Commit-ID: 6c434d6176c0cb42847c33245189667d645db7bf Gitweb: http://git.kernel.org/tip/6c434d6176c0cb42847c33245189667d645db7bf Author: Ross Zwisler <ross.zwis...@linux.intel.com> AuthorDate: Mon, 11 May 2015 10:15:49 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 11 May 2015 10:38:44 +0200
x86/mm: Do not flush last cacheline twice in clflush_cache_range() The current algorithm used in clflush_cache_range() can cause the last cache line of the buffer to be flushed twice. Fix that algorithm so that each cache line will only be flushed once. Reported-by: H. Peter Anvin <h...@zytor.com> Signed-off-by: Ross Zwisler <ross.zwis...@linux.intel.com> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Luis R. Rodriguez <mcg...@suse.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Toshi Kani <toshi.k...@hp.com> Link: http://lkml.kernel.org/r/1430259192-18802-1-git-send-email-ross.zwis...@linux.intel.com Link: http://lkml.kernel.org/r/1431332153-18566-5-git-send-email...@alien8.de [ Changed it to 'void *' to simplify the type conversions. ] Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/mm/pageattr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 89af288..5ddd900 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -129,16 +129,15 @@ within(unsigned long addr, unsigned long start, unsigned long end) */ void clflush_cache_range(void *vaddr, unsigned int size) { - void *vend = vaddr + size - 1; + unsigned long clflush_mask = boot_cpu_data.x86_clflush_size - 1; + void *vend = vaddr + size; + void *p; mb(); - for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size) - clflushopt(vaddr); - /* - * Flush any possible final partial cacheline: - */ - clflushopt(vend); + for (p = (void *)((unsigned long)vaddr & ~clflush_mask); + p < vend; p += boot_cpu_data.x86_clflush_size) + clflushopt(p); mb(); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
