diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
index 6eb567ac56bc..7a082aa183a8 100644
--- a/include/linux/string_helpers.h
+++ b/include/linux/string_helpers.h
@@ -47,22 +47,22 @@ static inline int string_unescape_any_inplace(char *buf)
#define ESCAPE_ANY_NP (ESCAPE_ANY | ESCAPE_NP)
#define ESCAPE_HEX 0x20
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+size_t string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
unsigned int flags, const char *esc);
-static inline int string_escape_mem_any_np(const char *src, size_t isz,
- char **dst, size_t osz, const char *esc)
+static inline size_t string_escape_mem_any_np(const char *src, size_t isz,
+ char *dst, size_t osz, const char *esc)
{
return string_escape_mem(src, isz, dst, osz, ESCAPE_ANY_NP, esc);
}
-static inline int string_escape_str(const char *src, char **dst, size_t sz,
+static inline size_t string_escape_str(const char *src, char *dst, size_t sz,
unsigned int flags, const char *esc)
{
return string_escape_mem(src, strlen(src), dst, sz, flags, esc);
}
-static inline int string_escape_str_any_np(const char *src, char **dst,
+static inline size_t string_escape_str_any_np(const char *src, char *dst,
size_t sz, const char *esc)
{
return string_escape_str(src, dst, sz, ESCAPE_ANY_NP, esc);diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 58b78ba57439..288bacca74aa 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -243,28 +243,20 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
}
EXPORT_SYMBOL(string_unescape);
-static int escape_passthrough(unsigned char c, char **dst, size_t *osz)
+static bool escape_passthrough(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 1)
- return -ENOMEM;
-
- *out++ = c;
-
- *dst = out;
- *osz -= 1;
-
- return 1;
+ if (out < end)
+ *out = c;
+ *dst = out + 1;
+ return true;
}
-static int escape_space(unsigned char c, char **dst, size_t *osz)
+static bool escape_space(unsigned char c, char **dst, char *end)
{
- char *out = *dst;
unsigned char to;
-
- if (*osz < 2)
- return -ENOMEM;
+ char *out = *dst;
switch (c) {
case '\n':@@ -283,25 +275,22 @@ static int escape_space(unsigned char c, char **dst, size_t *osz)
to = 'f';
break;
default:
- return 0;
+ return false;
}
- *out++ = '\\';
- *out++ = to;
-
- *dst = out;
- *osz -= 2;
+ if (out + 0 < end)
+ out[0] = '\\';
+ if (out + 1 < end)
+ out[1] = to;
- return 1;
+ *dst = out + 2;
+ return true;
}
-static int escape_special(unsigned char c, char **dst, size_t *osz)
+static bool escape_special(unsigned char c, char **dst, char *end)
{
- char *out = *dst;
unsigned char to;
-
- if (*osz < 2)
- return -ENOMEM;
+ char *out = *dst;
switch (c) {
case '\\':@@ -314,71 +303,66 @@ static int escape_special(unsigned char c, char **dst, size_t *osz)
to = 'e';
break;
default:
- return 0;
+ return false;
}
- *out++ = '\\';
- *out++ = to;
+ if (out + 0 < end)
+ out[0] = '\\';
+ if (out + 1 < end)
+ out[1] = to;
- *dst = out;
- *osz -= 2;
-
- return 1;
+ *dst = out + 2;
+ return true;
}
-static int escape_null(unsigned char c, char **dst, size_t *osz)
+static bool escape_null(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 2)
- return -ENOMEM;
-
if (c)
- return 0;
-
- *out++ = '\\';
- *out++ = '0';
+ return false;
- *dst = out;
- *osz -= 2;
+ if (out + 0 < end)
+ out[0] = '\\';
+ if (out + 1 < end)
+ out[1] = '0';
- return 1;
+ *dst = out + 2;
+ return true;
}
-static int escape_octal(unsigned char c, char **dst, size_t *osz)
+static bool escape_octal(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 4)
- return -ENOMEM;
-
- *out++ = '\\';
- *out++ = ((c >> 6) & 0x07) + '0';
- *out++ = ((c >> 3) & 0x07) + '0';
- *out++ = ((c >> 0) & 0x07) + '0';
+ if (out + 0 < end)
+ out[0] = '\\';
+ if (out + 1 < end)
+ out[1] = ((c >> 6) & 0x07) + '0';
+ if (out + 2 < end)
+ out[2] = ((c >> 3) & 0x07) + '0';
+ if (out + 3 < end)
+ out[3] = ((c >> 0) & 0x07) + '0';
- *dst = out;
