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authorKees Cook <keescook@chromium.org>2022-02-19 17:26:00 -0800
committerKees Cook <keescook@chromium.org>2022-02-25 18:21:23 -0800
commit92652cf986441b18282db6e5bd82afc74e8ed5e9 (patch)
tree7d2cab1235f3216501ef6a499575872083bab455 /arch/xtensa
parent2792d84e6da5e0fd7d3b22fd70bc69b7ee263609 (diff)
xtensa: Implement "current_stack_pointer"
To follow the existing per-arch conventions replace open-coded uses of asm "sp" as "current_stack_pointer". This will let it be used in non-arch places (like HARDENED_USERCOPY). Cc: Chris Zankel <chris@zankel.net> Cc: Marc Zyngier <maz@kernel.org> Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Link: https://lore.kernel.org/lkml/CAMo8BfJFJE-n3=AF+pb9_6oF3gzxX7a+7aBrASHjjNX5byqDqw@mail.gmail.com
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/Kconfig1
-rw-r--r--arch/xtensa/include/asm/current.h2
-rw-r--r--arch/xtensa/include/asm/stacktrace.h8
-rw-r--r--arch/xtensa/kernel/irq.c3
4 files changed, 8 insertions, 6 deletions
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 8ac599aa6d99..887432327613 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config XTENSA
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_HAS_BINFMT_FLAT if !MMU
+ select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DMA_PREP_COHERENT if MMU
select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU
diff --git a/arch/xtensa/include/asm/current.h b/arch/xtensa/include/asm/current.h
index 5d98a7ad4251..08010dbf5e09 100644
--- a/arch/xtensa/include/asm/current.h
+++ b/arch/xtensa/include/asm/current.h
@@ -26,6 +26,8 @@ static inline struct task_struct *get_current(void)
#define current get_current()
+register unsigned long current_stack_pointer __asm__("a1");
+
#else
#define GET_CURRENT(reg,sp) \
diff --git a/arch/xtensa/include/asm/stacktrace.h b/arch/xtensa/include/asm/stacktrace.h
index fe06e8ed162b..a85e785a6288 100644
--- a/arch/xtensa/include/asm/stacktrace.h
+++ b/arch/xtensa/include/asm/stacktrace.h
@@ -19,14 +19,14 @@ struct stackframe {
static __always_inline unsigned long *stack_pointer(struct task_struct *task)
{
- unsigned long *sp;
+ unsigned long sp;
if (!task || task == current)
- __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
+ sp = current_stack_pointer;
else
- sp = (unsigned long *)task->thread.sp;
+ sp = task->thread.sp;
- return sp;
+ return (unsigned long *)sp;
}
void walk_stackframe(unsigned long *sp,
diff --git a/arch/xtensa/kernel/irq.c b/arch/xtensa/kernel/irq.c
index 15051a8a1539..529fe9245821 100644
--- a/arch/xtensa/kernel/irq.c
+++ b/arch/xtensa/kernel/irq.c
@@ -36,9 +36,8 @@ asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
- unsigned long sp;
+ unsigned long sp = current_stack_pointer;
- __asm__ __volatile__ ("mov %0, a1\n" : "=a" (sp));
sp &= THREAD_SIZE - 1;
if (unlikely(sp < (sizeof(thread_info) + 1024)))