From patchwork Mon Nov 5 22:47:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [07/16] mm: fix cache coloring on x86_64 architecture Date: Mon, 05 Nov 2012 12:47:04 -0000 From: Michel Lespinasse X-Patchwork-Id: 197351 Message-Id: <1352155633-8648-8-git-send-email-walken@google.com> To: Andrew Morton , Rik van Riel , Hugh Dickins , linux-kernel@vger.kernel.org, Russell King , Ralf Baechle , Paul Mundt , "David S. Miller" , Chris Metcalf , x86@kernel.org, William Irwin Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org 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 Signed-off-by: Michel Lespinasse Proposed-by: Rik van Riel --- arch/x86/kernel/sys_x86_64.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index f00d006d60fd..97ef74b88e0f 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;