diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2017-07-14 12:23:09 +0100 |
|---|---|---|
| committer | Mark Rutland <mark.rutland@arm.com> | 2017-08-15 18:34:46 +0100 |
| commit | 48ac3c18cc62d4a23d5dc5c59f8720589d0de14b (patch) | |
| tree | cf21c9b379b4acf9a509d85f6b5edb02a2b86f80 /include/linux/thread_info.h | |
| parent | c5bc503cbeee8586395aa541d2b53c69c3dd6930 (diff) | |
fork: allow arch-override of VMAP stack alignment
In some cases, an architecture might wish its stacks to be aligned to a
boundary larger than THREAD_SIZE. For example, using an alignment of
double THREAD_SIZE can allow for stack overflows smaller than
THREAD_SIZE to be detected by checking a single bit of the stack
pointer.
This patch allows architectures to override the alignment of VMAP'd
stacks, by defining THREAD_ALIGN. Where not defined, this defaults to
THREAD_SIZE, as is the case today.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-kernel@vger.kernel.org
Diffstat (limited to 'include/linux/thread_info.h')
| -rw-r--r-- | include/linux/thread_info.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 250a27614328..905d769d8ddc 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -38,6 +38,10 @@ enum { #ifdef __KERNEL__ +#ifndef THREAD_ALIGN +#define THREAD_ALIGN THREAD_SIZE +#endif + #ifdef CONFIG_DEBUG_STACK_USAGE # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ __GFP_ZERO) |