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| author | Niklas Hambüchen <mail@nh2.me> | 2019-08-08 22:02:27 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2019-08-08 22:02:27 +0200 |
| commit | b6d2c4475d5abc05dd009575b90556bdd3c78ad0 (patch) | |
| tree | cc467df460e9dd8ca4776e91b12771ccc8253ee1 | |
| parent | a02cd8e4e091201cb395a805a9f3e2a9981cae37 (diff) | |
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malloc: Fix missing accounting of top chunk in malloc_info [BZ #24026]
Fixes `<total type="rest" size="..."> incorrectly showing as 0 most
of the time.
The rest value being wrong is significant because to compute the
actual amount of memory handed out via malloc, the user must subtract
it from <system type="current" size="...">. That result being wrong
makes investigating memory fragmentation issues like
<https://bugzilla.redhat.com/show_bug.cgi?id=843478> close to
impossible.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | malloc/malloc.c | 6 |
2 files changed, 12 insertions, 0 deletions
@@ -1,3 +1,9 @@ +2019-08-08 Niklas Hambüchen <mail@nh2.me> + Carlos O'Donell <carlos@redhat.com> + + [BZ #24026] + * malloc/malloc.c (__malloc_info): Account for top chunk. + 2019-08-07 Joseph Myers <joseph@codesourcery.com> * sysdeps/unix/sysv/linux/bits/fcntl-linux.h [__USE_GNU] diff --git a/malloc/malloc.c b/malloc/malloc.c index 343d89f489..0e65d636cd 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -5406,6 +5406,12 @@ __malloc_info (int options, FILE *fp) __libc_lock_lock (ar_ptr->mutex); + /* Account for top chunk. The top-most available chunk is + treated specially and is never in any bin. See "initial_top" + comments. */ + avail = chunksize (ar_ptr->top); + nblocks = 1; /* Top always exists. */ + for (size_t i = 0; i < NFASTBINS; ++i) { mchunkptr p = fastbin (ar_ptr, i); |