Hi Fred,
Thanks for your reply.
But there is a question, whether we should return an error code in error
path so that the caller of the 'cxl_get_fd' can know the specific
reason. rather than just return NULL.
Such as:
- int rc, flags, fdtmp;
+ int rc = 0, flags, fdtmp;
char *name = NULL;
/* only allow one per context */
- if (ctx->mapping)
- return ERR_PTR(-EEXIST);
+ if (ctx->mapping) {
+ rc = -EEXIST;
+ goto err;
+ }
flags = O_RDWR | O_CLOEXEC;
/* This code is similar to anon_inode_getfd() */
rc = get_unused_fd_flags(flags);
- if (rc < 0)
- return ERR_PTR(rc);
+ if (rc < 0) {
+ goto err;
+ }
fdtmp = rc;
name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe);
+ if (!name) {
+ rc = -ENOMEM;
+ goto err_fd;
+ }
file = cxl_getfile(name, fops, ctx, flags);
kfree(name);
@@ -434,6 +437,9 @@ struct file *cxl_get_fd(struct cxl_context *ctx,
struct file_operations *fops,
err_fd:
put_unused_fd(fdtmp);
+err:
+ if (rc)
+ return ERR_PTR(rc);
return NULL;
Thanks again,
Kunwu
On 2023/12/4 18:43, Frederic Barrat wrote:
On 04/12/2023 03:07, Kunwu Chan wrote:
kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.
Fixes: bdecf76e319a ("cxl: Fix coredump generation when cxl_get_fd()
is used")
Signed-off-by: Kunwu Chan <chen...@kylinos.cn>
---
drivers/misc/cxl/api.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index d85c56530863..bfd7ccd4d7e1 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -419,6 +419,10 @@ struct file *cxl_get_fd(struct cxl_context *ctx,
struct file_operations *fops,
fops = (struct file_operations *)&afu_fops;
name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe);
+ if (!name) {
+ put_unused_fd(fdtmp);
+ return ERR_PTR(-ENOMEM);
+ }
That works, but you might as well follow the existing error path:
name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe);
if (!name)
goto err_fd;
Fred
file = cxl_getfile(name, fops, ctx, flags);
kfree(name);
if (IS_ERR(file))
