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Hi! When some shared libraries have destructors that free objects allocated earlier and those destructors are run after libmemusage.so's destructor, the programs die on invalid pointer passed to free. One example is e.g. any program linked against libselinux.so.1 (which malloc's selinux_mnt in its constructor and frees it in its destructor), like id or ls. The problem is that libmemusage.so's malloc, free etc. substantially differ between not_me and !not_me cases (in the former case they just pass through to libc functions, while in the latter they allocate a header in front of the memory chunk). Now, in libmemusage.so's destructor we don't want the stat info to change when printing the statistics and set not_me to true to avoid that, but we don't restore this afterwards. This means selinux_mnt is malloced when not_me is false (i.e. with header in front of it), but freed when not_me is true (as if it was being allocated without the header in front of it). 2006-11-02 Jakub Jelinek <jakub@redhat.com> * malloc/memusage.c (dest): Reset not_me back to false after printing statistics. --- libc/malloc/memusage.c.jj 2006-10-19 17:26:39.000000000 +0200 +++ libc/malloc/memusage.c 2006-11-02 17:14:22.000000000 +0100 @@ -887,4 +887,10 @@ dest (void) fputc ('=', stderr); fputs ("\e[0;0m\n", stderr); } + + /* Any following malloc/free etc. calls should generate statistics again, + because otherwise freeing something that has been malloced before + this destructor (including struct header in front of it) wouldn't + be properly freed. */ + not_me = false; } Jakub
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