Messages in this thread | | | Date | Mon, 07 Jul 2008 15:26:46 +0200 | From | Carl-Daniel Hailfinger <> | Subject | Re: [Linux-NTFS-Dev] Oops with corrupted NTFS image |
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On 07.07.2008 15:03, Vegard Nossum wrote: > On Mon, Jul 7, 2008 at 2:24 PM, Eric Sesterhenn <snakebyte@gmx.de> wrote: > >> (gdb) l *(ntfs_read_locked_inode+0x16c) >> 0xc030adbc is in ntfs_read_locked_inode (fs/ntfs/time.h:90). >> 85 static inline struct timespec ntfs2utc(const sle64 time) >> 86 { >> 87 struct timespec ts; >> 88 >> 89 /* Subtract the NTFS time offset. */ >> 90 u64 t = (u64)(sle64_to_cpu(time) - NTFS_TIME_OFFSET); >> 91 /* >> 92 * Convert the time to 1-second intervals and the remainder to >> 93 * 1-nano-second intervals. >> 94 */ >> (gdb) quit >> >> Not sure why this happens. I checked out a fresh git tree to >> make sure my tree isnt broken or something. Might gcc be bogus >> or the debug information and the bug happens in reality somewhere else? >>
As I pointed out in my other mail, gcc compiler optimizations may have caused a slightly off location being printed. My suspicions about time were correct.
> Are you sure you didn't recompile/relink vmlinux after getting the > error? If not, maybe it's gdb which gets confused (somehow) by the > inlining. > > Your 'Code:' line decodes to these instructions: > > 0: 8b 58 08 mov 0x8(%eax),%ebx > 3: 8b 70 0c mov 0xc(%eax),%esi > > And I find this in my own compiled vmlinux at: > > c025bcc1: 8b 58 08 mov 0x8(%eax),%ebx > c025bcc4: 8b 70 0c mov 0xc(%eax),%esi > > which is at... > > $ addr2line -e vmlinux -i c025bcc1 > fs/ntfs/inode.c:670 > > which is... > > vi->i_mtime = ntfs2utc(si->last_data_change_time); > > which is probably what is causing the NULL pointer dereference. >
The problem of this theory is that there is no NULL pointer dereference, unless you meant "invalid memory access".
Regards, Carl-Daniel
-- http://www.hailfinger.org/
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