- *osz -= 4;
-
- return 1;
+ *dst = out + 4;
+ return true;
}
-static int escape_hex(unsigned char c, char **dst, size_t *osz)
+static bool escape_hex(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 4)
- return -ENOMEM;
+ if (out + 0 < end)
+ out[0] = '\\';
+ if (out + 1 < end)
+ out[1] = 'x';
+ if (out + 2 < end)
+ out[2] = hex_asc_hi(c);
+ if (out + 3 < end)
+ out[3] = hex_asc_lo(c);
- *out++ = '\\';
- *out++ = 'x';
- *out++ = hex_asc_hi(c);
- *out++ = hex_asc_lo(c);
-
- *dst = out;
- *osz -= 4;
-
- return 1;
+ *dst = out + 4;
+ return true;
}
/**@@ -430,19 +414,17 @@ static int escape_hex(unsigned char c, char **dst, size_t *osz)
* 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,
- unsigned int flags, const char *esc)
+size_t string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
+ unsigned int flags, const char *esc)
{
- char *out = *dst, *p = out;
+ char *p = dst;
+ char *end = dst + osz;
bool is_dict = esc && *esc;
- int ret = 0;
while (isz--) {
unsigned char c = *src++;@@ -462,55 +444,26 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
(is_dict && !strchr(esc, c))) {
/* do nothing */
} else {
- if (flags & ESCAPE_SPACE) {
- ret = escape_space(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
-
- if (flags & ESCAPE_SPECIAL) {
- ret = escape_special(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
-
- if (flags & ESCAPE_NULL) {
- ret = escape_null(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
+ if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+ continue;
+
+ if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+ continue;
+
+ if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+ continue;
/* ESCAPE_OCTAL and ESCAPE_HEX always go last */
- if (flags & ESCAPE_OCTAL) {
- ret = escape_octal(c, &p, &osz);
- if (ret < 0)
- break;
+ if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
continue;
- }
- if (flags & ESCAPE_HEX) {
- ret = escape_hex(c, &p, &osz);
- if (ret < 0)
- break;
+
+ if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
continue;
- }
}
- ret = escape_passthrough(c, &p, &osz);
- if (ret < 0)
- break;
+ escape_passthrough(c, &p, end);
}
- *dst = p;
-
- if (ret < 0)
- return ret;
-
- return p - out;
+ return p - dst;
}
EXPORT_SYMBOL(string_escape_mem);diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index ab0d30e1e18f..5f95114a2f86 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -264,12 +264,12 @@ 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;
+ size_t p = 0, q_test = 0;
+ size_t q_real;
if (!out_test || !out_real || !in)
goto out;@@ -301,29 +301,26 @@ 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);
+
+ memset(out_real, 'Z', out_size);
+ q_real = string_escape_mem(in, p, out_real, 0, flags, esc);
+ if (q_real != q_test)
+ pr_warn("Test '%s' failed: flags = %u, osz = 0, expected %zu, got %zu\n",
+ name, flags, q_test, q_real);
+ if (memchr_inv(out_real, 'Z', out_size))
+ pr_warn("Test '%s' failed: osz = 0 but string_escape_mem wrote to the buffer\n",
+ 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 +339,6 @@ 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 0d57be58448f..a3e474f9957f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1165,7 +1165,7 @@ 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);
+ buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
return buf;
}
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 33fb105d4352..22c4418057f4 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1068,12 +1068,14 @@ void qword_add(char **bpp, int *lp, char *str)
{
char *bp = *bpp;
int len = *lp;
- int ret;
+ int ret, written;
if (len < 0) return;
- ret = string_escape_str(str, &bp, len, ESCAPE_OCTAL, "\\ \n\t");
- if (ret < 0 || ret == len)
+ ret = string_escape_str(str, bp, len, ESCAPE_OCTAL, "\\ \n\t");
+ written = min(ret, len);
+ bp += written;
+ if (ret >= len)
len = -1;
else {
len -= ret;--
2.1.3