Re: g_ptr_array_sort crash

[Gyözö Both <gyboth bygfoot com>]

this is the valgrind output (with tool memcheck):


==6098== Invalid read of size 4
==6098==    at 0x807AC54: player_compare_func (player.c:393)
==6098==    by 0x1BD7504D: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0 .400.6)
==6098==    by 0x1BD50B40: g_ptr_array_sort_with_data (in
/opt/gnome/lib/libglib -2.0.so.0.400.6)
==6098==    by 0x805BF3A: game_get_penalty_taker (game.c:200)
==6098==  Address 0x9C61DD78 is not stack'd, malloc'd or (recently)
free'd ==6098== 
==6098== Process terminating with default action of signal 11 (SIGSEGV)
==6098==    at 0x807AC54: player_compare_func (player.c:393)
==6098==    by 0x1BD7504D: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0 .400.6)
==6098==    by 0x1BD50B40: g_ptr_array_sort_with_data (in
/opt/gnome/lib/libglib -2.0.so.0.400.6)
==6098==    by 0x805BF3A: game_get_penalty_taker (game.c:200)

and this with corecheck:

==6123== Process terminating with default action of signal 11 (SIGSEGV)
==6123==  Access not within mapped region at address 0x881C1614
==6123==    at 0x807AC54: player_compare_func (player.c:393)
==6123==    by 0x3ADEF04D: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0.400.6) ==6123==    by 0x3ADCAB40:
g_ptr_array_sort_with_data (in /opt/gnome/lib/libglib-2.0.so.0.400.6)
==6123==    by 0x805BF3A: game_get_penalty_taker (game.c:200)

and addrcheck:

==6138== Invalid read of size 4
==6138==    at 0x807AC52: player_compare_func (player.c:394)
==6138==    by 0x345BAE9B: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0.400.6) ==6138==    by 0x34596B40:
g_ptr_array_sort_with_data (in /opt/gnome/lib/libglib-2.0.so.0.400.6)
==6138==    by 0x805BF3A: game_get_penalty_taker (game.c:200) ==6138== 
Address 0x34E79174 is 4 bytes before a block of size 64 alloc'd ==6138==
   at 0x341492F4: malloc (in /usr/lib/valgrind/vgpreload_addrcheck.so)
==6138==    by 0x34149CF7: realloc (in
/usr/lib/valgrind/vgpreload_addrcheck.so) ==6138==    by 0x345B4C10:
g_realloc (in /opt/gnome/lib/libglib-2.0.so.0.400.6) ==6138==    by
0x34596E17: g_ptr_array_maybe_expand (in
/opt/gnome/lib/libglib-2.0.so.0.400.6) ==6138== 
==6138== Invalid read of size 4
==6138==    at 0x807ACAA: player_compare_func (player.c:404)
==6138==    by 0x345BAE9B: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0.400.6) ==6138==    by 0x34596B40:
g_ptr_array_sort_with_data (in /opt/gnome/lib/libglib-2.0.so.0.400.6)
==6138==    by 0x805BF3A: game_get_penalty_taker (game.c:200) ==6138== 
Address 0xF is not stack'd, malloc'd or (recently) free'd ==6138== 
==6138== Process terminating with default action of signal 11 (SIGSEGV)
==6138==  Access not within mapped region at address 0xF
==6138==    at 0x807ACAA: player_compare_func (player.c:404)
==6138==    by 0x345BAE9B: g_qsort_with_data (in
/opt/gnome/lib/libglib-2.0.so.0.400.6) ==6138==    by 0x34596B40:
g_ptr_array_sort_with_data (in /opt/gnome/lib/libglib-2.0.so.0.400.6)
==6138==    by 0x805BF3A: game_get_penalty_taker (game.c:200)

doesn't help me a lot :-(

gyözö

> On Sun, Feb 13, 2005 at 09:06:50AM +0100, Gyözö Both wrote:
> > i'm sorting a pointer array and every once in a while i get a
> > segfault. i'm checking the pointers before sorting with
> > g_ptr_array_sort_with_data, and they are fine. the data i pass, an
> > integer (with GINT_TO_POINTER) is also all right.
> >
> > ...
> >
> > i print out the two pointers pl1 and pl2, and mostly they are fine,
> > but sometimes one of them looks weird (0x049) and is obviously
> > invalid, so i get a segfault when the function tries to access the
> > struct members.
> >
> > as i said, the pointers in the array are all valid and ok before i
> > call g_ptr_array_sort.
>
> Try valgrind, because this looks like consequences of
> a memory problem that occurs elsewhere.  There are two
> common problems it may not catch: overwritten stack and
> wrong level of indirection (i.e., you used too much &'s
> somewhere), but chances are it will find that `elsewhere'.
>
> Yeti
>
>
> --
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing on usenet and in e-mail?


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