[PATCH] x86, dumpstack: fix code bytes breakage due to missing KERN_CONT

From: Clemens Ladisch
Date: Mon Dec 19 2011 - 16:08:23 EST


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@xxxxxxxxxx>
---
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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