From: madvenka@linux.microsoft.com
To: mark.rutland@arm.com, broonie@kernel.org, jpoimboe@redhat.com,
ardb@kernel.org, nobuta.keiya@fujitsu.com,
sjitindarsingh@gmail.com, catalin.marinas@arm.com,
will@kernel.org, jmorris@namei.org,
linux-arm-kernel@lists.infradead.org,
live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
madvenka@linux.microsoft.com
Subject: [PATCH v10 03/11] arm64: Make get_wchan() use arch_stack_walk()
Date: Thu, 14 Oct 2021 21:58:39 -0500 [thread overview]
Message-ID: <20211015025847.17694-4-madvenka@linux.microsoft.com> (raw)
In-Reply-To: <20211015025847.17694-1-madvenka@linux.microsoft.com>
From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
Currently, get_wchan() 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@linux.microsoft.com>
---
arch/arm64/kernel/process.c | 38 ++++++++++++++++++++++---------------
1 file changed, 23 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c8989b999250..48ed89acce0d 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -544,11 +544,27 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev,
return last;
}
+struct wchan_info {
+ unsigned long pc;
+ int count;
+};
+
+static bool get_wchan_cb(void *arg, unsigned long pc)
+{
+ struct wchan_info *wchan_info = arg;
+
+ if (!in_sched_functions(pc)) {
+ wchan_info->pc = pc;
+ return false;
+ }
+ return wchan_info->count++ < 16;
+}
+
unsigned long get_wchan(struct task_struct *p)
{
- struct stackframe frame;
- unsigned long stack_page, ret = 0;
- int count = 0;
+ unsigned long stack_page;
+ struct wchan_info wchan_info;
+
if (!p || p == current || task_is_running(p))
return 0;
@@ -556,20 +572,12 @@ unsigned long get_wchan(struct task_struct *p)
if (!stack_page)
return 0;
- start_backtrace(&frame, thread_saved_fp(p), thread_saved_pc(p));
+ wchan_info.pc = 0;
+ wchan_info.count = 0;
+ arch_stack_walk(get_wchan_cb, &wchan_info, p, NULL);
- do {
- if (unwind_frame(p, &frame))
- goto out;
- if (!in_sched_functions(frame.pc)) {
- ret = frame.pc;
- goto out;
- }
- } while (count++ < 16);
-
-out:
put_task_stack(p);
- return ret;
+ return wchan_info.pc;
}
unsigned long arch_align_stack(unsigned long sp)
--
2.25.1
next prev parent reply other threads:[~2021-10-15 2:59 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <c05ce30dcc9be1bd6b5e24a2ca8fe1d66246980b>
2021-10-15 2:34 ` [PATCH v9 00/11] arm64: Reorganize the unwinder and implement stack trace reliability checks madvenka
2021-10-15 2:34 ` [PATCH v9 01/11] arm64: Select STACKTRACE in arch/arm64/Kconfig madvenka
2021-10-15 2:34 ` [PATCH v9 10/11] arm64: Introduce stack trace reliability checks in the unwinder madvenka
2021-10-15 2:34 ` [PATCH v9 11/11] arm64: Create a list of SYM_CODE functions, check return PC against list madvenka
2021-10-15 2:34 ` [PATCH v9 02/11] arm64: Make perf_callchain_kernel() use arch_stack_walk() madvenka
2021-10-15 2:34 ` [PATCH v9 03/11] arm64: Make get_wchan() " madvenka
2021-10-15 2:34 ` [PATCH v9 04/11] arm64: Make return_address() " madvenka
2021-10-15 2:34 ` [PATCH v9 05/11] arm64: Make dump_stacktrace() " madvenka
2021-10-15 2:34 ` [PATCH v9 06/11] arm64: Make profile_pc() " madvenka
2021-10-15 2:34 ` [PATCH v9 07/11] arm64: Call stack_backtrace() only from within walk_stackframe() madvenka
2021-10-15 2:34 ` [PATCH v9 08/11] arm64: Rename unwinder functions, prevent them from being traced and kprobed madvenka
2021-10-15 2:34 ` [PATCH v9 09/11] arm64: Make the unwind loop in unwind() similar to other architectures madvenka
2021-10-15 2:53 ` [PATCH v9 00/11] arm64: Reorganize the unwinder and implement stack trace reliability checks Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 " madvenka
2021-10-15 2:58 ` [PATCH v10 01/11] arm64: Select STACKTRACE in arch/arm64/Kconfig madvenka
2021-10-15 18:28 ` Mark Brown
2021-10-21 12:28 ` Madhavan T. Venkataraman
2021-10-22 18:02 ` Mark Rutland
2021-11-12 17:44 ` Mark Rutland
2021-11-14 16:15 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 02/11] arm64: Make perf_callchain_kernel() use arch_stack_walk() madvenka
2021-10-20 14:59 ` Mark Brown
2021-10-21 12:28 ` Madhavan T. Venkataraman
2021-10-22 18:11 ` Mark Rutland
2021-10-23 12:49 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` madvenka [this message]
2021-10-20 16:10 ` [PATCH v10 03/11] arm64: Make get_wchan() " Mark Brown
2021-10-21 12:30 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 04/11] arm64: Make return_address() " madvenka
2021-10-20 15:03 ` Mark Brown
2021-10-21 12:29 ` Madhavan T. Venkataraman
2021-10-22 18:51 ` Mark Rutland
2021-10-23 12:51 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 05/11] arm64: Make dump_stacktrace() " madvenka
2021-10-25 16:49 ` Mark Rutland
2021-10-26 12:05 ` Mark Rutland
2021-10-27 16:09 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 06/11] arm64: Make profile_pc() " madvenka
2021-10-25 2:18 ` nobuta.keiya
2021-10-27 16:10 ` Madhavan T. Venkataraman
2021-10-27 13:32 ` Mark Rutland
2021-10-27 16:15 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 07/11] arm64: Call stack_backtrace() only from within walk_stackframe() madvenka
2021-10-15 2:58 ` [PATCH v10 08/11] arm64: Rename unwinder functions, prevent them from being traced and kprobed madvenka
2021-10-27 17:53 ` Mark Rutland
2021-10-27 20:07 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 09/11] arm64: Make the unwind loop in unwind() similar to other architectures madvenka
2021-10-15 2:58 ` [PATCH v10 10/11] arm64: Introduce stack trace reliability checks in the unwinder madvenka
2021-11-04 12:39 ` nobuta.keiya
2021-11-10 3:13 ` Madhavan T. Venkataraman
2021-10-15 2:58 ` [PATCH v10 11/11] arm64: Create a list of SYM_CODE functions, check return PC against list madvenka
2021-10-15 17:00 ` [PATCH v10 00/11] arm64: Reorganize the unwinder and implement stack trace reliability checks Madhavan T. Venkataraman
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