]>
Commit | Line | Data |
---|---|---|
59d5af67 | 1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
321d628a FG |
2 | From: Dave Hansen <dave.hansen@linux.intel.com> |
3 | Date: Mon, 4 Dec 2017 15:07:58 +0100 | |
59d5af67 | 4 | Subject: [PATCH] x86/mm: Abstract switching CR3 |
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 | In preparation to adding additional PCID flushing, abstract the | |
12 | loading of a new ASID into CR3. | |
13 | ||
14 | [ PeterZ: Split out from big combo patch ] | |
15 | ||
16 | Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> | |
17 | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> | |
18 | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> | |
19 | Cc: Andy Lutomirski <luto@kernel.org> | |
20 | Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> | |
21 | Cc: Borislav Petkov <bp@alien8.de> | |
22 | Cc: Brian Gerst <brgerst@gmail.com> | |
23 | Cc: David Laight <David.Laight@aculab.com> | |
24 | Cc: Denys Vlasenko <dvlasenk@redhat.com> | |
25 | Cc: Eduardo Valentin <eduval@amazon.com> | |
26 | Cc: Greg KH <gregkh@linuxfoundation.org> | |
27 | Cc: H. Peter Anvin <hpa@zytor.com> | |
28 | Cc: Josh Poimboeuf <jpoimboe@redhat.com> | |
29 | Cc: Juergen Gross <jgross@suse.com> | |
30 | Cc: Linus Torvalds <torvalds@linux-foundation.org> | |
31 | Cc: Peter Zijlstra <peterz@infradead.org> | |
32 | Cc: Will Deacon <will.deacon@arm.com> | |
33 | Cc: aliguori@amazon.com | |
34 | Cc: daniel.gruss@iaik.tugraz.at | |
35 | Cc: hughd@google.com | |
36 | Cc: keescook@google.com | |
37 | Signed-off-by: Ingo Molnar <mingo@kernel.org> | |
38 | (cherry picked from commit 48e111982cda033fec832c6b0592c2acedd85d04) | |
39 | Signed-off-by: Andy Whitcroft <apw@canonical.com> | |
40 | Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> | |
41 | (cherry picked from commit 1e2affe2a79305b3a5f3ad65d3f61ad9d1f9e168) | |
42 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
43 | --- | |
44 | arch/x86/mm/tlb.c | 22 ++++++++++++++++++++-- | |
45 | 1 file changed, 20 insertions(+), 2 deletions(-) | |
46 | ||
47 | diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c | |
48 | index ce87b69fb4e0..353f2f4e1d96 100644 | |
49 | --- a/arch/x86/mm/tlb.c | |
50 | +++ b/arch/x86/mm/tlb.c | |
51 | @@ -101,6 +101,24 @@ static void choose_new_asid(struct mm_struct *next, u64 next_tlb_gen, | |
52 | *need_flush = true; | |
53 | } | |
54 | ||
55 | +static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush) | |
56 | +{ | |
57 | + unsigned long new_mm_cr3; | |
58 | + | |
59 | + if (need_flush) { | |
60 | + new_mm_cr3 = build_cr3(pgdir, new_asid); | |
61 | + } else { | |
62 | + new_mm_cr3 = build_cr3_noflush(pgdir, new_asid); | |
63 | + } | |
64 | + | |
65 | + /* | |
66 | + * Caution: many callers of this function expect | |
67 | + * that load_cr3() is serializing and orders TLB | |
68 | + * fills with respect to the mm_cpumask writes. | |
69 | + */ | |
70 | + write_cr3(new_mm_cr3); | |
71 | +} | |
72 | + | |
73 | void leave_mm(int cpu) | |
74 | { | |
75 | struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm); | |
76 | @@ -228,7 +246,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, | |
77 | if (need_flush) { | |
78 | this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id); | |
79 | this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen); | |
80 | - write_cr3(build_cr3(next->pgd, new_asid)); | |
81 | + load_new_mm_cr3(next->pgd, new_asid, true); | |
82 | ||
83 | /* | |
84 | * NB: This gets called via leave_mm() in the idle path | |
85 | @@ -241,7 +259,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, | |
86 | trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL); | |
87 | } else { | |
88 | /* The new ASID is already up to date. */ | |
89 | - write_cr3(build_cr3_noflush(next->pgd, new_asid)); | |
90 | + load_new_mm_cr3(next->pgd, new_asid, false); | |
91 | ||
92 | /* See above wrt _rcuidle. */ | |
93 | trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0); | |
94 | -- | |
95 | 2.14.2 | |
96 |