New devolpments.
I have upgraded to 2.6.16.41, applied a patch sent by Frederik that
removed the changed made in http://lkml.org/lkml/2005/6/23/266 and
activated some more kernel debug, i.e., CONFIG_KALLSYMS_ALL,
CONFIG_DEBUG_KERNEL, CONFIG_DETECT_SOFTLOCKUP, CONFIG_DEBUG_SLAB,
CONFIG_DEBUG_MUTEXES, CONFIG_FRAME_POINTER and CONFIG_FORCED_INLINING
(thanks to vda for pointing me to the right doc.).
At first it seemed to work fine, but after some days of continuous
running I've got another kernel Oops!
I attach the dmesg output and the assembly dump of serial8250_startup()
and serial8250_shutdown().
Regards,
José Gonçalves
<1>[18840.304048] Unable to handle kernel NULL pointer dereference at virtual address 00000012
<1>[18840.313046] printing eip:
<4>[18840.321687] c01bfa7a
<1>[18840.321714] *pde = 00000000
<0>[18840.331287] Oops: 0000 [#1]
<4>[18840.340687] Modules linked in:
<0>[18840.349749] CPU: 0
<4>[18840.349767] EIP: 0060:[<c01bfa7a>] Not tainted VLI
<4>[18840.349782] EFLAGS: 00010202 (2.6.16.41-mtm5-debug1 #1)
<0>[18840.377277] EIP is at serial_in+0xa/0x4a
<0>[18840.387221] eax: 00000060 ebx: 00000000 ecx: 00000000 edx: 00000000
<0>[18840.397805] esi: 00000000 edi: 00000040 ebp: c728fe1c esp: c728fe18
<0>[18840.408579] ds: 007b es: 007b ss: 0068
<0>[18840.419624] Process gp_position (pid: 11629, threadinfo=c728e000 task=c7443a90)
<0>[18840.420509] Stack: <0>00000000 00000000 c01c0f88 00000000 00000000 c031fef0 00000005 00000202
<0>[18840.445655] c7161a1c c031fef0 c124b510 c728fe60 c01bd97d c031fef0 c124b510 c124b510
<0>[18840.460540] 00000000 c773dbcc c728fe7c c01befe7 c124b510 00000000 ffffffed c773dbcc
<0>[18840.475892] Call Trace:
<0>[18840.490039] [<c0102a35>] show_stack_log_lvl+0xa5/0xad
<0>[18840.504944] [<c0102b70>] show_registers+0x106/0x16f
<0>[18840.520104] [<c0102d06>] die+0xb6/0x127
<0>[18840.535497] [<c0109677>] do_page_fault+0x380/0x4b3
<0>[18840.550828] [<c01026bf>] error_code+0x4f/0x60
<0>[18840.566645] [<c01c0f88>] serial8250_startup+0x28f/0x2a9
<0>[18840.582471] Code: 38 43 78 75 02 b2 01 89 d0 eb 10 8b 41 70 39 43 70 0f 94 c0 0f b6 c0 eb 02 31 c0 5b 5d c3 90 90 90 55 89 e5 53 8b 5d 08 8b 55 0c <0f> b6 4b 12 0f b6 43 13 d3 e2 83 f8 02 74 1a 7f 05 48 74 09 eb
<4>[18840.680471] BUG: gp_position/11629, lock held at task exit time!
