linux-kernel - [PATCH v2] dma-debug: Make things less spammy under memory pressure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20220601145116.280040-1-robdclark@gmail.com>
Date:   Wed,  1 Jun 2022 07:51:16 -0700
From:   Rob Clark <robdclark@...il.com>
To:     linux-kernel@...r.kernel.org
Cc:     linux-arm-kernel@...ts.infradead.org,
        Christoph Hellwig <hch@....de>,
        Robin Murphy <robin.murphy@....com>,
        Rob Clark <robdclark@...omium.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        iommu@...ts.linux-foundation.org (open list:DMA MAPPING HELPERS)
Subject: [PATCH v2] dma-debug: Make things less spammy under memory pressure

From: Rob Clark <robdclark@...omium.org>

Limit the error msg to avoid flooding the console.  If you have a lot of
threads hitting this at once, they could have already gotten passed the
dma_debug_disabled() check before they get to the point of allocation
failure, resulting in quite a lot of this error message spamming the
log.  Use pr_err_once() to limit that.

Signed-off-by: Rob Clark <robdclark@...omium.org>
---
v2: Use pr_err_once() instead of ratelimited, and spiff out commit msg a bit.

 kernel/dma/debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index f8ff598596b8..754e3456f017 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -564,7 +564,7 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
 
 	rc = active_cacheline_insert(entry);
 	if (rc == -ENOMEM) {
-		pr_err("cacheline tracking ENOMEM, dma-debug disabled\n");
+		pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n");
 		global_disable = true;
 	} else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		err_printk(entry->dev, entry,
-- 
2.36.1