From c2255ece2be2454dff0b549e2ceb234bfe798181 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 23 Mar 2021 13:54:23 +0100 Subject: [PATCH] scsi: pm8001: Avoid -Wrestrict warning On some configurations, gcc warns about overlapping source and destination arguments to snprintf: drivers/scsi/pm8001/pm8001_init.c: In function 'pm8001_request_msix': drivers/scsi/pm8001/pm8001_init.c:977:3: error: 'snprintf' argument 4 may overlap destination object 'pm8001_ha' [-Werror=restrict] 977 | snprintf(drvname, len, "%s-%d", pm8001_ha->name, i); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/scsi/pm8001/pm8001_init.c:962:56: note: destination object referenced by 'restrict'-qualified argument 1 was declared here 962 | static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) | ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~ I first assumed this was a gcc bug, as that should not happen, but a reduced test case makes it clear that this happens when the loop counter is not bounded by the array size. Help the compiler out by adding an explicit limit here to make the code slightly more robust and avoid the warning. Link: https://godbolt.org/z/6T1qPM Link: https://lore.kernel.org/r/20210323125458.1825564-1-arnd@kernel.org Acked-by: Jack Wang Signed-off-by: Arnd Bergmann Signed-off-by: Martin K. Petersen --- drivers/scsi/pm8001/pm8001_init.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c index bbb6b23aa6b1..0f7b3fffb393 100644 --- a/drivers/scsi/pm8001/pm8001_init.c +++ b/drivers/scsi/pm8001/pm8001_init.c @@ -963,6 +963,7 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) { u32 i = 0, j = 0; int flag = 0, rc = 0; + int nr_irqs = pm8001_ha->number_of_intr; if (pm8001_ha->chip_id != chip_8001) flag &= ~IRQF_SHARED; @@ -971,7 +972,10 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) "pci_enable_msix request number of intr %d\n", pm8001_ha->number_of_intr); - for (i = 0; i < pm8001_ha->number_of_intr; i++) { + if (nr_irqs > ARRAY_SIZE(pm8001_ha->intr_drvname)) + nr_irqs = ARRAY_SIZE(pm8001_ha->intr_drvname); + + for (i = 0; i < nr_irqs; i++) { snprintf(pm8001_ha->intr_drvname[i], sizeof(pm8001_ha->intr_drvname[0]), "%s-%d", pm8001_ha->name, i); -- 2.34.1