[PATCH] x86/init: fix build with CONFIG_SWAP=n

From: Vlastimil Babka <vbabka@suse.cz>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Tomas Pruzina <pruzinat@gmail.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	stable@vger.kernel.org
Subject: [PATCH] x86/init: fix build with CONFIG_SWAP=n
Date: Tue, 14 Aug 2018 20:50:47 +0200	[thread overview]
Message-ID: <20180814185047.21139-1-vbabka@suse.cz> (raw)

The introduction of generic_max_swapfile_size and arch-specific versions has
broken linking on x86 with CONFIG_SWAP=n due to undefined reference to
'generic_max_swapfile_size'. Fix it by compiling the x86-specific
max_swapfile_size() only with CONFIG_SWAP=y.

Reported-by: Tomas Pruzina <pruzinat@gmail.com>
Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: stable@vger.kernel.org
---
 arch/x86/mm/init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 156ed8154af8..acfab322fbe0 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -914,6 +914,7 @@ void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
 	__pte2cachemode_tbl[entry] = cache;
 }
 
+#ifdef CONFIG_SWAP
 unsigned long max_swapfile_size(void)
 {
 	unsigned long pages;
@@ -934,3 +935,4 @@ unsigned long max_swapfile_size(void)
 	}
 	return pages;
 }
+#endif
-- 
2.18.0

