dma-debug: fix return value of __setup handlers

BugLink: https://bugs.launchpad.net/bugs/1969110
[ Upstream commit 80e4390981618e290616dbd06ea190d4576f219d ]

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 <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit c39a750b61f7b3a37243461f066b969ed27d1094)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 7a14ca29c37782d5b5b6e2a234cc9bdf57de9312..f8ff598596b8581e9d5bda5b5fa132594a5e35e5 100644 (file)
--- 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);