Hello, I noticed that wl1251_spi was crashing while rmmoding it with 2.6.33 kernels (from wireless-testing) on a nokia n900 (rx51_defconfig plus some changes). [1] I did some investigation and I think kernel/module.c is adding sysfs file with a null string as the name and that causes the crash during rmmod while the sysfs file is removed. For example, I can crash the kernel just by executing this command: [2] ls -a /sys/module/wl1251_spi/notes This happens everytime with wl1251_spi, but not with other modules. For example wl1251 seems to work fine: Nokia-N900-42-9:~# ls -a /sys/module/wl1251/notes/ . .. .note.gnu.build-id Nokia-N900-42-9:~# The toolchain I'm using: gcc version 4.4.1 (Sourcery G++ Lite 2009q3-67) Any ideas how to debug this further? Anyone seen, or heard, about similar problems? I didn't notice this problem on 2.6.32 with the same setup. [1] crash log from rmmod wl1251_spi: [ 3856.875579] wl1251: unloaded [ 3856.878784] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 3856.887084] pgd = cd02c000 [ 3856.889892] [00000000] *pgd=8d78d031, *pte=00000000, *ppte=00000000 [ 3856.896270] Internal error: Oops: 17 [#1] [ 3856.900329] last sysfs file: /sys/class/net/wlan0/flags [ 3856.905609] Modules linked in: wl1251 mac80211 cfg80211 [last unloaded: wl1251_spi] [ 3856.913421] CPU: 0 Not tainted (2.6.33-rc2-wl-47089-g7bfbe2a #449) [ 3856.920013] PC is at strcmp+0x4/0x34 [ 3856.923645] LR is at sysfs_find_dirent+0x18/0x38 [ 3856.928344] pc : [<c01475d0>] lr : [<c00f5f08>] psr: a0000013 [ 3856.928344] sp : cd073f00 ip : 22222222 fp : bea5767c [ 3856.939941] r10: 00000000 r9 : cd072000 r8 : c002bae4 [ 3856.945220] r7 : bea54de8 r6 : 00000000 r5 : 00000000 r4 : cd031458 [ 3856.951812] r3 : 00000000 r2 : ffffffd0 r1 : 00000000 r0 : 00000000 [ 3856.958404] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 3856.965637] Control: 10c5387d Table: 8d02c019 DAC: 00000015 [ 3856.971435] Process rmmod (pid: 4930, stack limit = 0xcd0722e8) [ 3856.977416] Stack: (0xcd073f00 to 0xcd074000) [ 3856.981842] 3f00: 22222222 cd031488 cd073f10 c00f4c94 cd031488 00000000 cfa4df00 00000000 [ 3856.990112] 3f20: cd073f44 c007c3ac bf08875c 00000000 cd073f44 c007c748 bf08875c c007ca54 [ 3856.998382] 3f40: cf11d108 32316c77 735f3135 cf006970 c009db38 cf374100 00000001 cf374100 [ 3857.006652] 3f60: c025e6c0 4001e000 cf11d0c0 c0072d44 00000001 cf374100 c002ba54 00a54e10 [ 3857.014953] 3f80: bf08875c 00000880 cd073f8c 00000000 bea54e10 00000000 bea54de8 bea54e10 [ 3857.023223] 3fa0: 00000081 c002b940 00000000 bea54de8 bea54de8 00000880 40151028 00000000 [ 3857.031494] 3fc0: 00000000 bea54de8 bea54e10 00000081 00000880 00000000 00000000 bea5767c [ 3857.039764] 3fe0: 00000003 bea54de0 00008b38 400f0efc 60000010 bea54de8 00004e15 00001f02 [ 3857.048034] [<c01475d0>] (strcmp+0x4/0x34) from [<c00f5f08>] (sysfs_find_dirent+0x18/0x38) [ 3857.056427] [<c00f5f08>] (sysfs_find_dirent+0x18/0x38) from [<c00f4c94>] (sysfs_hash_and_remove+0x2c/0x5c) [ 