* Andrew Morton ([EMAIL PROTECTED]) wrote:
> On Fri, 24 Aug 2007 18:47:07 -0400
> Mathieu Desnoyers <[EMAIL PROTECTED]> wrote:
>
> > Hi Andrew,
> >
> > I get the following BUG when booting 2.6.23-rc3-mm1 on i386. I wonder if
> > you would have some ideas about what is causing this problem. I'll start
> > bissecting it soon. I seems to be caused by an buggy skb_put call in
> > kobject_uevent_env.
> >
> > Thanks,
> >
> > Mathieu
> >
> >
>
> hm, don't know, sorry. Kay fixed a few things in there, but iirc pretty
> much all of the fixes were in rc3-mm1 anyway.
>
> I doubt if bisection will tell us a lot: it'll probably point at
> gregkh-driver-driver-core-change-add_uevent_var-to-use-a-struct.patch.
>
> What we _would_ like to know is which sysfs file is being written to. We
> used to have a debug patch to exactly address this problem but it got
> transferred into Greg's tree from whence it mysteriously disappeared.
>
Ok, here it is:
filename :
/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/rev
[ 13.737735] ------------[ cut here ]------------
[ 13.751544] Kernel BUG at c039e11c [verbose debug info unavailable]
[ 13.770287] invalid opcode: 0000 [#1] PREEMPT SMP
[ 13.784736] last sysfs file:
/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/rev
[ 13.809714] Modules linked in:
[ 13.818873]
[ 13.823330] Pid: 1038, comm: udevtrigger Not tainted
(2.6.23-rc3-mm1-testssmp #283)
[ 13.846218] EIP: 0060:[<c039e11c>] EFLAGS: 00010286 CPU: 1
[ 13.862616] EIP is at skb_over_panic+0x5c/0x60
[ 13.875894] EAX: 00000084 EBX: c2227e00 ECX: 10000000 EDX: 00000000
[ 13.894632] ESI: 00000000 EDI: c2227e56 EBP: c2ea9eb4 ESP: c2ea9e88
[ 13.913372] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 13.929516] Process udevtrigger (pid: 1038, ti=c2ea8000 task=c2baa070
task.ti=c2ea8000)
[ 13.952918] Stack: c05010f0 c0252e3e 00000061 0000000b c2227e00 c2227e00
c2227e61 c2227e60
[ 13.978200] c04d21c5 c2287c80 00000005 c2ea9efc c0252e43 c2227e00
c04d2168 c04ce0e4
[ 14.003471] c20fc2a0 00000000 c04ce0e4 c20fc2a0 c04e2eaf c05401e0
c225a000 c2ea9f04
[ 14.028749] Call Trace:
[ 14.036622] [<c010971a>] show_trace_log_lvl+0x1a/0x30
[ 14.052019] [<c01097d8>] show_stack_log_lvl+0xa8/0xe0
[ 14.067412] [<c01098da>] show_registers+0xca/0x250
[ 14.082028] [<c0109b75>] die+0x115/0x280
[ 14.094047] [<c04187c1>] do_trap+0x91/0xc0
[ 14.106586] [<c0109fc9>] do_invalid_op+0x89/0xa0
[ 14.120680] [<c041857a>] error_code+0x72/0x78
[ 14.134002] [<c0252e43>] kobject_uevent_env+0x353/0x380
[ 14.149915] [<c0252e7a>] kobject_uevent+0xa/0x10
[ 14.164012] [<c02c523b>] store_uevent+0x2b/0x70
[ 14.177851] [<c02c4f5f>] dev_attr_store+0x2f/0x40
[ 14.192207] [<c01cd080>] sysfs_write_file+0xa0/0x100
[ 14.207344] [<c018cb89>] vfs_write+0x99/0x130
[ 14.220661] [<c018d26d>] sys_write+0x3d/0x70
[ 14.233720] [<c0108596>] syscall_call+0x7/0xb
[ 14.247036] =======================
[ 14.257723] INFO: lockdep is turned off.
