From 7d025059650f1c41a427173789ac14b74212b361 Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Tue, 11 Dec 2012 16:01:56 -0800 Subject: [PATCH] mm: fix cache coloring on x86_64 architecture Fix the x86-64 cache alignment code to take pgoff into account. Use the x86 and MIPS cache alignment code as the basis for a generic cache alignment function. The old x86 code will always align the mmap to aliasing boundaries, even if the program mmaps the file with a non-zero pgoff. If program A mmaps the file with pgoff 0, and program B mmaps the file with pgoff 1. The old code would align the mmaps, resulting in misaligned pages: A: 0123 B: 123 After this patch, they are aligned so the pages line up: A: 0123 B: 123 Proposed by Rik van Riel. Signed-off-by: Michel Lespinasse Cc: Rik van Riel Cc: Hugh Dickins Cc: Russell King Cc: Ralf Baechle Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/sys_x86_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index f00d006d60f..97ef74b88e0 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -136,7 +136,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, info.low_limit = begin; info.high_limit = end; info.align_mask = filp ? get_align_mask() : 0; - info.align_offset = 0; + info.align_offset = pgoff << PAGE_SHIFT; return vm_unmapped_area(&info); } @@ -175,7 +175,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.low_limit = PAGE_SIZE; info.high_limit = mm->mmap_base; info.align_mask = filp ? get_align_mask() : 0; - info.align_offset = 0; + info.align_offset = pgoff << PAGE_SHIFT; addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) return addr;