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[pve-kernel.git] / patches / kernel / 0158-x86-entry-Clean-up-the-SYSENTER_stack-code.patch
1 From f9bbe642761e841720222bcb912d920875f6ead2 Mon Sep 17 00:00:00 2001
2 From: Andy Lutomirski <luto@kernel.org>
3 Date: Mon, 4 Dec 2017 15:07:28 +0100
4 Subject: [PATCH 158/233] x86/entry: Clean up the SYSENTER_stack code
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 The existing code was a mess, mainly because C arrays are nasty. Turn
12 SYSENTER_stack into a struct, add a helper to find it, and do all the
13 obvious cleanups this enables.
14
15 Signed-off-by: Andy Lutomirski <luto@kernel.org>
16 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
17 Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
18 Reviewed-by: Borislav Petkov <bpetkov@suse.de>
19 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
20 Cc: Borislav Petkov <bp@alien8.de>
21 Cc: Brian Gerst <brgerst@gmail.com>
22 Cc: Dave Hansen <dave.hansen@intel.com>
23 Cc: Dave Hansen <dave.hansen@linux.intel.com>
24 Cc: David Laight <David.Laight@aculab.com>
25 Cc: Denys Vlasenko <dvlasenk@redhat.com>
26 Cc: Eduardo Valentin <eduval@amazon.com>
27 Cc: Greg KH <gregkh@linuxfoundation.org>
28 Cc: H. Peter Anvin <hpa@zytor.com>
29 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
30 Cc: Juergen Gross <jgross@suse.com>
31 Cc: Linus Torvalds <torvalds@linux-foundation.org>
32 Cc: Peter Zijlstra <peterz@infradead.org>
33 Cc: Rik van Riel <riel@redhat.com>
34 Cc: Will Deacon <will.deacon@arm.com>
35 Cc: aliguori@amazon.com
36 Cc: daniel.gruss@iaik.tugraz.at
37 Cc: hughd@google.com
38 Cc: keescook@google.com
39 Link: https://lkml.kernel.org/r/20171204150606.653244723@linutronix.de
40 Signed-off-by: Ingo Molnar <mingo@kernel.org>
41 (cherry picked from commit 0f9a48100fba3f189724ae88a450c2261bf91c80)
42 Signed-off-by: Andy Whitcroft <apw@canonical.com>
43 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
44 (cherry picked from commit a308af33c794110c52427ad11d3a6d35ffc14b76)
45 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
46 ---
47 arch/x86/include/asm/fixmap.h | 5 +++++
48 arch/x86/include/asm/processor.h | 6 +++++-
49 arch/x86/kernel/asm-offsets.c | 6 ++----
50 arch/x86/kernel/cpu/common.c | 14 +++-----------
51 arch/x86/kernel/dumpstack.c | 7 +++----
52 arch/x86/entry/entry_32.S | 4 ++--
53 arch/x86/entry/entry_64.S | 2 +-
54 7 files changed, 21 insertions(+), 23 deletions(-)
55
56 diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
57 index 953aed54cb5e..56aaffbbffd6 100644
58 --- a/arch/x86/include/asm/fixmap.h
59 +++ b/arch/x86/include/asm/fixmap.h
60 @@ -225,5 +225,10 @@ static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
61 return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
62 }
63
64 +static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu)
65 +{
66 + return &get_cpu_entry_area(cpu)->tss.SYSENTER_stack;
67 +}
68 +
69 #endif /* !__ASSEMBLY__ */
70 #endif /* _ASM_X86_FIXMAP_H */
71 diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
72 index 4737d378d7b5..2d489a414a86 100644
73 --- a/arch/x86/include/asm/processor.h
74 +++ b/arch/x86/include/asm/processor.h
75 @@ -330,12 +330,16 @@ struct x86_hw_tss {
76 #define IO_BITMAP_OFFSET (offsetof(struct tss_struct, io_bitmap) - offsetof(struct tss_struct, x86_tss))
77 #define INVALID_IO_BITMAP_OFFSET 0x8000
78
79 +struct SYSENTER_stack {
80 + unsigned long words[64];
81 +};
82 +
83 struct tss_struct {
84 /*
85 * Space for the temporary SYSENTER stack, used for SYSENTER
86 * and the entry trampoline as well.
