We cannot get FP and PC when the task is running on another CPU, task->thread.cpu_context is the last time the task was switched out, we can use smp call to print backtrace itself.
Signed-off-by: Wang Qing <[email protected]> --- arch/arm64/kernel/traps.c | 11 +++++++++++ 1 file changed, 11 insertions(+) mode change 100644 => 100755 arch/arm64/kernel/traps.c diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 50cc30a..17a07b9 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -83,6 +83,11 @@ static void dump_kernel_instr(const char *lvl, struct pt_regs *regs) printk("%sCode: %s\n", lvl, str); } +static void dump_backtrace_smp_fun(struct task_struct *tsk) +{ + dump_backtrace(NULL, tsk, KERN_DEFAULT); +} + void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, const char *loglvl) { @@ -107,6 +112,12 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, start_backtrace(&frame, (unsigned long)__builtin_frame_address(0), (unsigned long)dump_backtrace); + } else if (task_curr(tsk)) { + /* + * The task is currently running on other cpu + */ + smp_call_function_single(tsk->cpu, dump_backtrace_fun, tsk, 0); + return; } else { /* * task blocked in __switch_to -- 2.7.4
