From 80e4390981618e290616dbd06ea190d4576f219d Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 28 Feb 2022 14:04:53 -0800 Subject: dma-debug: fix return value of __setup handlers When valid kernel command line parameters dma_debug=off dma_debug_entries=100 are used, they are reported as Unknown parameters and added to init's environment strings, polluting it. Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 dma_debug=off dma_debug_entries=100", will be passed to user space. and Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 dma_debug=off dma_debug_entries=100 Return 1 from these __setup handlers to indicate that the command line option has been handled. Fixes: 59d3daafa1726 ("dma-debug: add kernel command line parameters") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Cc: Joerg Roedel Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: iommu@lists.linux-foundation.org Cc: Robin Murphy Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 7a14ca29c377..f8ff598596b8 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -927,7 +927,7 @@ static __init int dma_debug_cmdline(char *str) global_disable = true; } - return 0; + return 1; } static __init int dma_debug_entries_cmdline(char *str) @@ -936,7 +936,7 @@ static __init int dma_debug_entries_cmdline(char *str) return -EINVAL; if (!get_option(&str, &nr_prealloc_entries)) nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; - return 0; + return 1; } __setup("dma_debug=", dma_debug_cmdline); -- cgit v1.2.3 From 84bc4f1dbbbb5f8aa68706a96711dccb28b518e5 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 10 May 2022 13:17:32 -0400 Subject: dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC We observed the error "cacheline tracking ENOMEM, dma-debug disabled" during a light system load (copying some files). The reason for this error is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation - so it can't access the emergency memory reserves and it fails as soon as anybody reaches the watermark. This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the emergency memory reserves. Signed-off-by: Mikulas Patocka Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index f8ff598596b8..ac740630c79c 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -448,7 +448,7 @@ void debug_dma_dump_mappings(struct device *dev) * other hand, consumes a single dma_debug_entry, but inserts 'nents' * entries into the tree. */ -static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT); +static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC); static DEFINE_SPINLOCK(radix_lock); #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1) #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT) -- cgit v1.2.3 From e19f8fa6ce1ca9b8b934ba7d2e8f34c95abc6e60 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Wed, 1 Jun 2022 07:51:16 -0700 Subject: dma-debug: make things less spammy under memory pressure 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 Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index ac740630c79c..2caafd13f8aa 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, -- cgit v1.2.3