From: Hamza Mahfooz Date: Fri, 10 Sep 2021 23:53:37 +0000 (-0400) Subject: dma-debug: prevent an error message from causing runtime problems X-Git-Tag: v5.15-rc2~21^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=510e1a724ab1bf38150be2c1acabb303f98d0047;p=thirdparty%2Fkernel%2Flinux.git dma-debug: prevent an error message from causing runtime problems For some drivers, that use the DMA API. This error message can be reached several millions of times per second, causing spam to the kernel's printk buffer and bringing the CPU usage up to 100% (so, it should be rate limited). However, since there is at least one driver that is in the mainline and suffers from the error condition, it is more useful to err_printk() here instead of just rate limiting the error message (in hopes that it will make it easier for other drivers that suffer from this issue to be spotted). Link: https://lkml.kernel.org/r/fd67fbac-64bf-f0ea-01e1-5938ccfab9d0@arm.com Reported-by: Jeremy Linton Signed-off-by: Hamza Mahfooz Signed-off-by: Christoph Hellwig --- diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 6c90c69e5311a..95445bd6eb725 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -567,7 +567,8 @@ static void add_dma_entry(struct dma_debug_entry *entry) pr_err("cacheline tracking ENOMEM, dma-debug disabled\n"); global_disable = true; } else if (rc == -EEXIST) { - pr_err("cacheline tracking EEXIST, overlapping mappings aren't supported\n"); + err_printk(entry->dev, entry, + "cacheline tracking EEXIST, overlapping mappings aren't supported\n"); } }