Changes between Version 5 and Version 6 of jazz/09-01-14

Timestamp:

Jan 14, 2009, 3:52:52 PM (16 years ago)

Author:

jazz

Comment:

--

jazz/09-01-14

@@ -21 +21 @@
  * （續 [wiki:jazz/08-11-17 08-11-17@GMT-6 BUGFIX: jfbterm (3)]）
 
+ * 在看 fbcommon.c 時，發現在這組出現錯誤的 mmap 前曾跑過另一組 mmap, 因此把參數印出來對照看看。
+ * gdb debug 程序
+{{{
+file jfbterm
+set args -e ls
+show args
+break fbcommon.c:500
+break fbcommon.c:557
+break fbcommon.c:566
+run
+p fb_fix
+c
+p fb_fix
+c
+p fb_fix.smem_len
+p p->soff
+p p->slen
+p fb_fix.mmem_len
+p p->moff
+p p->mlen
+}}}
+{{{
+This GDB was configured as "x86_64-linux-gnu".
+(gdb) file jfbterm
+Reading symbols from /root/jfbterm-0.4.7-dev/jfbterm...done.
+(gdb) set args -e ls
+(gdb) show args
+Argument list to give program being debugged when it is started is "-e ls".
+(gdb) break fbcommon.c:500
+Breakpoint 1 at 0x40303d: file fbcommon.c, line 500.
+(gdb) break fbcommon.c:557
+Breakpoint 2 at 0x40327e: file fbcommon.c, line 557.
+(gdb) break fbcommon.c:566
+Breakpoint 3 at 0x403301: file fbcommon.c, line 566.
+(gdb) run
+Starting program: /root/jfbterm-0.4.7-dev/jfbterm -e ls
+Breakpoint 1, tfbm_open (p=0x6146e0) at fbcommon.c:501
+501             if (fb_var.yres_virtual != fb_var.yres) {
+(gdb) p fb_fix
+$1 = {id = "▒▒C▒\210\177\000\000\006\000\000\000\000\000\000", smem_start = 30778096, smem_len = 3032756978, type = 32648, type_aux = 0, visual = 0,
+  xpanstep = 65535, ypanstep = 65535, ywrapstep = 65535, line_length = 1, mmio_start = 15, mmio_len = 30816528, accel = 0, reserved = {53071, 64, 0}}
+(gdb) c
+Continuing.
+Breakpoint 2, tfbm_open (p=0x6146e0) at fbcommon.c:557
+557             p->smem = (u_char*)mmap(NULL, p->slen, PROT_READ|PROT_WRITE,
+(gdb) p fb_fix
+$2 = {id = "VESA VGA\000\000\000\000\000\000\000", smem_start = 4026531840, smem_len = 1572864, type = 0, type_aux = 0, visual = 3, xpanstep = 0,
+  ypanstep = 0, ywrapstep = 0, line_length = 1024, mmio_start = 0, mmio_len = 0, accel = 0, reserved = {0, 0, 0}}
+(gdb) c
+Continuing.
+
+Breakpoint 3, tfbm_open (p=0x6146e0) at fbcommon.c:566
+566             if(p->mlen == 0)
+(gdb) p fb_fix.smem_len
+$3 = 1572864
+(gdb) p p->soff
+$4 = 0
+(gdb) p p->slen
+$5 = 1572864
+(gdb) p fb_fix.mmem_len
+There is no member named mmem_len.
+(gdb) p p->moff
+$6 = 0
+(gdb) p p->mlen
+$7 = 0
+(gdb)
+}}}