<4>[18840.702808] [c124b528] {uart_register_driver}
<4>[18840.722346] .. held by: gp_position:11629 [c7443a90, 117]
<4>[18840.742113] ... acquired at: uart_get+0x28/0xde
vmlinux-2.6.16.41-mtm5-debug1: file format elf32-i386
Disassembly of section .text:
c01c0cf9 <serial8250_startup>:
c01c0cf9: 55 push %ebp
c01c0cfa: 89 e5 mov %esp,%ebp
c01c0cfc: 57 push %edi
c01c0cfd: 56 push %esi
c01c0cfe: 53 push %ebx
c01c0cff: 53 push %ebx
c01c0d00: 8b 5d 08 mov 0x8(%ebp),%ebx
c01c0d03: 8b 43 60 mov 0x60(%ebx),%eax
c01c0d06: c6 83 a7 00 00 00 00 movb $0x0,0xa7(%ebx)
c01c0d0d: 89 c2 mov %eax,%edx
c01c0d0f: c1 e2 04 shl $0x4,%edx
c01c0d12: 83 f8 0a cmp $0xa,%eax
c01c0d15: 8b 92 ac 37 25 c0 mov 0xc02537ac(%edx),%edx
c01c0d1b: 66 89 93 9c 00 00 00 mov %dx,0x9c(%ebx)
c01c0d22: 75 66 jne c01c0d8a
<serial8250_startup+0x91>
c01c0d24: c6 83 a4 00 00 00 00 movb $0x0,0xa4(%ebx)
c01c0d2b: 68 bf 00 00 00 push $0xbf
c01c0d30: 6a 03 push $0x3
c01c0d32: 53 push %ebx
c01c0d33: e8 82 ed ff ff call c01bfaba <serial_out>
c01c0d38: 6a 10 push $0x10
c01c0d3a: 6a 02 push $0x2
c01c0d3c: 53 push %ebx
c01c0d3d: e8 78 ed ff ff call c01bfaba <serial_out>
c01c0d42: 6a 00 push $0x0
c01c0d44: 6a 01 push $0x1
c01c0d46: 53 push %ebx
c01c0d47: e8 6e ed ff ff call c01bfaba <serial_out>
c01c0d4c: 83 c4 24 add $0x24,%esp
c01c0d4f: 6a 00 push $0x0
c01c0d51: 6a 03 push $0x3
c01c0d53: 53 push %ebx
c01c0d54: e8 61 ed ff ff call c01bfaba <serial_out>
c01c0d59: 6a 00 push $0x0
c01c0d5b: 6a 0c push $0xc
c01c0d5d: 53 push %ebx
c01c0d5e: e8 a7 ed ff ff call c01bfb0a <serial_icr_write>
c01c0d63: 68 bf 00 00 00 push $0xbf
c01c0d68: 6a 03 push $0x3
c01c0d6a: 53 push %ebx
c01c0d6b: e8 4a ed ff ff call c01bfaba <serial_out>
c01c0d70: 83 c4 24 add $0x24,%esp
c01c0d73: 6a 10 push $0x10
c01c0d75: 6a 02 push $0x2
c01c0d77: 53 push %ebx
c01c0d78: e8 3d ed ff ff call c01bfaba <serial_out>
c01c0d7d: 6a 00 push $0x0
c01c0d7f: 6a 03 push $0x3
c01c0d81: 53 push %ebx
c01c0d82: e8 33 ed ff ff call c01bfaba <serial_out>
c01c0d87: 83 c4 18 add $0x18,%esp
c01c0d8a: f6 83 9d 00 00 00 01 testb $0x1,0x9d(%ebx)
c01c0d91: 74 27 je c01c0dba
<serial8250_startup+0xc1>
c01c0d93: 6a 01 push $0x1
c01c0d95: 6a 02 push $0x2
c01c0d97: 53 push %ebx
c01c0d98: e8 1d ed ff ff call c01bfaba <serial_out>
c01c0d9d: 83 c4 0c add $0xc,%esp
c01c0da0: 6a 07 push $0x7
c01c0da2: 6a 02 push $0x2
c01c0da4: 53 push %ebx
