summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/asm-offsets.c
diff options
context:
space:
mode:
authorWill Deacon <will@kernel.org>2020-05-15 14:11:05 +0100
committerWill Deacon <will@kernel.org>2020-05-18 17:47:22 +0100
commit51189c7a7ed1b4ed4493e27275d466ff60406d3a (patch)
treec06448db0ce33c2d4a5ae1494806a3b81082aa96 /arch/arm64/kernel/asm-offsets.c
parentcc49c71d2abe99c1c2c9bedf0693ad2d3ee4a067 (diff)
downloadlinux-next-51189c7a7ed1b4ed4493e27275d466ff60406d3a.tar.gz
arm64: scs: Store absolute SCS stack pointer value in thread_info
Storing the SCS information in thread_info as a {base,offset} pair introduces an additional load instruction on the ret-to-user path, since the SCS stack pointer in x18 has to be converted back to an offset by subtracting the base. Replace the offset with the absolute SCS stack pointer value instead and avoid the redundant load. Tested-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/asm-offsets.c')
-rw-r--r--arch/arm64/kernel/asm-offsets.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index d7934250b68c..a098a45f63d8 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -36,7 +36,7 @@ int main(void)
#endif
#ifdef CONFIG_SHADOW_CALL_STACK
DEFINE(TSK_TI_SCS_BASE, offsetof(struct task_struct, thread_info.scs_base));
- DEFINE(TSK_TI_SCS_OFFSET, offsetof(struct task_struct, thread_info.scs_offset));
+ DEFINE(TSK_TI_SCS_SP, offsetof(struct task_struct, thread_info.scs_sp));
#endif
DEFINE(TSK_STACK, offsetof(struct task_struct, stack));
#ifdef CONFIG_STACKPROTECTOR