Re: NetBSD-10.0/i386 spurious SIGSEGV

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Sun, Jun 09, 2024 at 08:44:19AM -0400, Mouse wrote:
> Okay, this is strictly a debugging workaround: how about building a
> kernel with code added so that, whenever a SIGSEGV is delivered, the
> siginfo is printed on the console?

Latest SIGSEGV on nagios:
   0xbb610570 <__gettimeofday50>:       mov    $0x1a2,%eax
   0xbb610575 <__gettimeofday50+5>:     int    $0x80
   0xbb610577 <__gettimeofday50+7>:     jb     0xbb61057a <__gettimeofday50+10>
   0xbb610579 <__gettimeofday50+9>:     ret    
=> 0xbb61057a <__gettimeofday50+10>:    push   %ebx

I enabled TRAP_SIGDEBUG in src/sys/arch/i386/i386/trap.c and here is what
it says:

pid 853.853 (nagios): signal 11 code=1 (trap 6) @eip 0xbb61057a addr 0x7513f5a9 error=14
trapframe 0xdd351fa8
eip 0xbb61057a  esp 0xbf7fdf34  efl 0x00010217
edi 0xb9a56b80  esi 0xb9be2380  edx 0x00000000
ecx 0xb9a56b8b
ebp 0xbf7fdf50  ebx 0xbf7fdfa0  eax 0x00000000
cs 0x0017  ds 0x001f  es 0x001f  fs 0x00ab  gs 0x00b3  ss 0x001f
fsbase 0x00cff3000000ffff gsbase 0xbbcff36e89b4ffff

Stack dump: 256 bytes @ 0xdd351fa8
b3 00 00 00 ab 00 00 00  1f 00 00 00 1f 00 7f bf | ................
80 6b a5 b9 80 23 be b9  50 df 7f bf a0 df 7f bf | .k...#..P.......
00 00 00 00 8b 6b a5 b9  00 00 00 00 06 00 00 00 | .....k..........
04 00 00 00 7a 05 61 bb  17 00 00 00 17 02 01 00 | ....z.a.........
34 df 7f bf 1f 00 00 00  00 00 00 00 00 00 00 00 | 4...............
00 00 00 00 00 00 00 00  f0 3f 35 dd b0 3c 35 dd | .........?5..<5.
f4 3c 35 dd 00 00 00 00  f0 e9 c5 ba 00 20 a7 00 | .<5.......... ..
01 00 00 00 ff ff 00 00  00 f3 cf 00 ff ff b4 39 | ...............9
e6 f3 cf ba 00 00 00 00  00 00 00 00 00 00 00 00 | ................
7f 03 00 00 00 00 00 00  00 00 00 00 00 00 00 00 | ................
00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 | ................
00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 | ................
00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 | ................
00 00 00 00 00 00 00 00  7f 03 00 00 00 00 00 00 | ................
00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 | ................
80 1f 00 00 ff ff 00 00  00 00 00 00 00 00 00 00 | ................


-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost