[PATCH v2 01/50] lib: Add memdup()
Simon Glass
sjg at chromium.org
Thu May 6 16:23:49 CEST 2021
Add a function to duplicate a memory region, a little like strdup().
Signed-off-by: Simon Glass <sjg at 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);
--
2.31.1.607.g51e8a6a459-goog
More information about the U-Boot
mailing list