linux-kernel - [tip:x86/mm] x86/mm: Clean up the TLB flushing code

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-4995ab9cf512e9a6cc07dfd6b1d4e2fc48ce7fef@git.kernel.org>
Date:	Thu, 31 Jul 2014 09:09:37 -0700
From:	tip-bot for Dave Hansen <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	riel@...hat.com, mgorman@...e.de, tglx@...utronix.de,
	dave.hansen@...ux.intel.com, hpa@...ux.intel.com
Subject: [tip:x86/mm] x86/mm: Clean up the TLB flushing code

Commit-ID:  4995ab9cf512e9a6cc07dfd6b1d4e2fc48ce7fef
Gitweb:     http://git.kernel.org/tip/4995ab9cf512e9a6cc07dfd6b1d4e2fc48ce7fef
Author:     Dave Hansen <dave.hansen@...ux.intel.com>
AuthorDate: Thu, 31 Jul 2014 08:40:54 -0700
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Thu, 31 Jul 2014 08:48:50 -0700

x86/mm: Clean up the TLB flushing code

The

	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)

line of code is not exactly the easiest to audit, especially when
it ends up at two different indentation levels.  This eliminates
one of the the copy-n-paste versions.  It also gives us a unified
exit point for each path through this function.  We need this in
a minute for our tracepoint.

Signed-off-by: Dave Hansen <dave.hansen@...ux.intel.com>
Link: http://lkml.kernel.org/r/20140731154054.44F1CDDC@viggo.jf.intel.com
Acked-by: Rik van Riel <riel@...hat.com>
Acked-by: Mel Gorman <mgorman@...e.de>
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
 arch/x86/mm/tlb.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index dd8dda1..378fbef 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -161,23 +161,24 @@ void flush_tlb_current_task(void)
 void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 				unsigned long end, unsigned long vmflag)
 {
+	bool need_flush_others_all = true;
 	unsigned long addr;
 	unsigned act_entries, tlb_entries = 0;
 	unsigned long nr_base_pages;
 
 	preempt_disable();
 	if (current->active_mm != mm)
-		goto flush_all;
+		goto out;
 
 	if (!current->mm) {
 		leave_mm(smp_processor_id());
-		goto flush_all;
+		goto out;
 	}
 
 	if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1
 					|| vmflag & VM_HUGETLB) {
 		local_flush_tlb();
-		goto flush_all;
+		goto out;
 	}
 
 	/* In modern CPU, last level tlb used for both data/ins */
@@ -196,22 +197,20 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 		count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
 		local_flush_tlb();
 	} else {
+		need_flush_others_all = false;
 		/* flush range by one by one 'invlpg' */
 		for (addr = start; addr < end;	addr += PAGE_SIZE) {
 			count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
 			__flush_tlb_single(addr);
 		}
-
-		if (cpumask_any_but(mm_cpumask(mm),
-				smp_processor_id()) < nr_cpu_ids)
-			flush_tlb_others(mm_cpumask(mm), mm, start, end);
-		preempt_enable();
-		return;
 	}
-
-flush_all:
+out:
+	if (need_flush_others_all) {
+		start = 0UL;
+		end = TLB_FLUSH_ALL;
+	}
 	if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
-		flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL);
+		flush_tlb_others(mm_cpumask(mm), mm, start, end);
 	preempt_enable();
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/