3857.066192] [<c00f4c94>] (sysfs_hash_and_remove+0x2c/0x5c) from [<c007c3ac>] (free_notes_attrs+0x28/0x4c) [ 3857.075866] [<c007c3ac>] (free_notes_attrs+0x28/0x4c) from [<c007c748>] (free_module+0x34/0xe4) [ 3857.084686] [<c007c748>] (free_module+0x34/0xe4) from [<c007ca54>] (sys_delete_module+0x224/0x260) [ 3857.093750] [<c007ca54>] (sys_delete_module+0x224/0x260) from [<c002b940>] (ret_fast_syscall+0x0/0x38) [ 3857.103179] Code: e28cc001 1afffff3 e8bd8030 e3a03000 (e7d02003) [ 3857.109405] ---[ end trace e201521161943231 ]--- [ 3857.114074] Kernel panic - not syncing: Fatal exception [2] crash log from ls: Nokia-N900-42-9:~# ls -a /sys/module/wl1251_spi/notes [ 3823.873168] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 3823.881530] pgd = cccfc000 [ 3823.884277] [00000000] *pgd=8f08b031, *pte=00000000, *ppte=00000000 [ 3823.890747] Internal error: Oops: 17 [#1] [ 3823.894805] last sysfs file: /sys/class/net/wlan0/flags [ 3823.900085] Modules linked in: wl1251_spi wl1251 mac80211 cfg80211 [ 3823.906402] CPU: 0 Not tainted (2.6.33-rc2-wl-47089-g7bfbe2a-dirty #1) [ 3823.913360] PC is at strlen+0xc/0x20 [ 3823.916992] LR is at sysfs_readdir+0x15c/0x1e0 [ 3823.921508] pc : [<c014772c>] lr : [<c00f5ec4>] psr: a0000013 [ 3823.921508] sp : cd1a1f28 ip : 22222222 fp : bef3760c [ 3823.933105] r10: cd1a1f80 r9 : 00000000 r8 : 00000000 [ 3823.938385] r7 : c00b9598 r6 : cd1a1f80 r5 : cd1d8458 r4 : cf398d80 [ 3823.944976] r3 : 00000000 r2 : 00000002 r1 : 22222222 r0 : 00000000 [ 3823.951599] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 3823.958801] Control: 10c5387d Table: 8ccfc019 DAC: 00000015 [ 3823.964599] Process ls (pid: 1143, stack limit = 0xcd1a02e8) [ 3823.970336] Stack: (0xcd1a1f28 to 0xcd1a2000) [ 3823.974731] 1f20: 00000001 00000000 00000e16 00000000 00000004 22222222 [ 3823.983032] 1f40: cf398d80 cf398d80 cf7a834c c00b9598 00000000 cf7a82b8 cd1a0000 c00b9884 [ 3823.991302] 1f60: 00000001 00000000 00001000 000690d0 cf398d80 c002bae4 00000000 c00b991c [ 3823.999572] 1f80: 00069100 000690e8 00000fd0 ffffffea 00000000 00000000 00000000 00000000 [ 3824.007843] 1fa0: 000000d9 c002b940 00000000 00000000 00000003 000690d0 00001000 00000000 [ 3824.016113] 1fc0: 00000000 00000000 00000000 000000d9 000690c8 00000001 00000000 bef3760c [ 3824.024383] 1fe0: 400ef954 bef37604 400efa10 400ef908 60000010 00000003 00001802 0005e91c [ 3824.032684] [<c014772c>] (strlen+0xc/0x20) from [<c00f5ec4>] (sysfs_readdir+0x15c/0x1e0) [ 3824.040893] [<c00f5ec4>] (sysfs_readdir+0x15c/0x1e0) from [<c00b9884>] (vfs_readdir+0x80/0xb4) [ 3824.049591] [<c00b9884>] (vfs_readdir+0x80/0xb4) from [<c00b991c>] (sys_getdents64+0x64/0xb4) [ 3824.058258] [<c00b991c>] (sys_getdents64+0x64/0xb4) from [<c002b940>] (ret_fast_syscall+0x0/0x38) [ 3824.067230] Code: c02770d4 e1a03000 ea000000 e2833001 (e5d32000) [ 3824.073455] ---[ end trace 7191ebb2793d480e ]--- [ 3824.078186] Kernel panic - not syncing: Fatal exception -- Kalle Valo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
