2022-07-21 14:16:49

by Andrey Strachuk

Subject: [PATCH v3] ACPI/PCI: Remove useless NULL pointer checks

Local variable 'p' is initialized by an address of field of acpi_resource,
so it does not make sense to compare 'p' with NULL.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Strachuk <[email protected]>
---
drivers/acpi/pci_link.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index 58647051c948..aa1038b8aec4 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -95,7 +95,7 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
case ACPI_RESOURCE_TYPE_IRQ:
{
struct acpi_resource_irq *p = &resource->data.irq;
- if (!p || !p->interrupt_count) {
+ if (!p->interrupt_count) {
acpi_handle_debug(handle,
"Blank _PRS IRQ resource\n");
return AE_OK;
@@ -121,7 +121,7 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
{
struct acpi_resource_extended_irq *p =
&resource->data.extended_irq;
- if (!p || !p->interrupt_count) {
+ if (!p->interrupt_count) {
acpi_handle_debug(handle,
"Blank _PRS EXT IRQ resource\n");
return AE_OK;
@@ -182,7 +182,7 @@ static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
case ACPI_RESOURCE_TYPE_IRQ:
{
struct acpi_resource_irq *p = &resource->data.irq;
- if (!p || !p->interrupt_count) {
+ if (!p->interrupt_count) {
/*
* IRQ descriptors may have no IRQ# bits set,
* particularly those w/ _STA disabled
@@ -197,7 +197,7 @@ static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
{
struct acpi_resource_extended_irq *p =
&resource->data.extended_irq;
- if (!p || !p->interrupt_count) {
+ if (!p->interrupt_count) {
/*
* extended IRQ descriptors must
* return at least 1 IRQ
--
2.25.1

2022-07-27 19:34:01

by Rafael J. Wysocki

Subject: Re: [PATCH v3] ACPI/PCI: Remove useless NULL pointer checks

On Thu, Jul 21, 2022 at 4:12 PM Andrey Strachuk <[email protected]> wrote:
>
> Local variable 'p' is initialized by an address of field of acpi_resource,
> so it does not make sense to compare 'p' with NULL.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Andrey Strachuk <[email protected]>
> ---
> drivers/acpi/pci_link.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index 58647051c948..aa1038b8aec4 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -95,7 +95,7 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
> case ACPI_RESOURCE_TYPE_IRQ:
> {
> struct acpi_resource_irq *p = &resource->data.irq;
> - if (!p || !p->interrupt_count) {
> + if (!p->interrupt_count) {
> acpi_handle_debug(handle,
> "Blank _PRS IRQ resource\n");
> return AE_OK;
> @@ -121,7 +121,7 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
> {
> struct acpi_resource_extended_irq *p =
> &resource->data.extended_irq;
> - if (!p || !p->interrupt_count) {
> + if (!p->interrupt_count) {
> acpi_handle_debug(handle,
> "Blank _PRS EXT IRQ resource\n");
> return AE_OK;
> @@ -182,7 +182,7 @@ static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
> case ACPI_RESOURCE_TYPE_IRQ:
> {
> struct acpi_resource_irq *p = &resource->data.irq;
> - if (!p || !p->interrupt_count) {
> + if (!p->interrupt_count) {
> /*
> * IRQ descriptors may have no IRQ# bits set,
> * particularly those w/ _STA disabled
> @@ -197,7 +197,7 @@ static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
> {
> struct acpi_resource_extended_irq *p =
> &resource->data.extended_irq;
> - if (!p || !p->interrupt_count) {
> + if (!p->interrupt_count) {
> /*
> * extended IRQ descriptors must
> * return at least 1 IRQ
> --

Applied as 5.20 material with the R-by tag from Bjorn which is still
applicable AFAICS.

Thanks!