Thanks Russell, This S2C: message just for program s2c. s2c can convert it to a core file. Then gdb can do a clear analyse with this file. Then you can get more message than current we can get. For example: (gdb) bt #0 0xc0008470 in kernel_init (unused=<value optimized out>) at /home/teawater/kernel/arm_versatile_926ejs.glibc_std.standard/build/linux/init/main.c:916 #1 0xc0042660 in sys_waitid (which=<value optimized out>, upid=<value optimized out>, infop=0x0, options=0, ru=0x14) at /home/teawater/kernel/arm_versatile_926ejs.glibc_std.standard/build/linux/kernel/exit.c:1798 Backtrace stopped: previous frame inner to this frame (corrupt stack?) a more clear backtrace. (gdb) frame 1 #1 0xc0042660 in sys_waitid (which=<value optimized out>, upid=<value optimized out>, infop=0x0, options=0, ru=0x14) at /home/teawater/kernel/arm_versatile_926ejs.glibc_std.standard/build/linux/kernel/exit.c:1798 1798 pid = find_get_pid(upid); (gdb) p pid $1 = (struct pid *) 0x0 A value of a val in stack in the frame. I think it will more helpful for user to deal with the kernel die. Best regards, Hui On Mon, Jan 4, 2010 at 00:03, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Sun, Jan 03, 2010 at 11:05:05PM +0800, Hui Zhu wrote: >> Hello, >> >> For, when the kernel die, the user will get some message like: >> PC is at kernel_init+0xd4/0x104 >> LR is at _atomic_dec_and_lock+0x48/0x6c >> pc : [<c0008470>] lr : [<c01911f8>] psr: 60000013 >> sp : c7823fd8 ip : c7823f48 fp : c7823ff4 >> Stack: (0xc7823fd8 to 0xc7824000) >> 3fc0: 00000000 00000001 >> Backtrace: >> [<c000839c>] (kernel_init+0x0/0x104) from [<c0042660>] (do_exit+0x0/0x880) >> This backtrace have some wrong message sometime and cannot get any >> val. Of course, kdump can get more message. But it need do some a lot >> of other config. > > If you have frame pointers enabled, the backtrace is _never_ wrong. > It only goes wrong if you disable frame pointers, at which point the > unwind tables have to be used. > >> When kernel die, show some message: >> S2C:elf_class=1 >> S2C:elf_data=1 >> S2C:elf_arch=40 >> S2C:elf_osabi=0 >> S2C:r0=0x00000000; >> S2C:r1=0xc7822000; >> S2C:r2=0xc7823f48; >> S2C:r3=0x00000003; >> S2C:r4=0x00000000; >> S2C:r5=0x00000000; >> S2C:r6=0x00000000; >> S2C:r7=0x00000000; >> S2C:r8=0x00000000; >> S2C:r9=0x00000000; >> S2C:r10=0x00000000; >> S2C:fp=0xc7823ff4; >> S2C:ip=0xc7823f48; >> S2C:sp=0xc7823fd8; >> S2C:lr=0xc01911f8; >> S2C:pc=0xc0008470; >> S2C:cpsr=0x60000013; >> S2C:ORIG_r0=0xffffffff; >> >> S2C:stack=0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, >> S2C:stack=0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, >> S2C:stack=0x00, 0x00, 0x00, 0x00, 0xf8, 0x3f, 0x82, 0xc7, >> S2C:stack=0x60, 0x26, 0x04, 0xc0, 0xa8, 0x83, 0x00, 0xc0, >> S2C:stack=0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > > Please don't invent yet another way of dumping stuff out of the kernel. > What we already have is sufficient for your needs - there's no reason > what so ever to change it to achieve your goals. We already dump the > registers and the stack, which seems to be all that you require. >
