Hello,
This series cleans up the usage of PCI EPC features in the pci-epf-test driver.
First patch fixes a smatch warning reported by Dan Carpenter and second one is a
cleanup suggested by Niklas.
- Mani
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
Changes in v2:
- Modified the patch 1/1 as per comments and added Fixes tag
- Added a new patch 2/2 to cleanup one more instance of 'epc_features'
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Manivannan Sadhasivam (2):
PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_init()
PCI: endpoint: pci-epf-test: Use 'msix_capable' flag directly in pci_epf_test_alloc_space()
drivers/pci/endpoint/functions/pci-epf-test.c | 22 +++++-----------------
1 file changed, 5 insertions(+), 17 deletions(-)
---
base-commit: 6e47dcb2ca223211c43c37497836cd9666c70674
change-id: 20240417-pci-epf-test-fix-2209ae22be80
Best regards,
--
Manivannan Sadhasivam <[email protected]>
Instead of getting the epc_features from pci_epc_get_features() API, use
the cached pci_epf_test::epc_features value to avoid the NULL check. Since
the NULL check is already performed in pci_epf_test_bind(), having one more
check in pci_epf_test_core_init() is redundant and it is not possible to
hit the NULL pointer dereference.
Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
flag"), 'epc_features' got dereferenced without the NULL check, leading to
the following false positive smatch warning:
drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init()
error: we previously assumed 'epc_features' could be null (see line 747)
So let's remove the redundant NULL check and also use the epc_features::
{msix_capable/msi_capable} flags directly to avoid local variables.
Reported-by: Dan Carpenter <[email protected]>
Closes: https://lore.kernel.org/linux-pci/[email protected]/
Fixes: 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization")
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 977fb79c1567..546d2a27955c 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -735,20 +735,12 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
{
struct pci_epf_test *epf_test = epf_get_drvdata(epf);
struct pci_epf_header *header = epf->header;
- const struct pci_epc_features *epc_features;
+ const struct pci_epc_features *epc_features = epf_test->epc_features;
struct pci_epc *epc = epf->epc;
struct device *dev = &epf->dev;
bool linkup_notifier = false;
- bool msix_capable = false;
- bool msi_capable = true;
int ret;
- epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
- if (epc_features) {
- msix_capable = epc_features->msix_capable;
- msi_capable = epc_features->msi_capable;
- }
-
if (epf->vfunc_no <= 1) {
ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no, header);
if (ret) {
@@ -761,7 +753,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
if (ret)
return ret;
- if (msi_capable) {
+ if (epc_features->msi_capable) {
ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
epf->msi_interrupts);
if (ret) {
@@ -770,7 +762,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
}
}
- if (msix_capable) {
+ if (epc_features->msix_capable) {
ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no,
epf->msix_interrupts,
epf_test->test_reg_bar,
--
2.25.1
Instead of using a local variable to cache the 'msix_capable' flag, use it
directly to simplify the code.
Suggested-by: Niklas Cassel <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 546d2a27955c..3de18a601e7b 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -802,19 +802,15 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
size_t msix_table_size = 0;
size_t test_reg_bar_size;
size_t pba_size = 0;
- bool msix_capable;
void *base;
enum pci_barno test_reg_bar = epf_test->test_reg_bar;
enum pci_barno bar;
- const struct pci_epc_features *epc_features;
+ const struct pci_epc_features *epc_features = epf_test->epc_features;
size_t test_reg_size;
- epc_features = epf_test->epc_features;
-
test_reg_bar_size = ALIGN(sizeof(struct pci_epf_test_reg), 128);
- msix_capable = epc_features->msix_capable;
- if (msix_capable) {
+ if (epc_features->msix_capable) {
msix_table_size = PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts;
epf_test->msix_table_offset = test_reg_bar_size;
/* Align to QWORD or 8 Bytes */
--
2.25.1
On Thu, Apr 18, 2024 at 01:29:58PM +0530, Manivannan Sadhasivam wrote:
> Instead of getting the epc_features from pci_epc_get_features() API, use
> the cached pci_epf_test::epc_features value to avoid the NULL check. Since
> the NULL check is already performed in pci_epf_test_bind(), having one more
> check in pci_epf_test_core_init() is redundant and it is not possible to
> hit the NULL pointer dereference.
>
> Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
> flag"), 'epc_features' got dereferenced without the NULL check, leading to
> the following false positive smatch warning:
>
> drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init()
> error: we previously assumed 'epc_features' could be null (see line 747)
>
> So let's remove the redundant NULL check and also use the epc_features::
> {msix_capable/msi_capable} flags directly to avoid local variables.
