diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2024-10-17 10:25:29 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-10-17 18:06:24 +0100 |
| commit | c87df9cb9a216bc87951087a2592633cdc2737d4 (patch) | |
| tree | 92968e2b156df5f7fd26f04a5bf0e2415e38ba25 /arch | |
| parent | 9852d85ec9d492ebef56dc5f229416c925758edc (diff) | |
arm64: pt_regs: assert pt_regs is a multiple of 16 bytes
To ensure that the stack is correctly aligned when branching to C code,
we require that struct pt_regs is a multiple of 16 bytes, as noted in a
comment.
Add an explicit assertion for this, so that any accidental violation of
this requirement will be caught by the compiler.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Puranjay Mohan <puranjay12@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241017092538.1859841-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index 0abe975d68a8..10eca3a3fed4 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -149,8 +149,7 @@ static inline unsigned long pstate_to_compat_psr(const unsigned long pstate) /* * This struct defines the way the registers are stored on the stack during an - * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for - * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs. + * exception. struct user_pt_regs must form a prefix of struct pt_regs. */ struct pt_regs { union { @@ -180,6 +179,9 @@ struct pt_regs { u64 exit_rcu; }; +/* For correct stack alignment, pt_regs has to be a multiple of 16 bytes. */ +static_assert(IS_ALIGNED(sizeof(struct pt_regs), 16)); + static inline bool in_syscall(struct pt_regs const *regs) { return regs->syscallno != NO_SYSCALL; |