diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/string_helpers.c | 49 | ||||
| -rw-r--r-- | lib/test-string_helpers.c | 40 | ||||
| -rw-r--r-- | lib/vsprintf.c | 8 |
3 files changed, 33 insertions, 64 deletions
diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 9c48ddad0f0d..1826c7407258 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -274,11 +274,6 @@ static bool escape_space(unsigned char c, char **dst, char *end) return false; } - if (out + 2 > end) { - *dst = out + 2; - return true; - } - if (out < end) *out = '\\'; ++out; @@ -309,11 +304,6 @@ static bool escape_special(unsigned char c, char **dst, char *end) return false; } - if (out + 2 > end) { - *dst = out + 2; - return true; - } - if (out < end) *out = '\\'; ++out; @@ -332,11 +322,6 @@ static bool escape_null(unsigned char c, char **dst, char *end) if (c) return false; - if (out + 2 > end) { - *dst = out + 2; - return true; - } - if (out < end) *out = '\\'; ++out; @@ -352,11 +337,6 @@ static bool escape_octal(unsigned char c, char **dst, char *end) { char *out = *dst; - if (out + 4 > end) { - *dst = out + 4; - return true; - } - if (out < end) *out = '\\'; ++out; @@ -378,11 +358,6 @@ static bool escape_hex(unsigned char c, char **dst, char *end) { char *out = *dst; - if (out + 4 > end) { - *dst = out + 4; - return true; - } - if (out < end) *out = '\\'; ++out; @@ -449,20 +424,17 @@ static bool escape_hex(unsigned char c, char **dst, char *end) * it if needs. * * Return: - * The amount of the characters processed to the destination buffer, or - * %-ENOMEM if the size of buffer is not enough to put an escaped character is - * returned. - * - * Even in the case of error @dst pointer will be updated to point to the byte - * after the last processed character. + * The total size of the escaped output that would be generated for + * the given input and flags. To check whether the output was + * truncated, compare the return value to osz. There is room left in + * dst for a '\0' terminator if and only if ret < osz. */ -int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz, +int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, unsigned int flags, const char *esc) { - char *p = *dst; + char *p = dst; char *end = p + osz; bool is_dict = esc && *esc; - int ret; while (isz--) { unsigned char c = *src++; @@ -502,13 +474,6 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz, escape_passthrough(c, &p, end); } - if (p > end) { - *dst = end; - return -ENOMEM; - } - - ret = p - *dst; - *dst = p; - return ret; + return p - dst; } EXPORT_SYMBOL(string_escape_mem); diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c index ab0d30e1e18f..8e376efd88a4 100644 --- a/lib/test-string_helpers.c +++ b/lib/test-string_helpers.c @@ -260,16 +260,28 @@ static __init const char *test_string_find_match(const struct test_string_2 *s2, return NULL; } +static __init void +test_string_escape_overflow(const char *in, int p, unsigned int flags, const char *esc, + int q_test, const char *name) +{ + int q_real; + + q_real = string_escape_mem(in, p, NULL, 0, flags, esc); + if (q_real != q_test) + pr_warn("Test '%s' failed: flags = %u, osz = 0, expected %d, got %d\n", + name, flags, q_test, q_real); +} + static __init void test_string_escape(const char *name, const struct test_string_2 *s2, unsigned int flags, const char *esc) { - int q_real = 512; - char *out_test = kmalloc(q_real, GFP_KERNEL); - char *out_real = kmalloc(q_real, GFP_KERNEL); + size_t out_size = 512; + char *out_test = kmalloc(out_size, GFP_KERNEL); + char *out_real = kmalloc(out_size, GFP_KERNEL); char *in = kmalloc(256, GFP_KERNEL); - char *buf = out_real; int p = 0, q_test = 0; + int q_real; if (!out_test || !out_real || !in) goto out; @@ -301,29 +313,19 @@ static __init void test_string_escape(const char *name, q_test += len; } - q_real = string_escape_mem(in, p, &buf, q_real, flags, esc); + q_real = string_escape_mem(in, p, out_real, out_size, flags, esc); test_string_check_buf(name, flags, in, p, out_real, q_real, out_test, q_test); + + test_string_escape_overflow(in, p, flags, esc, q_test, name); + out: kfree(in); kfree(out_real); kfree(out_test); } -static __init void test_string_escape_nomem(void) -{ - char *in = "\eb \\C\007\"\x90\r]"; - char out[64], *buf = out; - int rc = -ENOMEM, ret; - - ret = string_escape_str_any_np(in, &buf, strlen(in), NULL); - if (ret == rc) - return; - - pr_err("Test 'escape nomem' failed: got %d instead of %d\n", ret, rc); -} - static int __init test_string_helpers_init(void) { unsigned int i; @@ -342,8 +344,6 @@ static int __init test_string_helpers_init(void) for (i = 0; i < (ESCAPE_ANY_NP | ESCAPE_HEX) + 1; i++) test_string_escape("escape 1", escape1, i, TEST_STRING_2_DICT_1); - test_string_escape_nomem(); - return -EINVAL; } module_init(test_string_helpers_init); diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 4da1e7aaf9d5..3a1e0843f9a2 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1235,8 +1235,12 @@ char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, len = spec.field_width < 0 ? 1 : spec.field_width; - /* Ignore the error. We print as many characters as we can */ - string_escape_mem(addr, len, &buf, end - buf, flags, NULL); + /* + * string_escape_mem() writes as many characters as it can to + * the given buffer, and returns the total size of the output + * had the buffer been big enough. + */ + buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); return buf; } |