linux-kernel - [PATCH v9 06/11] arm64: Make profile_pc() use arch_stack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211015023413.16614-9-madvenka@linux.microsoft.com>
Date:   Thu, 14 Oct 2021 21:34:10 -0500
From:   madvenka@...ux.microsoft.com
To:     mark.rutland@....com, broonie@...nel.org, jpoimboe@...hat.com,
        ardb@...nel.org, nobuta.keiya@...itsu.com,
        sjitindarsingh@...il.com, catalin.marinas@....com, will@...nel.org,
        jmorris@...ei.org, linux-arm-kernel@...ts.infradead.org,
        live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
        madvenka@...ux.microsoft.com
Subject: [PATCH v9 06/11] arm64: Make profile_pc() use arch_stack_walk()

From: "Madhavan T. Venkataraman" <madvenka@...ux.microsoft.com>

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

Signed-off-by: Madhavan T. Venkataraman <madvenka@...ux.microsoft.com>
---
 arch/arm64/kernel/time.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index eebbc8d7123e..671b3038a772 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -32,22 +32,26 @@
 #include <asm/stacktrace.h>
 #include <asm/paravirt.h>
 
+static bool profile_pc_cb(void *arg, unsigned long pc)
+{
+	unsigned long *prof_pc = arg;
+
+	if (in_lock_functions(pc))
+		return true;
+	*prof_pc = pc;
+	return false;
+}
+
 unsigned long profile_pc(struct pt_regs *regs)
 {
-	struct stackframe frame;
+	unsigned long prof_pc = 0;
 
 	if (!in_lock_functions(regs->pc))
 		return regs->pc;
 
-	start_backtrace(&frame, regs->regs[29], regs->pc);
-
-	do {
-		int ret = unwind_frame(NULL, &frame);
-		if (ret < 0)
-			return 0;
-	} while (in_lock_functions(frame.pc));
+	arch_stack_walk(profile_pc_cb, &prof_pc, current, regs);
 
-	return frame.pc;
+	return prof_pc;
 }
 EXPORT_SYMBOL(profile_pc);
 
-- 
2.25.1