87 */
88 - unsigned long SYSENTER_stack[64];
89 + struct SYSENTER_stack SYSENTER_stack;
90
91 /*
92 * The fixed hardware portion. This must not cross a page boundary
93 diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
94 index 822be00c85ff..00ea20bfa857 100644
95 --- a/arch/x86/kernel/asm-offsets.c
96 +++ b/arch/x86/kernel/asm-offsets.c
97 @@ -93,10 +93,8 @@ void common(void) {
98 BLANK();
99 DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
100
101 - /* Offset from cpu_tss to SYSENTER_stack */
102 - OFFSET(CPU_TSS_SYSENTER_stack, tss_struct, SYSENTER_stack);
103 - /* Size of SYSENTER_stack */
104 - DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack));
105 + OFFSET(TSS_STRUCT_SYSENTER_stack, tss_struct, SYSENTER_stack);
106 + DEFINE(SIZEOF_SYSENTER_stack, sizeof(struct SYSENTER_stack));
107
108 /* Layout info for cpu_entry_area */
109 OFFSET(CPU_ENTRY_AREA_tss, cpu_entry_area, tss);
110 diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
111 index f487766855d3..f9541c48c290 100644
112 --- a/arch/x86/kernel/cpu/common.c
113 +++ b/arch/x86/kernel/cpu/common.c
114 @@ -1306,12 +1306,7 @@ void enable_sep_cpu(void)
115
116 tss->x86_tss.ss1 = __KERNEL_CS;
117 wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
118 -
119 - wrmsr(MSR_IA32_SYSENTER_ESP,
120 - (unsigned long)&get_cpu_entry_area(cpu)->tss +
121 - offsetofend(struct tss_struct, SYSENTER_stack),
122 - 0);
123 -
124 + wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1), 0);
125 wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
126
127 put_cpu();
128 @@ -1437,9 +1432,7 @@ void syscall_init(void)
129 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
130 */
131 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
132 - wrmsrl_safe(MSR_IA32_SYSENTER_ESP,
133 - (unsigned long)&get_cpu_entry_area(cpu)->tss +
134 - offsetofend(struct tss_struct, SYSENTER_stack));
135 + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1));
136 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
137 #else
138 wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
139 @@ -1653,8 +1646,7 @@ void cpu_init(void)
140 */
141 set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
142 load_TR_desc();
143 - load_sp0((unsigned long)&get_cpu_entry_area(cpu)->tss +
144 - offsetofend(struct tss_struct, SYSENTER_stack));
145 + load_sp0((unsigned long)(cpu_SYSENTER_stack(cpu) + 1));
146
147 load_mm_ldt(&init_mm);
148
149 diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
150 index c32c6cce9dcc..b005e5ef6738 100644
151 --- a/arch/x86/kernel/dumpstack.c
152 +++ b/arch/x86/kernel/dumpstack.c
153 @@ -45,11 +45,10 @@ bool in_task_stack(unsigned long *stack, struct task_struct *task,
154
155 bool in_sysenter_stack(unsigned long *stack, struct stack_info *info)
156 {
157 - int cpu = smp_processor_id();
158 - struct tss_struct *tss = &get_cpu_entry_area(cpu)->tss;
159 + struct SYSENTER_stack *ss = cpu_SYSENTER_stack(smp_processor_id());
160
161 - void *begin = &tss->SYSENTER_stack;
162 - void *end = (void *)&tss->SYSENTER_stack + sizeof(tss->SYSENTER_stack);
163 + void *begin = ss;
164 + void *end = ss + 1;
165
166 if ((void *)stack < begin || (void *)stack >= end)
167 return false;
168 diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
169 index 41e0e103f090..04abcd3f8e2d 100644
170 --- a/arch/x86/entry/entry_32.S
171 +++ b/arch/x86/entry/entry_32.S
172 @@ -949,7 +949,7 @@ ENTRY(debug)
173
174 /* Are we currently on the SYSENTER stack? */
175 movl PER_CPU_VAR(cpu_entry_area), %ecx
176 - addl $CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
177 + addl $CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
178 subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
179 cmpl $SIZEOF_SYSENTER_stack, %ecx
180 jb .Ldebug_from_sysenter_stack
181 @@ -993,7 +993,7 @@ ENTRY(nmi)
182
183 /* Are we currently on the SYSENTER stack? */
184 movl PER_CPU_VAR(cpu_entry_area), %ecx
185 - addl $CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
186 + addl $CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
187 subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
188 cmpl $SIZEOF_SYSENTER_stack, %ecx
189 jb .Lnmi_from_sysenter_stack
190 diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
191 index dc100a7052ee..7a5e9edcdaf4 100644
192 --- a/arch/x86/entry/entry_64.S
193 +++ b/arch/x86/entry/entry_64.S
194 @@ -153,7 +153,7 @@ END(native_usergs_sysret64)
195 _entry_trampoline - CPU_ENTRY_AREA_entry_trampoline(%rip)
196
197 /* The top word of the SYSENTER stack is hot and is usable as scratch space. */
198 -#define RSP_SCRATCH CPU_ENTRY_AREA_tss + CPU_TSS_SYSENTER_stack + \
199 +#define RSP_SCRATCH CPU_ENTRY_AREA_tss + TSS_STRUCT_SYSENTER_stack + \
200 SIZEOF_SYSENTER_stack - 8 + CPU_ENTRY_AREA
201
202 ENTRY(entry_SYSCALL_64_trampoline)
203 --
204 2.14.2
205
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