linux-kernel - [PATCH] x86, dumpstack: fix code bytes breakage due to missing KERN

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Date:	Mon, 19 Dec 2011 22:07:58 +0100
From:	Clemens Ladisch <clemens@...isch.de>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>
CC:	x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] x86, dumpstack: fix code bytes breakage due to missing KERN_CONT

When printing the code bytes in show_registers(), the markers around the
byte at the fault address could make the printk() format string look
like a valid log level and facility code.  This would prevent this byte
from being printed and result in a spurious newline:

[ 7555.765589] Code: 8b 32 e9 94 00 00 00 81 7d 00 ff 00 00 00 0f 87 96 00 00 00 48 8b 83 c0 00 00 00 44 89 e2 44 89 e6 48 89 df 48 8b 80 d8 02 00 00
[ 7555.765683]  8b 48 28 48 89 d0 81 e2 ff 0f 00 00 48 c1 e8 0c 48 c1 e0 04

Add KERN_CONT where needed, and elsewhere in show_registers() for
consistency.

Signed-off-by: Clemens Ladisch <clemens@...isch.de>
---
 arch/x86/kernel/dumpstack_32.c |    8 ++++----
 arch/x86/kernel/dumpstack_64.c |    8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

Now with a corrected mail address; sorry for the mixup.

--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -116,16 +116,16 @@ void show_registers(struct pt_regs *regs)
 		for (i = 0; i < code_len; i++, ip++) {
 			if (ip < (u8 *)PAGE_OFFSET ||
 					probe_kernel_address(ip, c)) {
-				printk(" Bad EIP value.");
+				printk(KERN_CONT " Bad EIP value.");
 				break;
 			}
 			if (ip == (u8 *)regs->ip)
-				printk("<%02x> ", c);
+				printk(KERN_CONT "<%02x> ", c);
 			else
-				printk("%02x ", c);
+				printk(KERN_CONT "%02x ", c);
 		}
 	}
-	printk("\n");
+	printk(KERN_CONT "\n");
 }

 int is_valid_bugaddr(unsigned long ip)
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -284,16 +284,16 @@ void show_registers(struct pt_regs *regs)
 		for (i = 0; i < code_len; i++, ip++) {
 			if (ip < (u8 *)PAGE_OFFSET ||
 					probe_kernel_address(ip, c)) {
-				printk(" Bad RIP value.");
+				printk(KERN_CONT " Bad RIP value.");
 				break;
 			}
 			if (ip == (u8 *)regs->ip)
-				printk("<%02x> ", c);
+				printk(KERN_CONT "<%02x> ", c);
 			else
-				printk("%02x ", c);
+				printk(KERN_CONT "%02x ", c);
 		}
 	}
-	printk("\n");
+	printk(KERN_CONT "\n");
 }

 int is_valid_bugaddr(unsigned long ip)
--
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