diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2021-11-24 12:09:48 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-12-06 12:49:16 +0100 |
| commit | 831a469bc1674b7898984ce96f2902534445c0cf (patch) | |
| tree | ff91d95c5492bbe7b61a0eaf4185a64c7aa353fb /arch/arm/kernel/entry-armv.S | |
| parent | 52d24087176055d5994ac98378426421b2d6d653 (diff) | |
ARM: entry: preserve thread_info pointer in switch_to
Tweak the UP stack protector handling code so that the thread info
pointer is preserved in R7 until set_current is called. This is needed
for a subsequent patch that implements THREAD_INFO_IN_TASK and
set_current for UP as well.
This also means we will prefer the per-task protector on UP systems that
implement the thread ID registers, so tweak the preprocessor
conditionals to reflect this.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 9744d087ee9f..1a6cf711a3b4 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -806,16 +806,16 @@ ENTRY(__switch_to) ldr r6, [r2, #TI_CPU_DOMAIN] #endif switch_tls r1, r4, r5, r3, r7 -#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) - ldr r7, [r2, #TI_TASK] +#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) && \ + !defined(CONFIG_STACKPROTECTOR_PER_TASK) + ldr r9, [r2, #TI_TASK] ldr r8, =__stack_chk_guard .if (TSK_STACK_CANARY > IMM12_MASK) - add r7, r7, #TSK_STACK_CANARY & ~IMM12_MASK + add r9, r9, #TSK_STACK_CANARY & ~IMM12_MASK .endif - ldr r7, [r7, #TSK_STACK_CANARY & IMM12_MASK] -#elif defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO) - mov r7, r2 @ Preserve 'next' + ldr r9, [r9, #TSK_STACK_CANARY & IMM12_MASK] #endif + mov r7, r2 @ Preserve 'next' #ifdef CONFIG_CPU_USE_DOMAINS mcr p15, 0, r6, c3, c0, 0 @ Set domain register #endif @@ -824,8 +824,9 @@ ENTRY(__switch_to) ldr r0, =thread_notify_head mov r1, #THREAD_NOTIFY_SWITCH bl atomic_notifier_call_chain -#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) - str r7, [r8] +#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP) && \ + !defined(CONFIG_STACKPROTECTOR_PER_TASK) + str r9, [r8] #endif mov r0, r5 #if !defined(CONFIG_THUMB2_KERNEL) && !defined(CONFIG_VMAP_STACK) |