From nobody Mon Jun 29 20:33:30 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4gpyfL5SQxz6jpYn for ; Mon, 29 Jun 2026 20:33:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "YR1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4gpyfL2k3Nz3NZG for ; Mon, 29 Jun 2026 20:33:30 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1782765210; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=B5sMRPHZVQTEcLH34/qQUjCRwYju4Z9EPuIHkz3yP0M=; b=vXmMlUMzXAVTcB0Tz3xRGOBGi7MNzgcAvnDFeiojCA70XJAZWU2pXInWjb/lp1DVRiHqdl P627+8md4hGwsoK08DkD+5nyfpjieqrhWyre6Wl955m1nvD9zbLxBg7uHafkDywhvF2uxa 6Bgb5QetgKQA7PYV0xYIE9yZt0l49eX2em3J2n2LidatNsk4EDh+DKLSNw6XzDdAuFq6Mc VF/4UQ0uIqbn2z39J6Z7Z2TdAycViM63bKCDST9NI86Fo6cHc8cSoDuR6FKkzDU1m/oBmw D9y2H1yYm1IvLuN++u57ubTOBOZunaHbptwrLW3yDbeSK2MByK6CGnBmHXZ9tQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1782765210; a=rsa-sha256; cv=none; b=p41TnrgKjdCRoJh0e2b9x36UYZVLk6n8JxEBzgmDuobKSZE7/+tPgxIpCL+vDwZGMut+e4 mzp3QKZjamCl2K06bB6DL4gMBkGLbyM3VWvsVF7B6QcXKe4YX9ifkR5ad1JjBt50ycwIEg Ju97PsVI1SAdx2BFw/KKrreSOOwqbpJGiLP9IBzsP7xMWLS9cuacESFm+Sln609MbPCErD mfbUt+A6Mxg4JD8tFc3/DtfxxR4VytG4yiQn625A1tPQtOqjrzGnojbHSXteQi1iqNO7Id IF7MBphO8vHq0YBTveG+hUrz5GmIYQ9+Xi9s1smYyscqApmLPFe/I1r2Hwapiw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1782765210; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=B5sMRPHZVQTEcLH34/qQUjCRwYju4Z9EPuIHkz3yP0M=; b=OdsMVoTglPDvBjsOMIQCrhhsbo9LhOW492Sg68tpaUXtAgGfEDjsMCKqiFPl7JQZINSyR1 /wvlWyMf2WjgesLCU26KkIf4M/AX4lednugbvLy+z67ag4c4PSbtSS7KAkxJ1wQ1//Aj4p phiUJ5sJ64g+2pb88EmiFOKKJQAY+VnSUNJm2ijfvqUl+sSOm8qJbno8gp4MNJMc3/T0bh FM0r1JmucmtOH5WboZ9djTniKgK30GiSXx9eRE0iwSWS+Uk2NwqoGfh6LAIWzc+RUjo0zF XXI4hp7JzyLQB7Snk9dkfb+MkbQ8VP+FR4B0+UwwniHN61WdrK/IFp6jpzwMVA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4gpyfL1FVwz1BXP for ; Mon, 29 Jun 2026 20:33:30 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 302c4 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Mon, 29 Jun 2026 20:33:30 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 559f45638dfa - main - rtld: add spinlock around the crt malloc calls List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 559f45638dfa50195c591bb0f7f3d3d8f3bb8dc0 Auto-Submitted: auto-generated Date: Mon, 29 Jun 2026 20:33:30 +0000 Message-Id: <6a42d69a.302c4.56f9007@gitrepo.freebsd.org> The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=559f45638dfa50195c591bb0f7f3d3d8f3bb8dc0 commit 559f45638dfa50195c591bb0f7f3d3d8f3bb8dc0 Author: Konstantin Belousov AuthorDate: 2026-06-27 18:50:29 +0000 Commit: Konstantin Belousov CommitDate: 2026-06-29 20:33:12 +0000 rtld: add spinlock around the crt malloc calls Right now, the rtld malloc is called under the write-locked rtld bind lock. A future change adds places where only read-locked rtld bind lock is held, and then the spinlock protects the malloc structures from the parallel updates. Reviewed by: kevans Tested by: Marek Zarychta Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D57908 --- libexec/rtld-elf/rtld.c | 25 ---------------- libexec/rtld-elf/xmalloc.c | 72 +++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 71 insertions(+), 26 deletions(-) diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c index 2a05afe66902..938e4b0b8a6b 100644 --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -6878,31 +6878,6 @@ getenv(const char *name) strlen(name)))); } -/* malloc */ -void * -malloc(size_t nbytes) -{ - return (__crt_malloc(nbytes)); -} - -void * -calloc(size_t num, size_t size) -{ - return (__crt_calloc(num, size)); -} - -void -free(void *cp) -{ - __crt_free(cp); -} - -void * -realloc(void *cp, size_t nbytes) -{ - return (__crt_realloc(cp, nbytes)); -} - extern int _rtld_version__FreeBSD_version __exported; int _rtld_version__FreeBSD_version = __FreeBSD_version; diff --git a/libexec/rtld-elf/xmalloc.c b/libexec/rtld-elf/xmalloc.c index 5f7c1b5ba10a..4c67939fc27f 100644 --- a/libexec/rtld-elf/xmalloc.c +++ b/libexec/rtld-elf/xmalloc.c @@ -26,6 +26,8 @@ */ #include +#include +#include #include #include #include @@ -35,12 +37,36 @@ #include "rtld_malloc.h" #include "rtld_libc.h" +static int rtld_malloc_spinlock; + +/* + * Almost always the rtld malloc is called under the write-locked rtld + * bind lock. Due to this, xlock() would need a single CAS to take + * the spinlock. But some places only own read-locked rtld bind lock, + * and then the spinlock protects the malloc structures from the + * parallel updates. + */ +static void +xlock(void) +{ + while (atomic_cmpset_acq_int(&rtld_malloc_spinlock, 0, 1) == 0) + cpu_spinwait(); +} + +static void +xunlock(void) +{ + atomic_store_rel_int(&rtld_malloc_spinlock, 0); +} + void * xcalloc(size_t number, size_t size) { void *p; + xlock(); p = __crt_calloc(number, size); + xunlock(); if (p == NULL) { rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); _exit(1); @@ -51,10 +77,11 @@ xcalloc(size_t number, size_t size) void * xmalloc(size_t size) { - void *p; + xlock(); p = __crt_malloc(size); + xunlock(); if (p == NULL) { rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); _exit(1); @@ -83,10 +110,53 @@ xmalloc_aligned(size_t size, size_t align, size_t offset) if (align < sizeof(void *)) align = sizeof(void *); + xlock(); res = __crt_aligned_alloc_offset(align, size, offset); + xunlock(); if (res == NULL) { rtld_fdputstr(STDERR_FILENO, "Out of memory\n"); _exit(1); } return (res); } + +void * +malloc(size_t size) +{ + void *p; + + xlock(); + p = __crt_malloc(size); + xunlock(); + return (p); +} + +void * +calloc(size_t num, size_t size) +{ + void *p; + + xlock(); + p = __crt_calloc(num, size); + xunlock(); + return (p); +} + +void +free(void *cp) +{ + xlock(); + __crt_free(cp); + xunlock(); +} + +void * +realloc(void *cp, size_t nbytes) +{ + void *p; + + xlock(); + p = __crt_realloc(cp, nbytes); + xunlock(); + return (p); +}