fix segfault on element removal #102
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when elements' lifetime reaches 0, and program is compiled with debug, bmon
gets a segmentation fault:
Program received signal SIGSEGV, Segmentation fault.
__strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
Downloading 0.00 MB source file /usr/src/debug/glibc-2.34-43.fc35.x86_64/string/../sysdeps/x86_64/multiarch/strlen-avx2.S
74 VPCMPEQ (%rdi), %ymm0, %ymm1
(gdb) bt
#0 __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:74
tgraf#1 0x00007ffff7a84228 in __vfprintf_internal (s=s@entry=0x7fffffffb9f0,
format=0x410f08 "[DBG] %20s:%-4u %s: Deleting dead element %s\n", ap=0x7fffffffdb30, mode_flags=0)
at vfprintf-internal.c:1647
tgraf#2 0x00007ffff7a849ef in buffered_vfprintf (s=0x7ffff7bfb6a0 <_IO_2_1_stderr_>,
format=format@entry=0x410f08 "[DBG] %20s:%-4u %s: Deleting dead element %s\n", args=args@entry=0x7fffffffdb30,
mode_flags=mode_flags@entry=0) at vfprintf-internal.c:2295
tgraf#3 0x00007ffff7a839cb in __vfprintf_internal (s=<optimized out>,
format=0x410f08 "[DBG] %20s:%-4u %s: Deleting dead element %s\n", ap=ap@entry=0x7fffffffdb30,
mode_flags=mode_flags@entry=0) at vfprintf-internal.c:1377
tgraf#4 0x00007ffff7a6f3ca in __fprintf (stream=<optimized out>, format=<optimized out>) at fprintf.c:32
tgraf#5 0x0000000000406339 in __group_foreach_element (g=g@entry=0x422ae0, list=list@entry=0x4da940,
cb=cb@entry=0x407260 <element_check_if_dead>, arg=arg@entry=0x0) at group.c:45
tgraf#6 0x0000000000406351 in __group_foreach_element (g=g@entry=0x422ae0, list=list@entry=0x4d6d40,
cb=cb@entry=0x407260 <element_check_if_dead>, arg=arg@entry=0x0) at group.c:48
tgraf#7 0x0000000000406351 in __group_foreach_element (g=0x422ae0, list=0x422af0, cb=0x407260 <element_check_if_dead>,
arg=arg@entry=0x0) at group.c:48
tgraf#8 0x0000000000406750 in group_foreach_recursive (arg=0x0, cb=<optimized out>) at group.c:67
tgraf#9 free_unused_elements () at group.c:192
tgraf#10 0x00000000004041f0 in main (argc=<optimized out>, argv=0x7fffffffdfb8) at bmon.c:350
(gdb)
this happens because 'e->e_name' is used by 'DBG()' after the call to
element_free(e); calling DBG(...) before element_free() proved to fix the
above crash.
Signed-off-by: Davide Caratti <[email protected]>
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seems related to issue #42.