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-rw-r--r--arch/x86_64/kernel/traps.c12
-rw-r--r--arch/x86_64/lib/usercopy.c12
-rw-r--r--include/asm-x86_64/uaccess.h1
3 files changed, 18 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index d345c712c6c..2671fd46ea8 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -340,7 +340,8 @@ bad:
void handle_BUG(struct pt_regs *regs)
{
struct bug_frame f;
- char tmp;
+ long len;
+ const char *prefix = "";
if (user_mode(regs))
return;
@@ -350,10 +351,15 @@ void handle_BUG(struct pt_regs *regs)
if (f.filename >= 0 ||
f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
return;
- if (__get_user(tmp, (char *)(long)f.filename))
+ len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
+ if (len < 0 || len >= PATH_MAX)
f.filename = (int)(long)"unmapped filename";
+ else if (len > 50) {
+ f.filename += len - 50;
+ prefix = "...";
+ }
printk("----------- [cut here ] --------- [please bite here ] ---------\n");
- printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", (char *)(long)f.filename, f.line);
+ printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
}
#ifdef CONFIG_BUG
diff --git a/arch/x86_64/lib/usercopy.c b/arch/x86_64/lib/usercopy.c
index db8abba1ad8..9bc2c295818 100644
--- a/arch/x86_64/lib/usercopy.c
+++ b/arch/x86_64/lib/usercopy.c
@@ -109,14 +109,11 @@ unsigned long clear_user(void __user *to, unsigned long n)
* Return 0 on exception, a value greater than N if too long
*/
-long strnlen_user(const char __user *s, long n)
+long __strnlen_user(const char __user *s, long n)
{
long res = 0;
char c;
- if (!access_ok(VERIFY_READ, s, n))
- return 0;
-
while (1) {
if (res>n)
return n+1;
@@ -129,6 +126,13 @@ long strnlen_user(const char __user *s, long n)
}
}
+long strnlen_user(const char __user *s, long n)
+{
+ if (!access_ok(VERIFY_READ, s, n))
+ return 0;
+ return __strnlen_user(s, n);
+}
+
long strlen_user(const char __user *s)
{
long res = 0;
diff --git a/include/asm-x86_64/uaccess.h b/include/asm-x86_64/uaccess.h
index 1bb8b8a2443..2892c4b7a28 100644
--- a/include/asm-x86_64/uaccess.h
+++ b/include/asm-x86_64/uaccess.h
@@ -348,6 +348,7 @@ static inline int __copy_in_user(void __user *dst, const void __user *src, unsig
long strncpy_from_user(char *dst, const char __user *src, long count);
long __strncpy_from_user(char *dst, const char __user *src, long count);
long strnlen_user(const char __user *str, long n);
+long __strnlen_user(const char __user *str, long n);
long strlen_user(const char __user *str);
unsigned long clear_user(void __user *mem, unsigned long len);
unsigned long __clear_user(void __user *mem, unsigned long len);