From 6bee69422590b333de8f18193e73f68a23e12047 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Fri, 3 May 2024 12:11:58 +0100 Subject: [PATCH] octeontx2-pf: Treat truncation of IRQ name as an error According to GCC, the constriction of irq_name in otx2_open() may, theoretically, be truncated. This patch takes the approach of treating such a situation as an error which it detects by making use of the return value of snprintf, which is the total number of bytes, excluding the trailing '\0', that would have been written. Based on the approach taken to a similar problem in commit 54b909436ede ("rtc: fix snprintf() checking in is_rtc_hctosys()") Flagged by gcc-13 W=1 builds as: .../otx2_pf.c:1933:58: warning: 'snprintf' output may be truncated before the last format character [-Wformat-truncation=] 1933 | snprintf(irq_name, NAME_SIZE, "%s-rxtx-%d", pf->netdev->name, | ^ .../otx2_pf.c:1933:17: note: 'snprintf' output between 8 and 33 bytes into a destination of size 32 1933 | snprintf(irq_name, NAME_SIZE, "%s-rxtx-%d", pf->netdev->name, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1934 | qidx); | ~~~~~ Compile tested only. Tested-by: Geetha sowjanya Reviewed-by: Andrew Lunn Signed-off-by: Simon Horman Link: https://lore.kernel.org/r/20240503-octeon2-pf-irq_name-truncation-v2-1-91099177b942@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c index 6a44dacff508d..14bccff0ee5c7 100644 --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c @@ -1886,9 +1886,17 @@ int otx2_open(struct net_device *netdev) vec = pf->hw.nix_msixoff + NIX_LF_CINT_VEC_START; for (qidx = 0; qidx < pf->hw.cint_cnt; qidx++) { irq_name = &pf->hw.irq_name[vec * NAME_SIZE]; + int name_len; - snprintf(irq_name, NAME_SIZE, "%s-rxtx-%d", pf->netdev->name, - qidx); + name_len = snprintf(irq_name, NAME_SIZE, "%s-rxtx-%d", + pf->netdev->name, qidx); + if (name_len >= NAME_SIZE) { + dev_err(pf->dev, + "RVUPF%d: IRQ registration failed for CQ%d, irq name is too long\n", + rvu_get_pf(pf->pcifunc), qidx); + err = -EINVAL; + goto err_free_cints; + } err = request_irq(pci_irq_vector(pf->pdev, vec), otx2_cq_intr_handler, 0, irq_name, -- 2.30.2