0aafeb8ba1
#144648 was reverted because it failed the new sanitizer test `munmap_clear_shadow.c` in IOS's CI. That issue could be fixed by disabling the test on some platforms, due to the incompatibility of the test on these platforms. In detail, we should disable the test in FreeBSD, Apple, NetBSD, Solaris, and Haiku, where `ReleaseMemoryPagesToOS` executes `madvise(beg, end, MADV_FREE)`, which tags the relevant pages as 'FREE' and does not release them immediately.
64 lines
1.9 KiB
C
64 lines
1.9 KiB
C
// RUN: %clang_tsan %s -o %t && %run %t | FileCheck %s
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// In these systems, the behavior of ReleaseMemoryPagesToOS is madvise(beg, end, MADV_FREE),
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// which tags the relevant pages as 'FREE' and does not release them immediately.
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// Therefore, we cannot assume that __tsan_read1 will not race with the shadow cleared.
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// UNSUPPORTED: darwin,target={{.*(freebsd|netbsd|solaris|haiku).*}}
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#include "test.h"
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#include <assert.h>
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#include <pthread.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <sys/mman.h>
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#include <unistd.h>
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void __tsan_read1(void *addr);
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struct thread_params {
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char *buf;
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unsigned int size;
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};
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static void *thread_func(void *arg) {
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struct thread_params *p = (struct thread_params *)arg;
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// Access 1
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p->buf[0] = 0x42;
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p->buf[p->size - 1] = 0x42;
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barrier_wait(&barrier);
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return 0;
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}
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int main() {
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const unsigned int kPageSize = sysconf(_SC_PAGESIZE);
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// The relevant shadow memory size should be exactly multiple of kPageSize,
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// even if Size = kPageSize - 1.
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const unsigned int Size = kPageSize - 1;
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barrier_init(&barrier, 2);
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char *buf = (char *)mmap(NULL, Size, PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
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assert(buf != MAP_FAILED);
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assert(((uintptr_t)buf % kPageSize) == 0);
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pthread_t t;
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struct thread_params p = {buf, Size};
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pthread_create(&t, 0, thread_func, &p);
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barrier_wait(&barrier);
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// Should clear all the shadow memory related to the mmaped memory.
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munmap(buf, Size);
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// If the shadow memory is cleared completely, the following reads should not
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// cause races and behave the same. However, previously, __tsan_read1(&buf[0])
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// would not report a race, while __tsan_read1(&buf[Size - 1]) did.
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// CHECK-NOT: WARNING: ThreadSanitizer: data race
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__tsan_read1(&buf[0]); // Access 2
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__tsan_read1(&buf[Size - 1]); // Access 2
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pthread_join(t, 0);
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puts("DONE");
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return 0;
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}
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