>
> Reported-by: Dan Carpenter <[email protected]>
> Closes: https://lore.kernel.org/linux-pci/[email protected]/
> Fixes: 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization")
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
Reviewed-by: Niklas Cassel <[email protected]>
On Thu, Apr 18, 2024 at 01:29:59PM +0530, Manivannan Sadhasivam wrote:
> Instead of using a local variable to cache the 'msix_capable' flag, use it
> directly to simplify the code.
>
> Suggested-by: Niklas Cassel <[email protected]>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
Reviewed-by: Niklas Cassel <[email protected]>
On Thu, Apr 18, 2024 at 01:29:58PM +0530, Manivannan Sadhasivam wrote:
> Instead of getting the epc_features from pci_epc_get_features() API, use
> the cached pci_epf_test::epc_features value to avoid the NULL check. Since
> the NULL check is already performed in pci_epf_test_bind(), having one more
> check in pci_epf_test_core_init() is redundant and it is not possible to
> hit the NULL pointer dereference.
>
> Also with commit a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier"
> flag"), 'epc_features' got dereferenced without the NULL check, leading to
> the following false positive smatch warning:
>
> drivers/pci/endpoint/functions/pci-epf-test.c:784 pci_epf_test_core_init()
> error: we previously assumed 'epc_features' could be null (see line 747)
>
> So let's remove the redundant NULL check and also use the epc_features::
> {msix_capable/msi_capable} flags directly to avoid local variables.
>
> Reported-by: Dan Carpenter <[email protected]>
> Closes: https://lore.kernel.org/linux-pci/[email protected]/
> Fixes: 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization")
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
Reviewed-by: Frank Li <[email protected]>
> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 14 +++-----------
> 1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 977fb79c1567..546d2a27955c 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -735,20 +735,12 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
> {
> struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> struct pci_epf_header *header = epf->header;
> - const struct pci_epc_features *epc_features;
> + const struct pci_epc_features *epc_features = epf_test->epc_features;
> struct pci_epc *epc = epf->epc;
> struct device *dev = &epf->dev;
> bool linkup_notifier = false;
> - bool msix_capable = false;
> - bool msi_capable = true;
> int ret;
>
> - epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
> - if (epc_features) {
> - msix_capable = epc_features->msix_capable;
> - msi_capable = epc_features->msi_capable;
> - }
> -
> if (epf->vfunc_no <= 1) {
> ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no, header);
> if (ret) {
> @@ -761,7 +753,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
> if (ret)
> return ret;
>
> - if (msi_capable) {
> + if (epc_features->msi_capable) {
> ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
> epf->msi_interrupts);
> if (ret) {
> @@ -770,7 +762,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf)
> }
> }
>
> - if (msix_capable) {
> + if (epc_features->msix_capable) {
> ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no,
> epf->msix_interrupts,
> epf_test->test_reg_bar,
>
> --
> 2.25.1
>
On Thu, Apr 18, 2024 at 01:29:59PM +0530, Manivannan Sadhasivam wrote:
> Instead of using a local variable to cache the 'msix_capable' flag, use it
> directly to simplify the code.
Reviewed-by: Frank Li <[email protected]>
>
> Suggested-by: Niklas Cassel <[email protected]>
> Signed-off-by: Manivannan Sadhasivam <[email protected]>
> ---
> drivers/pci/endpoint/functions/pci-epf-test.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index 546d2a27955c..3de18a601e7b 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -802,19 +802,15 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
> size_t msix_table_size = 0;
> size_t test_reg_bar_size;
> size_t pba_size = 0;
> - bool msix_capable;
> void *base;
> enum pci_barno test_reg_bar = epf_test->test_reg_bar;
> enum pci_barno bar;
> - const struct pci_epc_features *epc_features;
> + const struct pci_epc_features *epc_features = epf_test->epc_features;
> size_t test_reg_size;
>
> - epc_features = epf_test->epc_features;
> -
> test_reg_bar_size = ALIGN(sizeof(struct pci_epf_test_reg), 128);
>
> - msix_capable = epc_features->msix_capable;
> - if (msix_capable) {
> + if (epc_features->msix_capable) {
> msix_table_size = PCI_MSIX_ENTRY_SIZE * epf->msix_interrupts;
> epf_test->msix_table_offset = test_reg_bar_size;
> /* Align to QWORD or 8 Bytes */
>
> --
> 2.25.1
>