[ 14.269448] Code: 00 00 89 5c 24 14 8b 98 8c 00 00 00 89 54 24 0c 89 5c 24
10 8b 40 50 89 4c 24 04 c7 04 24 f0 10 50 c0 89 44 24 08 e8 94 20 d9 ff <0f> 0b
eb fe 55 89 e5 56 89 d6 53 89 c3 83 ec 0c 8b 40 50 39
[ 14.328022] EIP: [<c039e11c>] skb_over_panic+0x5c/0x60 SS:ESP 0068:c2ea9e88
/etc/rcS.d/S03udev: line 253: 1038 Segmentation fault udevtrigger
>
> Here it is again:
>
>
> Print the name of the last-accessed sysfs file when we oops, to help track
> down oopses which occur in sysfs store/read handlers. Because these oopses
> tend to not leave any trace of the offending code in the stack traces.
>
> Cc: Greg KH <[EMAIL PROTECTED]>
> Cc: Kay Sievers <[EMAIL PROTECTED]>
> Cc: Mathieu Desnoyers <[EMAIL PROTECTED]>
> Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
> ---
>
> arch/i386/kernel/traps.c | 1 +
> arch/x86_64/kernel/traps.c | 1 +
> fs/sysfs/file.c | 14 ++++++++++++++
> include/linux/sysfs.h | 5 +++++
> 4 files changed, 21 insertions(+)
>
> diff -puN arch/i386/kernel/traps.c~sysfs-crash-debugging
> arch/i386/kernel/traps.c
> --- a/arch/i386/kernel/traps.c~sysfs-crash-debugging
> +++ a/arch/i386/kernel/traps.c
> @@ -452,6 +452,7 @@ void die(const char * str, struct pt_reg
> #endif
> printk("\n");
>
> + sysfs_printk_last_file();
> if (notify_die(DIE_OOPS, str, regs, err,
> current->thread.trap_no, SIGSEGV) !=
> NOTIFY_STOP) {
> diff -puN arch/x86_64/kernel/traps.c~sysfs-crash-debugging
> arch/x86_64/kernel/traps.c
> --- a/arch/x86_64/kernel/traps.c~sysfs-crash-debugging
> +++ a/arch/x86_64/kernel/traps.c
> @@ -588,6 +588,7 @@ void __kprobes __die(const char * str, s
> printk("DEBUG_PAGEALLOC");
> #endif
> printk("\n");
> + sysfs_printk_last_file();
> notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
> show_registers(regs);
> add_taint(TAINT_DIE);
> diff -puN fs/sysfs/file.c~sysfs-crash-debugging fs/sysfs/file.c
> --- a/fs/sysfs/file.c~sysfs-crash-debugging
> +++ a/fs/sysfs/file.c
> @@ -9,12 +9,20 @@
> #include <linux/poll.h>
> #include <linux/list.h>
> #include <linux/mutex.h>
> +#include <linux/limits.h>
> #include <asm/uaccess.h>
>
> #include "sysfs.h"
>
> #define to_sattr(a) container_of(a,struct subsys_attribute, attr)
>
> +/* used in crash dumps to help with debugging */
> +static char last_sysfs_file[PATH_MAX];
> +void sysfs_printk_last_file(void)
> +{
> + printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
> +}
> +
> /*
> * Subsystem file operations.
> * These operations allow subsystems to have files that can be
> @@ -245,6 +253,12 @@ static int sysfs_open_file(struct inode
> struct sysfs_buffer * buffer;
> struct sysfs_ops * ops = NULL;
> int error;
> + char *p;
> +
> + p = d_path(file->f_dentry, sysfs_mount, last_sysfs_file,
> + sizeof(last_sysfs_file));
> + if (p)
> + memmove(last_sysfs_file, p, strlen(p) + 1);
>
> /* need attr_sd for attr and ops, its parent for kobj */
> if (!sysfs_get_active_two(attr_sd))
> diff -puN include/linux/sysfs.h~sysfs-crash-debugging include/linux/sysfs.h
> --- a/include/linux/sysfs.h~sysfs-crash-debugging
> +++ a/include/linux/sysfs.h
> @@ -133,6 +133,7 @@ void sysfs_remove_file_from_group(struct
> const struct attribute *attr, const char *group);
>
> void sysfs_notify(struct kobject * k, char *dir, char *attr);
> +void sysfs_printk_last_file(void);
>
> extern int __must_check sysfs_init(void);
>
> @@ -234,6 +235,10 @@ static inline int __must_check sysfs_ini
> return 0;
> }
>
> +static inline void sysfs_printk_last_file(void)
> +{
> +}
> +
> #endif /* CONFIG_SYSFS */
>
> #endif /* _SYSFS_H_ */
> _
>
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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