[PATCH 1/7] x86/boot/compressed/64: Fix trampoline page table address calculation

From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>,
	linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH 1/7] x86/boot/compressed/64: Fix trampoline page table address calculation
Date: Fri, 18 May 2018 13:35:22 +0300	[thread overview]
Message-ID: <20180518103528.59260-2-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20180518103528.59260-1-kirill.shutemov@linux.intel.com>

Hugh noticied that I calculate address of trampoline page table wrongly
in cleanup_trampoline(). TRAMPOLINE_32BIT_PGTABLE_OFFSET has to be
divided by sizeof(unsigned long) since trampoline_32bit is unsigned long
pointer.

TRAMPOLINE_32BIT_PGTABLE_OFFSET is zero so the bug doesn't have a
visible effect.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Hugh Dickins <hughd@google.com>
Fixes: e9d0e6330eb8 ("x86/boot/compressed/64: Prepare new top-level page table for trampoline")
---
 arch/x86/boot/compressed/pgtable_64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c
index a362fa0b849c..23707e1da1ff 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -130,7 +130,7 @@ void cleanup_trampoline(void *pgtable)
 {
 	void *trampoline_pgtable;
 
-	trampoline_pgtable = trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET;
+	trampoline_pgtable = trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET / sizeof(unsigned long);
 
 	/*
 	 * Move the top level page table out of trampoline memory,
-- 
2.17.0
