misc: fastrpc: Rework fastrpc_req_munmap

Move the lookup of the munmap request to the fastrpc_req_munmap and pass
on only the buf to the lower level fastrpc_req_munmap_impl. That way
we can use the lower level fastrpc_req_munmap_impl on error path in
fastrpc_req_mmap to free the buf without searching for the munmap
request it belongs to.

Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221125071405.148786-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 332626d..4590a11 100644 (file)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1627,30 +1627,14 @@ static int fastrpc_get_dsp_info(struct fastrpc_user *fl, char __user *argp)
        return 0;
 }
 
-static int fastrpc_req_munmap_impl(struct fastrpc_user *fl,
-                                  struct fastrpc_req_munmap *req)
+static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *buf)
 {
        struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
-       struct fastrpc_buf *buf = NULL, *iter, *b;
        struct fastrpc_munmap_req_msg req_msg;
        struct device *dev = fl->sctx->dev;
        int err;
        u32 sc;
 
-       spin_lock(&fl->lock);
-       list_for_each_entry_safe(iter, b, &fl->mmaps, node) {
-               if ((iter->raddr == req->vaddrout) && (iter->size == req->size)) {
-                       buf = iter;
-                       break;
-               }
-       }
-       spin_unlock(&fl->lock);
-
-       if (!buf) {
-               dev_err(dev, "mmap not in list\n");
-               return -EINVAL;
-       }
-
        req_msg.pgid = fl->tgid;
        req_msg.size = buf->size;
        req_msg.vaddr = buf->raddr;
@@ -1676,12 +1660,29 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl,
 
 static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 {
+       struct fastrpc_buf *buf = NULL, *iter, *b;
        struct fastrpc_req_munmap req;
+       struct device *dev = fl->sctx->dev;
 
        if (copy_from_user(&req, argp, sizeof(req)))
                return -EFAULT;
 
-       return fastrpc_req_munmap_impl(fl, &req);
+       spin_lock(&fl->lock);
+       list_for_each_entry_safe(iter, b, &fl->mmaps, node) {
+               if ((iter->raddr == req.vaddrout) && (iter->size == req.size)) {
+                       buf = iter;
+                       break;
+               }
+       }
+       spin_unlock(&fl->lock);
+
+       if (!buf) {
+               dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
+                       req.vaddrout, req.size);
+               return -EINVAL;
+       }
+
+       return fastrpc_req_munmap_impl(fl, buf);
 }
 
 static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
@@ -1690,7 +1691,6 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
        struct fastrpc_buf *buf = NULL;
        struct fastrpc_mmap_req_msg req_msg;
        struct fastrpc_mmap_rsp_msg rsp_msg;
-       struct fastrpc_req_munmap req_unmap;
        struct fastrpc_phy_page pages;
        struct fastrpc_req_mmap req;
        struct device *dev = fl->sctx->dev;
@@ -1752,11 +1752,8 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
        spin_unlock(&fl->lock);
 
        if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
-               /* unmap the memory and release the buffer */
-               req_unmap.vaddrout = buf->raddr;
-               req_unmap.size = buf->size;
-               fastrpc_req_munmap_impl(fl, &req_unmap);
-               return -EFAULT;
+               err = -EFAULT;
+               goto err_assign;
        }
 
        dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n",
@@ -1764,6 +1761,8 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 
        return 0;
 
+err_assign:
+       fastrpc_req_munmap_impl(fl, buf);
 err_invoke:
        fastrpc_buf_free(buf);