1 files changed, 50 insertions, 9 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index a8d01e4001..47dfb476d3 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -209,8 +209,8 @@ void os_tty_raw(int fd, bool allow_sigs)
 
 void *os_malloc(size_t length)
 {
-	struct os_mem_hdr *hdr;
 	int page_size = getpagesize();
+	struct os_mem_hdr *hdr;
 
 	/*
 	 * Use an address that is hopefully available to us so that pointers
@@ -229,30 +229,34 @@ void *os_malloc(size_t length)
 
 void os_free(void *ptr)
 {
-	struct os_mem_hdr *hdr = ptr;
+	int page_size = getpagesize();
+	struct os_mem_hdr *hdr;
 
-	hdr--;
-	if (ptr)
-		munmap(hdr, hdr->length + sizeof(*hdr));
+	if (ptr) {
+		hdr = ptr - page_size;
+		munmap(hdr, hdr->length + page_size);
+	}
 }
 
 void *os_realloc(void *ptr, size_t length)
 {
-	struct os_mem_hdr *hdr = ptr;
+	int page_size = getpagesize();
+	struct os_mem_hdr *hdr;
 	void *buf = NULL;
 
-	hdr--;
-	if (length != 0) {
+	if (length) {
 		buf = os_malloc(length);
 		if (!buf)
 			return buf;
 		if (ptr) {
+			hdr = ptr - page_size;
 			if (length > hdr->length)
 				length = hdr->length;
 			memcpy(buf, ptr, length);
 		}
 	}
-	os_free(ptr);
+	if (ptr)
+		os_free(ptr);
 
 	return buf;
 }
@@ -786,3 +790,40 @@ int os_mprotect_allow(void *start, size_t len)
 
 	return mprotect(start, len, PROT_READ | PROT_WRITE);
 }
+
+void *os_find_text_base(void)
+{
+	char line[500];
+	void *base = NULL;
+	int len;
+	int fd;
+
+	/*
+	 * This code assumes that the first line of /proc/self/maps holds
+	 * information about the text, for example:
+	 *
+	 * 5622d9907000-5622d9a55000 r-xp 00000000 08:01 15067168   u-boot
+	 *
+	 * The first hex value is assumed to be the address.
+	 *
+	 * This is tested in Linux 4.15.
+	 */
+	fd = open("/proc/self/maps", O_RDONLY);
+	if (fd == -1)
+		return NULL;
+	len = read(fd, line, sizeof(line));
+	if (len > 0) {
+		char *end = memchr(line, '-', len);
+
+		if (end) {
+			unsigned long long addr;
+
+			*end = '\0';
+			if (sscanf(line, "%llx", &addr) == 1)
+				base = (void *)addr;
+		}
+	}
+	close(fd);
+
+	return base;
+}