linux-kernel - [PATCH 1/1] x86: get rid of <0> from stack output

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-next>] [day] [month] [year] [list]

Message-Id: <1287586131-16222-1-git-send-email-jslaby@suse.cz>
Date:	Wed, 20 Oct 2010 16:48:51 +0200
From:	Jiri Slaby <jslaby@...e.cz>
To:	hpa@...or.com
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org, jirislaby@...il.com,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>
Subject: [PATCH 1/1] x86: get rid of <0> from stack output

The stack output currently looks like this:
 7fffffffffffffff 0000000a00000000 ffffffff81093341 0000000000000046
<0> ffff88003a545fd8 0000000000000000 0000000000000000 00007fffa39769c0
<0> ffff88003e403f58 ffffffff8102fc4c ffff88003e403f58 ffff88003e403f78

The superfluous <0> are caused by recent printk KERN_CONT change.
<*> is now ignored in printk unless some text follows the level and
even then it still has to be the first in the format message.

Note that the log_lvl parameter is now completely ignored in
show_stack_log_lvl and the stack is dumped with the default level
(like for quite some time already). It behaves the same as the rest of
the dump, function traces are dumped in the very same manner. Only
Code and maybe some lines are printed with EMERG level.

Unfortunately I see no way how to fix this conceptually to have the
whole oops/BUG/panic output with the same level, so this removed only
the superfluous characters for the time being.

Just for illustration:
<4>Process kworker/0:0 (pid: 0, threadinfo ffff88003c8a6000, task ffff88003c85c100)
<0>Stack:
<4> ffffffff818022c0 0000000a00000001 0000000000000001 0000000000000046
<4> ffff88003c8a7fd8 0000000000000001 ffff88003c8a7e58 0000000000000000
<4> ffff88003e503f48 ffffffff8102fc4c ffff88003e503f48 ffff88003e503f68
<0>Call Trace:
<0> <IRQ>
<4> [<ffffffff8102fc4c>] ? call_softirq+0x1c/0x30
...
<0>Code: 00 01 00 00 65 8b 04 25 80 c5 00 00 c7 45 ...

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
---
 arch/x86/kernel/dumpstack_32.c |    6 +++---
 arch/x86/kernel/dumpstack_64.c |    8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 0f6376f..1bc7f75 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -82,11 +82,11 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		if (kstack_end(stack))
 			break;
 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
-			printk("\n%s", log_lvl);
-		printk(" %08lx", *stack++);
+			printk(KERN_CONT "\n");
+		printk(KERN_CONT " %08lx", *stack++);
 		touch_nmi_watchdog();
 	}
-	printk("\n");
+	printk(KERN_CONT "\n");
 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 }
 
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 57a21f1..6a34048 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -265,20 +265,20 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		if (stack >= irq_stack && stack <= irq_stack_end) {
 			if (stack == irq_stack_end) {
 				stack = (unsigned long *) (irq_stack_end[-1]);
-				printk(" <EOI> ");
+				printk(KERN_CONT " <EOI> ");
 			}
 		} else {
 		if (((long) stack & (THREAD_SIZE-1)) == 0)
 			break;
 		}
 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
-			printk("\n%s", log_lvl);
-		printk(" %016lx", *stack++);
+			printk(KERN_CONT "\n");
+		printk(KERN_CONT " %016lx", *stack++);
 		touch_nmi_watchdog();
 	}
 	preempt_enable();
 
-	printk("\n");
+	printk(KERN_CONT "\n");
 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 }
 
-- 
1.7.3.1


--
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/