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321d628a FG |
1 | From bf670c55337b76ab2449abe15d3fd3c11b14c013 Mon Sep 17 00:00:00 2001 |
2 | From: Peter Zijlstra <peterz@infradead.org> | |
3 | Date: Tue, 5 Dec 2017 13:34:46 +0100 | |
b378f209 | 4 | Subject: [PATCH 177/233] x86/mm: Remove superfluous barriers |
321d628a FG |
5 | MIME-Version: 1.0 |
6 | Content-Type: text/plain; charset=UTF-8 | |
7 | Content-Transfer-Encoding: 8bit | |
8 | ||
9 | CVE-2017-5754 | |
10 | ||
11 | atomic64_inc_return() already implies smp_mb() before and after. | |
12 | ||
13 | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> | |
14 | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> | |
15 | Cc: Andy Lutomirski <luto@kernel.org> | |
16 | Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> | |
17 | Cc: Borislav Petkov <bp@alien8.de> | |
18 | Cc: Brian Gerst <brgerst@gmail.com> | |
19 | Cc: Dave Hansen <dave.hansen@linux.intel.com> | |
20 | Cc: David Laight <David.Laight@aculab.com> | |
21 | Cc: Denys Vlasenko <dvlasenk@redhat.com> | |
22 | Cc: Eduardo Valentin <eduval@amazon.com> | |
23 | Cc: Greg KH <gregkh@linuxfoundation.org> | |
24 | Cc: H. Peter Anvin <hpa@zytor.com> | |
25 | Cc: Josh Poimboeuf <jpoimboe@redhat.com> | |
26 | Cc: Juergen Gross <jgross@suse.com> | |
27 | Cc: Linus Torvalds <torvalds@linux-foundation.org> | |
28 | Cc: Peter Zijlstra <peterz@infradead.org> | |
29 | Cc: Will Deacon <will.deacon@arm.com> | |
30 | Cc: aliguori@amazon.com | |
31 | Cc: daniel.gruss@iaik.tugraz.at | |
32 | Cc: hughd@google.com | |
33 | Cc: keescook@google.com | |
34 | Cc: linux-mm@kvack.org | |
35 | Signed-off-by: Ingo Molnar <mingo@kernel.org> | |
36 | (cherry picked from commit b5fc6d943808b570bdfbec80f40c6b3855f1c48b) | |
37 | Signed-off-by: Andy Whitcroft <apw@canonical.com> | |
38 | Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> | |
39 | (cherry picked from commit 31a37930df33315a7006b46706f6babdb57db1f4) | |
40 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
41 | --- | |
42 | arch/x86/include/asm/tlbflush.h | 8 +------- | |
43 | 1 file changed, 1 insertion(+), 7 deletions(-) | |
44 | ||
45 | diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h | |
46 | index 6d2688a6fda0..bc1460b4737b 100644 | |
47 | --- a/arch/x86/include/asm/tlbflush.h | |
48 | +++ b/arch/x86/include/asm/tlbflush.h | |
49 | @@ -59,19 +59,13 @@ static inline void invpcid_flush_all_nonglobals(void) | |
50 | ||
51 | static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) | |
52 | { | |
53 | - u64 new_tlb_gen; | |
54 | - | |
55 | /* | |
56 | * Bump the generation count. This also serves as a full barrier | |
57 | * that synchronizes with switch_mm(): callers are required to order | |
58 | * their read of mm_cpumask after their writes to the paging | |
59 | * structures. | |
60 | */ | |
61 | - smp_mb__before_atomic(); | |
62 | - new_tlb_gen = atomic64_inc_return(&mm->context.tlb_gen); | |
63 | - smp_mb__after_atomic(); | |
64 | - | |
65 | - return new_tlb_gen; | |
66 | + return atomic64_inc_return(&mm->context.tlb_gen); | |
67 | } | |
68 | ||
69 | #ifdef CONFIG_PARAVIRT | |
70 | -- | |
71 | 2.14.2 | |
72 |