| Message ID | 20240417-pci-epf-test-fix-v1-1-653c911d1faa@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: endpoint: pci-epf-test: Make use of cached 'epc_features' in pci_epf_test_core_init() | expand |
On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> I think you forgot: Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > --- > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > index 977fb79c1567..0d28f413cb07 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > 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; > - } > + epc_features = epf_test->epc_features; How about: index 977fb79c1567..4d6105c07ac0 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -735,7 +735,7 @@ 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; @@ -743,12 +743,6 @@ static int pci_epf_test_core_init(struct pci_epf *epf) 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) { @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) if (ret) return ret; + msi_capable = epc_features->msi_capable; if (msi_capable) { ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, epf->msi_interrupts); @@ -770,6 +765,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) } } + msix_capable = epc_features->msix_capable; if (msix_capable) { ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no, epf->msix_interrupts, @@ -814,11 +810,9 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) 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; Instead? That way, we assign msi_capable/msix_capable just before the if-statement where it is used. (Which matches how we already assign msix_capable just before the if-statement in pci_epf_test_alloc_space().) Kind regards, Niklas > + > + 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); > > --- > base-commit: 6e47dcb2ca223211c43c37497836cd9666c70674 > change-id: 20240417-pci-epf-test-fix-2209ae22be80 > > Best regards, > -- > Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> >
On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > if (ret) > return ret; > > + msi_capable = epc_features->msi_capable; > if (msi_capable) { Or just: if (epc_features->msi_capable) { ;) > ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, > epf->msi_interrupts); regards, dan carpenter
On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > I think you forgot: > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > --- > > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- > > 1 file changed, 4 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > index 977fb79c1567..0d28f413cb07 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > 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; > > - } > > + epc_features = epf_test->epc_features; > > How about: > > index 977fb79c1567..4d6105c07ac0 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -735,7 +735,7 @@ 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; > @@ -743,12 +743,6 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > 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) { > @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > if (ret) > return ret; > > + msi_capable = epc_features->msi_capable; > if (msi_capable) { > ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, > epf->msi_interrupts); > @@ -770,6 +765,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > } > } > > + msix_capable = epc_features->msix_capable; > if (msix_capable) { > ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no, > epf->msix_interrupts, > @@ -814,11 +810,9 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > 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; > > > Instead? > > That way, we assign msi_capable/msix_capable just before the if-statement > where it is used. (Which matches how we already assign msix_capable just > before the if-statement in pci_epf_test_alloc_space().) ...or just kill the local variables: bool msi_capable/msix_capable in pci_epf_test_core_init(), and bool msix_capable pci_epf_test_alloc_space() and just do: if (epc_features->msix_capable) / if (epc_features->msi_capable) directly? Kind regards, Niklas
On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > I think you forgot: > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > No, that's not the correct fixes tag I suppose. This redudant check is introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization") and this commit removes the redundant check (fixing smatch warning is a side effect). So if the fixes tag needs to be added, then this commit should be referenced. > > > --- > > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- > > 1 file changed, 4 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > index 977fb79c1567..0d28f413cb07 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > 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; > > - } > > + epc_features = epf_test->epc_features; > > How about: > > index 977fb79c1567..4d6105c07ac0 100644 > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > @@ -735,7 +735,7 @@ 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; > @@ -743,12 +743,6 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > 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) { > @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > if (ret) > return ret; > > + msi_capable = epc_features->msi_capable; > if (msi_capable) { > ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, > epf->msi_interrupts); > @@ -770,6 +765,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > } > } > > + msix_capable = epc_features->msix_capable; > if (msix_capable) { > ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no, > epf->msix_interrupts, > @@ -814,11 +810,9 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > 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; > > > Instead? > > That way, we assign msi_capable/msix_capable just before the if-statement > where it is used. (Which matches how we already assign msix_capable just > before the if-statement in pci_epf_test_alloc_space().) > Ok, if we go with this pattern, then pci_epf_test_set_bar() also needs to be updated. - Mani
