File: segv_read_write.c

package info (click to toggle)
llvm-toolchain-14 1%3A14.0.6-12
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,496,180 kB
  • sloc: cpp: 5,593,972; ansic: 986,872; asm: 585,869; python: 184,223; objc: 72,530; lisp: 31,119; f90: 27,793; javascript: 9,780; pascal: 9,762; sh: 9,482; perl: 7,468; ml: 5,432; awk: 3,523; makefile: 2,538; xml: 953; cs: 573; fortran: 567
file content (26 lines) | stat: -rw-r--r-- 1,026 bytes parent folder | download | duplicates (18) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
 
// RUN: %clangxx_asan -std=c++11 -O0 %s -o %t
// RUN: not %run %t       2>&1 | FileCheck %s --check-prefix=READ
// RUN: not %run %t write 2>&1 | FileCheck %s --check-prefix=WRITE
// UNSUPPORTED: powerpc64,mips,s390

#include <sys/mman.h>

static volatile int sink;
__attribute__((noinline)) void Read(int *ptr) { sink = *ptr; }
__attribute__((noinline)) void Write(int *ptr) { *ptr = 0; }
int main(int argc, char **argv) {
  // Writes to shadow are detected as reads from shadow gap (because of how the
  // shadow mapping works). This is kinda hard to fix. Test a random address in
  // the application part of the address space.
  void *volatile p =
      mmap(nullptr, 4096, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
  munmap(p, 4096);
  if (argc == 1)
    Read((int *)p);
  else
    Write((int *)p);
}
// READ: AddressSanitizer: SEGV on unknown address
// READ: The signal is caused by a READ memory access.
// WRITE: AddressSanitizer: SEGV on unknown address
// WRITE: The signal is caused by a WRITE memory access.