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From:   madvenka@linux.microsoft.com
To:     mark.rutland@arm.com, broonie@kernel.org, jpoimboe@redhat.com,
        ardb@kernel.org, nobuta.keiya@fujitsu.com,
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        madvenka@linux.microsoft.com
Subject: [PATCH v10 02/11] arm64: Make perf_callchain_kernel() use arch_stack_walk()
Date:   Thu, 14 Oct 2021 21:58:38 -0500
Message-Id: <20211015025847.17694-3-madvenka@linux.microsoft.com>
In-Reply-To: <20211015025847.17694-1-madvenka@linux.microsoft.com>
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 <20211015025847.17694-1-madvenka@linux.microsoft.com>
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From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>

Currently, perf_callchain_kernel() in ARM64 code walks the stack using
start_backtrace() and walk_stackframe(). Make it use arch_stack_walk()
instead. This makes maintenance easier.

Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
---
 arch/arm64/kernel/perf_callchain.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c
index 4a72c2727309..f173c448e852 100644
--- a/arch/arm64/kernel/perf_callchain.c
+++ b/arch/arm64/kernel/perf_callchain.c
@@ -140,22 +140,18 @@ void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
 static bool callchain_trace(void *data, unsigned long pc)
 {
 	struct perf_callchain_entry_ctx *entry = data;
-	perf_callchain_store(entry, pc);
-	return true;
+	return perf_callchain_store(entry, pc) == 0;
 }
 
 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 			   struct pt_regs *regs)
 {
-	struct stackframe frame;
-
 	if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
 		/* We don't support guest os callchain now */
 		return;
 	}
 
-	start_backtrace(&frame, regs->regs[29], regs->pc);
-	walk_stackframe(current, &frame, callchain_trace, entry);
+	arch_stack_walk(callchain_trace, entry, current, regs);
 }
 
 unsigned long perf_instruction_pointer(struct pt_regs *regs)
-- 
2.25.1