From aa0a20f521516ba83ea29b510fcc12fb35920b48 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel <ardb@kernel.org> Date: Mon, 24 Jan 2022 19:36:03 +0100 Subject: [PATCH] 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> --- arch/arm/kernel/entry-armv.S | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index b58bda51e4b87..038aabb6578f6 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 -- 2.30.2