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KPTI: add follow-up fixes
[pve-kernel.git] / patches / kernel / 0158-x86-entry-Clean-up-the-SYSENTER_stack-code.patch
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321d628a
FG		 1From f9bbe642761e841720222bcb912d920875f6ead2 Mon Sep 17 00:00:00 2001
2From: Andy Lutomirski <luto@kernel.org>
3Date: Mon, 4 Dec 2017 15:07:28 +0100
e4cdf2a5 4Subject: [PATCH 158/241] x86/entry: Clean up the SYSENTER_stack code
321d628a
FG		 5MIME-Version: 1.0
6Content-Type: text/plain; charset=UTF-8
7Content-Transfer-Encoding: 8bit
8
9CVE-2017-5754
10
11The existing code was a mess, mainly because C arrays are nasty. Turn
12SYSENTER_stack into a struct, add a helper to find it, and do all the
13obvious cleanups this enables.
14
15Signed-off-by: Andy Lutomirski <luto@kernel.org>
16Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
17Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
18Reviewed-by: Borislav Petkov <bpetkov@suse.de>
19Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
20Cc: Borislav Petkov <bp@alien8.de>
21Cc: Brian Gerst <brgerst@gmail.com>
22Cc: Dave Hansen <dave.hansen@intel.com>
23Cc: Dave Hansen <dave.hansen@linux.intel.com>
24Cc: David Laight <David.Laight@aculab.com>
25Cc: Denys Vlasenko <dvlasenk@redhat.com>
26Cc: Eduardo Valentin <eduval@amazon.com>
27Cc: Greg KH <gregkh@linuxfoundation.org>
28Cc: H. Peter Anvin <hpa@zytor.com>
29Cc: Josh Poimboeuf <jpoimboe@redhat.com>
30Cc: Juergen Gross <jgross@suse.com>
31Cc: Linus Torvalds <torvalds@linux-foundation.org>
32Cc: Peter Zijlstra <peterz@infradead.org>
33Cc: Rik van Riel <riel@redhat.com>
34Cc: Will Deacon <will.deacon@arm.com>
35Cc: aliguori@amazon.com
36Cc: daniel.gruss@iaik.tugraz.at
37Cc: hughd@google.com
38Cc: keescook@google.com
39Link: https://lkml.kernel.org/r/20171204150606.653244723@linutronix.de
40Signed-off-by: Ingo Molnar <mingo@kernel.org>
41(cherry picked from commit 0f9a48100fba3f189724ae88a450c2261bf91c80)
42Signed-off-by: Andy Whitcroft <apw@canonical.com>
43Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
44(cherry picked from commit a308af33c794110c52427ad11d3a6d35ffc14b76)
45Signed-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
56diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
57index 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 */
71diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
72index 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
93diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
94index 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);
110diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
111index 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
149diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
150index 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;
168diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
169index 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
190diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
191index 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--
2042.14.2
205
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