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[msan] Prevent initialization failure with newer (2.23+) glibc in use.
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This patch is pretty the same as http://reviews.llvm.org/D20235 that we used
for ASan. Using the same hack for MSan fixes its initialization with newer
Glibc in use.

Differential Revision: https://reviews.llvm.org/D24736

llvm-svn: 282232
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Maxim Ostapenko committed Sep 23, 2016
1 parent a02e394 commit f42c138
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Showing 2 changed files with 36 additions and 13 deletions.
6 changes: 5 additions & 1 deletion compiler-rt/lib/asan/asan_malloc_linux.cc
Expand Up @@ -78,7 +78,11 @@ INTERCEPTOR(void*, realloc, void *ptr, uptr size) {
if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
void *new_ptr = asan_malloc(size, &stack);
void *new_ptr;
if (UNLIKELY(!asan_inited))
new_ptr = AllocateFromLocalPool(size);
else
new_ptr = asan_malloc(size, &stack);
internal_memcpy(new_ptr, ptr, copy_size);
return new_ptr;
}
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43 changes: 31 additions & 12 deletions compiler-rt/lib/msan/msan_interceptors.cc
Expand Up @@ -64,6 +64,23 @@ bool IsInInterceptorScope() {
return in_interceptor_scope;
}

static uptr allocated_for_dlsym;
static const uptr kDlsymAllocPoolSize = 1024;
static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];

static bool IsInDlsymAllocPool(const void *ptr) {
uptr off = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
return off < sizeof(alloc_memory_for_dlsym);
}

static void *AllocateFromLocalPool(uptr size_in_bytes) {
uptr size_in_words = RoundUpTo(size_in_bytes, kWordSize) / kWordSize;
void *mem = (void *)&alloc_memory_for_dlsym[allocated_for_dlsym];
allocated_for_dlsym += size_in_words;
CHECK_LT(allocated_for_dlsym, kDlsymAllocPoolSize);
return mem;
}

#define ENSURE_MSAN_INITED() do { \
CHECK(!msan_init_is_running); \
if (!msan_inited) { \
Expand Down Expand Up @@ -227,14 +244,14 @@ INTERCEPTOR(void *, pvalloc, SIZE_T size) {

INTERCEPTOR(void, free, void *ptr) {
GET_MALLOC_STACK_TRACE;
if (!ptr) return;
if (!ptr || UNLIKELY(IsInDlsymAllocPool(ptr))) return;
MsanDeallocate(&stack, ptr);
}

#if !SANITIZER_FREEBSD
INTERCEPTOR(void, cfree, void *ptr) {
GET_MALLOC_STACK_TRACE;
if (!ptr) return;
if (!ptr || UNLIKELY(IsInDlsymAllocPool(ptr))) return;
MsanDeallocate(&stack, ptr);
}
#define MSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
Expand Down Expand Up @@ -907,27 +924,29 @@ INTERCEPTOR(int, epoll_pwait, int epfd, void *events, int maxevents,

INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
GET_MALLOC_STACK_TRACE;
if (UNLIKELY(!msan_inited)) {
if (UNLIKELY(!msan_inited))
// Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
const SIZE_T kCallocPoolSize = 1024;
static uptr calloc_memory_for_dlsym[kCallocPoolSize];
static SIZE_T allocated;
SIZE_T size_in_words = ((nmemb * size) + kWordSize - 1) / kWordSize;
void *mem = (void*)&calloc_memory_for_dlsym[allocated];
allocated += size_in_words;
CHECK(allocated < kCallocPoolSize);
return mem;
}
return AllocateFromLocalPool(nmemb * size);
return MsanCalloc(&stack, nmemb, size);
}

INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
GET_MALLOC_STACK_TRACE;
if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
void *new_ptr = AllocateFromLocalPool(size);
internal_memcpy(new_ptr, ptr, copy_size);
return new_ptr;
}
return MsanReallocate(&stack, ptr, size, sizeof(u64), false);
}

INTERCEPTOR(void *, malloc, SIZE_T size) {
GET_MALLOC_STACK_TRACE;
if (UNLIKELY(!msan_inited))
// Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
return AllocateFromLocalPool(size);
return MsanReallocate(&stack, nullptr, size, sizeof(u64), false);
}

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