From: madvenka@linux.microsoft.com
To: broonie@kernel.org, mark.rutland@arm.com, jpoimboe@redhat.com,
jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org,
live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
madvenka@linux.microsoft.com
Subject: [RFC PATCH v2 8/8] arm64: Implement arch_stack_walk_reliable()
Date: Mon, 15 Mar 2021 11:58:00 -0500 [thread overview]
Message-ID: <20210315165800.5948-9-madvenka@linux.microsoft.com> (raw)
In-Reply-To: <20210315165800.5948-1-madvenka@linux.microsoft.com>
From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
unwind_frame() already sets the reliable flag in the stack frame during
a stack walk to indicate whether the stack trace is reliable or not.
Implement arch_stack_walk_reliable() like arch_stack_walk() but abort
the stack walk as soon as the reliable flag is set to false for any
reason.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/stacktrace.c | 35 ++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1f212b47a48a..954f60c35b26 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -167,6 +167,7 @@ config ARM64
if $(cc-option,-fpatchable-function-entry=2)
select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
if DYNAMIC_FTRACE_WITH_REGS
+ select HAVE_RELIABLE_STACKTRACE
select HAVE_EFFICIENT_UNALIGNED_ACCESS
select HAVE_FAST_GUP
select HAVE_FTRACE_MCOUNT_RECORD
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 752b77f11c61..5d15c111f3aa 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -361,4 +361,39 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
walk_stackframe(task, &frame, consume_entry, cookie);
}
+/*
+ * Walk the stack like arch_stack_walk() but stop the walk as soon as
+ * some unreliability is detected in the stack.
+ */
+int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
+ void *cookie, struct task_struct *task)
+{
+ struct stackframe frame;
+ int ret = 0;
+
+ if (task == current) {
+ start_backtrace(&frame,
+ (unsigned long)__builtin_frame_address(0),
+ (unsigned long)arch_stack_walk_reliable);
+ } else {
+ /*
+ * The task must not be running anywhere for the duration of
+ * arch_stack_walk_reliable(). The caller must guarantee
+ * this.
+ */
+ start_backtrace(&frame, thread_saved_fp(task),
+ thread_saved_pc(task));
+ }
+
+ while (!ret) {
+ if (!frame.reliable)
+ return -EINVAL;
+ if (!consume_entry(cookie, frame.pc))
+ return -EINVAL;
+ ret = unwind_frame(task, &frame);
+ }
+
+ return ret == -ENOENT ? 0 : -EINVAL;
+}
+
#endif
--
2.25.1
next prev parent reply other threads:[~2021-03-15 16:59 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5997dfe8d261a3a543667b83c902883c1e4bd270>
2021-03-15 16:57 ` [RFC PATCH v2 0/8] arm64: Implement reliable stack trace madvenka
2021-03-15 16:57 ` [RFC PATCH v2 1/8] arm64: Implement stack trace termination record madvenka
2021-03-18 15:09 ` Mark Brown
2021-03-18 20:26 ` Madhavan T. Venkataraman
2021-03-19 12:30 ` Mark Brown
2021-03-19 14:29 ` Madhavan T. Venkataraman
2021-03-19 18:19 ` Madhavan T. Venkataraman
2021-03-19 22:03 ` Madhavan T. Venkataraman
2021-03-23 10:24 ` Mark Rutland
2021-03-23 12:39 ` Madhavan T. Venkataraman
2021-03-15 16:57 ` [RFC PATCH v2 2/8] arm64: Implement frame types madvenka
2021-03-18 17:40 ` Mark Brown
2021-03-18 22:22 ` Madhavan T. Venkataraman
2021-03-19 13:22 ` Mark Brown
2021-03-19 14:40 ` Madhavan T. Venkataraman
2021-03-19 15:02 ` Madhavan T. Venkataraman
2021-03-19 16:20 ` Mark Brown
2021-03-19 16:27 ` Madhavan T. Venkataraman
2021-03-23 10:34 ` Mark Rutland
2021-03-15 16:57 ` [RFC PATCH v2 3/8] arm64: Terminate the stack trace at TASK_FRAME and EL0_FRAME madvenka
2021-03-18 18:26 ` Mark Brown
2021-03-18 20:29 ` Madhavan T. Venkataraman
2021-03-23 10:36 ` Mark Rutland
2021-03-23 12:40 ` Madhavan T. Venkataraman
2021-03-15 16:57 ` [RFC PATCH v2 4/8] arm64: Detect an EL1 exception frame and mark a stack trace unreliable madvenka
2021-03-23 10:42 ` Mark Rutland
2021-03-23 12:46 ` Madhavan T. Venkataraman
2021-03-23 13:04 ` Mark Rutland
2021-03-23 13:31 ` Madhavan T. Venkataraman
2021-03-23 14:33 ` Mark Rutland
2021-03-23 15:22 ` Madhavan T. Venkataraman
2021-03-15 16:57 ` [RFC PATCH v2 5/8] arm64: Detect an FTRACE " madvenka
2021-03-23 10:51 ` Mark Rutland
2021-03-23 12:56 ` Madhavan T. Venkataraman
2021-03-23 13:36 ` Mark Rutland
2021-03-23 13:38 ` Madhavan T. Venkataraman
2021-03-23 14:15 ` Madhavan T. Venkataraman
2021-03-23 14:57 ` Mark Rutland
2021-03-23 15:26 ` Madhavan T. Venkataraman
2021-03-23 16:20 ` Madhavan T. Venkataraman
2021-03-23 17:02 ` Mark Rutland
2021-03-23 17:23 ` Madhavan T. Venkataraman
2021-03-23 17:27 ` Madhavan T. Venkataraman
2021-03-23 18:27 ` Mark Brown
2021-03-23 20:23 ` Madhavan T. Venkataraman
2021-03-23 18:30 ` Mark Rutland
2021-03-23 20:24 ` Madhavan T. Venkataraman
2021-03-23 21:04 ` Madhavan T. Venkataraman
2021-03-23 16:48 ` Mark Rutland
2021-03-23 16:53 ` Madhavan T. Venkataraman
2021-03-23 17:09 ` Mark Rutland
2021-03-15 16:57 ` [RFC PATCH v2 6/8] arm64: Check the return PC of every stack frame madvenka
2021-03-15 16:57 ` [RFC PATCH v2 7/8] arm64: Detect kretprobed functions in stack trace madvenka
2021-03-15 16:58 ` madvenka [this message]
2021-03-15 19:01 ` [RFC PATCH v2 0/8] arm64: Implement reliable " Madhavan T. Venkataraman
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