path: root/arch/arm64/include/asm
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authorMark Rutland <mark.rutland@arm.com>2017-08-01 18:51:15 +0100
committerMark Rutland <mark.rutland@arm.com>2017-08-15 18:36:12 +0100
commit12964443e8d1914010f9269f9f9abc4e122bc6ca (patch)
treed111b3b683530290cc4d65992456b68167916a20 /arch/arm64/include/asm
parentarm64: add basic VMAP_STACK support (diff)
arm64: add on_accessible_stack()
Both unwind_frame() and dump_backtrace() try to check whether a stack address is sane to access, with very similar logic. Both will need updating in order to handle overflow stacks. Factor out this logic into a helper, so that we can avoid further duplication when we add overflow stacks. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Tested-by: Laura Abbott <labbott@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com>
Diffstat (limited to '')
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 4c68d8a81988..92ddb6d25cf3 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -57,4 +57,20 @@ static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
return (low <= sp && sp < high);
+ * We can only safely access per-cpu stacks from current in a non-preemptible
+ * context.
+ */
+static inline bool on_accessible_stack(struct task_struct *tsk, unsigned long sp)
+ if (on_task_stack(tsk, sp))
+ return true;
+ if (tsk != current || preemptible())
+ return false;
+ if (on_irq_stack(sp))
+ return true;
+ return false;
#endif /* __ASM_STACKTRACE_H */