diff options
| author | Nicholas Piggin | 2018-11-15 12:34:27 +1000 |
|---|---|---|
| committer | Michael Ellerman | 2018-11-15 14:48:43 +1100 |
| commit | 66f93c5a02d5ba6ef17fef459143961382593212 (patch) | |
| tree | 28698e7d100f525b169a199a11fa8c25a8bbf92e | |
| parent | 437ccdc8ce629470babdda1a7086e2f477048cbd (diff) | |
powerpc/64: Fix kernel stack 16-byte alignment
Commit 4c2de74cc869 ("powerpc/64: Interrupts save PPR on stack rather
than thread_struct") changed sizeof(struct pt_regs) % 16 from 0 to 8,
which causes the interrupt frame allocation on kernel entry to put the
kernel stack out of alignment.
Quadword (16-byte) alignment for the stack is required by both the
64-bit v1 ABI (v1.9 § 3.2.2) and the 64-bit v2 ABI (v1.1 § 2.2.2.1).
Add a pad field to fix alignment, and add a BUILD_BUG_ON to catch this
in future.
Fixes: 4c2de74cc869 ("powerpc/64: Interrupts save PPR on stack rather than thread_struct")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/include/asm/ptrace.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 2 |
2 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h index f73886a1a7f5..0b8a735b6d85 100644 --- a/arch/powerpc/include/asm/ptrace.h +++ b/arch/powerpc/include/asm/ptrace.h @@ -54,6 +54,7 @@ struct pt_regs #ifdef CONFIG_PPC64 unsigned long ppr; + unsigned long __pad; /* Maintain 16 byte interrupt stack alignment */ #endif }; #endif diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 2a51e4cc8246..236c1151a3a7 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -636,6 +636,8 @@ static void *__init alloc_stack(unsigned long limit, int cpu) { unsigned long pa; + BUILD_BUG_ON(STACK_INT_FRAME_SIZE % 16); + pa = memblock_alloc_base_nid(THREAD_SIZE, THREAD_SIZE, limit, early_cpu_to_node(cpu), MEMBLOCK_NONE); if (!pa) { |