tsan: another attempt to fix the tls_get_addr crash

llvm-svn: 202405
This commit is contained in:
Dmitry Vyukov 2014-02-27 15:07:45 +00:00
parent 52a07b819e
commit d8c2fbd57f
2 changed files with 16 additions and 13 deletions
compiler-rt
lib/sanitizer_common
test/asan/TestCases/Linux

View File

@ -75,26 +75,29 @@ void DTLS_on_tls_get_addr(void *arg_void, void *res) {
return;
uptr tls_size = 0;
uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset;
// Don't do anything fancy in this function, in particular don't print.
// Some versions of libstdc++ are miscompiled and call this function
// with mis-aligned stack:
// This function uses the fancy 2147483647 verbosity level,
// because printing in this function crashes with some versions of libstdc++
// because of the following bug:
// http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
// Printf uses SSE instructions that crash with mis-aligned accesses.
// VPrintf(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p\n", arg,
// arg->dso_id, arg->offset, res, tls_beg, &tls_beg);
// The bug leads to mis-aligned stack in this function, and subsequently
// SSE instructions in Printf crash.
// But there is a test that searches for printfs from this function.
// The bug can affect any code, so do as less as possible here.
VPrintf(2147483647, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p\n",
arg, arg->dso_id, arg->offset, res, tls_beg, &tls_beg);
if (dtls.last_memalign_ptr == tls_beg) {
tls_size = dtls.last_memalign_size;
// VPrintf(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
// tls_beg, tls_size);
VPrintf(2147483647, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
tls_beg, tls_size);
} else if ((tls_beg % 4096) == sizeof(Glibc_2_19_tls_header)) {
// We may want to check gnu_get_libc_version().
Glibc_2_19_tls_header *header = (Glibc_2_19_tls_header *)tls_beg - 1;
tls_size = header->size;
tls_beg = header->start;
//VPrintf(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
// tls_beg, tls_size);
VPrintf(2147483647, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
tls_beg, tls_size);
} else {
//VPrintf(2, "__tls_get_addr: Can't guess glibc version\n");
VPrintf(2147483647, "__tls_get_addr: Can't guess glibc version\n");
// This may happen inside the DTOR of main thread, so just ignore it.
tls_size = 0;
}
@ -103,7 +106,7 @@ void DTLS_on_tls_get_addr(void *arg_void, void *res) {
}
void DTLS_on_libc_memalign(void *ptr, uptr size) {
// VPrintf(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
VPrintf(2147483647, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
dtls.last_memalign_ptr = reinterpret_cast<uptr>(ptr);
dtls.last_memalign_size = size;
}

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@ -12,7 +12,7 @@
// RUN: %clangxx_asan %s -o %t
// RUN: %t 0 3
// RUN: %t 2 3
// RUN: ASAN_OPTIONS=verbosity=2 %t 2 2 2>&1 | FileCheck %s
// RUN: ASAN_OPTIONS=verbosity=2147483647 %t 2 2 2>&1 | FileCheck %s
// CHECK: __tls_get_addr
// CHECK: __tls_get_addr
// CHECK: __tls_get_addr