[PATCH v1 2/4] powerpc/mm: print warning in arch_remove_linear_mapping()

From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org,
	David Hildenbrand <david@redhat.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Rashmica Gupta <rashmica.g@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Mike Rapoport <rppt@kernel.org>, Michal Hocko <mhocko@suse.com>,
	Oscar Salvador <osalvador@suse.de>,
	Wei Yang <richard.weiyang@linux.alibaba.com>
Subject: [PATCH v1 2/4] powerpc/mm: print warning in arch_remove_linear_mapping()
Date: Thu, 29 Oct 2020 17:27:16 +0100	[thread overview]
Message-ID: <20201029162718.29910-3-david@redhat.com> (raw)
In-Reply-To: <20201029162718.29910-1-david@redhat.com>

Let's print a warning similar to in arch_add_linear_mapping() instead of
WARN_ON_ONCE() and eventually crashing the kernel.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rashmica Gupta <rashmica.g@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/mm/mem.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 8a86d81f8df0..685028451dd2 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -145,7 +145,9 @@ void __ref arch_remove_linear_mapping(u64 start, u64 size)
 	flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE);
 
 	ret = remove_section_mapping(start, start + size);
-	WARN_ON_ONCE(ret);
+	if (ret)
+		pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
+			start, start + size, ret);
 
 	/* Ensure all vmalloc mappings are flushed in case they also
 	 * hit that section of memory
-- 
2.26.2

