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-rw-r--r--arch/arm/kernel/stacktrace.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index 6582c4adc..5a80ddf 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -3,6 +3,7 @@
#include <linux/stacktrace.h>
#include <asm/stacktrace.h>
+#include <asm/traps.h>
#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND)
/*
@@ -61,6 +62,7 @@ EXPORT_SYMBOL(walk_stackframe);
#ifdef CONFIG_STACKTRACE
struct stack_trace_data {
struct stack_trace *trace;
+ unsigned long last_pc;
unsigned int no_sched_functions;
unsigned int skip;
};
@@ -69,6 +71,7 @@ static int save_trace(struct stackframe *frame, void *d)
{
struct stack_trace_data *data = d;
struct stack_trace *trace = data->trace;
+ struct pt_regs *regs;
unsigned long addr = frame->pc;
if (data->no_sched_functions && in_sched_functions(addr))
@@ -80,6 +83,25 @@ static int save_trace(struct stackframe *frame, void *d)
trace->entries[trace->nr_entries++] = addr;
+ if (trace->nr_entries >= trace->max_entries)
+ return 1;
+
+ /*
+ * in_exception_text() is designed to test if the PC is one of
+ * the functions which has an exception stack above it, but
+ * unfortunately what is in frame->pc is the return LR value,
+ * not the saved PC value. So, we need to track the previous
+ * frame PC value when doing this.
+ */
+ addr = data->last_pc;
+ data->last_pc = frame->pc;
+ if (!in_exception_text(addr))
+ return 0;
+
+ regs = (struct pt_regs *)frame->sp;
+
+ trace->entries[trace->nr_entries++] = regs->ARM_pc;
+
return trace->nr_entries >= trace->max_entries;
}
@@ -91,6 +113,7 @@ static noinline void __save_stack_trace(struct task_struct *tsk,
struct stackframe frame;
data.trace = trace;
+ data.last_pc = ULONG_MAX;
data.skip = trace->skip;
data.no_sched_functions = nosched;
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