From 7fd89545f3374a061669a279ae0e084b0ddbb53d Mon Sep 17 00:00:00 2001 From: Shannon Nelson Date: Wed, 21 Oct 2015 19:47:04 -0400 Subject: [PATCH] i40e: remove BUG_ON from feature string building There's really no reason to kill the kernel thread just because of a little info string. This reworks the code to use snprintf's limiting to assure that the string is never too long, and WARN_ON to still put out a warning that we might want to look at the feature list length. Prompted by a recent Linus diatribe. Change-ID: If52ba5ca1c2344d8bf454a31bbb805eb5d2c5802 Signed-off-by: Shannon Nelson Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_main.c | 34 +++++++++++---------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 7715c5486818..7a4595a6b28e 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -10111,10 +10111,12 @@ static int i40e_setup_pf_filter_control(struct i40e_pf *pf) } #define INFO_STRING_LEN 255 +#define REMAIN(__x) (INFO_STRING_LEN - (__x)) static void i40e_print_features(struct i40e_pf *pf) { struct i40e_hw *hw = &pf->hw; char *buf, *string; + int i = 0; string = kzalloc(INFO_STRING_LEN, GFP_KERNEL); if (!string) { @@ -10124,42 +10126,42 @@ static void i40e_print_features(struct i40e_pf *pf) buf = string; - buf += sprintf(string, "Features: PF-id[%d] ", hw->pf_id); + i += snprintf(&buf[i], REMAIN(i), "Features: PF-id[%d] ", hw->pf_id); #ifdef CONFIG_PCI_IOV - buf += sprintf(buf, "VFs: %d ", pf->num_req_vfs); + i += snprintf(&buf[i], REMAIN(i), "VFs: %d ", pf->num_req_vfs); #endif - buf += sprintf(buf, "VSIs: %d QP: %d RX: %s ", - pf->hw.func_caps.num_vsis, - pf->vsi[pf->lan_vsi]->num_queue_pairs, - pf->flags & I40E_FLAG_RX_PS_ENABLED ? "PS" : "1BUF"); + i += snprintf(&buf[i], REMAIN(i), "VSIs: %d QP: %d RX: %s ", + pf->hw.func_caps.num_vsis, + pf->vsi[pf->lan_vsi]->num_queue_pairs, + pf->flags & I40E_FLAG_RX_PS_ENABLED ? "PS" : "1BUF"); if (pf->flags & I40E_FLAG_RSS_ENABLED) - buf += sprintf(buf, "RSS "); + i += snprintf(&buf[i], REMAIN(i), "RSS "); if (pf->flags & I40E_FLAG_FD_ATR_ENABLED) - buf += sprintf(buf, "FD_ATR "); + i += snprintf(&buf[i], REMAIN(i), "FD_ATR "); if (pf->flags & I40E_FLAG_FD_SB_ENABLED) { - buf += sprintf(buf, "FD_SB "); - buf += sprintf(buf, "NTUPLE "); + i += snprintf(&buf[i], REMAIN(i), "FD_SB "); + i += snprintf(&buf[i], REMAIN(i), "NTUPLE "); } if (pf->flags & I40E_FLAG_DCB_CAPABLE) - buf += sprintf(buf, "DCB "); + i += snprintf(&buf[i], REMAIN(i), "DCB "); #if IS_ENABLED(CONFIG_VXLAN) - buf += sprintf(buf, "VxLAN "); + i += snprintf(&buf[i], REMAIN(i), "VxLAN "); #endif if (pf->flags & I40E_FLAG_PTP) - buf += sprintf(buf, "PTP "); + i += snprintf(&buf[i], REMAIN(i), "PTP "); #ifdef I40E_FCOE if (pf->flags & I40E_FLAG_FCOE_ENABLED) - buf += sprintf(buf, "FCOE "); + i += snprintf(&buf[i], REMAIN(i), "FCOE "); #endif if (pf->flags & I40E_FLAG_VEB_MODE_ENABLED) - buf += sprintf(buf, "VEB "); + i += snprintf(&buf[i], REMAIN(i), "VEPA "); else buf += sprintf(buf, "VEPA "); - BUG_ON(buf > (string + INFO_STRING_LEN)); dev_info(&pf->pdev->dev, "%s\n", string); kfree(string); + WARN_ON(i > INFO_STRING_LEN); } /**