c01c0da5: e8 10 ed ff ff call c01bfaba <serial_out>
c01c0daa: 83 c4 0c add $0xc,%esp
c01c0dad: 6a 00 push $0x0
c01c0daf: 6a 02 push $0x2
c01c0db1: 53 push %ebx
c01c0db2: e8 03 ed ff ff call c01bfaba <serial_out>
c01c0db7: 83 c4 0c add $0xc,%esp
c01c0dba: 6a 05 push $0x5
c01c0dbc: 53 push %ebx
c01c0dbd: e8 ae ec ff ff call c01bfa70 <serial_in>
c01c0dc2: 6a 00 push $0x0
c01c0dc4: 53 push %ebx
c01c0dc5: e8 a6 ec ff ff call c01bfa70 <serial_in>
c01c0dca: 6a 02 push $0x2
c01c0dcc: 53 push %ebx
c01c0dcd: e8 9e ec ff ff call c01bfa70 <serial_in>
c01c0dd2: 6a 06 push $0x6
c01c0dd4: 53 push %ebx
c01c0dd5: e8 96 ec ff ff call c01bfa70 <serial_in>
c01c0dda: 83 c4 20 add $0x20,%esp
c01c0ddd: f6 43 55 40 testb $0x40,0x55(%ebx)
c01c0de1: 75 28 jne c01c0e0b
<serial8250_startup+0x112>
c01c0de3: 6a 05 push $0x5
c01c0de5: 53 push %ebx
c01c0de6: e8 85 ec ff ff call c01bfa70 <serial_in>
c01c0deb: 5a pop %edx
c01c0dec: 3d ff 00 00 00 cmp $0xff,%eax
c01c0df1: 59 pop %ecx
c01c0df2: 75 17 jne c01c0e0b
<serial8250_startup+0x112>
c01c0df4: ff 73 6c pushl 0x6c(%ebx)
c01c0df7: 68 fb 4e 26 c0 push $0xc0264efb
c01c0dfc: e8 5c cd f4 ff call c010db5d <printk>
c01c0e01: b8 ed ff ff ff mov $0xffffffed,%eax
c01c0e06: e9 8f 01 00 00 jmp c01c0f9a
<serial8250_startup+0x2a1>
c01c0e0b: 83 7b 60 0c cmpl $0xc,0x60(%ebx)
c01c0e0f: 75 61 jne c01c0e72
<serial8250_startup+0x179>
c01c0e11: 68 bf 00 00 00 push $0xbf
c01c0e16: 6a 03 push $0x3
c01c0e18: 53 push %ebx
c01c0e19: e8 9c ec ff ff call c01bfaba <serial_out>
c01c0e1e: 6a 01 push $0x1
c01c0e20: 53 push %ebx
c01c0e21: e8 4a ec ff ff call c01bfa70 <serial_in>
c01c0e26: 83 e0 7f and $0x7f,%eax
c01c0e29: 89 c6 mov %eax,%esi
c01c0e2b: 83 c8 30 or $0x30,%eax
c01c0e2e: 0f b6 c0 movzbl %al,%eax
c01c0e31: 50 push %eax
c01c0e32: 6a 01 push $0x1
c01c0e34: 53 push %ebx
c01c0e35: e8 80 ec ff ff call c01bfaba <serial_out>
c01c0e3a: 83 c4 20 add $0x20,%esp
c01c0e3d: 83 ce b0 or $0xffffffb0,%esi
c01c0e40: 6a 60 push $0x60
c01c0e42: 6a 00 push $0x0
c01c0e44: 53 push %ebx
c01c0e45: e8 70 ec ff ff call c01bfaba <serial_out>
c01c0e4a: 89 f2 mov %esi,%edx
c01c0e4c: 0f b6 c2 movzbl %dl,%eax
c01c0e4f: 50 push %eax
c01c0e50: 6a 01 push $0x1
c01c0e52: 53 push %ebx
c01c0e53: e8 62 ec ff ff call c01bfaba <serial_out>
c01c0e58: 6a 60 push $0x60
c01c0e5a: 6a 00 push $0x0
c01c0e5c: 53 push %ebx
