2019-04-07 01:17:31

by Qian Cai

Subject: [PATCH -next] acpi/hmat: fix an uninitialized memory_target

The commit 665ac7e92757 ("acpi/hmat: Register processor domain to its
memory") introduced an uninitialized "struct memory_target" that could
cause an incorrect branching.

drivers/acpi/hmat/hmat.c:385:6: warning: variable 'target' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/acpi/hmat/hmat.c:392:6: note: uninitialized use occurs here
if (target && p->flags & ACPI_HMAT_PROCESSOR_PD_VALID) {
^~~~~~
drivers/acpi/hmat/hmat.c:385:2: note: remove the 'if' if its condition
is always true
if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/acpi/hmat/hmat.c:369:30: note: initialize the variable 'target'
to silence this warning
struct memory_target *target;
^
= NULL

Signed-off-by: Qian Cai <[email protected]>
---
drivers/acpi/hmat/hmat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
index c9b8abcf012c..6653dba3b377 100644
--- a/drivers/acpi/hmat/hmat.c
+++ b/drivers/acpi/hmat/hmat.c
@@ -366,7 +366,7 @@ static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *heade
const unsigned long end)
{
struct acpi_hmat_proximity_domain *p = (void *)header;
- struct memory_target *target;
+ struct memory_target *target = NULL;

if (p->header.length != sizeof(*p)) {
pr_notice("HMAT: Unexpected address range header length: %d\n",
--
2.17.2 (Apple Git-113)

2019-04-07 06:22:14

by Mukesh Ojha

Subject: Re: [PATCH -next] acpi/hmat: fix an uninitialized memory_target

On 4/7/2019 6:42 AM, Qian Cai wrote:
> The commit 665ac7e92757 ("acpi/hmat: Register processor domain to its
> memory") introduced an uninitialized "struct memory_target" that could
> cause an incorrect branching.
>
> drivers/acpi/hmat/hmat.c:385:6: warning: variable 'target' is used
> uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
> if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/acpi/hmat/hmat.c:392:6: note: uninitialized use occurs here
> if (target && p->flags & ACPI_HMAT_PROCESSOR_PD_VALID) {
> ^~~~~~
> drivers/acpi/hmat/hmat.c:385:2: note: remove the 'if' if its condition
> is always true
> if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/acpi/hmat/hmat.c:369:30: note: initialize the variable 'target'
> to silence this warning
> struct memory_target *target;
> ^
> = NULL
>
> Signed-off-by: Qian Cai <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>

Cheers,
-Mukesh

> ---
> drivers/acpi/hmat/hmat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
> index c9b8abcf012c..6653dba3b377 100644
> --- a/drivers/acpi/hmat/hmat.c
> +++ b/drivers/acpi/hmat/hmat.c
> @@ -366,7 +366,7 @@ static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *heade
> const unsigned long end)
> {
> struct acpi_hmat_proximity_domain *p = (void *)header;
> - struct memory_target *target;
> + struct memory_target *target = NULL;
>
> if (p->header.length != sizeof(*p)) {
> pr_notice("HMAT: Unexpected address range header length: %d\n",

2019-04-07 11:24:56

by Nathan Chancellor

Subject: Re: [PATCH -next] acpi/hmat: fix an uninitialized memory_target

On Sat, Apr 06, 2019 at 09:12:22PM -0400, Qian Cai wrote:
> The commit 665ac7e92757 ("acpi/hmat: Register processor domain to its
> memory") introduced an uninitialized "struct memory_target" that could
> cause an incorrect branching.
>
> drivers/acpi/hmat/hmat.c:385:6: warning: variable 'target' is used
> uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
> if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/acpi/hmat/hmat.c:392:6: note: uninitialized use occurs here
> if (target && p->flags & ACPI_HMAT_PROCESSOR_PD_VALID) {
> ^~~~~~
> drivers/acpi/hmat/hmat.c:385:2: note: remove the 'if' if its condition
> is always true
> if (p->flags & ACPI_HMAT_MEMORY_PD_VALID) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/acpi/hmat/hmat.c:369:30: note: initialize the variable 'target'
> to silence this warning
> struct memory_target *target;
> ^
> = NULL
>
> Signed-off-by: Qian Cai <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
> drivers/acpi/hmat/hmat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
> index c9b8abcf012c..6653dba3b377 100644
> --- a/drivers/acpi/hmat/hmat.c
> +++ b/drivers/acpi/hmat/hmat.c
> @@ -366,7 +366,7 @@ static int __init hmat_parse_proximity_domain(union acpi_subtable_headers *heade
> const unsigned long end)
> {
> struct acpi_hmat_proximity_domain *p = (void *)header;
> - struct memory_target *target;
> + struct memory_target *target = NULL;
>
> if (p->header.length != sizeof(*p)) {
> pr_notice("HMAT: Unexpected address range header length: %d\n",
> --
> 2.17.2 (Apple Git-113)
>

2019-04-08 16:07:38

by Keith Busch

Subject: Re: [PATCH -next] acpi/hmat: fix an uninitialized memory_target

On Sat, Apr 06, 2019 at 09:12:22PM -0400, Qian Cai wrote:
> The commit 665ac7e92757 ("acpi/hmat: Register processor domain to its
> memory") introduced an uninitialized "struct memory_target" that could
> cause an incorrect branching.

Thanks for the catch. We do have another patch submitted a few days that
fixes this, though:

https://patchwork.kernel.org/patch/10887487/