock, arch: Update and fix spin_unlock_wait() implementations 2016-06-14 11:55:15 +02:00
bitops.h arch: Prepare for smp_mb__{before,after}_atomic() 2014-04-18 11:40:30 +02:00
bitsperlong.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
bug.h asm-generic/bug.h: declare struct pt_regs; before function prototype 2017-07-10 16:32:34 -07:00
bugs.h
cache.h
cacheflush.h
checksum.h ipv4: Update parameters for csum_tcpudp_magic to their original types 2016-03-13 23:55:13 -04:00
clkdev.h asm-generic: COMMON_CLK defines __clk_{get,put} 2014-09-25 18:00:45 -07:00
cmpxchg-local.h LLVMLinux: Remove warning about returning an uninitialized variable 2014-04-09 13:44:35 -07:00
cmpxchg.h asm-generic: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations 2015-10-15 00:21:13 +02:00
current.h
delay.h
device.h
div64.h __div64_32(): make it overridable at compile time 2015-11-16 14:42:12 -05:00
dma-contiguous.h asm-generic: Add dma-contiguous.h 2014-09-22 13:35:51 +02:00
dma.h
early_ioremap.h x86/mm: Extend early_memremap() support with additional attrs 2017-07-18 11:38:00 +02:00
emergency-restart.h
exec.h
export.h modversions: treat symbol CRCs as 32 bit quantities 2017-02-03 08:28:25 -08:00
extable.h add asm-generic/extable.h 2017-03-27 20:27:28 -04:00
fb.h
fixmap.h asm-generic: Fix local variable shadow in __set_fixmap_offset 2016-02-16 15:10:44 +00:00
ftrace.h
futex.h futex: Remove duplicated code and fix undefined behaviour 2017-08-25 22:49:59 +02:00
getorder.h
gpio.h gpio: allow setting ARCH_NR_GPIOS from Kconfig 2016-02-19 00:22:54 +01:00
hardirq.h
hugetlb.h mm/hugetlb: allow architectures to override huge_pte_clear() 2017-07-06 16:24:34 -07:00
hw_irq.h
ide_iops.h
int-ll64.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
io.h x86/io: Remove xlate_dev_kmem_ptr() duplication 2017-07-24 11:18:21 +02:00
ioctl.h include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error 2014-06-06 16:08:13 -07:00
iomap.h asm-generic/io.h: add io{read,write}64 accessors 2016-05-31 16:41:50 +08:00
irq_regs.h
irq_work.h irq_work: Introduce arch_irq_work_has_interrupt() 2014-09-13 18:38:07 +02:00
irq.h
irqflags.h
kdebug.h
kmap_types.h asm-generic: remove km_type definitions 2012-07-24 15:27:30 +08:00
kprobes.h kprobes: move kprobe declarations to asm-generic/kprobes.h 2017-02-27 18:43:45 -08:00
kvm_para.h KVM: add kvm_para_available to asm-generic/kvm_para.h 2013-06-05 13:21:29 +03:00
linkage.h
local64.h
local.h
mcs_spinlock.h locking/mcs: Allow architecture specific asm files to be used for contended case 2014-02-09 21:18:52 +01:00
memory_model.h mm: add PHYS_PFN, use it in __phys_to_pfn() 2016-01-14 16:00:49 -08:00
mm_hooks.h mm/gup: Drop the arch_pte_access_permitted() MMU callback 2017-03-18 09:48:01 +01:00
mm-arch-hooks.h mm: clean up per architecture MM hook header files 2015-07-17 16:39:53 -07:00
mmu_context.h asm-generic: Remove asm-generic arch_bprm_mm_init() 2014-11-22 21:52:08 +01:00
mmu.h asm-generic/mmu.h: Add support for FDPIC 2012-12-09 23:14:14 +01:00
module.h Make most arch asm/module.h files use asm-generic/module.h 2012-09-28 14:31:03 +09:30
msi.h asm-generic: Add msi.h 2014-11-23 13:01:47 +01:00
page.h asm-generic: page.h: Remove useless get_user_page and free_user_page 2016-02-26 15:24:55 +01:00
param.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
parport.h include: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
pci_iomap.h PCI: Add pci_iomap_wc() variants 2015-08-25 09:59:45 +02:00
pci.h PCI: Remove unused pcibios_select_root() (again) 2015-06-08 07:56:21 -05:00
percpu.h percpu: use notrace variant of preempt_disable/preempt_enable 2016-11-08 10:29:44 +01:00
pgalloc.h
pgtable-nop4d-hack.h asm-generic: introduce __ARCH_USE_5LEVEL_HACK 2017-03-09 11:48:47 -08:00
pgtable-nop4d.h asm-generic: introduce <asm-generic/pgtable-nop4d.h> 2017-03-09 11:48:47 -08:00
pgtable-nopmd.h
pgtable-nopud.h asm-generic: introduce <asm-generic/pgtable-nop4d.h> 2017-03-09 11:48:47 -08:00
pgtable.h mm: soft-dirty: keep soft-dirty bits over thp migration 2017-09-08 18:26:45 -07:00
preempt.h sched/preempt: Fix preempt_count manipulations 2016-05-17 12:24:21 +02:00
ptrace.h
qrwlock_types.h locking/qrwlock: Rename ->lock to ->wait_lock 2015-09-18 09:27:29 +02:00
qrwlock.h locking/qrwlock: Fix write unlock bug on big endian systems 2016-08-10 14:13:27 +02:00
qspinlock_types.h locking/qspinlock: Move __ARCH_SPIN_LOCK_UNLOCKED to qspinlock_types.h 2016-02-29 10:02:43 +01:00
qspinlock.h locking: Remove spin_unlock_wait() generic definitions 2017-08-17 08:08:58 -07:00
resource.h asm-generic: remove _STK_LIM_MAX 2014-05-15 00:32:09 +01:00
rwsem.h locking/rwsem: Remove unnecessary atomic_long_t casts 2017-01-20 09:46:44 +01:00
seccomp.h seccomp: Get compat syscalls from asm-generic header 2016-05-13 14:02:00 +02:00
sections.h irq: Make the irqentry text section unconditional 2017-08-10 16:28:53 +02:00
segment.h
serial.h
set_memory.h treewide: move set_memory_* functions away from cacheflush.h 2017-05-08 17:15:13 -07:00
signal.h unify default ptrace_signal_deliver 2012-11-29 00:01:23 -05:00
simd.h crypto: create generic version of ablk_helper 2013-09-24 06:02:24 +10:00
sizes.h ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h> 2012-06-28 17:14:34 +01:00
spinlock.h
statfs.h UAPI: (Scripted) Disintegrate include/asm-generic 2012-10-04 18:20:15 +01:00
string.h
switch_to.h
syscall.h syscall.h: fix doc text for syscall_get_arch() 2014-09-23 16:20:00 -04:00
syscalls.h burying unused conditionals 2013-02-14 09:21:15 -05:00
termios-base.h Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
termios.h Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
timex.h
tlb.h mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem 2017-08-10 15:54:07 -07:00
tlbflush.h
topology.h cpumask: fix spurious cpumask_of_node() on non-NUMA multi-node configs 2017-08-28 16:13:16 -07:00
trace_clock.h tracing,x86: Add a TSC trace_clock 2012-11-13 15:48:27 -05:00
uaccess.h fix the __user misannotations in asm-generic get_user/put_user 2017-09-04 12:07:24 -04:00
unaligned.h asm-generic: allow generic unaligned access if the arch supports it 2014-05-08 10:22:23 +02:00
unistd.h We get rid of the general module prefix confusion with a binary config option, 2013-05-05 10:58:06 -07:00
user.h
vga.h
vmlinux.lds.h locking/refcounts, x86/asm: Use unique .text section for refcount exceptions 2017-09-28 09:45:05 +02:00
vtime.h include/asm-generic/vtime.h: avoid zero-length file 2013-09-30 14:31:02 -07:00
word-at-a-time.h Make asm/word-at-a-time.h available on all architectures 2015-07-08 16:41:55 -04:00
xor.h asm-generic: xor: mark static functions as __maybe_unused 2012-10-03 21:21:06 +02:00