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authorArd Biesheuvel <ardb@kernel.org>2022-01-24 19:36:03 +0100
committerArd Biesheuvel <ardb@kernel.org>2022-01-25 09:53:52 +0100
commitaa0a20f521516ba83ea29b510fcc12fb35920b48 (patch)
treecbf4e8efd0f78d41baf6a9c6dede06dd014a7cfa
parentARM: smp: elide HWCAP_TLS checks or __entry_task updates on SMP+v6 (diff)
ARM: entry: avoid clobbering R9 in IRQ handler
Avoid using R9 in the IRQ handler code, as the entry code uses it for tsk, and expects it to remain untouched between the IRQ entry and exit code. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-rw-r--r--arch/arm/kernel/entry-armv.S9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index b58bda51e4b8..038aabb6578f 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -38,11 +38,10 @@
#ifdef CONFIG_UNWINDER_ARM
mov fpreg, sp @ Preserve original SP
#else
- mov r8, fp @ Preserve original FP
- mov r9, sp @ Preserve original SP
+ mov r7, fp @ Preserve original FP
+ mov r8, sp @ Preserve original SP
#endif
ldr_this_cpu sp, irq_stack_ptr, r2, r3
-
.if \from_user == 0
UNWIND( .setfp fpreg, sp )
@
@@ -82,8 +81,8 @@ UNWIND( .setfp fpreg, sp )
#ifdef CONFIG_UNWINDER_ARM
mov sp, fpreg @ Restore original SP
#else
- mov fp, r8 @ Restore original FP
- mov sp, r9 @ Restore original SP
+ mov fp, r7 @ Restore original FP
+ mov sp, r8 @ Restore original SP
#endif // CONFIG_UNWINDER_ARM
#endif // CONFIG_IRQSTACKS
.endm