Sat, 12 Oct 2024 19:41:04 +0200
fix invalid reads when removing linked list nodes
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "util_allocator.h" #include "cx/test.h" static void cx_testing_allocator_track(CxTestingAllocator *alloc, void *ptr) { for (size_t i = 0; i < alloc->tracked_count; i++) { if (alloc->tracked[i] == ptr) return; // is already tracked } if (alloc->tracked_count == alloc->tracked_capacity) { size_t newcapa = alloc->tracked_capacity + 64; void *newarr = realloc(alloc->tracked, newcapa * sizeof(void *)); if (newarr == NULL) abort(); alloc->tracked = newarr; alloc->tracked_capacity = newcapa; } alloc->tracked[alloc->tracked_count] = ptr; alloc->tracked_count++; } static bool cx_testing_allocator_untrack(CxTestingAllocator *alloc, void *ptr) { for (size_t i = 0; i < alloc->tracked_count; i++) { if (alloc->tracked[i] == ptr) { size_t last = alloc->tracked_count - 1; if (i < last) { alloc->tracked[i] = alloc->tracked[last]; } alloc->tracked_count--; return true; } } return false; } static void *cx_malloc_testing(void *d, size_t n) { CxTestingAllocator *data = d; void *ptr = malloc(n); data->alloc_total++; if (ptr == NULL) { data->alloc_failed++; } else { cx_testing_allocator_track(data, ptr); } return ptr; } static void *cx_realloc_testing(void *d, void *mem, size_t n) { CxTestingAllocator *data = d; void *ptr = realloc(mem, n); if (ptr == mem) { return ptr; } else { data->alloc_total++; if (ptr == NULL) { data->alloc_failed++; } else { data->free_total++; #if !defined(__clang__) && __GNUC__ > 11 #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wuse-after-free" #endif if (!cx_testing_allocator_untrack(data, mem)) { data->free_failed++; } #if !defined(__clang__) && __GNUC__ > 11 #pragma GCC diagnostic pop #endif cx_testing_allocator_track(data, ptr); } return ptr; } } static void *cx_calloc_testing(void *d, size_t nelem, size_t n) { CxTestingAllocator *data = d; void *ptr = calloc(nelem, n); data->alloc_total++; if (ptr == NULL) { data->alloc_failed++; } else { cx_testing_allocator_track(data, ptr); } return ptr; } static void cx_free_testing(void *d, void *mem) { CxTestingAllocator *data = d; data->free_total++; if (cx_testing_allocator_untrack(data, mem)) { free(mem); } else { data->free_failed++; // do not even attempt to free mem, because it is likely to segfault } } cx_allocator_class cx_testing_allocator_class = { cx_malloc_testing, cx_realloc_testing, cx_calloc_testing, cx_free_testing }; void cx_testing_allocator_init(CxTestingAllocator *alloc) { alloc->base.cl = &cx_testing_allocator_class; alloc->base.data = alloc; alloc->alloc_failed = 0; alloc->alloc_total = 0; alloc->free_failed = 0; alloc->free_total = 0; size_t initial_capa = 16; alloc->tracked_capacity = initial_capa; alloc->tracked_count = 0; alloc->tracked = calloc(initial_capa, sizeof(void *)); } void cx_testing_allocator_destroy(CxTestingAllocator *alloc) { free(alloc->tracked); } bool cx_testing_allocator_used(const CxTestingAllocator *alloc) { return alloc->alloc_total > 0; } bool cx_testing_allocator_verify(const CxTestingAllocator *alloc) { return alloc->tracked_count == 0 && alloc->alloc_failed == 0 && alloc->free_failed == 0 && alloc->alloc_total == alloc->free_total; } // SELF-TEST CX_TEST(test_util_allocator_expect_free) { CxTestingAllocator talloc; cx_testing_allocator_init(&talloc); CxAllocator *alloc = &talloc.base; CX_TEST_DO { CX_TEST_ASSERTM(cx_testing_allocator_verify(&talloc), "Fresh testing allocator fails to verify."); CX_TEST_ASSERTM(!cx_testing_allocator_used(&talloc), "Fresh testing allocator already used."); void *ptr = cxMalloc(alloc, 16); CX_TEST_ASSERTM(!cx_testing_allocator_verify(&talloc), "Testing allocator verifies with unfreed memory."); CX_TEST_ASSERT(cx_testing_allocator_used(&talloc)); CX_TEST_ASSERT(ptr != NULL); cxFree(alloc, ptr); CX_TEST_ASSERTM(cx_testing_allocator_verify(&talloc), "Testing allocator fails to verify after everything freed."); } cx_testing_allocator_destroy(&talloc); } CX_TEST(test_util_allocator_detect_double_free) { CxTestingAllocator talloc; cx_testing_allocator_init(&talloc); CxAllocator *alloc = &talloc.base; CX_TEST_DO { CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); void *ptr = cxMalloc(alloc, 16); CX_TEST_ASSERT(ptr != NULL); cxFree(alloc, ptr); CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); cxFree(alloc, ptr); CX_TEST_ASSERTM(!cx_testing_allocator_verify(&talloc), "Testing allocator does not detect double-free."); } cx_testing_allocator_destroy(&talloc); } CX_TEST(test_util_allocator_free_untracked) { CxTestingAllocator talloc; cx_testing_allocator_init(&talloc); CxAllocator *alloc = &talloc.base; void *ptr = malloc(16); CX_TEST_DO { CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); cxFree(alloc, ptr); CX_TEST_ASSERTM(!cx_testing_allocator_verify(&talloc), "Testing allocator does not detect free of untracked memory."); } free(ptr); cx_testing_allocator_destroy(&talloc); } CX_TEST(test_util_allocator_full_lifecycle_with_realloc) { CxTestingAllocator talloc; cx_testing_allocator_init(&talloc); CxAllocator *alloc = &talloc.base; CX_TEST_DO { CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); void *ptr = cxMalloc(alloc, 16); CX_TEST_ASSERT(!cx_testing_allocator_verify(&talloc)); CX_TEST_ASSERT(ptr != NULL); CX_TEST_ASSERT(talloc.tracked_count == 1); ptr = cxRealloc(alloc, ptr, 256); CX_TEST_ASSERT(!cx_testing_allocator_verify(&talloc)); CX_TEST_ASSERT(ptr != NULL); CX_TEST_ASSERT(talloc.tracked_count == 1); cxFree(alloc, ptr); CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); } cx_testing_allocator_destroy(&talloc); } CX_TEST(test_util_allocator_calloc_initializes) { CxTestingAllocator talloc; cx_testing_allocator_init(&talloc); CxAllocator *alloc = &talloc.base; CX_TEST_DO { const char zeros[16] = {0}; void *ptr = cxCalloc(alloc, 16, 1); CX_TEST_ASSERT(memcmp(ptr, zeros, 16) == 0); cxFree(alloc, ptr); CX_TEST_ASSERT(cx_testing_allocator_verify(&talloc)); } cx_testing_allocator_destroy(&talloc); } CxTestSuite *cx_test_suite_testing_allocator(void) { CxTestSuite *suite = cx_test_suite_new("testing allocator self-test"); cx_test_register(suite, test_util_allocator_expect_free); cx_test_register(suite, test_util_allocator_detect_double_free); cx_test_register(suite, test_util_allocator_free_untracked); cx_test_register(suite, test_util_allocator_full_lifecycle_with_realloc); cx_test_register(suite, test_util_allocator_calloc_initializes); return suite; }