On Wed, Apr 17, 2024 at 07:54:56PM +0200, Niklas Cassel wrote: > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > I think you forgot: > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > > > > --- > > > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- > > > 1 file changed, 4 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > > index 977fb79c1567..0d28f413cb07 100644 > > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > > @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > > 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; > > > - } > > > + epc_features = epf_test->epc_features; > > > > How about: > > > > index 977fb79c1567..4d6105c07ac0 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -735,7 +735,7 @@ 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; > > @@ -743,12 +743,6 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > 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) { > > @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > if (ret) > > return ret; > > > > + msi_capable = epc_features->msi_capable; > > if (msi_capable) { > > ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, > > epf->msi_interrupts); > > @@ -770,6 +765,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > } > > } > > > > + msix_capable = epc_features->msix_capable; > > if (msix_capable) { > > ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no, > > epf->msix_interrupts, > > @@ -814,11 +810,9 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > > 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; > > > > > > Instead? > > > > That way, we assign msi_capable/msix_capable just before the if-statement > > where it is used. (Which matches how we already assign msix_capable just > > before the if-statement in pci_epf_test_alloc_space().) > > ...or just kill the local variables: > bool msi_capable/msix_capable in pci_epf_test_core_init(), and > bool msix_capable pci_epf_test_alloc_space() > and just do: > > if (epc_features->msix_capable) / if (epc_features->msi_capable) > > directly? > Yeah, that will also work. - Mani
On Thu, Apr 18, 2024 at 11:13:19AM +0530, Manivannan Sadhasivam wrote: > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > I think you forgot: > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > No, that's not the correct fixes tag I suppose. This redudant check is > introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer > core initialization") and this commit removes the redundant check (fixing smatch > warning is a side effect). So if the fixes tag needs to be added, then this > commit should be referenced. Well, you have a Closes: tag that links to a bug report about a smatch warning that was introduced with 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization"). So if you want to reference another commit, then you should probably drop the Closes: tag. > > > > > > --- > > > drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- > > > 1 file changed, 4 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > > index 977fb79c1567..0d28f413cb07 100644 > > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > > @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > > 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; > > > - } > > > + epc_features = epf_test->epc_features; > > > > How about: > > > > index 977fb79c1567..4d6105c07ac0 100644 > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > @@ -735,7 +735,7 @@ 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; > > @@ -743,12 +743,6 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > 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) { > > @@ -761,6 +755,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > if (ret) > > return ret; > > > > + msi_capable = epc_features->msi_capable; > > if (msi_capable) { > > ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no, > > epf->msi_interrupts); > > @@ -770,6 +765,7 @@ static int pci_epf_test_core_init(struct pci_epf *epf) > > } > > } > > > > + msix_capable = epc_features->msix_capable; > > if (msix_capable) { > > ret = pci_epc_set_msix(epc, epf->func_no, epf->vfunc_no, > > epf->msix_interrupts, > > @@ -814,11 +810,9 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf) > > 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; > > > > > > Instead? > > > > That way, we assign msi_capable/msix_capable just before the if-statement > > where it is used. (Which matches how we already assign msix_capable just > > before the if-statement in pci_epf_test_alloc_space().) > > > > Ok, if we go with this pattern, then pci_epf_test_set_bar() also needs to be > updated. pci_epf_test_set_bar() ? I presume that you mean pci_epf_test_alloc_space(). How about a 1/2 patch that modifies pci_epf_test_core_init() and Closes: the bug report, and a 2/2 patch that modifies pci_epf_test_alloc_space() ? Kind regards, Niklas
On Thu, Apr 18, 2024 at 08:46:47AM +0200, Niklas Cassel wrote: > On Thu, Apr 18, 2024 at 11:13:19AM +0530, Manivannan Sadhasivam wrote: > > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > > > I think you forgot: > > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > > > > No, that's not the correct fixes tag I suppose. This redudant check is > > introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer > > core initialization") and this commit removes the redundant check (fixing smatch > > warning is a side effect). So if the fixes tag needs to be added, then this > > commit should be referenced. > > Well, you have a Closes: tag that links to a bug report about a smatch > warning that was introduced with 5e50ee27d4a5 ("PCI: pci-epf-test: Add > support to defer core initialization"). > > So if you want to reference another commit, then you should probably > drop the Closes: tag. > Then checkpatch will complain... But I think I can keep the two tags? One is for fixing the redudant check and another is for the smatch warning reported. > > > > > > [...] > > > That way, we assign msi_capable/msix_capable just before the if-statement > > > where it is used. (Which matches how we already assign msix_capable just > > > before the if-statement in pci_epf_test_alloc_space().) > > > > > > > Ok, if we go with this pattern, then pci_epf_test_set_bar() also needs to be > > updated. > > pci_epf_test_set_bar() ? I presume that you mean pci_epf_test_alloc_space(). > Oops. I referred from an old branch. > How about a 1/2 patch that modifies pci_epf_test_core_init() and Closes: the > bug report, and a 2/2 patch that modifies pci_epf_test_alloc_space() ? > Yes, that's the plan. - Mani
