[PATCH -next] btf: fix return value check in btf_vmlinux_init()

[PATCH -next] btf: fix return value check in btf_vmlinux_init()

[Wei Yongjun]

In case of error, the function kobject_create_and_add() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Fixes: 341dfcf8d78e ("btf: expose BTF info through sysfs")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 kernel/bpf/sysfs_btf.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
index 4659349fc795..be5557deb958 100644
--- a/kernel/bpf/sysfs_btf.c
+++ b/kernel/bpf/sysfs_btf.c
@@ -30,16 +30,13 @@ static struct kobject *btf_kobj;
 
 static int __init btf_vmlinux_init(void)
 {
-	int err;
-
 	if (!_binary__btf_vmlinux_bin_start)
 		return 0;
 
 	btf_kobj = kobject_create_and_add("btf", kernel_kobj);
-	if (IS_ERR(btf_kobj)) {
-		err = PTR_ERR(btf_kobj);
+	if (!btf_kobj) {
 		btf_kobj = NULL;
-		return err;
+		return -ENOMEM;
 	}
 
 	bin_attr_btf_vmlinux.size = _binary__btf_vmlinux_bin_end -

Re: [PATCH -next] btf: fix return value check in btf_vmlinux_init()

[Andrii Nakryiko]

On Thu, Aug 15, 2019 at 7:21 AM Wei Yongjun <weiyongjun1@huawei.com> wrote:
>
> In case of error, the function kobject_create_and_add() returns NULL
> pointer not ERR_PTR(). The IS_ERR() test in the return value check
> should be replaced with NULL test.
>
> Fixes: 341dfcf8d78e ("btf: expose BTF info through sysfs")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> ---


Argh... Thanks for the fix! Fix the comment below addressed:

Acked-by: Andrii Nakryiko <andriin@fb.com>

>  kernel/bpf/sysfs_btf.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
> index 4659349fc795..be5557deb958 100644
> --- a/kernel/bpf/sysfs_btf.c
> +++ b/kernel/bpf/sysfs_btf.c
> @@ -30,16 +30,13 @@ static struct kobject *btf_kobj;
>
>  static int __init btf_vmlinux_init(void)
>  {
> -       int err;
> -
>         if (!_binary__btf_vmlinux_bin_start)
>                 return 0;
>
>         btf_kobj = kobject_create_and_add("btf", kernel_kobj);
> -       if (IS_ERR(btf_kobj)) {
> -               err = PTR_ERR(btf_kobj);
> +       if (!btf_kobj) {
>                 btf_kobj = NULL;

This is now not necessary, please drop (and don't forget to remove {}
for this single-line if afterwards).

> -               return err;
> +               return -ENOMEM;
>         }
>
>         bin_attr_btf_vmlinux.size = _binary__btf_vmlinux_bin_end -
>
>
>

[PATCH -next v2] btf: fix return value check in btf_vmlinux_init()

[Wei Yongjun]

In case of error, the function kobject_create_and_add() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Fixes: 341dfcf8d78e ("btf: expose BTF info through sysfs")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
---
 kernel/bpf/sysfs_btf.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
index 4659349fc795..7ae5dddd1fe6 100644
--- a/kernel/bpf/sysfs_btf.c
+++ b/kernel/bpf/sysfs_btf.c
@@ -30,17 +30,12 @@ static struct kobject *btf_kobj;
 
 static int __init btf_vmlinux_init(void)
 {
-	int err;
-
 	if (!_binary__btf_vmlinux_bin_start)
 		return 0;
 
 	btf_kobj = kobject_create_and_add("btf", kernel_kobj);
-	if (IS_ERR(btf_kobj)) {
-		err = PTR_ERR(btf_kobj);
-		btf_kobj = NULL;
-		return err;
-	}
+	if (!btf_kobj)
+		return -ENOMEM;
 
 	bin_attr_btf_vmlinux.size = _binary__btf_vmlinux_bin_end -
 				    _binary__btf_vmlinux_bin_start;

Re: [PATCH -next v2] btf: fix return value check in btf_vmlinux_init()

[Alexei Starovoitov]

On Thu, Aug 15, 2019 at 7:36 PM Wei Yongjun <weiyongjun1@huawei.com> wrote:
>
> In case of error, the function kobject_create_and_add() returns NULL
> pointer not ERR_PTR(). The IS_ERR() test in the return value check
> should be replaced with NULL test.
>
> Fixes: 341dfcf8d78e ("btf: expose BTF info through sysfs")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> Acked-by: Andrii Nakryiko <andriin@fb.com>

Applied. Thanks.

Please spell out [PATCH v2 bpf-next] in the subject next time.