03.應用程序調試

1、應用調試1：使用strace命令來跟蹤系統調用
1.strace移植

cd /work/debug/strace-4.5.15

tar xjf strace-4.5.15.tar.bz2

cd strace-4.5.15

patch -p1 ../strace-fix-arm-bad-syscall.patch

配置

./configure --host=arm-linux CC=arm-linux-gcc

編譯

make

會生成一個strace的可執行文件，將其複製到文件系統的/bin目錄下便可。

2.程序測試

strace -o log.txt ./firstdrvtest on

vi log.txt能夠獲得如下結果

 1 execve("./firstdrvtest", ["./firstdrvtest", "on"], [/* 7 vars */]) = 0
 2 uname({sys="Linux", node="(none)", ...}) = 0
 3 brk(0)                                  = 0x11000
 4 access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
 5 open("/etc/ld.so.cache", O_RDONLY)      = -1 ENOENT (No such file or directory)
 6 open("/lib/v4l/half/libc.so.6", O_RDONLY) = -1 ENOENT (No such file or directory
 7 stat64("/lib/v4l/half", 0xbea5e4f0)     = -1 ENOENT (No such file or directory)
 8 open("/lib/v4l/libc.so.6", O_RDONLY)    = -1 ENOENT (No such file or directory)
 9 stat64("/lib/v4l", 0xbea5e4f0)          = -1 ENOENT (No such file or directory)
10 open("/lib/half/libc.so.6", O_RDONLY)   = -1 ENOENT (No such file or directory)
11 stat64("/lib/half", 0xbea5e4f0)         = -1 ENOENT (No such file or directory)
12 open("/lib/libc.so.6", O_RDONLY)        = 3
13 read(3, "\177ELF\1\1\1a\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\330o\1\000"..., 512) = 51
14 fstat64(3, {st_mode=S_IFREG|0755, st_size=1435660, ...}) = 0
15 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40
16 mmap2(NULL, 1150612, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x4
17 mprotect(0x40129000, 56980, PROT_NONE)  = 0
18 mmap2(0x40131000, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRI
19 mmap2(0x40135000, 7828, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOU
20 close(3)                                = 0
21 open("/dev/xyz", O_RDWR)                = 3
22 write(3, "\1\0\0\0", 4)                 = 0
23 exit_group(0)                           = ?