c01c0e5d: e8 58 ec ff ff call c01bfaba <serial_out>
c01c0e62: 83 c4 24 add $0x24,%esp
c01c0e65: 6a 00 push $0x0
c01c0e67: 6a 03 push $0x3
c01c0e69: 53 push %ebx
c01c0e6a: e8 4b ec ff ff call c01bfaba <serial_out>
c01c0e6f: 83 c4 0c add $0xc,%esp
c01c0e72: 83 7b 08 00 cmpl $0x0,0x8(%ebx)
c01c0e76: 75 2d jne c01c0ea5
<serial8250_startup+0x1ac>
c01c0e78: 8b 43 5c mov 0x5c(%ebx),%eax
c01c0e7b: ba 01 00 00 00 mov $0x1,%edx
c01c0e80: 83 f8 06 cmp $0x6,%eax
c01c0e83: 76 05 jbe c01c0e8a
<serial8250_startup+0x191>
c01c0e85: d1 e8 shr %eax
c01c0e87: 8d 50 fe lea 0xfffffffe(%eax),%edx
c01c0e8a: 89 9b 8c 00 00 00 mov %ebx,0x8c(%ebx)
c01c0e90: a1 38 98 28 c0 mov 0xc0289838,%eax
c01c0e95: 01 d0 add %edx,%eax
c01c0e97: 50 push %eax
c01c0e98: 8d 43 7c lea 0x7c(%ebx),%eax
c01c0e9b: 50 push %eax
c01c0e9c: e8 8f 2d f5 ff call c0113c30 <mod_timer>
c01c0ea1: 5f pop %edi
c01c0ea2: 58 pop %eax
c01c0ea3: eb 0f jmp c01c0eb4
<serial8250_startup+0x1bb>
c01c0ea5: 53 push %ebx
c01c0ea6: e8 2e fc ff ff call c01c0ad9 <serial_link_irq_chain>
c01c0eab: 5e pop %esi
c01c0eac: 85 c0 test %eax,%eax
c01c0eae: 0f 85 e6 00 00 00 jne c01c0f9a
<serial8250_startup+0x2a1>
c01c0eb4: 6a 03 push $0x3
c01c0eb6: 6a 03 push $0x3
c01c0eb8: 53 push %ebx
c01c0eb9: e8 fc eb ff ff call c01bfaba <serial_out>
c01c0ebe: 9c pushf
c01c0ebf: 8f 45 f0 popl 0xfffffff0(%ebp)
c01c0ec2: fa cli
c01c0ec3: 83 c4 0c add $0xc,%esp
c01c0ec6: 8b 43 08 mov 0x8(%ebx),%eax
c01c0ec9: f6 43 54 02 testb $0x2,0x54(%ebx)
c01c0ecd: 74 0d je c01c0edc
<serial8250_startup+0x1e3>
c01c0ecf: 85 c0 test %eax,%eax
c01c0ed1: 75 14 jne c01c0ee7
<serial8250_startup+0x1ee>
c01c0ed3: 81 4b 58 00 20 00 00 orl $0x2000,0x58(%ebx)
c01c0eda: eb 0b jmp c01c0ee7
<serial8250_startup+0x1ee>
c01c0edc: 85 c0 test %eax,%eax
c01c0ede: 74 07 je c01c0ee7
<serial8250_startup+0x1ee>
c01c0ee0: 81 4b 58 00 40 00 00 orl $0x4000,0x58(%ebx)
c01c0ee7: ff 73 58 pushl 0x58(%ebx)
c01c0eea: 53 push %ebx
c01c0eeb: e8 7a fd ff ff call c01c0c6a <serial8250_set_mctrl>
c01c0ef0: 6a 02 push $0x2
c01c0ef2: 6a 01 push $0x1
c01c0ef4: 53 push %ebx
c01c0ef5: e8 c0 eb ff ff call c01bfaba <serial_out>
c01c0efa: 6a 05 push $0x5
c01c0efc: 53 push %ebx
c01c0efd: e8 6e eb ff ff call c01bfa70 <serial_in>
c01c0f02: 89 c7 mov %eax,%edi
c01c0f04: 6a 02 push $0x2
c01c0f06: 53 push %ebx
c01c0f07: e8 64 eb ff ff call c01bfa70 <serial_in>
c01c0f0c: 83 c4 24 add $0x24,%esp
