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[compiler-rt][rtsan] mremap for Linux interception. #124234

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Merged
devnexen merged 2 commits into from
Jan 29, 2025
Merged

[compiler-rt][rtsan] mremap for Linux interception. #124234

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[compiler-rt][rtsan] mremap for Linux interception.
devnexen Jan 24, 2025
e133bee
changes from feedback
devnexen Jan 27, 2025
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28 changes: 28 additions & 0 deletions compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,7 @@ void OSSpinLockLock(volatile OSSpinLock *__lock);
#include <stdarg.h>
#include <stdio.h>
#if SANITIZER_LINUX
#include <linux/mman.h>
#include <sys/inotify.h>
#endif
#include <sys/select.h>
Expand Down Expand Up @@ -850,6 +851,32 @@ INTERCEPTOR(void *, mmap64, void *addr, size_t length, int prot, int flags,
#define RTSAN_MAYBE_INTERCEPT_MMAP64
#endif // SANITIZER_INTERCEPT_MMAP64

#if SANITIZER_LINUX
// Note that even if rtsan is ported to netbsd, it has a slighty different
// and non-variadic signature
INTERCEPTOR(void *, mremap, void *oaddr, size_t olength, size_t nlength,
int flags, ...) {
__rtsan_notify_intercepted_call("mremap");

// the last optional argument is only used in this case
// as the new page region will be assigned to. Is ignored otherwise.
if (flags & MREMAP_FIXED) {
va_list args;

va_start(args, flags);
void *naddr = va_arg(args, void *);
va_end(args);
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@cjappl cjappl Jan 27, 2025

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For this will you follow the pattern set forth in our open/openat interceptor? that is, call REAL in two places so we don't have to pass in nullptr on 873?


return REAL(mremap)(oaddr, olength, nlength, flags, naddr);
}

return REAL(mremap)(oaddr, olength, nlength, flags);
}
#define RTSAN_MAYBE_INTERCEPT_MREMAP INTERCEPT_FUNCTION(mremap)
#else
#define RTSAN_MAYBE_INTERCEPT_MREMAP
#endif

INTERCEPTOR(int, munmap, void *addr, size_t length) {
__rtsan_notify_intercepted_call("munmap");
return REAL(munmap)(addr, length);
Expand Down Expand Up @@ -1321,6 +1348,7 @@ void __rtsan::InitializeInterceptors() {
INTERCEPT_FUNCTION(posix_memalign);
INTERCEPT_FUNCTION(mmap);
RTSAN_MAYBE_INTERCEPT_MMAP64;
RTSAN_MAYBE_INTERCEPT_MREMAP;
INTERCEPT_FUNCTION(munmap);
RTSAN_MAYBE_INTERCEPT_MADVISE;
RTSAN_MAYBE_INTERCEPT_POSIX_MADVISE;
Expand Down
10 changes: 10 additions & 0 deletions compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
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Expand Up @@ -197,6 +197,16 @@ TEST(TestRtsanInterceptors, MmapDiesWhenRealtime) {
ExpectNonRealtimeSurvival(Func);
}

#if SANITIZER_LINUX
TEST(TestRtsanInterceptors, MremapDiesWhenRealtime) {
void *addr = mmap(nullptr, 8, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
auto Func = [addr]() { void *_ = mremap(addr, 8, 16, 0); };
ExpectRealtimeDeath(Func, "mremap");
ExpectNonRealtimeSurvival(Func);
}
#endif

TEST(TestRtsanInterceptors, MunmapDiesWhenRealtime) {
void *ptr = mmap(nullptr, 8, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
Expand Down
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