We provide os_malloc() and os_free() but not os_realloc(). Add this,
following the usual semantics. Also update os_malloc() to behave correctly
when passed a zero size.
Signed-off-by: Simon Glass <s...@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.g...@gmx.de>
---
(no changes since v3)
Changes in v3:
- Add comments as to why we have os_malloc() and os_realloc()
Changes in v2:
- Add new patch to add os_realloc()
arch/sandbox/cpu/os.c | 48 +++++++++++++++++++++++++++++++++++++++++++
include/os.h | 12 ++++++++++-
2 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 3d8af0a52bb..d23aad318be 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -267,11 +267,18 @@ void os_tty_raw(int fd, bool allow_sigs)
signal(SIGINT, os_sigint_handler);
}
+/*
+ * Provide our own malloc so we don't use space in the sandbox ram_buf for
+ * allocations that are internal to sandbox, or need to be done before U-Boot's
+ * malloc() is ready.
+ */
void *os_malloc(size_t length)
{
int page_size = getpagesize();
struct os_mem_hdr *hdr;
+ if (!length)
+ return NULL;
/*
* Use an address that is hopefully available to us so that pointers
* to this memory are fairly obvious. If we end up with a different
@@ -298,6 +305,47 @@ void os_free(void *ptr)
}
}
+/* These macros are from kernel.h but not accessible in this file */
+#define ALIGN(x, a) __ALIGN_MASK((x), (typeof(x))(a) - 1)
+#define __ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
+
+/*
+ * Provide our own malloc so we don't use space in the sandbox ram_buf for
+ * allocations that are internal to sandbox, or need to be done before U-Boot's
+ * malloc() is ready.
+ */
+void *os_realloc(void *ptr, size_t length)
+{
+ int page_size = getpagesize();
+ struct os_mem_hdr *hdr;
+ void *new_ptr;
+
+ /* Reallocating a NULL pointer is just an alloc */
+ if (!ptr)
+ return os_malloc(length);
+
+ /* Changing a length to 0 is just a free */
+ if (length) {
+ os_free(ptr);
+ return NULL;
+ }
+
+ /*
+ * If the new size is the same number of pages as the old, nothing to
+ * do. There isn't much point in shrinking things
+ */
+ hdr = ptr - page_size;
+ if (ALIGN(length, page_size) <= ALIGN(hdr->length, page_size))
+ return ptr;
+
+ /* We have to grow it, so allocate something new */
+ new_ptr = os_malloc(length);
+ memcpy(new_ptr, ptr, hdr->length);
+ os_free(ptr);
+
+ return new_ptr;
+}
+
void os_usleep(unsigned long usec)
{
usleep(usec);
diff --git a/include/os.h b/include/os.h
index 65bcb232cab..fd010cfee83 100644
--- a/include/os.h
+++ b/include/os.h
@@ -114,7 +114,7 @@ void os_fd_restore(void);
* os_malloc() - aquires some memory from the underlying os.
*
* @length: Number of bytes to be allocated
- * Return: Pointer to length bytes or NULL on error
+ * Return: Pointer to length bytes or NULL if @length is 0 or on error
*/
void *os_malloc(size_t length);
@@ -127,6 +127,16 @@ void *os_malloc(size_t length);
*/
void os_free(void *ptr);
+/**
+ * os_realloc() - reallocate memory
+ *
+ * This follows the semantics of realloc(), so can perform an os_malloc() or
+ * os_free() depending on @ptr and @length.
+ *
+ * Return: Pointer to reallocated memory or NULL if @length is 0
+ */
+void *os_realloc(void *ptr, size_t length);
+
/**
* os_usleep() - access to the usleep function of the os
*
--
2.30.0.478.g8a0d178c01-goog
