sandbox: Improve/augment memory allocation functions
Implement realloc() and free() for sandbox, by adding a header to each
block which contains the block size.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Che-Liang Chiou <clchiou@chromium.org>
Reviewed-by: Hung-ying Tyan <tyanh@chromium.org>
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 26f44cb..88dd371 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -27,6 +27,10 @@
/* Operating System Interface */
+struct os_mem_hdr {
+ size_t length; /* number of bytes in the block */
+};
+
ssize_t os_read(int fd, void *buf, size_t count)
{
return read(fd, buf, count);
@@ -128,8 +132,45 @@
void *os_malloc(size_t length)
{
- return mmap(NULL, length, PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ struct os_mem_hdr *hdr;
+
+ hdr = mmap(NULL, length + sizeof(*hdr), PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (hdr == MAP_FAILED)
+ return NULL;
+ hdr->length = length;
+
+ return hdr + 1;
+}
+
+void *os_free(void *ptr)
+{
+ struct os_mem_hdr *hdr = ptr;
+
+ hdr--;
+ if (ptr)
+ munmap(hdr, hdr->length + sizeof(*hdr));
+}
+
+void *os_realloc(void *ptr, size_t length)
+{
+ struct os_mem_hdr *hdr = ptr;
+ void *buf = NULL;
+
+ hdr--;
+ if (length != 0) {
+ buf = os_malloc(length);
+ if (!buf)
+ return buf;
+ if (ptr) {
+ if (length > hdr->length)
+ length = hdr->length;
+ memcpy(buf, ptr, length);
+ }
+ }
+ os_free(ptr);
+
+ return buf;
}
void os_usleep(unsigned long usec)