Add a function to duplicate a memory region, a little like strdup().
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v2: - Add a patch to introduce a memdup() function
include/linux/string.h | 13 +++++++++++++ lib/string.c | 13 +++++++++++++ test/lib/string.c | 32 ++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h index dd255f21633..3169c93796e 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -129,6 +129,19 @@ extern void * memchr(const void *,int,__kernel_size_t); void *memchr_inv(const void *, int, size_t); #endif
+/** + * memdup() - allocate a buffer and copy in the contents + * + * Note that this returns a valid pointer even if @len is 0 + * + * @src: data to copy in + * @len: number of bytes to copy + * @return allocated buffer with the copied contents, or NULL if not enough + * memory is available + * + */ +char *memdup(const void *src, size_t len); + unsigned long ustrtoul(const char *cp, char **endp, unsigned int base); unsigned long long ustrtoull(const char *cp, char **endp, unsigned int base);
diff --git a/lib/string.c b/lib/string.c index a0cff8fe88e..1be61ee0499 100644 --- a/lib/string.c +++ b/lib/string.c @@ -658,6 +658,19 @@ void * memscan(void * addr, int c, size_t size) } #endif
+char *memdup(const void *src, size_t len) +{ + char *p; + + p = malloc(len); + if (!p) + return NULL; + + memcpy(p, src, len); + + return p; +} + #ifndef __HAVE_ARCH_STRSTR /** * strstr - Find the first substring in a %NUL terminated string diff --git a/test/lib/string.c b/test/lib/string.c index 64234bef36c..5dcf4d6db00 100644 --- a/test/lib/string.c +++ b/test/lib/string.c @@ -23,6 +23,8 @@ /* Allow for copying up to 32 bytes */ #define BUFLEN (SWEEP + 33)
+#define TEST_STR "hello" + /** * init_buffer() - initialize buffer * @@ -193,3 +195,33 @@ static int lib_memmove(struct unit_test_state *uts) }
LIB_TEST(lib_memmove, 0); + +/** lib_memdup() - unit test for memdup() */ +static int lib_memdup(struct unit_test_state *uts) +{ + char buf[BUFLEN]; + size_t len; + char *p, *q; + + /* Zero size should do nothing */ + p = memdup(NULL, 0); + ut_assertnonnull(p); + free(p); + + p = memdup(buf, 0); + ut_assertnonnull(p); + free(p); + + strcpy(buf, TEST_STR); + len = sizeof(TEST_STR); + p = memdup(buf, len); + ut_asserteq_mem(p, buf, len); + + q = memdup(p, len); + ut_asserteq_mem(q, buf, len); + free(q); + free(p); + + return 0; +} +LIB_TEST(lib_memdup, 0);