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652707a645
* The performance is better than the glibc allocator. * Allocator interface functions, sanitizer allocator options, and MallocHooks/FreeHooks are supported. * Shadow memory has specific memory layout requirement. Using libc allocator could lead to conflicts. * When we add a mmap interceptor for reliability (the VMA could reuse a previously released VMA that is poisoned): glibc may invoke an internal system call to call unmmap, which cannot be intercepted. We will not be able to return the shadow memory to the OS. Similar to dfsan https://reviews.llvm.org/D101204 . Also intercept operator new/delete to be similar to other sanitizers using the sanitizer allocator. The align_val_t overload of operator new has slightly less overhead. Pull Request: https://github.com/llvm/llvm-project/pull/102764
31 lines
861 B
C++
31 lines
861 B
C++
/// From msan/allocator_mapping.cpp
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/// Test that a module constructor can not map memory over the NSan heap
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/// (without MAP_FIXED, of course).
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// RUN: %clangxx_nsan -O0 %s -o %t_1
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// RUN: %clangxx_nsan -O0 -DHEAP_ADDRESS=$(%run %t_1) %s -o %t_2 && %run %t_2
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#ifdef HEAP_ADDRESS
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struct A {
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A() {
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void *const hint = reinterpret_cast<void *>(HEAP_ADDRESS);
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void *p = mmap(hint, 4096, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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// This address must be already mapped. Check that mmap() succeeds, but at a
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// different address.
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assert(p != reinterpret_cast<void *>(-1));
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assert(p != hint);
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}
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} a;
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#endif
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int main() {
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void *p = malloc(10);
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printf("0x%zx\n", reinterpret_cast<size_t>(p) & (~0xfff));
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free(p);
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}
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