On Sun, 03 Dec 2006 02:55:04 +0300 Michael Tokarev <[EMAIL PROTECTED]> wrote:
> When /sbin/hotplug is present in initramfs, and it's a shell > script, kernel OOPSes on every hotplug invocation. Here's an > example: > > <4> <1>BUG: unable to handle kernel NULL pointer dereference at virtual > address 00000014 > <1> printing eip: > <4>c015c80a > <1>*pde = 00000000 > <0>Oops: 0000 [#2] > <4>Modules linked in: > <0>CPU: 0 > <0>EIP: 0060:[<c015c80a>] Not tainted VLI > <0>EFLAGS: 00010282 (2.6.19-c3 #2.6.19.0) > <0>EIP is at create_write_pipe+0x1a/0x1c0 > <0>eax: 00000000 ebx: bfb07cfc ecx: 00000000 edx: c13915a0 > <0>esi: cf739820 edi: ffffffff ebp: c13a2fa8 esp: c13a2f40 > <0>ds: 007b es: 007b ss: 0068 > <0>Process hotplug (pid: 34, ti=c13a2000 task=c13915a0 task.ti=c13a2000) > <0>Stack: 00001fff c1382da0 c137fba0 c1387b7c 00000000 c12b2ce0 080dfd04 > 080dfd04 > <0> 00000003 c015a27f 00000000 c1382da0 b7f64d30 00000004 c011412a > 00000000 > <0> bfb07cfc 00000004 ffffffff c015cfde c137fba0 bfb07cfc 00000004 > ffffffff > <0>Call Trace: > <0> [<c015cfde>] do_pipe+0xe/0xa0 > <0> [<c0107cac>] sys_pipe+0xc/0x40 > <0> [<c0102eb7>] syscall_call+0x7/0xb > <0> [<b7f6607d>] 0xb7f6607d > <0> ======================= > <0>Code: 00 00 00 89 b3 74 01 00 00 89 d8 5b 5e c3 8d 76 00 57 56 53 83 ec 40 > e8 35 bb ff ff 89 c6 85 c0 0f 84 7b 01 00 00 a1 c0 85 2d c0 <8b> 40 14 e8 de > d0 00 00 89 c3 85 c0 0f 84 44 01 00 00 e8 8f ff > <0>EIP: [<c015c80a>] create_write_pipe+0x1a/0x1c0 SS:ESP 0068:c13a2f40 > <4> <1>BUG: unable to handle kernel NULL pointer dereference at virtual > address 00000014 > <1> printing eip: > ...[more entries like this follows]... > > (note also the formatting is a bit wrong here -- that <4> prefix in front of > <1>BUG..) > > The only pipe() call in my hotplug script is this: > > case "$ACTION:$SUBSYSTEM" in > add:block) > ... > usage="$(/bin/blkid $dev 2>/dev/null | cut -d\ -f2-)" > ... > > > This is 2.6.19 running on an x86 machine (VIA C3 "Ezra" CPU if that matters). > The same thing happens on 2.6.18, but the error was slightly different (due > to introduction of create_write_pipe() routine in 2.6.19). > > Are pipes disallowed in hotplug fired off initramfs? > (Even if they are, kernel probably still should not OOPS like that ;) > > The error seems to be harmful however. That is, hotplug script does not > run, but the kernel continues running. > blah. pipefs isn't mounted yet. I assume that swapping the order of the calls to populate_rootfs() and do_basic_setup() in init/main.c:init() will help. I wonder what to do about this. Perhaps create a new post-initramfs initcall level. Or mount pipefs before running populate_rootfs(). Or require that the "drivers which want to access firmware files" be modular. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
