| From 5996b113deb6b1307f1da1746f2ae18a5a724e7f Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 29 Nov 2022 18:35:14 -0800 |
| Subject: RISC-V: Align the shadow stack |
| |
| From: Palmer Dabbelt <palmer@rivosinc.com> |
| |
| [ Upstream commit b003b3b77d65133a0011ae3b7b255347438c12f6 ] |
| |
| The standard RISC-V ABIs all require 16-byte stack alignment. We're |
| only calling that one function on the shadow stack so I doubt it'd |
| result in a real issue, but might as well keep this lined up. |
| |
| Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") |
| Reviewed-by: Jisheng Zhang <jszhang@kernel.org> |
| Link: https://lore.kernel.org/r/20221130023515.20217-1-palmer@rivosinc.com |
| Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/riscv/kernel/traps.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c |
| index 6e8822446069..026b45833158 100644 |
| --- a/arch/riscv/kernel/traps.c |
| +++ b/arch/riscv/kernel/traps.c |
| @@ -211,7 +211,7 @@ static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], |
| * shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used |
| * to get per-cpu overflow stack(get_overflow_stack). |
| */ |
| -long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)]; |
| +long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)] __aligned(16); |
| asmlinkage unsigned long get_overflow_stack(void) |
| { |
| return (unsigned long)this_cpu_ptr(overflow_stack) + |
| -- |
| 2.35.1 |
| |
