199 lines
5.9 KiB
C
199 lines
5.9 KiB
C
/* Test reporting of Safe-Linking caught errors.
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Copyright (C) 2020-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <signal.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <memory.h>
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#include <string.h>
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#include <time.h>
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#include <stdbool.h>
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#include <support/capture_subprocess.h>
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#include <support/check.h>
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/* Run CALLBACK and check that the data on standard error equals
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EXPECTED. */
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static void
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check (const char *test, void (*callback) (void *),
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const char *expected)
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{
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int i, rand_mask;
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int success = 0; /* 0 == fail, 1 == other check 2 == safe linking */
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/* There is a chance of 1/16 that a corrupted pointer will be aligned.
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Try multiple times so that statistical failure will be improbable. */
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for (i = 0; i < 16; ++i)
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{
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rand_mask = rand () & 0xFF;
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struct support_capture_subprocess result
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= support_capture_subprocess (callback, &rand_mask);
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printf ("%s\n", result.out.buffer);
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/* Did not crash, could happen. Try again. */
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if (strlen (result.err.buffer) == 0)
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continue;
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/* Crashed, it may either be safe linking or some other check. If it's
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not safe linking then try again. */
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if (strcmp (result.err.buffer, expected) != 0)
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{
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printf ("test %s failed with a different error\n"
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" expected: %s\n"
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" actual: %s\n",
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test, expected, result.err.buffer);
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success = 1;
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continue;
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}
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TEST_VERIFY (WIFSIGNALED (result.status));
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if (WIFSIGNALED (result.status))
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TEST_VERIFY (WTERMSIG (result.status) == SIGABRT);
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support_capture_subprocess_free (&result);
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success = 2;
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break;
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}
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/* The test fails only if the corruption was not caught by any of the malloc
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mechanisms in all those iterations. This has a lower than 1 in 2^64
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chance of a false positive. */
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TEST_VERIFY (success);
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}
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/* Implementation details must be kept in sync with malloc. */
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#define TCACHE_FILL_COUNT 7
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#define TCACHE_ALLOC_SIZE 0x20
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#define MALLOC_CONSOLIDATE_SIZE 256*1024
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/* Try corrupting the tcache list. */
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static void
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test_tcache (void *closure)
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{
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int mask = ((int *)closure)[0];
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size_t size = TCACHE_ALLOC_SIZE;
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printf ("++ tcache ++\n");
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/* Populate the tcache list. */
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void * volatile a = malloc (size);
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void * volatile b = malloc (size);
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void * volatile c = malloc (size);
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printf ("a=%p, b=%p, c=%p\n", a, b, c);
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free (a);
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free (b);
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free (c);
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/* Corrupt the pointer with a random value, and avoid optimizations. */
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printf ("Before: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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memset (c, mask & 0xFF, size);
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printf ("After: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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c = malloc (size);
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printf ("Allocated: c=%p\n", c);
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/* This line will trigger the Safe-Linking check. */
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b = malloc (size);
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printf ("b=%p\n", b);
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}
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/* Try corrupting the fastbin list. */
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static void
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test_fastbin (void *closure)
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{
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int i;
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int mask = ((int *)closure)[0];
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size_t size = TCACHE_ALLOC_SIZE;
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printf ("++ fastbin ++\n");
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/* Take the tcache out of the game. */
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for (i = 0; i < TCACHE_FILL_COUNT; ++i)
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{
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void * volatile p = calloc (1, size);
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printf ("p=%p\n", p);
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free (p);
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}
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/* Populate the fastbin list. */
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void * volatile a = calloc (1, size);
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void * volatile b = calloc (1, size);
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void * volatile c = calloc (1, size);
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printf ("a=%p, b=%p, c=%p\n", a, b, c);
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free (a);
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free (b);
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free (c);
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/* Corrupt the pointer with a random value, and avoid optimizations. */
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printf ("Before: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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memset (c, mask & 0xFF, size);
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printf ("After: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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c = calloc (1, size);
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printf ("Allocated: c=%p\n", c);
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/* This line will trigger the Safe-Linking check. */
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b = calloc (1, size);
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printf ("b=%p\n", b);
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}
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/* Try corrupting the fastbin list and trigger a consolidate. */
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static void
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test_fastbin_consolidate (void *closure)
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{
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int i;
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int mask = ((int*)closure)[0];
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size_t size = TCACHE_ALLOC_SIZE;
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printf ("++ fastbin consolidate ++\n");
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/* Take the tcache out of the game. */
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for (i = 0; i < TCACHE_FILL_COUNT; ++i)
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{
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void * volatile p = calloc (1, size);
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free (p);
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}
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/* Populate the fastbin list. */
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void * volatile a = calloc (1, size);
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void * volatile b = calloc (1, size);
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void * volatile c = calloc (1, size);
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printf ("a=%p, b=%p, c=%p\n", a, b, c);
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free (a);
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free (b);
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free (c);
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/* Corrupt the pointer with a random value, and avoid optimizations. */
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printf ("Before: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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memset (c, mask & 0xFF, size);
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printf ("After: c=%p, c[0]=%p\n", c, ((void **)c)[0]);
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/* This line will trigger the Safe-Linking check. */
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b = malloc (MALLOC_CONSOLIDATE_SIZE);
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printf ("b=%p\n", b);
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}
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static int
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do_test (void)
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{
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/* Seed the random for the test. */
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srand (time (NULL));
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check ("test_tcache", test_tcache,
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"malloc(): unaligned tcache chunk detected\n");
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check ("test_fastbin", test_fastbin,
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"malloc(): unaligned fastbin chunk detected 2\n");
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check ("test_fastbin_consolidate", test_fastbin_consolidate,
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"malloc_consolidate(): unaligned fastbin chunk detected\n");
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return 0;
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}
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#include <support/test-driver.c>
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