c01c0f0f: 89 c6 mov %eax,%esi
c01c0f11: 6a 00 push $0x0
c01c0f13: 6a 01 push $0x1
c01c0f15: 53 push %ebx
c01c0f16: e8 9f eb ff ff call c01bfaba <serial_out>
c01c0f1b: 83 c4 0c add $0xc,%esp
c01c0f1e: 83 e7 40 and $0x40,%edi
c01c0f21: 74 1c je c01c0f3f
<serial8250_startup+0x246>
c01c0f23: 83 e6 01 and $0x1,%esi
c01c0f26: 74 17 je c01c0f3f
<serial8250_startup+0x246>
c01c0f28: 66 8b 83 9e 00 00 00 mov 0x9e(%ebx),%ax
c01c0f2f: a8 02 test $0x2,%al
c01c0f31: 75 14 jne c01c0f47
<serial8250_startup+0x24e>
c01c0f33: 83 c8 02 or $0x2,%eax
c01c0f36: 66 89 83 9e 00 00 00 mov %ax,0x9e(%ebx)
c01c0f3d: eb 08 jmp c01c0f47
<serial8250_startup+0x24e>
c01c0f3f: 66 83 a3 9e 00 00 00 andw $0xfffffffd,0x9e(%ebx)
c01c0f46: fd
c01c0f47: ff 75 f0 pushl 0xfffffff0(%ebp)
c01c0f4a: 9d popf
c01c0f4b: c6 83 a5 00 00 00 05 movb $0x5,0xa5(%ebx)
c01c0f52: 6a 05 push $0x5
c01c0f54: 6a 01 push $0x1
c01c0f56: 53 push %ebx
c01c0f57: e8 5e eb ff ff call c01bfaba <serial_out>
c01c0f5c: 83 c4 0c add $0xc,%esp
c01c0f5f: f6 43 54 02 testb $0x2,0x54(%ebx)
c01c0f63: 74 13 je c01c0f78
<serial8250_startup+0x27f>
c01c0f65: 8b 13 mov (%ebx),%edx
c01c0f67: b0 80 mov $0x80,%al
c01c0f69: 81 e2 e0 0f 00 00 and $0xfe0,%edx
c01c0f6f: 83 ca 1f or $0x1f,%edx
c01c0f72: ee out %al,(%dx)
c01c0f73: e6 80 out %al,$0x80
c01c0f75: ec in (%dx),%al
c01c0f76: e6 80 out %al,$0x80
c01c0f78: 6a 05 push $0x5
c01c0f7a: 53 push %ebx
c01c0f7b: e8 f0 ea ff ff call c01bfa70 <serial_in>
c01c0f80: 6a 00 push $0x0
c01c0f82: 53 push %ebx
c01c0f83: e8 e8 ea ff ff call c01bfa70 <serial_in>
c01c0f88: 6a 02 push $0x2
c01c0f8a: 53 push %ebx
c01c0f8b: e8 e0 ea ff ff call c01bfa70 <serial_in>
c01c0f90: 6a 06 push $0x6
c01c0f92: 53 push %ebx
c01c0f93: e8 d8 ea ff ff call c01bfa70 <serial_in>
c01c0f98: 31 c0 xor %eax,%eax
c01c0f9a: 8d 65 f4 lea 0xfffffff4(%ebp),%esp
c01c0f9d: 5b pop %ebx
c01c0f9e: 5e pop %esi
c01c0f9f: 5f pop %edi
c01c0fa0: 5d pop %ebp
c01c0fa1: c3 ret
c01c0fa2 <serial8250_shutdown>:
c01c0fa2: 55 push %ebp
c01c0fa3: 89 e5 mov %esp,%ebp
c01c0fa5: 56 push %esi
c01c0fa6: 53 push %ebx
c01c0fa7: 8b 5d 08 mov 0x8(%ebp),%ebx
c01c0faa: c6 83 a5 00 00 00 00 movb $0x0,0xa5(%ebx)
c01c0fb1: 6a 00 push $0x0
c01c0fb3: 6a 01 push $0x1
c01c0fb5: 53 push %ebx
c01c0fb6: e8 ff ea ff ff call c01bfaba <serial_out>
c01c0fbb: 9c pushf
c01c0fbc: 5e pop %esi
c01c0fbd: fa cli
c01c0fbe: 83 c4 0c add $0xc,%esp
