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sanitizer: Fix asan against glibc 2.34 [PR100114] 

As mentioned in the PR, SIGSTKSZ is no longer a compile time constant in
glibc 2.34 and later, so
static const uptr kAltStackSize = SIGSTKSZ * 4;
needs dynamic initialization, but is used by a function called indirectly
from .preinit_array and therefore before the variable is constructed.
This results in using 0 size instead and all asan instrumented programs
die with:
==91==ERROR: AddressSanitizer failed to allocate 0x0 (0) bytes of SetAlternateSignalStack (error code: 22)

Here is a cherry-pick from upstream to fix this.

2021-04-17  Jakub Jelinek  <jakub@redhat.com>

	PR sanitizer/100114
	* sanitizer_common/sanitizer_posix_libcdep.cpp: Cherry-pick
	llvm-project revisions 82150606fb11d28813ae6da1101f5bda638165fe
	and b93629dd335ffee2fc4b9b619bf86c3f9e6b0023.
This commit is contained in:
Jakub Jelinek 2021-04-17 11:27:14 +02:00
parent 8ae884c09f
commit d9f462fb37
1 changed files with 8 additions and 5 deletions
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13
libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cpp
View File

@ -165,7 +165,11 @@ bool SupportsColoredOutput(fd_t fd) {
#if !SANITIZER_GO
// TODO(glider): different tools may require different altstack size.
static const uptr kAltStackSize = SIGSTKSZ * 4; // SIGSTKSZ is not enough.
static uptr GetAltStackSize() {
// SIGSTKSZ is not enough.
static const uptr kAltStackSize = SIGSTKSZ * 4;
return kAltStackSize;
}
void SetAlternateSignalStack() {
stack_t altstack, oldstack;
@ -176,10 +180,9 @@ void SetAlternateSignalStack() {
// TODO(glider): the mapped stack should have the MAP_STACK flag in the
// future. It is not required by man 2 sigaltstack now (they're using
// malloc()).
void* base = MmapOrDie(kAltStackSize, __func__);
altstack.ss_sp = (char*) base;
altstack.ss_size = GetAltStackSize();
altstack.ss_sp = (char *)MmapOrDie(altstack.ss_size, __func__);
altstack.ss_flags = 0;
altstack.ss_size = kAltStackSize;
CHECK_EQ(0, sigaltstack(&altstack, nullptr));
}
@ -187,7 +190,7 @@ void UnsetAlternateSignalStack() {
stack_t altstack, oldstack;
altstack.ss_sp = nullptr;
altstack.ss_flags = SS_DISABLE;
altstack.ss_size = kAltStackSize; // Some sane value required on Darwin.
altstack.ss_size = GetAltStackSize(); // Some sane value required on Darwin.
CHECK_EQ(0, sigaltstack(&altstack, &oldstack));
UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
}