Hi
I don't exactly know but:
objdump -sx xx.o :
ucAsserv.o: file format elf32-big
ucAsserv.o
architecture: UNKNOWN!, flags 0x00000011:
HAS_RELOC, HAS_SYMS
start address 0x00000000
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 00000058 00000000 00000000 00000034 2**2
CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
1 .data 00000000 00000000 00000000 0000008c 2**2
CONTENTS, ALLOC, LOAD, DATA
2 .bss 0000000c 00000000 00000000 0000008c 2**2
ALLOC
3 .modinfo 00000045 00000000 00000000 0000008c 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 .rodata 00000019 00000000 00000000 000000d1 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
5 .comment 000000a6 00000000 00000000 000000ea 2**0
CONTENTS, READONLY
SYMBOL TABLE:
00000000 l df *ABS* 00000000 ucAsserv.c
00000000 l d .text 00000000 .text
00000000 l d .data 00000000 .data
00000000 l d .bss 00000000 .bss
00000000 l .text 00000000 gcc2_compiled.
00000000 l d .modinfo 00000000 .modinfo
00000000 l O .modinfo 00000021 __module_kernel_version
00000000 l d .rodata 00000000 .rodata
00000008 l O .bss 00000004 VitL
00000004 l O .bss 00000004 global_left_encoder
00000000 l O .bss 00000004 global_right_encoder
00000039 l O .modinfo 0000000c __module_license
00000000 l d .comment 00000000 .comment
00000000 g F .text 00000050 init_module
00000000 *UND* 00000000 printk
00000050 g F .text 00000008 cleanup_module
00000021 g O .modinfo 00000018 __module_author
RELOCATION RECORDS FOR [.text]:
OFFSET TYPE VALUE
00000006 UNKNOWN .bss+0x00000008
0000000c UNKNOWN .bss+0x00000004
00000012 UNKNOWN .bss
00000018 UNKNOWN .rodata
0000001e UNKNOWN printk
00000026 UNKNOWN .bss+0x00000004
0000002e UNKNOWN .bss
00000034 UNKNOWN .bss+0x00000008
0000003a UNKNOWN .rodata+0x00000009
00000040 UNKNOWN printk
Contents of section .text:
0000 4e560000 42b90000 000042b9 00000000 NV..B.....B.....
0010 42b90000 00004879 00000000 4eb90000 B.....Hy....N...
0020 0000588f 20390000 00004c39 08000000 ..X. 9....L9....
0030 000023c0 00000000 48790000 00004eb9 ..#.....Hy....N.
0040 00000000 588f4280 60000002 4e5e4e75 ....X.B.`...N^Nu
0050 4e560000 4e5e4e75 NV..N^Nu
Contents of section .modinfo:
0000 6b65726e 656c5f76 65727369 6f6e3d32 kernel_version=2
0010 2e342e33 312d7563 302d414e 492d3130 .4.31-uc0-ANI-10
0020 00617574 686f723d 53746570 68616e65 .author=Stephane
0030 20476572 6d61696e 006c6963 656e7365 Germain.license
0040 3d47504c 00 =GPL.
Contents of section .rodata:
0000 3c363e42 75673a0a 003c363e 4e657665 <6>Bug:..<6>Neve
0010 72205265 6163680a 00 r Reach..
Contents of section .comment:
0000 00474343 3a202847 4e552920 322e3935 .GCC: (GNU) 2.95
0010 2e332032 30303130 33313520 2872656c .3 20010315 (rel
0020 65617365 2928436f 6c644669 72652070 ease)(ColdFire p
0030 61746368 6573202d 20323030 31303331 atches - 2001031
0040 38206672 6f6d2068 7474703a 2f2f6669 8 from http://fi
0050 64646573 2e6e6574 2f636f6c 64666972 ddes.net/coldfir
0060 652f2928 75436c69 6e757820 58495020 e/)(uClinux XIP
0070 616e6420 73686172 6564206c 69622070 and shared lib p
0080 61746368 65732066 726f6d20 68747470 atches from http
0090 3a2f2f77 77772e73 6e617067 6561722e ://www.snapgear.
00a0 636f6d2f 2900 com/).
Wolfgang Reissnegger a écrit :
> Hi Stéphane,
>
> can you also generate an objdump of the module and post it?
