udebug: fix file descriptor initialization for __udebug_buf_map

Pass the fd to __udebug_buf_map, set buf->fd only if mapping worked

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/udebug.c b/udebug.c
index 81afc789d9b646d2fa3fd8152e323a15280dd9e5..31b0210d7068d36333485330a443359074277ba6 100644 (file)
--- a/udebug.c
+++ b/udebug.c
@@ -113,7 +113,7 @@ uint64_t udebug_timestamp(void)
 }
 
 static int
-__udebug_buf_map(struct udebug_buf *buf)
+__udebug_buf_map(struct udebug_buf *buf, int fd)
 {
        unsigned int pad = 0;
        void *ptr, *ptr2;
@@ -131,12 +131,12 @@ __udebug_buf_map(struct udebug_buf *buf)
 #endif
 
        ptr2 = mmap(ptr, buf->head_size + buf->data_size,
-                   PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, buf->fd, 0);
+                   PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd, 0);
        if (ptr2 != ptr)
                goto err_unmap;
 
        ptr2 = mmap(ptr + buf->head_size + buf->data_size, buf->data_size,
-                   PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, buf->fd,
+                   PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, fd,
                    buf->head_size);
        if (ptr2 != ptr + buf->head_size + buf->data_size)
                goto err_unmap;
@@ -425,7 +425,6 @@ int udebug_buf_open(struct udebug_buf *buf, int fd, uint32_t ring_size, uint32_t
 {
        udebug_init_page_size();
        INIT_LIST_HEAD(&buf->list);
-       buf->fd = fd;
        buf->ring_size = ring_size;
        buf->head_size = __udebug_headsize(ring_size);
        buf->data_size = data_size;
@@ -433,7 +432,7 @@ int udebug_buf_open(struct udebug_buf *buf, int fd, uint32_t ring_size, uint32_t
        if (buf->ring_size > (1U << 24) || buf->data_size > (1U << 29))
                return -1;
 
-       if (__udebug_buf_map(buf))
+       if (__udebug_buf_map(buf, fd))
                return -1;
 
        if (buf->ring_size != buf->hdr->ring_size ||
@@ -443,6 +442,8 @@ int udebug_buf_open(struct udebug_buf *buf, int fd, uint32_t ring_size, uint32_t
                return -1;
        }
 
+       buf->fd = fd;
+
        return 0;
 }
 
@@ -483,7 +484,7 @@ int udebug_buf_init(struct udebug_buf *buf, size_t entries, size_t size)
        buf->data_size = size;
        buf->ring_size = entries;
 
-       if (__udebug_buf_map(buf))
+       if (__udebug_buf_map(buf, fd))
                goto err_close;
 
        buf->fd = fd;