diff options
| author | Colin Ian King <colin.king@canonical.com> | 2016-05-11 19:56:54 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-05-12 16:20:49 +0300 |
| commit | e6d9a52543338603e25e71e0e4942f05dae0dd8a (patch) | |
| tree | fd4dc45735731b36083579528999ae2ac53f230c /arch | |
| parent | 61462c8a6b140fe2f93cb911684837e05950e680 (diff) | |
| download | linux-e6d9a52543338603e25e71e0e4942f05dae0dd8a.tar.xz | |
arm64: do not enforce strict 16 byte alignment to stack pointer
copy_thread should not be enforcing 16 byte aligment and returning
-EINVAL. Other architectures trap misaligned stack access with SIGBUS
so arm64 should follow this convention, so remove the strict enforcement
check.
For example, currently clone(2) fails with -EINVAL when passing
a misaligned stack and this gives little clue to what is wrong. Instead,
it is arguable that a SIGBUS on the fist access to a misaligned stack
allows one to figure out that it is a misaligned stack issue rather
than trying to figure out why an unconventional (and undocumented)
-EINVAL is being returned.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/process.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index ad4a7e132ead..48eea6866c67 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -265,9 +265,6 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, if (stack_start) { if (is_compat_thread(task_thread_info(p))) childregs->compat_sp = stack_start; - /* 16-byte aligned stack mandatory on AArch64 */ - else if (stack_start & 15) - return -EINVAL; else childregs->sp = stack_start; } |