arm64: stacktrace: Factor out backtrace initialisation

Some common code is required by each stacktrace user to initialise
struct stackframe before the first call to unwind_frame().

In preparation for adding to the common code, this patch factors it
out into a separate function start_backtrace(), and modifies the
stacktrace callers appropriately.

No functional change.

Signed-off-by: Dave Martin <dave.martin@arm.com>
[Mark: drop tsk argument, update more callsites]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 1e0c5a7cdce536f0255f1cf6fab42563ef696e7f..7fa0dfedb8e9b76b5c954cd4f95d32a0380ecc31 100644 (file)
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -131,4 +131,14 @@ static inline bool on_accessible_stack(const struct task_struct *tsk,
        return false;
 }
 
+static inline void start_backtrace(struct stackframe *frame,
+                                  unsigned long fp, unsigned long pc)
+{
+       frame->fp = fp;
+       frame->pc = pc;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+       frame->graph = 0;
+#endif
+}
+
 #endif /* __ASM_STACKTRACE_H */

diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 9d63514b983673bfd7ae55603254f48b297dd90f..b0e03e052dd1d5e2d80db3448b37a77b5634e094 100644 (file)
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -154,12 +154,7 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
                return;
        }
 
-       frame.fp = regs->regs[29];
-       frame.pc = regs->pc;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
-
+       start_backtrace(&frame, regs->regs[29], regs->pc);
        walk_stackframe(current, &frame, callchain_trace, entry);
 }
 

diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 6a869d9f304f73f4e6d91f52e5c4ac446fc9bf1a..8d836d0abc964677ff0001d84ba3183ce66c7c7f 100644 (file)
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -498,11 +498,8 @@ unsigned long get_wchan(struct task_struct *p)
        if (!stack_page)
                return 0;
 
-       frame.fp = thread_saved_fp(p);
-       frame.pc = thread_saved_pc(p);
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
+       start_backtrace(&frame, thread_saved_fp(p), thread_saved_pc(p));
+
        do {
                if (unwind_frame(p, &frame))
                        goto out;

diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index b21cba90f82dd22d51ba63bbf9bd4801c1cb9cff..c4ae647d2306128d01f6c375e93a5b7ebb22c145 100644 (file)
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -38,12 +38,9 @@ void *return_address(unsigned int level)
        data.level = level + 2;
        data.addr = NULL;
 
-       frame.fp = (unsigned long)__builtin_frame_address(0);
-       frame.pc = (unsigned long)return_address; /* dummy */
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
-
+       start_backtrace(&frame,
+                       (unsigned long)__builtin_frame_address(0),
+                       (unsigned long)return_address);
        walk_stackframe(current, &frame, save_return_addr, &data);
 
        if (!data.level)

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 62d395151abe650db40e14df52c9061c531a2bfa..017972c2de90a754ebf476d543bc17822470107d 100644 (file)
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -122,12 +122,7 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
        data.skip = trace->skip;
        data.no_sched_functions = 0;
 
-       frame.fp = regs->regs[29];
-       frame.pc = regs->pc;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
-
+       start_backtrace(&frame, regs->regs[29], regs->pc);
        walk_stackframe(current, &frame, save_trace, &data);
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_regs);
@@ -146,17 +141,15 @@ static noinline void __save_stack_trace(struct task_struct *tsk,
        data.no_sched_functions = nosched;
 
        if (tsk != current) {
-               frame.fp = thread_saved_fp(tsk);
-               frame.pc = thread_saved_pc(tsk);
+               start_backtrace(&frame, thread_saved_fp(tsk),
+                               thread_saved_pc(tsk));
        } else {
                /* We don't want this function nor the caller */
                data.skip += 2;
-               frame.fp = (unsigned long)__builtin_frame_address(0);
-               frame.pc = (unsigned long)__save_stack_trace;
+               start_backtrace(&frame,
+                               (unsigned long)__builtin_frame_address(0),
+                               (unsigned long)__save_stack_trace);
        }
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
 
        walk_stackframe(tsk, &frame, save_trace, &data);
 

diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index 9f25aedeac9dddda7cd9293cf38fac4532419139..0b2946414dc9ccc6fdb2b62b4a0de58b239c7fa2 100644 (file)
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -38,11 +38,8 @@ unsigned long profile_pc(struct pt_regs *regs)
        if (!in_lock_functions(regs->pc))
                return regs->pc;
 
-       frame.fp = regs->regs[29];
-       frame.pc = regs->pc;
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
+       start_backtrace(&frame, regs->regs[29], regs->pc);
+
        do {
                int ret = unwind_frame(NULL, &frame);
                if (ret < 0)

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8c03456dade6a477f62a2d051b267ae925704132..d3313797cca92b63cfe7ada88b40618c5bdfc6d0 100644 (file)
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -100,18 +100,17 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
                return;
 
        if (tsk == current) {
-               frame.fp = (unsigned long)__builtin_frame_address(0);
-               frame.pc = (unsigned long)dump_backtrace;
+               start_backtrace(&frame,
+                               (unsigned long)__builtin_frame_address(0),
+                               (unsigned long)dump_backtrace);
        } else {
                /*
                 * task blocked in __switch_to
                 */
-               frame.fp = thread_saved_fp(tsk);
-               frame.pc = thread_saved_pc(tsk);
+               start_backtrace(&frame,
+                               thread_saved_fp(tsk),
+                               thread_saved_pc(tsk));
        }
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-       frame.graph = 0;
-#endif
 
        printk("Call trace:\n");
        do {