>
> Stéphane wrote:
>> Hmm,
>>
>> In Makefile:
>>
>> /********************/
>>
>> INCLUDE := -isystem ../uClinux-dist-20060803/linux-2.4.x/include
>> CFLAGS := -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE}
>> CC := /opt/uClinux-m68k-elf/bin/m68k-elf-gcc
>> ${TARGET}.o: ${TARGET}.c
>>
>> /************************/
>>
>> and with -S :
>>
>> /*****************************************/
>>
>> .file "ucAsserv.c"
>> gcc2_compiled.:
>> .section .modinfo,"a",@progbits
>> .type __module_kernel_version,@object
>> .size __module_kernel_version,33
>> __module_kernel_version:
>> .string "kernel_version=2.4.31-uc0-ANI-10"
>> .section .rodata
>> .LC0:
>> .string "<6>Bug:\n"
>> .LC1:
>> .string "<6>Never Reach\n"
>> .text
>> .align 2
>> .globl init_module
>> .type init_module,@function
>> init_module:
>> link.w %a6,#0
>> clr.l VitL
>> clr.l global_left_encoder
>> clr.l global_right_encoder
>> pea .LC0
>> jsr printk
>> addq.l #4,%sp
>> move.l global_left_encoder,%d0
>> muls.l global_right_encoder,%d0
>> move.l %d0,VitL
>> pea .LC1
>> jsr printk
>> addq.l #4,%sp
>> clr.l %d0
>> jbra .L95
>> .align 2
>> .L95:
>> unlk %a6
>> rts
>> .Lfe1:
>> .size init_module,.Lfe1-init_module
>> .align 2
>> .globl cleanup_module
>> .type cleanup_module,@function
>> cleanup_module:
>> link.w %a6,#0
>> .L96:
>> unlk %a6
>> rts
>> .Lfe2:
>> .size cleanup_module,.Lfe2-cleanup_module
>> .globl __module_author
>> .section .modinfo
>> .type __module_author,@object
>> .size __module_author,24
>> __module_author:
>> .string "author=Stephane Germain"
>> .type __module_license,@object
>> .size __module_license,12
>> __module_license:
>> .string "license=GPL"
>> .local global_right_encoder
>> .comm global_right_encoder,4,2
>> .local global_left_encoder
>> .comm global_left_encoder,4,2
>> .local VitL
>> .comm VitL,4,2
>> .ident "GCC: (GNU) 2.95.3 20010315 (release)(ColdFire patches -
>> 20010318 from
>> http://fiddes.net/coldfire/)(uClinux XIP and shared lib patches from
>> http://www.snapgear.com/)"
>>
>> /***************************************************/
>>
>>
>> I use the default toolchain
>>
>> /opt/uClinux-m68k-elf/bin/m68k-elf-gcc -v :
>> Reading specs from
>> /opt/uClinux-m68k-elf/lib/gcc-lib/m68k-elf/2.95.3/specs
>> gcc version 2.95.3 20010315 (release)(ColdFire patches - 20010318 from
>> http://fiddes.net/coldfire/)(uClinux XIP
>> and shared lib patches from http://www.snapgear.com/)
>>
>> thanks
>>
>>
>> Wolfgang Reissnegger a écrit :
>>> Hi Stéphane,
>>>
>>> looks like you are compiling your code with compiler flags that
>>> generate instructions that the processor does not support. That's why
>>> you see the illegal instruction trap.
>>>
>>> The reason that it all works if the variables are local is probably
>>> that you also use an optimization flag (e.g. -O3) that causes the
>>> compiler to optimize the whole multiplication away in main because it
>>> has no effect on the function's result and is local to the function.
>>>
>>> You should try to compile the code with gcc -S to generate assembler
>>> output. Then you can identify the instruction that causes the problem.
>>>
>>> Cheers,
>>> Wolfgang
>>>
>>> Stéphane wrote:
>>>> Hi,
>>>>
>>>> I have a bug that I can be resume as:
>>>>
>>>> /***************************/
>>>> #include <linux/module.h> // Needed by all modules
>>>> #include <linux/kernel.h> // Needed for KERN_INFO
>>>>
>>>> static long global_right_encoder;
>>>> static long global_left_encoder;
>>>> static long VitL;
>>>>
>>>> int init_module(void)
>>>> {
>>>> VitL = 0;
>>>> global_left_encoder = 0;
>>>> global_right_encoder = 0;
>>>>
>>>> printk(KERN_INFO "Bug:\n");
>>>> VitL = global_left_encoder*global_right_encoder;
>>>> printk(KERN_INFO "Never Reach\n");
>>>> return 0;
>>>> }
>>>>
>>>>
>>>> void cleanup_module(void)
>>>> {
>>>> }
>>>>
>>>> MODULE_AUTHOR("Stephane Germain");
>>>> MODULE_LICENSE("GPL");
>>>> /**********************************/
>>>>
>>>> result:
>>>>
>>>> insmod xxx.o:
>>>> SIGSEGV
>>>>
>>>> dmesg:
>>>> Bug:
>>>> *** ILLEGAL INSTRUCTION *** FORMAT=0
>>>> Current process id is 47
>>>> BAD KERNEL TRAP: 00000000
>>>> PC: [<000a8bec>]
>>>> SR: 2014 SP: 007dbee8 a2: 10c16b34
>>>> d0: 00000000 d1: 00000991 d2: 00000000 d3: ffffffea
>>>> d4: 00000060 d5: 00000008 a0: 0003dc8c a1: 0003dca8
>>>> Process insmod (pid: 47, stackpage=007db000)
>>>> Frame format=0
>>>> Stack from 007dbf1c:
>>>> 000a8c14 007d3000 007dbfc4 10c17856 007c5348 00102428 007c5348
>>>> 000000e8
>>>> 00000002 00000001 007da000 00192e00 007c51c0 00190004 00140560
>>>> 0015fae0
>>>> 007d3000 007d4000 00000060 0003dd58 000a8bc0 000000e8 00000000
>>>> 00000000
>>>> 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>>>> 00000000
>>>> 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>>>> 00000000
>>>> 00000000 00000000 0019fdc8 10c127d2 00192e00 007c5348 00102428
>>>> 007c5348
>>>> Call Trace:
>>>> [<10c17856>] [<10c127d2>]
>>>> Code: 4c39 0800 000a 8c3c 23c0 000a 8c44 4879 000a 8c1d
>>>>
>>>> /*****************************/
>>>>
>>>>
>>>> if the variables are local, all work!
>>>>
>>>> Somebody know something that I don't about that?
>>>>
>>>> Thanks
>>>>
>>>> Stephane Germain
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>
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