7740565f56
StackSafetyAnalysis determines whether stack-allocated variables are guaranteed to be safe from memory access bugs and enables the removal of certain unneeded instrumentations. (hwasan enables StackSafetyAnalysis in https://reviews.llvm.org/D108381) In a release build of clang, text sections are 9% smaller. Test updates: * asan-stack-safety.ll: test the -asan-use-stack-safety=1 default * lifetime-uar-uas.ll: switch to an indexed store to prevent StackSafetyAnalysis from optimizing out instrumentation for %c * alloca_vla_interact.cpp: add a load to prevent StackSafetyAnalysis from optimizing out `__asan_alloca_poison` for the VLA `array` * scariness_score_test.cpp: add -asan-use-stack-safety=0 to make a load of a `__asan_poison_memory_region`-poisoned local variable fail as intended. * other .ll tests: add -asan-use-stack-safety=0 Reviewed By: kstoimenov Pull Request: https://github.com/llvm/llvm-project/pull/77210
52 lines
1.5 KiB
C++
52 lines
1.5 KiB
C++
// RUN: %clangxx_asan -O0 -mllvm -asan-instrument-dynamic-allocas %s -o %t
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// RUN: %run %t 2>&1
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//
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// REQUIRES: stable-runtime
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// This testcase checks correct interaction between VLAs and allocas.
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#include <assert.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include "sanitizer/asan_interface.h"
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// MSVC provides _alloca instead of alloca.
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#if defined(_MSC_VER) && !defined(alloca)
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# define alloca _alloca
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#endif
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#if defined(__sun__) && defined(__svr4__)
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#include <alloca.h>
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#endif
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#define RZ 32
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__attribute__((noinline)) void foo(int len) {
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char *top, *bot;
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// This alloca call should live until the end of foo.
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char *alloca1 = (char *)alloca(len);
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assert(!(reinterpret_cast<uintptr_t>(alloca1) & 31L));
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// This should be first poisoned address after loop.
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top = alloca1 - RZ;
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for (int i = 0; i < 32; ++i) {
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// Check that previous alloca was unpoisoned at the end of iteration.
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if (i) assert(!__asan_region_is_poisoned(bot, 96));
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// VLA is unpoisoned at the end of iteration.
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volatile char array[i];
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// Ensure that asan-use-stack-safety does not optimize out the poisoning.
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if (i) array[0] = 0;
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assert(!(reinterpret_cast<uintptr_t>(array) & 31L));
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// Alloca is unpoisoned at the end of iteration,
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// because dominated by VLA.
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bot = (char *)alloca(i) - RZ;
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}
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// Check that all allocas from loop were unpoisoned correctly.
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void *q = __asan_region_is_poisoned(bot, (char *)top - (char *)bot + 1);
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assert(q == top);
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}
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int main(int argc, char **argv) {
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foo(32);
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return 0;
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}
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