summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/stacktrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kernel/stacktrace.c')
-rw-r--r--arch/arm64/kernel/stacktrace.c60
1 files changed, 10 insertions, 50 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 09d37d66b630..3144584617e7 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -42,33 +42,17 @@
*/
int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
{
- unsigned long high, low;
unsigned long fp = frame->fp;
- unsigned long irq_stack_ptr;
+
+ if (fp & 0xf)
+ return -EINVAL;
if (!tsk)
tsk = current;
- /*
- * Switching between stacks is valid when tracing current and in
- * non-preemptible context.
- */
- if (tsk == current && !preemptible())
- irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
- else
- irq_stack_ptr = 0;
-
- low = frame->sp;
- /* irq stacks are not THREAD_SIZE aligned */
- if (on_irq_stack(frame->sp, raw_smp_processor_id()))
- high = irq_stack_ptr;
- else
- high = ALIGN(low, THREAD_SIZE) - 0x20;
-
- if (fp < low || fp > high || fp & 0xf)
+ if (!on_accessible_stack(tsk, fp))
return -EINVAL;
- frame->sp = fp + 0x10;
frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
@@ -86,34 +70,13 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/*
- * Check whether we are going to walk through from interrupt stack
- * to task stack.
- * If we reach the end of the stack - and its an interrupt stack,
- * unpack the dummy frame to find the original elr.
- *
- * Check the frame->fp we read from the bottom of the irq_stack,
- * and the original task stack pointer are both in current->stack.
+ * Frames created upon entry from EL0 have NULL FP and PC values, so
+ * don't bother reporting these. Frames created by __noreturn functions
+ * might have a valid FP even if PC is bogus, so only terminate where
+ * both are NULL.
*/
- if (frame->sp == irq_stack_ptr) {
- struct pt_regs *irq_args;
- unsigned long orig_sp = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);
-
- if (object_is_on_stack((void *)orig_sp) &&
- object_is_on_stack((void *)frame->fp)) {
- frame->sp = orig_sp;
-
- /* orig_sp is the saved pt_regs, find the elr */
- irq_args = (struct pt_regs *)orig_sp;
- frame->pc = irq_args->pc;
- } else {
- /*
- * This frame has a non-standard format, and we
- * didn't fix it, because the data looked wrong.
- * Refuse to output this frame.
- */
- return -EINVAL;
- }
- }
+ if (!frame->fp && !frame->pc)
+ return -EINVAL;
return 0;
}
@@ -167,7 +130,6 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
data.no_sched_functions = 0;
frame.fp = regs->regs[29];
- frame.sp = regs->sp;
frame.pc = regs->pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
frame.graph = current->curr_ret_stack;
@@ -192,12 +154,10 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
if (tsk != current) {
data.no_sched_functions = 1;
frame.fp = thread_saved_fp(tsk);
- frame.sp = thread_saved_sp(tsk);
frame.pc = thread_saved_pc(tsk);
} else {
data.no_sched_functions = 0;
frame.fp = (unsigned long)__builtin_frame_address(0);
- frame.sp = current_stack_pointer;
frame.pc = (unsigned long)save_stack_trace_tsk;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER