From 3c5f2467984c23aae5a64548dcb15efae18e207e Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 22 May 2023 14:04:38 -0500 Subject: [PATCH] cutils: Set value in all integral qemu_strto* error paths Our goal in writing qemu_strtoi() and friends is to have an interface harder to abuse than libc's strtol(). Leaving the return value uninitialized on some but not all error paths does not lend itself well to this goal; and our documentation wasn't helpful on what to expect. Note that the previous patch changed all qemu_strtosz() EINVAL error paths to slam value to 0 rather than stay uninitialized, even when the EINVAL eror occurs because of trailing junk. But for the remaining integral qemu_strto*, it's easier to return the parsed value than to force things back to zero, in part because of how check_strtox_error works; in part because people expect that from libc strto* (while there is no libc strtosz to compare to), and in part because doing so creates less churn in the testsuite. Here, the list of affected callers is much longer ('git grep "qemu_strto[ui]" "*.c" "**/*.c" | grep -v tests/ |wc -l' outputs 107, although a few of those are the implementation in in cutils.c), so touching as little as possible is the wisest course of action. Signed-off-by: Eric Blake Reviewed-by: Hanna Czenczek Message-Id: <20230522190441.64278-17-eblake@redhat.com> --- tests/unit/test-cutils.c | 24 ++++++++++++------------ util/cutils.c | 42 ++++++++++++++++++++++++++---------------- 2 files changed, 38 insertions(+), 28 deletions(-) diff --git a/tests/unit/test-cutils.c b/tests/unit/test-cutils.c index f4dfb6ae14..cfe1fc8a17 100644 --- a/tests/unit/test-cutils.c +++ b/tests/unit/test-cutils.c @@ -320,7 +320,7 @@ static void test_qemu_strtoi_null(void) err = qemu_strtoi(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); g_assert_null(endptr); } @@ -661,7 +661,7 @@ static void test_qemu_strtoi_full_null(void) err = qemu_strtoi(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); g_assert_null(endptr); } @@ -764,7 +764,7 @@ static void test_qemu_strtoui_null(void) err = qemu_strtoui(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); g_assert_null(endptr); } @@ -1102,7 +1102,7 @@ static void test_qemu_strtoui_full_null(void) err = qemu_strtoui(NULL, NULL, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); } static void test_qemu_strtoui_full_empty(void) @@ -1202,7 +1202,7 @@ static void test_qemu_strtol_null(void) err = qemu_strtol(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); g_assert_null(endptr); } @@ -1516,7 +1516,7 @@ static void test_qemu_strtol_full_null(void) err = qemu_strtol(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); g_assert_null(endptr); } @@ -1619,7 +1619,7 @@ static void test_qemu_strtoul_null(void) err = qemu_strtoul(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); g_assert_null(endptr); } @@ -1932,7 +1932,7 @@ static void test_qemu_strtoul_full_null(void) err = qemu_strtoul(NULL, NULL, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); } static void test_qemu_strtoul_full_empty(void) @@ -2032,7 +2032,7 @@ static void test_qemu_strtoi64_null(void) err = qemu_strtoi64(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); g_assert_null(endptr); } @@ -2322,7 +2322,7 @@ static void test_qemu_strtoi64_full_null(void) err = qemu_strtoi64(NULL, NULL, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpint(res, ==, 999); + g_assert_cmpint(res, ==, 0); } static void test_qemu_strtoi64_full_empty(void) @@ -2425,7 +2425,7 @@ static void test_qemu_strtou64_null(void) err = qemu_strtou64(NULL, &endptr, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); g_assert_null(endptr); } @@ -2714,7 +2714,7 @@ static void test_qemu_strtou64_full_null(void) err = qemu_strtou64(NULL, NULL, 0, &res); g_assert_cmpint(err, ==, -EINVAL); - g_assert_cmpuint(res, ==, 999); + g_assert_cmpuint(res, ==, 0); } static void test_qemu_strtou64_full_empty(void) diff --git a/util/cutils.c b/util/cutils.c index c5530a5c2b..edfb71a217 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -384,12 +384,13 @@ static int check_strtox_error(const char *nptr, char *ep, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store INT_MAX in @result, * and return -ERANGE. @@ -410,6 +411,7 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -439,12 +441,13 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store UINT_MAX in @result, * and return -ERANGE. @@ -465,6 +468,7 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -508,12 +512,13 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store LONG_MAX in @result, * and return -ERANGE. @@ -530,6 +535,7 @@ int qemu_strtol(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -550,12 +556,13 @@ int qemu_strtol(const char *nptr, const char **endptr, int base, * * @nptr may be null, and no conversion is performed then. * - * If no conversion is performed, store @nptr in *@endptr and return - * -EINVAL. + * If no conversion is performed, store @nptr in *@endptr, 0 in + * @result, and return -EINVAL. * * If @endptr is null, and the string isn't fully converted, return - * -EINVAL. This is the case when the pointer that would be stored in - * a non-null @endptr points to a character other than '\0'. + * -EINVAL with @result set to the parsed value. This is the case + * when the pointer that would be stored in a non-null @endptr points + * to a character other than '\0'. * * If the conversion overflows @result, store ULONG_MAX in @result, * and return -ERANGE. @@ -573,6 +580,7 @@ int qemu_strtoul(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -601,6 +609,7 @@ int qemu_strtoi64(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } @@ -628,6 +637,7 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, assert((unsigned) base <= 36 && base != 1); if (!nptr) { + *result = 0; if (endptr) { *endptr = nptr; } -- 2.11.4.GIT