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authorNiklas Hambüchen <mail@nh2.me>2019-08-08 22:02:27 +0200
committerAndreas K. Hüttel <dilfridge@gentoo.org>2019-11-25 02:07:59 +0100
commit4cc3627ac5c4453ba0725734f3c636c6bf23f88b (patch)
tree9b64f04e927d700057e95e59a18e0f5e4bb6c289
parentmalloc: Remove unwanted leading whitespace in malloc_info [BZ #24867] (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. (cherry picked from commit b6d2c4475d5abc05dd009575b90556bdd3c78ad0) (cherry picked from commit c6e4c3198b0ec78a921bfc03874fca662c5e9599)
-rw-r--r--ChangeLog6
-rw-r--r--malloc/malloc.c6
2 files changed, 12 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 95411e59a6..8bfc29a02f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.
+
2019-08-01 Florian Weimer <fweimer@redhat.com>
[BZ #24867]
diff --git a/malloc/malloc.c b/malloc/malloc.c
index f1e5eb878a..5c44dcdb66 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -5433,6 +5433,12 @@ __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);