From: Masami Hiramatsu <mhiramat@kernel.org> To: Steven Rostedt <rostedt@goodmis.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>, Ananth N Mavinakayanahalli <ananth@linux.ibm.com>, Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org, mhiramat@kernel.org, Sven Schnelle <svens@linux.ibm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Russell King <linux@armlinux.org.uk>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 6/8] ARM: clang: Do not relay on lr register for stacktrace Date: Fri, 8 Oct 2021 21:29:08 +0900 [thread overview] Message-ID: <163369614818.636038.5019945597127474028.stgit@devnote2> (raw) In-Reply-To: <163369609308.636038.15295764725220907794.stgit@devnote2> Currently the stacktrace on clang compiled arm kernel uses the 'lr' register to find the first frame address from pt_regs. However, that is wrong after calling another function, because the 'lr' register is used by 'bl' instruction and never be recovered. As same as gcc arm kernel, directly use the frame pointer (x11) of the pt_regs to find the first frame address. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- arch/arm/kernel/stacktrace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 76ea4178a55c..db798eac7431 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -54,8 +54,7 @@ int notrace unwind_frame(struct stackframe *frame) frame->sp = frame->fp; frame->fp = *(unsigned long *)(fp); - frame->pc = frame->lr; - frame->lr = *(unsigned long *)(fp + 4); + frame->pc = *(unsigned long *)(fp + 4); #else /* check current frame pointer is within bounds */ if (fp < low + 12 || fp > high - 4)
WARNING: multiple messages have this Message-ID (diff)
From: Masami Hiramatsu <mhiramat@kernel.org> To: Steven Rostedt <rostedt@goodmis.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>, Ananth N Mavinakayanahalli <ananth@linux.ibm.com>, Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org, mhiramat@kernel.org, Sven Schnelle <svens@linux.ibm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Russell King <linux@armlinux.org.uk>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 6/8] ARM: clang: Do not relay on lr register for stacktrace Date: Fri, 8 Oct 2021 21:29:08 +0900 [thread overview] Message-ID: <163369614818.636038.5019945597127474028.stgit@devnote2> (raw) In-Reply-To: <163369609308.636038.15295764725220907794.stgit@devnote2> Currently the stacktrace on clang compiled arm kernel uses the 'lr' register to find the first frame address from pt_regs. However, that is wrong after calling another function, because the 'lr' register is used by 'bl' instruction and never be recovered. As same as gcc arm kernel, directly use the frame pointer (x11) of the pt_regs to find the first frame address. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- arch/arm/kernel/stacktrace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 76ea4178a55c..db798eac7431 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -54,8 +54,7 @@ int notrace unwind_frame(struct stackframe *frame) frame->sp = frame->fp; frame->fp = *(unsigned long *)(fp); - frame->pc = frame->lr; - frame->lr = *(unsigned long *)(fp + 4); + frame->pc = *(unsigned long *)(fp + 4); #else /* check current frame pointer is within bounds */ if (fp < low + 12 || fp > high - 4) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-10-08 12:29 UTC|newest] Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-08 12:28 [PATCH 0/8] kprobes: Make KUnit and add stacktrace on kretprobe tests Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-08 12:28 ` [PATCH 1/8] kprobes: convert tests to kunit Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-08 12:28 ` [PATCH 2/8] kprobes: Add a test case for stacktrace from kretprobe handler Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-08 12:28 ` [PATCH 3/8] arm64: kprobes: Record frame pointer with kretprobe instance Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-13 8:14 ` Will Deacon 2021-10-13 8:14 ` Will Deacon 2021-10-13 10:01 ` Mark Rutland 2021-10-13 10:01 ` Mark Rutland 2021-10-14 8:04 ` Masami Hiramatsu 2021-10-14 8:04 ` Masami Hiramatsu 2021-10-14 9:13 ` Mark Rutland 2021-10-14 9:13 ` Mark Rutland 2021-10-14 10:01 ` Masami Hiramatsu 2021-10-14 10:01 ` Masami Hiramatsu 2021-10-14 10:27 ` Mark Rutland 2021-10-14 10:27 ` Mark Rutland 2021-10-14 13:50 ` Masami Hiramatsu 2021-10-14 13:50 ` Masami Hiramatsu 2021-10-08 12:28 ` [PATCH 4/8] arm64: kprobes: Make a frame pointer on __kretprobe_trampoline Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-13 8:14 ` Will Deacon 2021-10-13 8:14 ` Will Deacon 2021-10-08 12:28 ` [PATCH 5/8] arm64: Recover kretprobe modified return address in stacktrace Masami Hiramatsu 2021-10-08 12:28 ` Masami Hiramatsu 2021-10-13 8:14 ` Will Deacon 2021-10-13 8:14 ` Will Deacon 2021-10-14 8:05 ` Masami Hiramatsu 2021-10-14 8:05 ` Masami Hiramatsu 2021-10-13 10:13 ` Mark Rutland 2021-10-13 10:13 ` Mark Rutland 2021-10-14 9:57 ` Masami Hiramatsu 2021-10-14 9:57 ` Masami Hiramatsu 2021-10-08 12:29 ` Masami Hiramatsu [this message] 2021-10-08 12:29 ` [PATCH 6/8] ARM: clang: Do not relay on lr register for stacktrace Masami Hiramatsu 2021-10-11 18:45 ` Nick Desaulniers 2021-10-11 18:45 ` Nick Desaulniers 2021-10-12 14:18 ` Masami Hiramatsu 2021-10-12 14:18 ` Masami Hiramatsu 2021-10-13 19:54 ` Nick Desaulniers 2021-10-13 19:54 ` Nick Desaulniers 2021-10-14 16:53 ` Russell King (Oracle) 2021-10-14 16:53 ` Russell King (Oracle) 2021-10-15 0:18 ` Masami Hiramatsu 2021-10-15 0:18 ` Masami Hiramatsu 2021-10-08 12:29 ` [PATCH 7/8] ARM: kprobes: Make a frame pointer on __kretprobe_trampoline Masami Hiramatsu 2021-10-08 12:29 ` Masami Hiramatsu 2021-10-11 19:06 ` Nick Desaulniers 2021-10-11 19:06 ` Nick Desaulniers 2021-10-08 12:29 ` [PATCH 8/8] ARM: Recover kretprobe modified return address in stacktrace Masami Hiramatsu 2021-10-08 12:29 ` Masami Hiramatsu
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