commit 54252394c25ddf0062e288d4a6ab7a885f8ae009 Author: Florian Weimer Date: Thu Jun 27 16:26:56 2024 +0200 Enhanced test coverage for strncmp, wcsncmp Add string/test-strncmp-nonarray and wcsmbs/test-wcsncmp-nonarray. This is the test that uncovered bug 31934. Test run time is more than one minute on a fairly current system, so turn these into xtests that do not run automatically. Reviewed-by: Noah Goldstein diff -Nrup a/string/Makefile b/string/Makefile --- a/string/Makefile 2024-09-03 11:42:30.396319962 -0400 +++ b/string/Makefile 2024-09-03 11:52:17.707438963 -0400 @@ -76,7 +76,10 @@ tests-unsupported += $(tests-translation endif # This test allocates a lot of memory and can run for a long time. -xtests = tst-strcoll-overflow +xtests += tst-strcoll-overflow + +# This test runs for a long time. +xtests += test-strncmp-nonarray # This test needs libdl. ifeq (yes,$(build-shared)) diff -Nrup a/string/test-Xncmp-nonarray.c b/string/test-Xncmp-nonarray.c --- a/string/test-Xncmp-nonarray.c 1969-12-31 19:00:00.000000000 -0500 +++ b/string/test-Xncmp-nonarray.c 2024-09-03 11:52:17.707438963 -0400 @@ -0,0 +1,183 @@ +/* Test non-array inputs to string comparison functions. + Copyright (C) 2024 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +/* This skeleton file is included from string/test-strncmp-nonarray.c and + wcsmbs/test-wcsncmp-nonarray.c to test that reading of the arrays stops + at the first null character. + + TEST_IDENTIFIER must be the test function identifier. TEST_NAME is + the same as a string. + + CHAR must be defined as the character type. */ + +#include +#include +#include +#include +#include +#include +#include + +/* Much shorter than test-Xnlen-nonarray.c because of deeply nested loops. */ +enum { buffer_length = 80 }; + +/* The test buffer layout follows what is described test-Xnlen-nonarray.c, + except that there two buffers, left and right. The variables + a_count, zero_count, start_offset are all duplicated. */ + +/* Return the maximum string length for a string that starts at + start_offset. */ +static int +string_length (int a_count, int start_offset) +{ + if (start_offset == buffer_length || start_offset >= a_count) + return 0; + else + return a_count - start_offset; +} + +/* This is the valid maximum length argument computation for + strnlen/wcsnlen. See text-Xnlen-nonarray.c. */ +static int +maximum_length (int start_offset, int zero_count) +{ + if (start_offset == buffer_length) + return 0; + else if (zero_count > 0) + /* Effectively unbounded, but we need to stop fairly low, + otherwise testing takes too long. */ + return buffer_length + 32; + else + return buffer_length - start_offset; +} + +typedef __typeof (TEST_IDENTIFIER) *proto_t; + +#define TEST_MAIN +#include "test-string.h" + +IMPL (TEST_IDENTIFIER, 1) + +static int +test_main (void) +{ + TEST_VERIFY_EXIT (sysconf (_SC_PAGESIZE) >= buffer_length); + test_init (); + + struct support_next_to_fault left_ntf + = support_next_to_fault_allocate (buffer_length * sizeof (CHAR)); + CHAR *left_buffer = (CHAR *) left_ntf.buffer; + struct support_next_to_fault right_ntf + = support_next_to_fault_allocate (buffer_length * sizeof (CHAR)); + CHAR *right_buffer = (CHAR *) right_ntf.buffer; + + FOR_EACH_IMPL (impl, 0) + { + printf ("info: testing %s\n", impl->name); + for (size_t i = 0; i < buffer_length; ++i) + left_buffer[i] = 'A'; + + for (int left_zero_count = 0; left_zero_count <= buffer_length; + ++left_zero_count) + { + if (left_zero_count > 0) + left_buffer[buffer_length - left_zero_count] = 0; + int left_a_count = buffer_length - left_zero_count; + for (size_t i = 0; i < buffer_length; ++i) + right_buffer[i] = 'A'; + for (int right_zero_count = 0; right_zero_count <= buffer_length; + ++right_zero_count) + { + if (right_zero_count > 0) + right_buffer[buffer_length - right_zero_count] = 0; + int right_a_count = buffer_length - right_zero_count; + for (int left_start_offset = 0; + left_start_offset <= buffer_length; + ++left_start_offset) + { + CHAR *left_start_pointer = left_buffer + left_start_offset; + int left_maxlen + = maximum_length (left_start_offset, left_zero_count); + int left_length + = string_length (left_a_count, left_start_offset); + for (int right_start_offset = 0; + right_start_offset <= buffer_length; + ++right_start_offset) + { + CHAR *right_start_pointer + = right_buffer + right_start_offset; + int right_maxlen + = maximum_length (right_start_offset, right_zero_count); + int right_length + = string_length (right_a_count, right_start_offset); + + /* Maximum length is modelled after strnlen/wcsnlen, + and must be valid for both pointer arguments at + the same time. */ + int maxlen = MIN (left_maxlen, right_maxlen); + + for (int length_argument = 0; length_argument <= maxlen; + ++length_argument) + { + if (test_verbose) + { + printf ("left: zero_count=%d" + " a_count=%d start_offset=%d\n", + left_zero_count, left_a_count, + left_start_offset); + printf ("right: zero_count=%d" + " a_count=%d start_offset=%d\n", + right_zero_count, right_a_count, + right_start_offset); + printf ("length argument: %d\n", + length_argument); + } + + /* Effective lengths bounded by length argument. + The effective length determines the + outcome of the comparison. */ + int left_effective + = MIN (left_length, length_argument); + int right_effective + = MIN (right_length, length_argument); + if (left_effective == right_effective) + TEST_COMPARE (CALL (impl, + left_start_pointer, + right_start_pointer, + length_argument), 0); + else if (left_effective < right_effective) + TEST_COMPARE (CALL (impl, + left_start_pointer, + right_start_pointer, + length_argument) < 0, 1); + else + TEST_COMPARE (CALL (impl, + left_start_pointer, + right_start_pointer, + length_argument) > 0, 1); + } + } + } + } + } + } + + return 0; +} + +#include diff -Nrup a/string/test-strncmp-nonarray.c b/string/test-strncmp-nonarray.c --- a/string/test-strncmp-nonarray.c 1969-12-31 19:00:00.000000000 -0500 +++ b/string/test-strncmp-nonarray.c 2024-09-03 11:52:17.707438963 -0400 @@ -0,0 +1,4 @@ +#define TEST_IDENTIFIER strncmp +#define TEST_NAME "strncmp" +typedef char CHAR; +#include "test-Xncmp-nonarray.c" diff -Nrup a/wcsmbs/Makefile b/wcsmbs/Makefile --- a/wcsmbs/Makefile 2024-09-03 11:42:30.398319976 -0400 +++ b/wcsmbs/Makefile 2024-09-03 11:53:44.806049806 -0400 @@ -56,6 +56,10 @@ tests := tst-wcstof wcsmbs-tst1 tst-wcsn $(addprefix test-,$(strop-tests)) tst-mbstowcs \ test-wcsdup +# This test runs for a long time. +xtests += test-wcsncmp-nonarray + + include ../Rules ifeq ($(run-built-tests),yes) diff -Nrup a/wcsmbs/test-wcsncmp-nonarray.c b/wcsmbs/test-wcsncmp-nonarray.c --- a/wcsmbs/test-wcsncmp-nonarray.c 1969-12-31 19:00:00.000000000 -0500 +++ b/wcsmbs/test-wcsncmp-nonarray.c 2024-09-03 11:52:17.708438970 -0400 @@ -0,0 +1,5 @@ +#include +#define TEST_IDENTIFIER wcsncmp +#define TEST_NAME "wcsncmp" +typedef wchar_t CHAR; +#include "../string/test-Xncmp-nonarray.c"