From a4ea27de9287744c5584e5f4eb755030661e665d Mon Sep 17 00:00:00 2001 From: Alexander Richardson Date: Wed, 31 Jul 2019 16:31:55 +0000 Subject: [PATCH] [Sanitizer][ASAN][MSAN] Fix infinite recursion on FreeBSD Summary: MSAN was broken on FreeBSD by https://reviews.llvm.org/D55703: after this change accesses to the key variable call __tls_get_addr, which is intercepted. The interceptor then calls GetCurrentThread which calls MsanTSDGet which again calls __tls_get_addr, etc... Using the default implementation in the SANITIZER_FREEBSD case fixes MSAN for me. I then applied the same change to ASAN (introduced in https://reviews.llvm.org/D55596) but that did not work yet. In the ASAN case, we get infinite recursion again during initialization, this time because calling pthread_key_create() early on results in infinite recursion. pthread_key_create() calls sysctlbyname() which is intercepted but COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED returns true, so the interceptor calls internal_sysctlbyname() which then ends up calling the interceptor again. I fixed this issue by using dlsym() to get the libc version of sysctlbyname() instead. This fixes https://llvm.org/PR40761 Reviewers: vitalybuka, krytarowski, devnexen, dim, bsdjhb, #sanitizers, MaskRay Reviewed By: MaskRay Subscribers: MaskRay, emaste, kubamracek, jfb, #sanitizers, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D65221 llvm-svn: 367442 --- compiler-rt/lib/asan/asan_posix.cc | 4 ++-- compiler-rt/lib/msan/msan_linux.cc | 4 ++-- compiler-rt/lib/sanitizer_common/sanitizer_linux.cc | 6 +++++- compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc | 3 --- compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc | 2 -- compiler-rt/test/msan/tzset.cc | 1 - 6 files changed, 9 insertions(+), 11 deletions(-) diff --git a/compiler-rt/lib/asan/asan_posix.cc b/compiler-rt/lib/asan/asan_posix.cc index 5c5e035..f3fbda0 100644 --- a/compiler-rt/lib/asan/asan_posix.cc +++ b/compiler-rt/lib/asan/asan_posix.cc @@ -39,8 +39,8 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) { // ---------------------- TSD ---------------- {{{1 -#if SANITIZER_NETBSD || SANITIZER_FREEBSD -// Thread Static Data cannot be used in early init on NetBSD and FreeBSD. +#if SANITIZER_NETBSD +// Thread Static Data cannot be used in early init on NetBSD. // Reuse the Asan TSD API for compatibility with existing code // with an alternative implementation. diff --git a/compiler-rt/lib/msan/msan_linux.cc b/compiler-rt/lib/msan/msan_linux.cc index 3b6e6cb..0567830 100644 --- a/compiler-rt/lib/msan/msan_linux.cc +++ b/compiler-rt/lib/msan/msan_linux.cc @@ -174,8 +174,8 @@ void InstallAtExitHandler() { // ---------------------- TSD ---------------- {{{1 -#if SANITIZER_NETBSD || SANITIZER_FREEBSD -// Thread Static Data cannot be used in early init on NetBSD and FreeBSD. +#if SANITIZER_NETBSD +// Thread Static Data cannot be used in early init on NetBSD. // Reuse the MSan TSD API for compatibility with existing code // with an alternative implementation. diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc index 88ab097..455fd4c 100644 --- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc +++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc @@ -779,7 +779,11 @@ int internal_sysctl(const int *name, unsigned int namelen, void *oldp, #if SANITIZER_FREEBSD int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp, const void *newp, uptr newlen) { - return sysctlbyname(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen); + static decltype(sysctlbyname) *real = nullptr; + if (!real) + real = (decltype(sysctlbyname) *)dlsym(RTLD_NEXT, "sysctlbyname"); + CHECK(real); + return real(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen); } #endif #endif diff --git a/compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc b/compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc index 6402488..c062926 100644 --- a/compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc +++ b/compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc @@ -1,9 +1,6 @@ // RUN: %clangxx_asan -g %s -o %t // RUN: not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-FWRITE // RUN: not %run %t 1 2>&1 | FileCheck %s --check-prefix=CHECK-FREAD -// -// On FreeBSD stack overflow error instead -// XFAIL: freebsd #include #include diff --git a/compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc b/compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc index 26109fe..860f345 100644 --- a/compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc +++ b/compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc @@ -3,8 +3,6 @@ // RUN: %clangxx_asan -O1 %s -pthread -o %t // RUN: %env_asan_opts=quarantine_size_mb=0 %run %t // XFAIL: x86_64-netbsd -// Assertion fails -// XFAIL: x86_64-freebsd #include #include #include diff --git a/compiler-rt/test/msan/tzset.cc b/compiler-rt/test/msan/tzset.cc index 86805cd..05915e0 100644 --- a/compiler-rt/test/msan/tzset.cc +++ b/compiler-rt/test/msan/tzset.cc @@ -1,5 +1,4 @@ // RUN: %clangxx_msan -O0 %s -o %t && %run %t -// XFAIL: freebsd #include #include -- 2.7.4