[PATCH 7/7] arch: Fix STACKTRACE_SUPPORT

Peter Zijlstra
2021-10-08T11:18:44Z

A few archs got save_stack_trace_tsk() vs in_sched_functions() wrong.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/csky/kernel/stacktrace.c | 7 ++++++-
arch/mips/kernel/stacktrace.c | 27 ++++++++++++++++-----------
arch/nds32/kernel/stacktrace.c | 21 +++++++++++----------
3 files changed, 33 insertions(+), 22 deletions(-)

--- a/arch/csky/kernel/stacktrace.c
+++ b/arch/csky/kernel/stacktrace.c
@@ -122,12 +122,17 @@ static bool save_trace(unsigned long pc,
return __save_trace(pc, arg, false);
}

+static bool save_trace_nosched(unsigned long pc, void *arg)
+{
+ return __save_trace(pc, arg, true);
+}
+
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
- walk_stackframe(tsk, NULL, save_trace, trace);
+ walk_stackframe(tsk, NULL, save_trace_nosched, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);

--- a/arch/mips/kernel/stacktrace.c
+++ b/arch/mips/kernel/stacktrace.c
@@ -66,16 +66,7 @@ static void save_context_stack(struct st
#endif
}

-/*
- * Save stack-backtrace addresses into a stack_trace buffer.
- */
-void save_stack_trace(struct stack_trace *trace)
-{
- save_stack_trace_tsk(current, trace);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace);
-
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+static void __save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace, bool savesched)
{
struct pt_regs dummyregs;
struct pt_regs *regs = &dummyregs;
@@ -88,6 +79,20 @@ void save_stack_trace_tsk(struct task_st
regs->cp0_epc = tsk->thread.reg31;
} else
prepare_frametrace(regs);
- save_context_stack(trace, tsk, regs, tsk == current);
+ save_context_stack(trace, tsk, regs, savesched);
+}
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+ __save_stack_trace_tsk(current, trace, true);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ __save_stack_trace_tsk(tsk, trace, false);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
--- a/arch/nds32/kernel/stacktrace.c
+++ b/arch/nds32/kernel/stacktrace.c
@@ -6,25 +6,16 @@
#include <linux/stacktrace.h>
#include <linux/ftrace.h>

-void save_stack_trace(struct stack_trace *trace)
-{
- save_stack_trace_tsk(current, trace);
-}
-EXPORT_SYMBOL_GPL(save_stack_trace);
-
-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+static void __save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace, bool savesched)
{
unsigned long *fpn;
int skip = trace->skip;
- int savesched;
int graph_idx = 0;

if (tsk == current) {
__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn));
- savesched = 1;
} else {
fpn = (unsigned long *)thread_saved_fp(tsk);
- savesched = 0;
}

while (!kstack_end(fpn) && !((unsigned long)fpn & 0x3)
@@ -50,4 +41,14 @@ void save_stack_trace_tsk(struct task_st
fpn = (unsigned long *)fpp;
}
}
+void save_stack_trace(struct stack_trace *trace)
+{
+ __save_stack_trace_tsk(current, trace, true);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ __save_stack_trace_tsk(tsk, trace, false);
+}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);