From ef195a39d0d3b929cc676302d074b42c25460601 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Sat, 17 Apr 2021 11:27:14 +0200 Subject: [PATCH] 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 PR sanitizer/100114 * sanitizer_common/sanitizer_posix_libcdep.cc: Cherry-pick llvm-project revisions 82150606fb11d28813ae6da1101f5bda638165fe and b93629dd335ffee2fc4b9b619bf86c3f9e6b0023. (cherry picked from commit 950bac27d63c1c2ac3a6ed867692d6a13f21feb3) --- .../sanitizer_common/sanitizer_posix_libcdep.cc | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc index 1a37118c299..066079b3954 100644 --- a/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc +++ b/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc @@ -159,7 +159,11 @@ 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; @@ -170,10 +174,9 @@ 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)); } @@ -181,7 +184,7 @@ 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); } -- 2.27.0