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

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

[Qian Cai]

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 <cai@lca.pw>
---
 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)

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

[Mukesh Ojha]

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 <cai@lca.pw>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>

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",

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

[Nathan Chancellor]

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 <cai@lca.pw>

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

> ---
>  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)
> 

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

[Keith Busch]

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/