linux-kernel - [PATCH 2/3] tracing/events: fix output format of kernel 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: <1244016090-7814-2-git-send-email-walimisdev@gmail.com>
Date:	Wed,  3 Jun 2009 16:01:29 +0800
From:	walimis <walimisdev@...il.com>
To:	Steven Rostedt <rostedt@...dmis.org>, Ingo Molnar <mingo@...e.hu>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] tracing/events: fix output format of kernel stack

According to "events/ftrace/kernel_stack/format", output format of
kernel stack should use "=>" instead of "<=".

The second problem is that we shouldn't skip the first entry in the stack,
although it seems to be duplicated when used in the "function" tracer,
but events also use it. If we skip the first one, we will drop the topmost
entry of the stack.

The last problem is that if the last entry is ULONG_MAX(0xffffffff), we should
drop it, otherwise it will print a NULL name line.

before fix:

      sh-1072  [000]   26.957239: sched_process_fork: parent sh:1072 child sh:1073
      sh-1072  [000]   26.957262:
 <= syscall_call
 <=
      sh-1072  [000]   26.957744: sched_switch: task sh:1072 [120] (R) ==> sh:1073 [120]
      sh-1072  [000]   26.957752:
 <= preempt_schedule
 <= wake_up_new_task
 <= do_fork
 <= sys_clone
 <= syscall_call
 <=

After fix:

      sh-1075  [000]    39.791848: sched_process_fork: parent sh:1075  child sh:1076
      sh-1075  [000]    39.791871:
 => sys_clone
 => syscall_call
      sh-1075  [000]    39.792713: sched_switch: task sh:1075 [120] (R) ==> sh:1076 [120]
      sh-1075  [000]    39.792722:
 => schedule
 => preempt_schedule
 => wake_up_new_task
 => do_fork
 => sys_clone
 => syscall_call

Signed-off-by: walimis <walimisdev@...il.com>
---
 kernel/trace/trace_output.c |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 0fe3b22..64596a5 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -975,16 +975,16 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 
 	trace_assign_type(field, iter->ent);
 
+	if (!trace_seq_puts(s, "\n"))
+		goto partial;
 	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
-		if (!field->caller[i])
+		if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
 			break;
-		if (i) {
-			if (!trace_seq_puts(s, " <= "))
-				goto partial;
+		if (!trace_seq_puts(s, " => "))
+			goto partial;
 
-			if (!seq_print_ip_sym(s, field->caller[i], flags))
-				goto partial;
-		}
+		if (!seq_print_ip_sym(s, field->caller[i], flags))
+			goto partial;
 		if (!trace_seq_puts(s, "\n"))
 			goto partial;
 	}
-- 
1.6.0.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/