Date: Sun, 1 Sep 2013 20:52:23 +1000 (EST) From: Peter Jeremy <peterj@freebsd.org> To: FreeBSD-gnats-submit@freebsd.org Subject: arm/181722: gdb on ARM unable to sensibly debug core file from assert(3) Message-ID: <201309011052.r81AqNiV096349@server.rulingia.com> Resent-Message-ID: <201309011100.r81B00T2008112@freefall.freebsd.org>
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>Number: 181722
>Category: arm
>Synopsis: gdb on ARM unable to sensibly debug core file from assert(3)
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-arm
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Sep 01 11:00:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator: Peter Jeremy
>Release: FreeBSD 10.0-CURRENT arm
>Organization:
n/a
>Environment:
System: FreeBSD rpi1.rulingia.com 10.0-CURRENT FreeBSD 10.0-CURRENT #0: Mon Jul 8 19:45:57 UTC 2013 root@rpi1.rulingia.com:/usr/obj/usr/src/sys/RPI-PJ arm
>Description:
Whilst trying to build head r254986 with clang on my Raspberry Pi,
I consistently get an assertion failure and core file. Attempting
to examine the core file with gdb gives a truncated backtrace (see
below). If clang is run under gdb, setting a breakpoint at
__assert, correct backtraces are shown.
root@rpi1:/a # gdb /a/obj/usr/src/tmp/usr/bin/cc cc.core
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "armv6-marcel-freebsd"...
Core was generated by `cc'.
Program terminated with signal 6, Aborted.
#0 0x01f92094 in kill ()
(gdb) where
#0 0x01f92094 in kill ()
#1 0x01f92038 in raise ()
#2 0x01f901a0 in abort ()
#3 0x01f7b55c in __assert ()
#4 0x01f7b55c in __assert ()
(gdb)
...
(gdb) up
#4 0x01f7b55c in __assert ()
(gdb) info regi
r0 0x0 0
r1 0x0 0
r2 0x0 0
r3 0xffffffdf -33
r4 0x0 0
r5 0xbfffcb74 -1073755276
r6 0x3 3
r7 0x57 87
r8 0x228152b8 578900664
r9 0x2284fb00 579140352
r10 0x22876000 579297280
r11 0xbfffcba8 -1073755224
r12 0xbfffcb94 -1073755244
sp *value not available*
lr 0x1f7b55c 33011036
pc 0x1f7b55c 33011036
fps 0x0 0
cpsr 0x80000010 -2147483632
(gdb) disas 0x1f7b55c
Dump of assembler code for function $d:
0x01f7b55c <$d+0>: eorseq r8, r11, #12845056 ; 0xc40000
0x01f7b560 <$d+4>: eorseq r3, r10, #16515072 ; 0xfc0000
0x01f7b564 <$d+8>: eorseq r3, r10, #655360 ; 0xa0000
End of assembler dump.
(gdb) disas __assert
Dump of assembler code for function __assert:
0x01f7b4fc <__assert+0>: mov r12, sp
0x01f7b500 <__assert+4>: push {r11, r12, lr, pc}
0x01f7b504 <__assert+8>: sub r11, r12, #4 ; 0x4
0x01f7b508 <__assert+12>: sub sp, sp, #8 ; 0x8
0x01f7b50c <__assert+16>: mov lr, r1
0x01f7b510 <__assert+20>: mov r4, r3
0x01f7b514 <__assert+24>: subs r12, r0, #0 ; 0x0
0x01f7b518 <__assert+28>: bne 0x1f7b53c <__assert+64>
0x01f7b51c <__assert+32>: ldr r3, [pc, #56] ; 0x1f7b55c <$d>
0x01f7b520 <__assert+36>: ldr r0, [r3]
0x01f7b524 <__assert+40>: str r2, [sp]
0x01f7b528 <__assert+44>: ldr r1, [pc, #48] ; 0x1f7b560 <$d+4>
0x01f7b52c <__assert+48>: mov r2, r4
0x01f7b530 <__assert+52>: mov r3, lr
0x01f7b534 <__assert+56>: bl 0x1f7b6c0 <fprintf>
0x01f7b538 <__assert+60>: b 0x1f7b558 <__assert+92>
0x01f7b53c <__assert+64>: ldr r3, [pc, #24] ; 0x1f7b55c <$d>
0x01f7b540 <__assert+68>: ldr r0, [r3]
0x01f7b544 <__assert+72>: stm sp, {r1, r2}
0x01f7b548 <__assert+76>: ldr r1, [pc, #20] ; 0x1f7b564 <$d+8>
0x01f7b54c <__assert+80>: mov r2, r4
0x01f7b550 <__assert+84>: mov r3, r12
0x01f7b554 <__assert+88>: bl 0x1f7b6c0 <fprintf>
0x01f7b558 <__assert+92>: bl 0x1f90104 <abort>
End of assembler dump.
(gdb) x/20x $r12
0xbfffcb94: Cannot access memory at address 0xbfffcb94
(gdb)
>How-To-Repeat:
$ cat <<E*O*F > /tmp/test.i
extern void __stack_chk_fail (void);
void
__attribute__((visibility ("hidden")))
__stack_chk_fail_local (void)
{
__stack_chk_fail ();
}
E*O*F
$ clang -cc1 -triple armv6--freebsd10.0-gnueabi -S -disable-free -main-file-name ssp-local.c -mrelocation-model pic -pic-level 2 -mdisable-fp-elim -mconstructor-aliases -target-abi aapcs-linux -target-cpu arm1136jf-s -msoft-float -mfloat-abi soft -target-feature +soft-float -target-feature +soft-float-abi -target-feature -neon -g -coverage-file /tmp/test.s -O2 -std=gnu99 -fno-dwarf-directory-asm -fdebug-compilation-dir /usr/obj/usr/src/gnu/lib/libssp/libssp_nonshared -ferror-limit 19 -fmessage-length 168 -fvisibility hidden -mstackrealign -fno-signed-char -fobjc-runtime=gnustep -fobjc-default-synthesize-properties -fdiagnostics-show-option -fcolor-diagnostics -backend-option -vectorize-loops -o /tmp/test.s -x c /tmp/test.i
$ gdb clang clang.core
(gdb) where
>Fix:
Unknown.
>Release-Note:
>Audit-Trail:
>Unformatted:
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