Date:   Wed, 1 Feb 2023 19:11:52 +0900
From:   Hyunmin Lee <hn.min.lee@gmail.com>
To:     Andrew Morton <akpm@linux-foundation.org>,
        Uladzislau Rezki <urezki@gmail.com>,
        Christoph Hellwig <hch@infradead.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>,
        Jeungwoo Yoo <casionwoo@gmail.com>,
        Sangyun Kim <sangyun.kim@snu.ac.kr>,
        Mike Rapoport <rppt@kernel.org>
Subject: [PATCH v3] mm/vmalloc: replace BUG_ON to a simple if statement
Message-ID: <20230201101152.GA5535@min-iamroot>
MIME-Version: 1.0
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As per the coding standards, in the event of an abnormal condition that
should not occur under normal circumstances, the kernel should attempt
recovery and proceed with execution, rather than halting the machine.

Specifically, in the alloc_vmap_area() function, use a simple if()
instead of using BUG_ON() halting the machine.

Co-Developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Co-Developed-by: Jeungwoo Yoo <casionwoo@gmail.com>
Co-Developed-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Signed-off-by: Hyunmin Lee <hn.min.lee@gmail.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com>
Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
---
v1->v2 : Add commit description
v2->v3 : Change WARN_ON() to if()
---
 mm/vmalloc.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 74afa2208558..52a346bc02a1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1587,9 +1587,14 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 	int purged = 0;
 	int ret;
 
-	BUG_ON(!size);
-	BUG_ON(offset_in_page(size));
-	BUG_ON(!is_power_of_2(align));
+	if (unlikely(!size))
+		return ERR_PTR(-EINVAL);
+
+	if (unlikely(offset_in_page(size)))
+		return ERR_PTR(-EINVAL);
+
+	if (unlikely(!is_power_of_2(align)))
+		return ERR_PTR(-EINVAL);
 
 	if (unlikely(!vmap_initialized))
 		return ERR_PTR(-EBUSY);
-- 
2.25.1