[PATCH] i386: handle_BUG(): don't print garbage if debug info unavailable

handle_BUG() tries to print file and line number even when they're not
available (CONFIG_DEBUG_BUGVERBOSE is not set.) Change this to print a
message stating info is unavailable instead of printing a misleading
message.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 5cfd4f42eeba08f3650f47e0ae6cd405c98486c1..313ac1f7dc5aaf88795748554118a8d9e393f83f 100644 (file)
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -324,35 +324,35 @@ void show_registers(struct pt_regs *regs)
 
 static void handle_BUG(struct pt_regs *regs)
 {
+       unsigned long eip = regs->eip;
        unsigned short ud2;
-       unsigned short line;
-       char *file;
-       char c;
-       unsigned long eip;
-
-       eip = regs->eip;
 
        if (eip < PAGE_OFFSET)
-               goto no_bug;
+               return;
        if (__get_user(ud2, (unsigned short __user *)eip))
-               goto no_bug;
+               return;
        if (ud2 != 0x0b0f)
-               goto no_bug;
-       if (__get_user(line, (unsigned short __user *)(eip + 2)))
-               goto bug;
-       if (__get_user(file, (char * __user *)(eip + 4)) ||
-               (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
-               file = "<bad filename>";
+               return;
 
        printk(KERN_EMERG "------------[ cut here ]------------\n");
-       printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
 
-no_bug:
-       return;
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+       do {
+               unsigned short line;
+               char *file;
+               char c;
 
-       /* Here we know it was a BUG but file-n-line is unavailable */
-bug:
-       printk(KERN_EMERG "Kernel BUG\n");
+               if (__get_user(line, (unsigned short __user *)(eip + 2)))
+                       break;
+               if (__get_user(file, (char * __user *)(eip + 4)) ||
+                   (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
+                       file = "<bad filename>";
+
+               printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
+               return;
+       } while (0);
+#endif
+       printk(KERN_EMERG "Kernel BUG at [verbose debug info unavailable]\n");
 }
 
 /* This is gone through when something in the kernel