c01c0fc1: 8b 4b 58 mov 0x58(%ebx),%ecx
c01c0fc4: f6 43 54 02 testb $0x2,0x54(%ebx)
c01c0fc8: 74 11 je c01c0fdb
<serial8250_shutdown+0x39>
c01c0fca: 8b 13 mov (%ebx),%edx
c01c0fcc: 81 e2 e0 0f 00 00 and $0xfe0,%edx
c01c0fd2: 83 ca 1f or $0x1f,%edx
c01c0fd5: ec in (%dx),%al
c01c0fd6: 80 cd 20 or $0x20,%ch
c01c0fd9: eb 03 jmp c01c0fde
<serial8250_shutdown+0x3c>
c01c0fdb: 80 e5 bf and $0xbf,%ch
c01c0fde: 89 4b 58 mov %ecx,0x58(%ebx)
c01c0fe1: ff 73 58 pushl 0x58(%ebx)
c01c0fe4: 53 push %ebx
c01c0fe5: e8 80 fc ff ff call c01c0c6a <serial8250_set_mctrl>
c01c0fea: 58 pop %eax
c01c0feb: 5a pop %edx
c01c0fec: 56 push %esi
c01c0fed: 9d popf
c01c0fee: 6a 03 push $0x3
c01c0ff0: 53 push %ebx
c01c0ff1: e8 7a ea ff ff call c01bfa70 <serial_in>
c01c0ff6: 83 e0 bf and $0xffffffbf,%eax
c01c0ff9: 59 pop %ecx
c01c0ffa: 5e pop %esi
c01c0ffb: 50 push %eax
c01c0ffc: 6a 03 push $0x3
c01c0ffe: 53 push %ebx
c01c0fff: e8 b6 ea ff ff call c01bfaba <serial_out>
c01c1004: 83 c4 0c add $0xc,%esp
c01c1007: f6 83 9d 00 00 00 01 testb $0x1,0x9d(%ebx)
c01c100e: 74 27 je c01c1037
<serial8250_shutdown+0x95>
c01c1010: 6a 01 push $0x1
c01c1012: 6a 02 push $0x2
c01c1014: 53 push %ebx
c01c1015: e8 a0 ea ff ff call c01bfaba <serial_out>
c01c101a: 83 c4 0c add $0xc,%esp
c01c101d: 6a 07 push $0x7
c01c101f: 6a 02 push $0x2
c01c1021: 53 push %ebx
c01c1022: e8 93 ea ff ff call c01bfaba <serial_out>
c01c1027: 83 c4 0c add $0xc,%esp
c01c102a: 6a 00 push $0x0
c01c102c: 6a 02 push $0x2
c01c102e: 53 push %ebx
c01c102f: e8 86 ea ff ff call c01bfaba <serial_out>
c01c1034: 83 c4 0c add $0xc,%esp
c01c1037: 6a 00 push $0x0
c01c1039: 53 push %ebx
c01c103a: e8 31 ea ff ff call c01bfa70 <serial_in>
c01c103f: 83 7b 08 00 cmpl $0x0,0x8(%ebx)
c01c1043: 58 pop %eax
c01c1044: 5a pop %edx
c01c1045: 75 0b jne c01c1052
<serial8250_shutdown+0xb0>
c01c1047: 8d 43 7c lea 0x7c(%ebx),%eax
c01c104a: 50 push %eax
c01c104b: e8 09 2c f5 ff call c0113c59 <del_timer>
c01c1050: eb 06 jmp c01c1058
<serial8250_shutdown+0xb6>
c01c1052: 53 push %ebx
c01c1053: e8 14 fb ff ff call c01c0b6c
<serial_unlink_irq_chain>
c01c1058: 5e pop %esi
c01c1059: 8d 65 f8 lea 0xfffffff8(%ebp),%esp
c01c105c: 5b pop %ebx
c01c105d: 5e pop %esi
c01c105e: 5d pop %ebp
c01c105f: c3 ret
Disassembly of section .init.text:
Disassembly of section .altinstr_replacement:
Disassembly of section .exit.text:
