| Message ID | 20211018160541.13512-1-tim.gardner@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [linux-next] soc: fsl: dpio: Unsigned compared against 0 in qbman_swp_set_irq_coalescing() | expand |
> > Subject: [PATCH][linux-next] soc: fsl: dpio: Unsigned compared against 0 in > > Coverity complains of unsigned compare against 0. There are 2 cases in > this function: > > 1821 itp = (irq_holdoff * 1000) / p->desc->qman_256_cycles_per_ns; > > CID 121131 (#1 of 1): Unsigned compared against 0 (NO_EFFECT) > unsigned_compare: This less-than-zero comparison of an unsigned value is never true. itp < 0U. > 1822 if (itp < 0 || itp > 4096) { > 1823 max_holdoff = (p->desc->qman_256_cycles_per_ns * 4096) / 1000; > 1824 pr_err("irq_holdoff must be between 0..%dus\n", max_holdoff); > 1825 return -EINVAL; > 1826 } > 1827 > unsigned_compare: This less-than-zero comparison of an unsigned value is never true. irq_threshold < 0U. > 1828 if (irq_threshold >= p->dqrr.dqrr_size || irq_threshold < 0) { > 1829 pr_err("irq_threshold must be between 0..%d\n", > 1830 p->dqrr.dqrr_size - 1); > 1831 return -EINVAL; > 1832 } > > Fix this by checking for 0. Also fix a minor comment typo. > > Fixes ed1d2143fee53755ec601eb4d48a337a93933f71 ("soc: fsl: dpio: add support for > irq coalescing per software portal") I think this should be formatted as following: Fixes: ed1d2143fee5 ("soc: fsl: dpio: add support for irq coalescing per software portal") > > Cc: Roy Pledge <Roy.Pledge@nxp.com> > Cc: Li Yang <leoyang.li@nxp.com> > Cc: linux-kernel@vger.kernel.org > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-arm-kernel@lists.infradead.org > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> > --- > > I'm not 100% sure this is the right way to fix the warning, but according to the > pr_err() comments these values should never be 0. These threshold values can be 0, the pr_err comment tries to say that those are the ranges, 0 and the maximum included. > > --- > drivers/soc/fsl/dpio/qbman-portal.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/soc/fsl/dpio/qbman-portal.c b/drivers/soc/fsl/dpio/qbman-portal.c > index d3c58df6240d..b768a14bb271 100644 > --- a/drivers/soc/fsl/dpio/qbman-portal.c > +++ b/drivers/soc/fsl/dpio/qbman-portal.c > @@ -1816,16 +1816,16 @@ int qbman_swp_set_irq_coalescing(struct qbman_swp *p, u32 irq_threshold, > u32 itp, max_holdoff; > > /* Convert irq_holdoff value from usecs to 256 QBMAN clock cycles > - * increments. This depends to the QBMAN internal frequency. > + * increments. This depends on the QBMAN internal frequency. > */ > itp = (irq_holdoff * 1000) / p->desc->qman_256_cycles_per_ns; > - if (itp < 0 || itp > 4096) { > + if (!itp || itp > 4096) { > max_holdoff = (p->desc->qman_256_cycles_per_ns * 4096) / 1000; > pr_err("irq_holdoff must be between 0..%dus\n", max_holdoff); > return -EINVAL; > } > > - if (irq_threshold >= p->dqrr.dqrr_size || irq_threshold < 0) { > + if (irq_threshold >= p->dqrr.dqrr_size || !irq_threshold) { > pr_err("irq_threshold must be between 0..%d\n", > p->dqrr.dqrr_size - 1); > return -EINVAL; > These 'value < 0' checks should be removed all together. Somehow I missed that those are unsigned values. Anyhow, thanks a lot that you spotted this. Could you please sent the v2 towards the net-next tree since that's the tree that adds the fixed patch? Thanks. -Ioana
diff --git a/drivers/soc/fsl/dpio/qbman-portal.c b/drivers/soc/fsl/dpio/qbman-portal.c index d3c58df6240d..b768a14bb271 100644 --- a/drivers/soc/fsl/dpio/qbman-portal.c +++ b/drivers/soc/fsl/dpio/qbman-portal.c @@ -1816,16 +1816,16 @@ int qbman_swp_set_irq_coalescing(struct qbman_swp *p, u32 irq_threshold, u32 itp, max_holdoff; /* Convert irq_holdoff value from usecs to 256 QBMAN clock cycles - * increments. This depends to the QBMAN internal frequency. + * increments. This depends on the QBMAN internal frequency. */ itp = (irq_holdoff * 1000) / p->desc->qman_256_cycles_per_ns; - if (itp < 0 || itp > 4096) { + if (!itp || itp > 4096) { max_holdoff = (p->desc->qman_256_cycles_per_ns * 4096) / 1000; pr_err("irq_holdoff must be between 0..%dus\n", max_holdoff); return -EINVAL; } - if (irq_threshold >= p->dqrr.dqrr_size || irq_threshold < 0) { + if (irq_threshold >= p->dqrr.dqrr_size || !irq_threshold) { pr_err("irq_threshold must be between 0..%d\n", p->dqrr.dqrr_size - 1); return -EINVAL;
Coverity complains of unsigned compare against 0. There are 2 cases in this function: 1821 itp = (irq_holdoff * 1000) / p->desc->qman_256_cycles_per_ns; CID 121131 (#1 of 1): Unsigned compared against 0 (NO_EFFECT) unsigned_compare: This less-than-zero comparison of an unsigned value is never true. itp < 0U. 1822 if (itp < 0 || itp > 4096) { 1823 max_holdoff = (p->desc->qman_256_cycles_per_ns * 4096) / 1000; 1824 pr_err("irq_holdoff must be between 0..%dus\n", max_holdoff); 1825 return -EINVAL; 1826 } 1827 unsigned_compare: This less-than-zero comparison of an unsigned value is never true. irq_threshold < 0U. 1828 if (irq_threshold >= p->dqrr.dqrr_size || irq_threshold < 0) { 1829 pr_err("irq_threshold must be between 0..%d\n", 1830 p->dqrr.dqrr_size - 1); 1831 return -EINVAL; 1832 } Fix this by checking for 0. Also fix a minor comment typo. Fixes ed1d2143fee53755ec601eb4d48a337a93933f71 ("soc: fsl: dpio: add support for irq coalescing per software portal") Cc: Roy Pledge <Roy.Pledge@nxp.com> Cc: Li Yang <leoyang.li@nxp.com> Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- I'm not 100% sure this is the right way to fix the warning, but according to the pr_err() comments these values should never be 0. --- drivers/soc/fsl/dpio/qbman-portal.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)