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| author | DJ Delorie <dj@delorie.com> | 2018-11-20 13:24:09 -0500 |
|---|---|---|
| committer | DJ Delorie <dj@delorie.com> | 2018-11-20 13:24:09 -0500 |
| commit | bcdaad21d4635931d1bd3b54a7894276925d081d (patch) | |
| tree | 283d6b7b18006862bbac9ac711834b70dabd629f /manual | |
| parent | 5770c0ad1e0c784e817464ca2cf9436a58c9beb7 (diff) | |
| download | glibc-bcdaad21d4635931d1bd3b54a7894276925d081d.tar.gz | |
malloc: tcache double free check
* malloc/malloc.c (tcache_entry): Add key field.
(tcache_put): Set it.
(tcache_get): Likewise.
(_int_free): Check for double free in tcache.
* malloc/tst-tcfree1.c: New.
* malloc/tst-tcfree2.c: New.
* malloc/Makefile: Run the new tests.
* manual/probes.texi: Document memory_tcache_double_free probe.
* dlfcn/dlerror.c (check_free): Prevent double frees.
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/probes.texi | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/manual/probes.texi b/manual/probes.texi index ab2a3102bb..0ea560ed78 100644 --- a/manual/probes.texi +++ b/manual/probes.texi @@ -243,6 +243,18 @@ This probe is triggered when the value of this tunable. @end deftp +@deftp Probe memory_tcache_double_free (void *@var{$arg1}, int @var{$arg2}) +This probe is triggered when @code{free} determines that the memory +being freed has probably already been freed, and resides in the +per-thread cache. Note that there is an extremely unlikely chance +that this probe will trigger due to random payload data remaining in +the allocated memory matching the key used to detect double frees. +This probe actually indicates that an expensive linear search of the +tcache, looking for a double free, has happened. Argument @var{$arg1} +is the memory location as passed to @code{free}, Argument @var{$arg2} +is the tcache bin it resides in. +@end deftp + @node Mathematical Function Probes @section Mathematical Function Probes |