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[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
This commit is contained in:
Alexander Richardson 2019-07-31 16:31:55 +00:00
parent af44f18ad6
commit a4ea27de92
6 changed files with 9 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
compiler-rt/lib/asan/asan_posix.cc
View File

@ -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.

4
compiler-rt/lib/msan/msan_linux.cc
View File

@ -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.

6
compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
View File

@ -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

3
compiler-rt/test/asan/TestCases/Posix/fread_fwrite.cc
View File

@ -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 <stdio.h>
#include <stdlib.h>

2
compiler-rt/test/asan/TestCases/Posix/tsd_dtor_leak.cc
View File

@ -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 <pthread.h>
#include <stdio.h>
#include <stdlib.h>

1
compiler-rt/test/msan/tzset.cc
View File

@ -1,5 +1,4 @@
// RUN: %clangxx_msan -O0 %s -o %t && %run %t
// XFAIL: freebsd
#include <stdlib.h>
#include <string.h>