測試程序

分析可知程序出錯都是因爲沒有相對應的文件所形成的，並且使用這種方法調試比較直觀。

2、應用調試2：使用GDB來調試應用程序編譯gdb,gdbservertar xjf gdb-7.4.tar.bz2cd gdb-7.4/./configure --target=arm-linuxmake把arm-linux-gdb複製到/bin目錄cd gdb/gdbserver/./configure --host=arm-linuxcp gdbserver /work/nfs_root/first_fs/bin編譯要調試的應用，編譯時加上-g選項調試：1. 在ARM板上gdbserver 192.168.1.17:2345 ./test_debug 2. 在PC上/bin/arm-linux-gdb ./test_debug輸入：target remote 192.168.1.17:2345而後: 使用gdb命令來控制程序另外一種方法：讓程序在開發板上直接運行，當它發生錯誤時，令它產生core dump文件而後使用gdb根據core dump文件找到發生錯誤的地方在ARM板上：1. ulimit -c unlimited2. 執行應用程序 : 程序出錯時會在當前目錄下生成名爲core的文件在PC上：3. /bin/arm-linux-gdb ./test_debug ./core 3、應用調試3：配置內核輸出應用程序的段錯誤信息arch/arm/mm/fault.c__do_user_fault(struct task_struct *tsk, unsigned long addr,        unsigned int fsr, unsigned int sig, int code,        struct pt_regs *regs){    struct siginfo si;#ifdef CONFIG_DEBUG_USER   // 1. 配置內核    if (user_debug & UDBG_SEGV) {        printk(KERN_DEBUG "%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",               tsk->comm, sig, addr, fsr);        show_pte(tsk->mm, addr);        show_regs(regs);    }#endif2. uboot: set bootargs user_debug=0xffset bootargs console=ttySAC0 root=/dev/nfs nfsroot=192.168.1.123:/work/nfs_root/first_fs ip=192.168.1.17 ipaddr=192.168.1.17 user_debug=0xff3. 執行APP./test_debug a = 0x12pgd = c04c8000[00000000] *pgd=33d08031, *pte=00000000, *ppte=00000000Pid: 772, comm:           test_debugCPU: 0    Not tainted  (2.6.22.6 #1)PC is at 0x84acLR is at 0x84d0pc : [<000084ac>]    lr : [<000084d0>]    psr: 60000010sp : bed9fe40  ip : bed9fe54  fp : bed9fe50r10: 4013365c  r9 : 00000000  r8 : 00008514r7 : 00000001  r6 : 000085cc  r5 : 00008568  r4 : bed9fec4r3 : 00000012  r2 : 00000000  r1 : 00001000  r0 : 00000000Flags: nZCv  IRQs on  FIQs on  Mode USER_32  Segment userControl: c000717f  Table: 304c8000  DAC: 00000015[<c002cd1c>] (show_regs+0x0/0x4c) from [<c0031a98>] (__do_user_fault+0x5c/0xa4) r4:c04a6840[<c0031a3c>] (__do_user_fault+0x0/0xa4) from [<c0031d38>] (do_page_fault+0x1dc/0x20c) r7:c00261e0 r6:c0024cf8 r5:c04a6840 r4:ffffffec[<c0031b5c>] (do_page_fault+0x0/0x20c) from [<c002b224>] (do_DataAbort+0x3c/0xa0)[<c002b1e8>] (do_DataAbort+0x0/0xa0) from [<c002be48>] (ret_from_exception+0x0/0x10)Exception stack(0xc3e7bfb0 to 0xc3e7bff8)bfa0:                                     00000000 00001000 00000000 00000012 bfc0: bed9fec4 00008568 000085cc 00000001 00008514 00000000 4013365c bed9fe50 bfe0: bed9fe54 bed9fe40 000084d0 000084ac 60000010 ffffffff                    r8:00008514 r7:00000001 r6:000085cc r5:00008568 r4:c039bfc8Segmentation faultStack: 00000000 becd3e64 becd3e54 000084d0 000084a0 00000000 becd3e78 becd3e68 C's sp                     return addr       B's sp000084f0 000084c4 00000000 becd3e98 becd3e7c 00008554 000084e4 00000000 ret addr          A's sp                     ret addr          main's sp00000012 becd3ec4 00000001 00000000 becd3e9c 40034f14 00008524 00000000                                              ret addr          caller's sp                                             對於動態連接，已經退出的程序很差肯定動態庫的地址00000000 0000839c 00000000 00000000 4001d594 000083c4 000085cc 4000c02c becd3ec4 becd3f7b 00000000 becd3f88 becd3f92 becd3f99 becd3fad becd3fb8 becd3fdb becd3fe9 00000000 00000010 00000003 00000006 00001000 00000011 00000064 00000003 00008034 00000004 00000020 00000005 00000006 00000007 40000000 00000008 00000000 00000009 0000839c 0000000b 00000000 0000000c 00000000 0000000d 00000000 0000000e 00000000 00000017 00000000 0000000f becd3f77 00000000 00000000 00000000 00000000 76000000 2e006c34 7365742f 65645f74 00677562 52455355 6f6f723d 4f480074 2f3d454d 61706900 3d726464 2e323931 2e383631 37312e31 52455400 74763d4d 00323031 48544150 62732f3d 2f3a6e69 2f727375 6e696273 69622f3a 752f3a6e 622f7273 53006e69 4c4c4548 69622f3d 68732f6e 44575000 2e002f3d 7365742f 65645f74 00677562 00000000 4. 反彙編app:arm-linux-objdump -D test_debug > test_debug.dis對於靜態連接的test_debugPC is at 0x81e0LR is at 0x8204pc : [<000081e0>]    lr : [<00008204>]    psr: 60000010sp : be93dc60  ip : be93dc74  fp : be93dc70r10: 000085f4  r9 : 00008248  r8 : be93deb4r7 : 00000001  r6 : 00000000  r5 : be93dd3e  r4 : 00000000r3 : 00000012  r2 : 00000000  r1 : 00001000  r0 : 00000000Flags: nZCv  IRQs on  FIQs on  Mode USER_32  Segment userStack: 00000000 be93dc84 be93dc74 00008204 000081d4 00000000 be93dc98 be93dc88 C'sp                       ret addr          B'sp 00008224 000081f8 00000000 be93dcb8 be93dc9c 00008288 00008218 00000000 ret addr          A'sp                       ret addr          main'sp00000012 be93deb4 00000001 00000000 be93dcbc 000084ac 00008258 756e694c                                              ret addr          __libc_start_main'sp00000078 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 32393100 3836312e 312e312e 00000037 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 2e320000 32322e36 0000362e 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 23000000 54203335 4d206575 31207961 31322035 3a34303a 43203834 32205453 00323130 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 766d7261 006c7434 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 6f6e2800 0029656e 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 000080f8 00008680 00000000 be93deb4 be93df6a 00000000 be93df77 be93df81 be93df92 be93df99 be93dfad be93dfb8 be93dfdb be93dfe9 00000000 00000010 00000003 00000006 00001000 00000011 00000064 00000003 00008034 00000004 00000020 00000005 00000003 00000007 00000000 00000008 00000000 00000009 000080d0 0000000b 00000000 0000000c 00000000 0000000d 00000000 0000000e 00000000 00000017 00000000 0000000f be93df66 00000000 00000000 00000000 34760000 2f2e006c 74736574 6265645f 55006775 3d524553 746f6f72 444c4f00 3d445750 6f72702f 34372f63 4f480033 2f3d454d 61706900 3d726464 2e323931 2e383631 37312e31 52455400 74763d4d 00323031 48544150 62732f3d 2f3a6e69 2f727375 6e696273 69622f3a 752f3a6e 622f7273 53006e69 4c4c4548 69622f3d 68732f6e 44575000 2e002f3d 7365742f 65645f74 00677562 00000000 4、應用調試4：自制系統調用、編寫進程查看器把29th_app_system_call\kernel裏的文件複製到內核目錄syscalls.h    ==> include/linuxread_write.c  ==> fs/calls.S       ==> arch/arm/kernel5、應用調試5：編寫輸入模擬器1. 產品要通過測試才能發佈，通常都是人工操做，好比手機觸摸屏、遙控器2. 操做過程當中發現錯誤，要再次復現，找到規律，修改程序3. 可否在驅動程序裏把全部的操做記錄下來，存爲文件   當出錯時，能夠經過文件裏的數據來"復現"輸入      input_event