On Thu, Apr 18, 2024 at 12:23:08PM +0530, Manivannan Sadhasivam wrote: > On Thu, Apr 18, 2024 at 08:46:47AM +0200, Niklas Cassel wrote: > > On Thu, Apr 18, 2024 at 11:13:19AM +0530, Manivannan Sadhasivam wrote: > > > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > > > > > I think you forgot: > > > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > > > > > > > No, that's not the correct fixes tag I suppose. This redudant check is > > > introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer > > > core initialization") and this commit removes the redundant check (fixing smatch > > > warning is a side effect). So if the fixes tag needs to be added, then this > > > commit should be referenced. > > > > Well, you have a Closes: tag that links to a bug report about a smatch > > warning that was introduced with 5e50ee27d4a5 ("PCI: pci-epf-test: Add > > support to defer core initialization"). > > > > So if you want to reference another commit, then you should probably > > drop the Closes: tag. > > > > Then checkpatch will complain... But I think I can keep the two tags? One is for > fixing the redudant check and another is for the smatch warning reported. Yes, I think so too. You can have Fixes: to the commit that introduced the redundant check, since this was obviously not the correct thing to do, and then perhaps just mention commit 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer core initialization") somewhere in the commit log. Kind regards, Niklas
On Thu, Apr 18, 2024 at 09:14:23AM +0200, Niklas Cassel wrote: > On Thu, Apr 18, 2024 at 12:23:08PM +0530, Manivannan Sadhasivam wrote: > > On Thu, Apr 18, 2024 at 08:46:47AM +0200, Niklas Cassel wrote: > > > On Thu, Apr 18, 2024 at 11:13:19AM +0530, Manivannan Sadhasivam wrote: > > > > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > > > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > > > > > > > I think you forgot: > > > > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > > > > > > > > > > No, that's not the correct fixes tag I suppose. This redudant check is > > > > introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer > > > > core initialization") and this commit removes the redundant check (fixing smatch > > > > warning is a side effect). So if the fixes tag needs to be added, then this > > > > commit should be referenced. > > > > > > Well, you have a Closes: tag that links to a bug report about a smatch > > > warning that was introduced with 5e50ee27d4a5 ("PCI: pci-epf-test: Add > > > support to defer core initialization"). > > > > > > So if you want to reference another commit, then you should probably > > > drop the Closes: tag. > > > > > > > Then checkpatch will complain... But I think I can keep the two tags? One is for > > fixing the redudant check and another is for the smatch warning reported. > > Yes, I think so too. > > You can have Fixes: to the commit that introduced the redundant check, That is 5e50ee27d4a5. > since this was obviously not the correct thing to do, and then perhaps > just mention commit 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to > defer core initialization") somewhere in the commit log. You mean a01e7214bef9 here? - Mani
On Thu, Apr 18, 2024 at 01:00:23PM +0530, Manivannan Sadhasivam wrote: > On Thu, Apr 18, 2024 at 09:14:23AM +0200, Niklas Cassel wrote: > > On Thu, Apr 18, 2024 at 12:23:08PM +0530, Manivannan Sadhasivam wrote: > > > On Thu, Apr 18, 2024 at 08:46:47AM +0200, Niklas Cassel wrote: > > > > On Thu, Apr 18, 2024 at 11:13:19AM +0530, Manivannan Sadhasivam wrote: > > > > > On Wed, Apr 17, 2024 at 07:49:45PM +0200, Niklas Cassel wrote: > > > > > > On Wed, Apr 17, 2024 at 10:47:25PM +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. This also leads to the following 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) > > > > > > > > > > > > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > > > > > > > Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ > > > > > > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > > > > > > > > > > > I think you forgot: > > > > > > Fixes: a01e7214bef9 ("PCI: endpoint: Remove "core_init_notifier" flag") > > > > > > > > > > > > > > > > No, that's not the correct fixes tag I suppose. This redudant check is > > > > > introduced by commit, 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to defer > > > > > core initialization") and this commit removes the redundant check (fixing smatch > > > > > warning is a side effect). So if the fixes tag needs to be added, then this > > > > > commit should be referenced. > > > > > > > > Well, you have a Closes: tag that links to a bug report about a smatch > > > > warning that was introduced with 5e50ee27d4a5 ("PCI: pci-epf-test: Add > > > > support to defer core initialization"). > > > > > > > > So if you want to reference another commit, then you should probably > > > > drop the Closes: tag. > > > > > > > > > > Then checkpatch will complain... But I think I can keep the two tags? One is for > > > fixing the redudant check and another is for the smatch warning reported. > > > > Yes, I think so too. > > > > You can have Fixes: to the commit that introduced the redundant check, > > That is 5e50ee27d4a5. Yes :) > > > since this was obviously not the correct thing to do, and then perhaps > > just mention commit 5e50ee27d4a5 ("PCI: pci-epf-test: Add support to > > defer core initialization") somewhere in the commit log. > > You mean a01e7214bef9 here? Yes :) (I copied the wrong SHA1 here...) Kind regards, Niklas
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 977fb79c1567..0d28f413cb07 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -743,11 +743,10 @@ static int pci_epf_test_core_init(struct pci_epf *epf) 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; - } + epc_features = epf_test->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);
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. This also leads to the following 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) Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/linux-pci/024b5826-7180-4076-ae08-57d2584cca3f@moroto.mountain/ Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- drivers/pci/endpoint/functions/pci-epf-test.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- base-commit: 6e47dcb2ca223211c43c37497836cd9666c70674 change-id: 20240417-pci-epf-test-fix-2209ae22be80 Best regards,