an oops in 2.6-test2 (oops)

I've got another one yesterday:

ksymoops 2.4.8 on i686 2.6.0-test3. Options used
-V (default)
-k /proc/ksyms (default)
-l /proc/modules (default)
-o /lib/modules/2.6.0-test3/ (default)
-m /boot/System.map-2.6.0-test3 (default)

Warning: You did not tell me where to find symbol information. I will assume that the log matches the kernel and modules that are running right now and I'll use the default options above for symbol resolution. If the current kernel and/or modules do not match the log, you can get more accurate output by telling me the kernel version and where to find map, modules, ksyms etc. ksymoops -h explains the options.

Error (regular_file): read_ksyms stat /proc/ksyms failed No modules in ksyms, skipping objects
No ksyms, skipping lsmod

Aug 15 14:35:44 wonderland kernel: 8139too Fast Ethernet driver 0.9.26
Aug 16 07:26:51 wonderland kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
Aug 16 07:26:51 wonderland kernel: c015c80a
Aug 16 07:26:51 wonderland kernel: *pde = 00000000
Aug 16 07:26:51 wonderland kernel: Oops: 0000 [#1]
Aug 16 07:26:51 wonderland kernel: CPU:    0
Aug 16 07:26:51 wonderland kernel: EIP:    0060:[<c015c80a>]    Not tainted
Using defaults from ksymoops -t elf32-i386 -a i386
Aug 16 07:26:51 wonderland kernel: EFLAGS: 00010286
Aug 16 07:26:51 wonderland kernel: eax: c1521110   ebx: 0005fa96   ecx: d19b1b50   edx: 00000000
Aug 16 07:26:51 wonderland kernel: esi: df60aa00   edi: c1521110   ebp: cd54de2c   esp: cd54de1c
Aug 16 07:26:51 wonderland kernel: ds: 007b   es: 007b   ss: 0068
Aug 16 07:26:51 wonderland kernel: Stack: df530300 0005fa96 0005fa96 df60aa00 cd54de50 c015cd0b df60aa00 c1521110 
Aug 16 07:26:51 wonderland kernel:        0005fa96 c1521110 0005fa96 c615e300 df60aa00 cd54de70 c017bc77 df60aa00 
Aug 16 07:26:51 wonderland kernel:        0005fa96 df4facec fffffff4 df5c54b8 df5c5450 cd54de94 c0152740 df5c5450 
Aug 16 07:26:51 wonderland kernel: Call Trace:
Aug 16 07:26:51 wonderland kernel:  [<c015cd0b>] iget_locked+0x4b/0xa0
Aug 16 07:26:51 wonderland kernel:  [<c017bc77>] ext3_lookup+0x67/0xc0
Aug 16 07:26:51 wonderland kernel:  [<c0152740>] real_lookup+0xc0/0xf0
Aug 16 07:26:51 wonderland kernel:  [<c0152984>] do_lookup+0x84/0x90
Aug 16 07:26:51 wonderland kernel:  [<c0152d84>] link_path_walk+0x3f4/0x760
Aug 16 07:26:51 wonderland kernel:  [<c015353e>] __user_walk+0x3e/0x60
Aug 16 07:26:51 wonderland kernel:  [<c014efbe>] vfs_stat+0x1e/0x60
Aug 16 07:26:51 wonderland kernel:  [<c013c8c2>] free_pgtables+0x82/0xa0
Aug 16 07:26:51 wonderland kernel:  [<c013c956>] unmap_vma+0x76/0x80
Aug 16 07:26:51 wonderland kernel:  [<c014f62b>] sys_stat64+0x1b/0x40
Aug 16 07:26:51 wonderland kernel:  [<c014643b>] filp_close+0x4b/0x80
Aug 16 07:26:51 wonderland kernel:  [<c01464c1>] sys_close+0x51/0x60
Aug 16 07:26:51 wonderland kernel:  [<c01090b3>] syscall_call+0x7/0xb
Aug 16 07:26:51 wonderland kernel: Code: 0f 18 02 90 39 59 18 89 c8 74 10 85 d2 89 d1 75 ed 31 c0 83 

Trace; c015cd0b <iget_locked+4b/a0>
Trace; c017bc77 <ext3_lookup+67/c0>
Trace; c0152740 <real_lookup+c0/f0>
Trace; c0152984 <do_lookup+84/90>
Trace; c0152d84 <link_path_walk+3f4/760>
Trace; c015353e <__user_walk+3e/60>
Trace; c014efbe <vfs_stat+1e/60>
Trace; c013c8c2 <free_pgtables+82/a0>
Trace; c013c956 <unmap_vma+76/80>
Trace; c014f62b <sys_stat64+1b/40>
Trace; c014643b <filp_close+4b/80>
Trace; c01464c1 <sys_close+51/60>
Trace; c01090b3 <syscall_call+7/b>

Code; c015c80a <find_inode_fast+1a/60>
00000000 <_EIP>:
Code; c015c80a <find_inode_fast+1a/60> <=====
0: 0f 18 02 prefetchnta (%edx) <=====
Code; c015c80d <find_inode_fast+1d/60>
3: 90 nop
Code; c015c80e <find_inode_fast+1e/60>
4: 39 59 18 cmp %ebx,0x18(%ecx)
Code; c015c811 <find_inode_fast+21/60>
7: 89 c8 mov %ecx,%eax
Code; c015c813 <find_inode_fast+23/60>
9: 74 10 je 1b <_EIP+0x1b>
Code; c015c815 <find_inode_fast+25/60>
b: 85 d2 test %edx,%edx
Code; c015c817 <find_inode_fast+27/60>
d: 89 d1 mov %edx,%ecx
Code; c015c819 <find_inode_fast+29/60>
f: 75 ed jne fffffffe <_EIP+0xfffffffe>
Code; c015c81b <find_inode_fast+2b/60>
11: 31 c0 xor %eax,%eax
Code; c015c81d <find_inode_fast+2d/60>
13: 83 00 00 addl $0x0,(%eax)

1 warning and 1 error issued. Results may not be reliable.

ciao, |
Marco | [1302 arB35F5/Z7koA]

And you'll continue to get them until someone does something about it. Discussion seemed to die off on this problem.

Until it is sorted, something like this is needed.

diff -puN include/asm-i386/processor.h~disble-athlon-prefetch include/asm-i386/processor.h
@@ -568,6 +568,8 @@ static inline void rep_nop(void)
 #define ARCH_HAS_PREFETCH
 extern inline void prefetch(const void *x)
 {
+	if (current_cpu_data.x86_vendor == X86_VENDOR_AMD)
+		return;
 	alternative_input(ASM_NOP4,
 			  "prefetchnta (%1)",
 			  X86_FEATURE_XMM,

_