On 2/27/21 10:30 AM, Dan Carpenter wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> master
> head: 8b83369ddcb3fb9cab5c1088987ce477565bb630
> commit: 97ef275077932c65b1b8ec5022abd737a9fbf3e0 powerpc/xive: Fix xmon
> support on the PowerNV platform
> config: powerpc64-randconfig-m031-20210226 (attached as .config)
> compiler: powerpc64-linux-gcc (GCC) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot
> Reported-by: Dan Carpenter
>
> smatch warnings:
> arch/powerpc/sysdev/xive/common.c:279 xmon_xive_get_irq_config() warn:
> variable dereferenced before check 'd' (see line 261)
Yes. That's ugly :/
I would prefer to address this issue after the cleanup provided
by the patchset adding an IRQ domain for IPIs.
http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=228762
Most of the mess comes from the XIVE IPI HW IRQ number which
hijacks IRQ number 0. It should be easier after this is fixed.
Thanks,
C.
> vim +/d +279 arch/powerpc/sysdev/xive/common.c
>
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 259 int
> xmon_xive_get_irq_config(u32 hw_irq, struct irq_data *d)
> b4868ff55d082bc Cédric Le Goater 2019-08-14 260 {
> 97ef275077932c6 Cédric Le Goater 2020-03-06 @261 struct irq_chip *chip =
> irq_data_get_irq_chip(d);
>
> ^
> Dereferenced inside function
>
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 262 int rc;
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 263 u32 target;
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 264 u8 prio;
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 265 u32 lirq;
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 266
> 97ef275077932c6 Cédric Le Goater 2020-03-06 267 if (!is_xive_irq(chip))
> 97ef275077932c6 Cédric Le Goater 2020-03-06 268 return -EINVAL;
> 97ef275077932c6 Cédric Le Goater 2020-03-06 269
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 270 rc =
> xive_ops->get_irq_config(hw_irq, , , );
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 271 if (rc) {
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 272
> xmon_printf("IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 273 return rc;
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 274 }
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 275
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 276 xmon_printf("IRQ 0x%08x
> : target=0x%x prio=%02x lirq=0x%x ",
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 277 hw_irq,
> target, prio, lirq);
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 278
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 @279 if (d) {
> ^^
> Checked too late
>
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 280 struct
> xive_irq_data *xd = irq_data_get_irq_handler_data(d);
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 281 u64 val =
> xive_esb_read(xd, XIVE_ESB_GET);
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 282
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 283
> xmon_printf("PQ=%c%c",
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 284 val
> & XIVE_ESB_VAL_P ? 'P' : '-',
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 285 val
> & XIVE_ESB_VAL_Q ? 'Q' : '-');
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 286 }
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 287
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 288 xmon_printf("\n");
> 5896163f7f91c05 Cédric Le Goater 2019-09-10 289 return 0;
> b4868ff55d082bc Cédric Le Goater 2019-08-14 290 }
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
>
