Bug #1047
closed
ksh overwrites child core files
100%
Description
This script:
#!/bin/sh find . -name '*.[ch]' -print | sort
Run with these environment settings:
LANG=en_US.UTF-8
LC_COLLATE=C
and run in this illumos directory:
$ cd $SRC/cmd/smbsrv
$ ~/bin/findch
Memory fault(coredump)
$ file core
core: ELF 32-bit LSB core file 80386 Version 1, from 'findch'
$ mdb core
08047858 libc_hwcap1.so.1`kill+0x15(fee07bb0, 0, a, fedb01c5)
08047938 libshell.so.1`sh_main+0x840(2, 8047998, 0, fee6e9f2, 4, 0)
08047968 main+0x4a(2, 8047998, 80479a4, 804798c)
0804798c _start+0x7d(2, 8047ab8, 8047ac0, 0, 8061210, 8047af9)
After using coreadm as follows:
coreadm -i core.%p
one can observe that the real reason for this core was
the child (sort) having dumped core, after which ksh
does a kill(2) of itself with the signal from the child.
[alanc reports this is 7008357]
The reason for the child core was
https://www.illumos.org/issues/1046
ksh should avoid making itself dump core here.
Related issues
Updated by Gordon Ross about 12 years ago
- Subject changed from ksh script (find|sort) core dump to ksh overwrites child core files
This appears to be in libshell : fault.c 630
if(savxit&SH_EXITSIG)
sig = savxit&SH_EXITMASK;
if(sig)
{
/* generate fault termination code */
signal(sig,SIG_DFL);
sigrelease(sig);
kill(getpid(),sig);
pause();
}
Updated by Gordon Ross about 12 years ago
ksh93 appears to have fixed this by doing an "rlimit core 0"
before sending itself the fatal signal from the child status.
--- a/usr/src/lib/libshell/common/sh/fault.c Tue Apr 13 14:24:21 2010
+++ b/usr/src/lib/libshell/common/sh/fault.c Wed Mar 9 22:04:01 2011
@@ -632,6 +645,17 @@
if(sig)
{
/* generate fault termination code */
+ if(RLIMIT_CORE!=RLIMIT_UNKNOWN)
+ {
+#ifdef _lib_getrlimit
+ struct rlimit rlp;
+ getrlimit(RLIMIT_CORE,&rlp);
+ rlp.rlim_cur = 0;
+ setrlimit(RLIMIT_CORE,&rlp);
+#else
+ vlimit(RLIMIT_CORE,0);
+#endif
+ }
signal(sig,SIG_DFL);
sigrelease(sig);
kill(getpid(),sig);
Updated by Andy Fiddaman over 2 years ago
- Related to Feature #13405: ksh93 update to 2012-08-01 added
Updated by Electric Monk over 2 years ago
- Status changed from New to Closed
- % Done changed from 0 to 100
git commit b30d193948be5a7794d7ae3ba0ed9c2f72c88e0f
commit b30d193948be5a7794d7ae3ba0ed9c2f72c88e0f
Author: Andy Fiddaman <omnios@citrus-it.co.uk>
Date: 2021-01-30T17:13:33.000Z
13405 ksh93 update to 2012-08-01
13434 sh: mishandles backslash as last character of a block of input
11750 ksh mkdir builtin doesn't honor special file permissions
9199 ksh93 builtin *grep -v mishandles blank lines, blows up libgcrypt-config
6756 sh (and ksh) have issues with ${1+"$@"}
6520 ksh: sleep could wait forever
4860 ksh93: core in printf
3791 /bin/sh's builtin 'rm' busted: 'rm -f' without arguments returns error
1047 ksh overwrites child core files
880 ksh93 coredumps on 'unset'
499 "interrupted system call" when using "tee" builtin in ksh
Reviewed by: Robert Mustacchi <rm@fingolfin.org>
Reviewed by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Reviewed by: Dominik Hassler <hadfl@omnios.org>
Approved by: Rich Lowe <richlowe@richlowe.net>