[PATCH] i386: Use probe_kernel_address instead of __get_user in fault paths
Makes the intention of the code cleaner to read and avoids
a potential deadlock on mmap_sem. Also change the types of
the arguments to not include __user because they're really
not user addresses.
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 237f488..7b2f9f0 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -380,7 +380,7 @@
* time of the fault..
*/
if (in_kernel) {
- u8 __user *eip;
+ u8 *eip;
int code_bytes = 64;
unsigned char c;
@@ -389,18 +389,20 @@
printk(KERN_EMERG "Code: ");
- eip = (u8 __user *)regs->eip - 43;
- if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
+ eip = (u8 *)regs->eip - 43;
+ if (eip < (u8 *)PAGE_OFFSET ||
+ probe_kernel_address(eip, c)) {
/* try starting at EIP */
- eip = (u8 __user *)regs->eip;
+ eip = (u8 *)regs->eip;
code_bytes = 32;
}
for (i = 0; i < code_bytes; i++, eip++) {
- if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
+ if (eip < (u8 *)PAGE_OFFSET ||
+ probe_kernel_address(eip, c)) {
printk(" Bad EIP value.");
break;
}
- if (eip == (u8 __user *)regs->eip)
+ if (eip == (u8 *)regs->eip)
printk("<%02x> ", c);
else
printk("%02x ", c);
@@ -416,7 +418,7 @@
if (eip < PAGE_OFFSET)
return;
- if (probe_kernel_address((unsigned short __user *)eip, ud2))
+ if (probe_kernel_address((unsigned short *)eip, ud2))
return;
if (ud2 != 0x0b0f)
return;
@@ -429,11 +431,11 @@
char *file;
char c;
- if (probe_kernel_address((unsigned short __user *)(eip + 2),
- line))
+ if (probe_kernel_address((unsigned short *)(eip + 2), line))
break;
- if (__get_user(file, (char * __user *)(eip + 4)) ||
- (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
+ if (probe_kernel_address((char **)(eip + 4), file) ||
+ (unsigned long)file < PAGE_OFFSET ||
+ probe_kernel_address(file, c))
file = "<bad filename>";
printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);