From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1944) id 96FD5385020D; Wed, 12 Oct 2022 14:18:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 96FD5385020D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1665584322; bh=93rLzDBGejX266BYxnJbt5aleiZ9L5vYkmdlzV1Lkps=; h=From:To:Subject:Date:From; b=Sj3LUyfqqiunN2V2djedU5iF5URMfdo8RI7C6XKmq52WOM7y9qdyt2/g6x9Qi4VFo yxcZoA5rVmESOtbybz+saN1y4AjqDGfP7SMFWX9C3Kype/ufHWw4KfOR2YVd20Snz4 7ZPNiTKVSkRpn/eRH6DS7fc0HwaohlU0/M0oGor8= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Szabolcs Nagy To: glibc-cvs@sourceware.org Subject: [glibc/arm/morello/main] malloc: Don't use __libc_free for tcache cleanup X-Act-Checkin: glibc X-Git-Author: Szabolcs Nagy X-Git-Refname: refs/heads/arm/morello/main X-Git-Oldrev: c0a839639b6a9baeaafe5dad8f7739e6176a2c62 X-Git-Newrev: 3d959e4b0e6e746203bfa22992d7749ff31f58be Message-Id: <20221012141842.96FD5385020D@sourceware.org> Date: Wed, 12 Oct 2022 14:18:42 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3d959e4b0e6e746203bfa22992d7749ff31f58be commit 3d959e4b0e6e746203bfa22992d7749ff31f58be Author: Szabolcs Nagy Date: Mon Oct 3 11:58:09 2022 +0100 malloc: Don't use __libc_free for tcache cleanup __libc_free must only be used for memory given out by __libc_malloc and similar public apis, but tcache stores a cache of already freed pointers and itself is allocated using internal malloc apis. Strong double free detection in __libc_free breaks tcache_thread_shutdown, so use a cut down version of free to reset tcache entries. Diff: --- malloc/malloc.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/malloc/malloc.c b/malloc/malloc.c index 02df29d2ad..56d6116102 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -3197,6 +3197,35 @@ tcache_get (size_t tc_idx) return (void *) e; } +/* Cut down __libc_free for cleaning up tcache entries. */ +static void +tcache_libc_free (void *mem) +{ + int err = errno; + mchunkptr p = mem2chunk(mem); + if (chunk_is_mmapped (p)) + { + /* See if the dynamic brk/mmap threshold needs adjusting. + Dumped fake mmapped chunks do not affect the threshold. */ + if (!mp_.no_dyn_threshold + && chunksize_nomask (p) > mp_.mmap_threshold + && chunksize_nomask (p) <= DEFAULT_MMAP_THRESHOLD_MAX) + { + mp_.mmap_threshold = chunksize (p); + mp_.trim_threshold = 2 * mp_.mmap_threshold; + LIBC_PROBE (memory_mallopt_free_dyn_thresholds, 2, + mp_.mmap_threshold, mp_.trim_threshold); + } + munmap_chunk (p); + } + else + { + mstate ar_ptr = arena_for_chunk (p); + _int_free (ar_ptr, p, 0); + } + __set_errno (err); +} + static void tcache_thread_shutdown (void) { @@ -3222,11 +3251,11 @@ tcache_thread_shutdown (void) malloc_printerr ("tcache_thread_shutdown(): " "unaligned tcache chunk detected"); tcache_tmp->entries[i] = REVEAL_PTR (e->next); - __libc_free (e); + tcache_libc_free (e); } } - __libc_free (tcache_tmp); + tcache_libc_free (tcache_tmp); } static void