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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2015-12-04 14:02:26 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-12-08 14:41:51 +0300 |
| commit | 132cd887b5c54758d04bf25c52fa48f45e843a30 (patch) | |
| tree | 5c911127a290dcd7a78c417ced4ae096dd93bd5c /arch/arm64/kernel/traps.c | |
| parent | 6cdf9c7ca687e01840d0215437620a20263012fc (diff) | |
| download | linux-132cd887b5c54758d04bf25c52fa48f45e843a30.tar.xz | |
arm64: Modify stack trace and dump for use with irq_stack
This patch allows unwind_frame() to traverse from interrupt stack to task
stack correctly. It requires data from a dummy stack frame, created
during irq_stack_entry(), added by a later patch.
A similar approach is taken to modify dump_backtrace(), which expects to
find struct pt_regs underneath any call to functions marked __exception.
When on an irq_stack, the struct pt_regs is stored on the old task stack,
the location of which is stored in the dummy stack frame.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
[james.morse: merged two patches, reworked for per_cpu irq_stacks, and
no alignment guarantees, added irq_stack definitions]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/traps.c')
| -rw-r--r-- | arch/arm64/kernel/traps.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index e9b9b5364393..8a0084541f84 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -146,6 +146,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; + unsigned long irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id()); pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); @@ -180,9 +181,20 @@ static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) if (ret < 0) break; stack = frame.sp; - if (in_exception_text(where)) + if (in_exception_text(where)) { + /* + * If we switched to the irq_stack before calling this + * exception handler, then the pt_regs will be on the + * task stack. The easiest way to tell is if the large + * pt_regs would overlap with the end of the irq_stack. + */ + if (stack < irq_stack_ptr && + (stack + sizeof(struct pt_regs)) > irq_stack_ptr) + stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr); + dump_mem("", "Exception stack", stack, stack + sizeof(struct pt_regs), false); + } } } |