arm64: stacktrace: Make stack walk callback consistent with generic code

As with the generic arch_stack_walk() code the arm64 stack walk code takes
a callback that is called per stack frame. Currently the arm64 code always
passes a struct stackframe to the callback and the generic code just passes
the pc, however none of the users ever reference anything in the struct
other than the pc value. The arm64 code also uses a return type of int
while the generic code uses a return type of bool though in both cases the
return value is a boolean value and the sense is inverted between the two.

In order to reduce code duplication when arm64 is converted to use
arch_stack_walk() change the signature and return sense of the arm64
specific callback to match that of the generic code.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20200914153409.25097-3-broonie@kernel.org
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 fc7613023c19209fdb7c015ddf647ff07ad892e9..eb29b1fe8255eb23d0cf2e9e588dd19ddee5061b 100644 (file)
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -63,7 +63,7 @@ struct stackframe {
 
 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
-                           int (*fn)(struct stackframe *, void *), void *data);
+                           bool (*fn)(void *, unsigned long), void *data);
 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
                           const char *loglvl);
 

diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index b0e03e052dd1d5e2d80db3448b37a77b5634e094..88ff471b0bce5f2c49cb49cd38a3603fc952b2aa 100644 (file)
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -137,11 +137,11 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
  * whist unwinding the stackframe and is like a subroutine return so we use
  * the PC.
  */
-static int callchain_trace(struct stackframe *frame, void *data)
+static bool callchain_trace(void *data, unsigned long pc)
 {
        struct perf_callchain_entry_ctx *entry = data;
-       perf_callchain_store(entry, frame->pc);
-       return 0;
+       perf_callchain_store(entry, pc);
+       return true;
 }
 
 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,

diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c
index a5e8b3b9d798301285b2db09b031dbba6c481875..a6d18755652fa11033bbb84c8ea8fbe3b4a32b01 100644 (file)
--- a/arch/arm64/kernel/return_address.c
+++ b/arch/arm64/kernel/return_address.c
@@ -18,16 +18,16 @@ struct return_address_data {
        void *addr;
 };
 
-static int save_return_addr(struct stackframe *frame, void *d)
+static bool save_return_addr(void *d, unsigned long pc)
 {
        struct return_address_data *data = d;
 
        if (!data->level) {
-               data->addr = (void *)frame->pc;
-               return 1;
+               data->addr = (void *)pc;
+               return false;
        } else {
                --data->level;
-               return 0;
+               return true;
        }
 }
 NOKPROBE_SYMBOL(save_return_addr);

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 2dd8e3b8b94b76b7f31962772e4dc94429b008ce..05eaba21fd46833ab85ea003dd590a6726d0fe9f 100644 (file)
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -118,12 +118,12 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
 NOKPROBE_SYMBOL(unwind_frame);
 
 void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
-                    int (*fn)(struct stackframe *, void *), void *data)
+                            bool (*fn)(void *, unsigned long), void *data)
 {
        while (1) {
                int ret;
 
-               if (fn(frame, data))
+               if (!fn(data, frame->pc))
                        break;
                ret = unwind_frame(tsk, frame);
                if (ret < 0)
@@ -139,17 +139,16 @@ struct stack_trace_data {
        unsigned int skip;
 };
 
-static int save_trace(struct stackframe *frame, void *d)
+static bool save_trace(void *d, unsigned long addr)
 {
        struct stack_trace_data *data = d;
        struct stack_trace *trace = data->trace;
-       unsigned long addr = frame->pc;
 
        if (data->no_sched_functions && in_sched_functions(addr))
-               return 0;
+               return false;
        if (data->skip) {
                data->skip--;
-               return 0;
+               return false;
        }
 
        trace->entries[trace->nr_entries++] = addr;