Date: Tue, 13 Dec 2016 18:05:14 +0000 (UTC) From: Bryan Drewery <bdrewery@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r310025 - head/libexec/rtld-elf Message-ID: <201612131805.uBDI5EDm054866@repo.freebsd.org>
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Author: bdrewery Date: Tue Dec 13 18:05:14 2016 New Revision: 310025 URL: https://svnweb.freebsd.org/changeset/base/310025 Log: Take write lock for rtld_bind before modifying obj_list in dl_iterate_phdr(). This avoids a race with readers such as dladdr(3)/dlinfo(3)/dlsym(3) and the atexit(3) handler. This race was introduced in r294373. Reviewed by: markj, kib, kan MFC after: 2 weeks Sponsored by: Dell EMC Isilon Modified: head/libexec/rtld-elf/rtld.c Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Tue Dec 13 16:53:58 2016 (r310024) +++ head/libexec/rtld-elf/rtld.c Tue Dec 13 18:05:14 2016 (r310025) @@ -3549,7 +3549,7 @@ dl_iterate_phdr(__dl_iterate_hdr_callbac error = 0; wlock_acquire(rtld_phdr_lock, &phdr_lockstate); - rlock_acquire(rtld_bind_lock, &bind_lockstate); + wlock_acquire(rtld_bind_lock, &bind_lockstate); for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); rtld_fill_dl_phdr_info(obj, &phdr_info); @@ -3557,7 +3557,7 @@ dl_iterate_phdr(__dl_iterate_hdr_callbac error = callback(&phdr_info, sizeof phdr_info, param); - rlock_acquire(rtld_bind_lock, &bind_lockstate); + wlock_acquire(rtld_bind_lock, &bind_lockstate); obj = globallist_next(&marker); TAILQ_REMOVE(&obj_list, &marker, next); if (error != 0) {
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