[PATCH][next] ACPI: scan: ensure ret is initialized to avoid garbage being returned

[PATCH][next] ACPI: scan: ensure ret is initialized to avoid garbage being returned

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

In the unlikely event that there are no callback calls made then ret
will be returned as an uninitialized value. Clean up static analysis
warnings by ensuring ret is initialized.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: a9e10e587304 ("ACPI: scan: Extend acpi_walk_dep_device_list()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/acpi/scan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index c3067e8bfc47..0945d952f0fc 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2151,7 +2151,7 @@ int acpi_walk_dep_device_list(acpi_handle handle,
 			      void *data)
 {
 	struct acpi_dep_data *dep, *tmp;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&acpi_dep_list_lock);
 	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
-- 
2.31.1

Re: [PATCH][next] ACPI: scan: ensure ret is initialized to avoid garbage being returned

[Daniel Scally]

Hi Colin

On Wed, Jun 9, 2021 at 6:33 PM Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> In the unlikely event that there are no callback calls made then ret
> will be returned as an uninitialized value. Clean up static analysis
> warnings by ensuring ret is initialized.

Ah, thanks - good spot.

> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: a9e10e587304 ("ACPI: scan: Extend acpi_walk_dep_device_list()")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Reviewed-by: Daniel Scally <djrscally@gmail.com>

I'm still bad at Git; will the commit hash here be right, since the
patch that this fixes isn't upstream yet?

(hope the gmail web client doesn't maul this too badly...)
> ---
>  drivers/acpi/scan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index c3067e8bfc47..0945d952f0fc 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2151,7 +2151,7 @@ int acpi_walk_dep_device_list(acpi_handle handle,
>                               void *data)
>  {
>         struct acpi_dep_data *dep, *tmp;
> -       int ret;
> +       int ret = 0;
>
>         mutex_lock(&acpi_dep_list_lock);
>         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
> --
> 2.31.1
>

Re: [PATCH][next] ACPI: scan: ensure ret is initialized to avoid garbage being returned

[Dan Carpenter]

On Wed, Jun 09, 2021 at 10:38:04PM +0100, Daniel Scally wrote:
> Hi Colin
> 
> On Wed, Jun 9, 2021 at 6:33 PM Colin King <colin.king@canonical.com> wrote:
> >
> > From: Colin Ian King <colin.king@canonical.com>
> >
> > In the unlikely event that there are no callback calls made then ret
> > will be returned as an uninitialized value. Clean up static analysis
> > warnings by ensuring ret is initialized.
> 
> Ah, thanks - good spot.
> 
> > Addresses-Coverity: ("Uninitialized scalar variable")
> > Fixes: a9e10e587304 ("ACPI: scan: Extend acpi_walk_dep_device_list()")
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
> 
> Reviewed-by: Daniel Scally <djrscally@gmail.com>
> 
> I'm still bad at Git; will the commit hash here be right, since the
> patch that this fixes isn't upstream yet?

The hash is stable unless the branch rebases.  When maintainers rebase a
branch, they're expected to update the Fixes tags as well.  Most people
probably have a script to do it.  I think Stephen Rothwell has a script
which checks whether Fixes tags are correct?

regards,
dan carpenter

Re: [PATCH][next] ACPI: scan: ensure ret is initialized to avoid garbage being returned

[Rafael J. Wysocki]

On Wed, Jun 9, 2021 at 7:33 PM Colin King <colin.king@canonical.com> wrote:
>
> From: Colin Ian King <colin.king@canonical.com>
>
> In the unlikely event that there are no callback calls made then ret
> will be returned as an uninitialized value. Clean up static analysis
> warnings by ensuring ret is initialized.
>
> Addresses-Coverity: ("Uninitialized scalar variable")
> Fixes: a9e10e587304 ("ACPI: scan: Extend acpi_walk_dep_device_list()")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/acpi/scan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index c3067e8bfc47..0945d952f0fc 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2151,7 +2151,7 @@ int acpi_walk_dep_device_list(acpi_handle handle,
>                               void *data)
>  {
>         struct acpi_dep_data *dep, *tmp;
> -       int ret;
> +       int ret = 0;
>
>         mutex_lock(&acpi_dep_list_lock);
>         list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
> --

Applied with some edits in the subject and changelog.

Basically, if you make changes like this, please specify which piece
of code you change in the subject/changelog.

Thanks!