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From:   Chen Zhongjin <chenzhongjin@huawei.com>
To:     <linux-kernel@vger.kernel.org>, <linux-riscv@lists.infradead.org>,
        <linux-perf-users@vger.kernel.org>
CC:     <paul.walmsley@sifive.com>, <palmer@dabbelt.com>,
        <aou@eecs.berkeley.edu>, <peterz@infradead.org>,
        <mingo@redhat.com>, <acme@kernel.org>, <mark.rutland@arm.com>,
        <alexander.shishkin@linux.intel.com>, <namhyung@kernel.org>,
        <jolsa@kernel.org>, <guoren@kernel.org>, <frederic@kernel.org>,
        <vincent.chen@sifive.com>, <ardb@kernel.org>,
        <mhiramat@kernel.org>, <rostedt@goodmis.org>,
        <keescook@chromium.org>, <catalin.marinas@arm.com>,
        <chenzhongjin@huawei.com>
Subject: [PATCH for-next v2 1/4] riscv: stacktrace: Replace walk_stackframe with arch_stack_walk
Date:   Wed, 21 Sep 2022 20:51:24 +0800
Message-ID: <20220921125128.33913-2-chenzhongjin@huawei.com>
In-Reply-To: <20220921125128.33913-1-chenzhongjin@huawei.com>
References: <20220921125128.33913-1-chenzhongjin@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

walk_stackframe can be all replaced by arch_stack_walk.

Since walk_stackframe is only called by arch_stack_walk and their only
difference is the argument sequence.

Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
 arch/riscv/include/asm/stacktrace.h |  2 --
 arch/riscv/kernel/perf_callchain.c  |  2 +-
 arch/riscv/kernel/stacktrace.c      | 29 +++++++++++++----------------
 3 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/arch/riscv/include/asm/stacktrace.h b/arch/riscv/include/asm/stacktrace.h
index 3450c1912afd..b6cd3eddfd38 100644
--- a/arch/riscv/include/asm/stacktrace.h
+++ b/arch/riscv/include/asm/stacktrace.h
@@ -11,8 +11,6 @@ struct stackframe {
 	unsigned long ra;
 };
 
-extern void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
-				    bool (*fn)(void *, unsigned long), void *arg);
 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *task,
 			   const char *loglvl);
 
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index 3348a61de7d9..c023e0b1eb81 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -74,5 +74,5 @@ static bool fill_callchain(void *entry, unsigned long pc)
 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 			   struct pt_regs *regs)
 {
-	walk_stackframe(NULL, regs, fill_callchain, entry);
+	arch_stack_walk(fill_callchain, entry, NULL, regs);
 }
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 08d11a53f39e..b51e32d50a0e 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -16,8 +16,9 @@
 
 #ifdef CONFIG_FRAME_POINTER
 
-void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
-			     bool (*fn)(void *, unsigned long), void *arg)
+noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
+		  void *cookie, struct task_struct *task,
+		  struct pt_regs *regs)
 {
 	unsigned long fp, sp, pc;
 	int level = 0;
@@ -29,7 +30,7 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 	} else if (task == NULL || task == current) {
 		fp = (unsigned long)__builtin_frame_address(0);
 		sp = current_stack_pointer;
-		pc = (unsigned long)walk_stackframe;
+		pc = (unsigned long)arch_stack_walk;
 	} else {
 		/* task blocked in __switch_to */
 		fp = task->thread.s[0];
@@ -41,7 +42,8 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 		unsigned long low, high;
 		struct stackframe *frame;
 
-		if (unlikely(!__kernel_text_address(pc) || (level++ >= 1 && !fn(arg, pc))))
+		if (unlikely(!__kernel_text_address(pc) ||
+		   (level++ >= 1 && !consume_entry(cookie, pc))))
 			break;
 
 		/* Validate frame pointer */
@@ -66,8 +68,9 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 
 #else /* !CONFIG_FRAME_POINTER */
 
-void notrace walk_stackframe(struct task_struct *task,
-	struct pt_regs *regs, bool (*fn)(void *, unsigned long), void *arg)
+noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
+		  void *cookie, struct task_struct *task,
+		  struct pt_regs *regs)
 {
 	unsigned long sp, pc;
 	unsigned long *ksp;
@@ -77,7 +80,7 @@ void notrace walk_stackframe(struct task_struct *task,
 		pc = instruction_pointer(regs);
 	} else if (task == NULL || task == current) {
 		sp = current_stack_pointer;
-		pc = (unsigned long)walk_stackframe;
+		pc = (unsigned long)arch_stack_walk;
 	} else {
 		/* task blocked in __switch_to */
 		sp = task->thread.sp;
@@ -89,7 +92,7 @@ void notrace walk_stackframe(struct task_struct *task,
 
 	ksp = (unsigned long *)sp;
 	while (!kstack_end(ksp)) {
-		if (__kernel_text_address(pc) && unlikely(!fn(arg, pc)))
+		if (__kernel_text_address(pc) && unlikely(!consume_entry(cookie, pc)))
 			break;
 		pc = (*ksp++) - 0x4;
 	}
@@ -108,7 +111,7 @@ static bool print_trace_address(void *arg, unsigned long pc)
 noinline void dump_backtrace(struct pt_regs *regs, struct task_struct *task,
 		    const char *loglvl)
 {
-	walk_stackframe(task, regs, print_trace_address, (void *)loglvl);
+	arch_stack_walk(print_trace_address, (void *)loglvl, task, regs);
 }
 
 void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
@@ -133,13 +136,7 @@ unsigned long __get_wchan(struct task_struct *task)
 
 	if (!try_get_task_stack(task))
 		return 0;
-	walk_stackframe(task, NULL, save_wchan, &pc);
+	arch_stack_walk(save_wchan, &pc, task, NULL);
 	put_task_stack(task);
 	return pc;
 }
-
-noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
-		     struct task_struct *task, struct pt_regs *regs)
-{
-	walk_stackframe(task, regs, consume_entry, cookie);
-}
-- 
2.17.1