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[pve-kernel.git] / patches / kernel / 0029-x86-xen-Get-rid-of-paravirt-op-adjust_exception_fram.patch
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321d628a
FG		 1From e5688fb8c2c243658f3fe754d33c7250c8aed146 Mon Sep 17 00:00:00 2001
2From: Juergen Gross <jgross@suse.com>
3Date: Thu, 31 Aug 2017 19:42:49 +0200
633c5ed1 4Subject: [PATCH 029/242] x86/xen: Get rid of paravirt op
321d628a
FG		 5 adjust_exception_frame
6MIME-Version: 1.0
7Content-Type: text/plain; charset=UTF-8
8Content-Transfer-Encoding: 8bit
9
10CVE-2017-5754
11
12When running as Xen pv-guest the exception frame on the stack contains
13%r11 and %rcx additional to the other data pushed by the processor.
14
15Instead of having a paravirt op being called for each exception type
16prepend the Xen specific code to each exception entry. When running as
17Xen pv-guest just use the exception entry with prepended instructions,
18otherwise use the entry without the Xen specific code.
19
20[ tglx: Merged through tip to avoid ugly merge conflict ]
21
22Signed-off-by: Juergen Gross <jgross@suse.com>
23Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
24Cc: xen-devel@lists.xenproject.org
25Cc: boris.ostrovsky@oracle.com
26Cc: luto@amacapital.net
27Link: http://lkml.kernel.org/r/20170831174249.26853-1-jg@pfupf.net
28(backported from commit 5878d5d6fdef6447d73b0acc121ba445bef37f53)
29Signed-off-by: Andy Whitcroft <apw@canonical.com>
30Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
31(cherry picked from commit 9a6fb927deb3ebbe831741ca82081714637181a7)
32Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
33---
34 arch/x86/include/asm/paravirt.h | 5 --
35 arch/x86/include/asm/paravirt_types.h | 3 --
36 arch/x86/include/asm/proto.h | 3 ++
37 arch/x86/include/asm/traps.h | 28 ++++++++--
38 arch/x86/xen/xen-ops.h | 1 -
39 arch/x86/kernel/asm-offsets_64.c | 1 -
40 arch/x86/kernel/paravirt.c | 3 --
41 arch/x86/xen/enlighten_pv.c | 98 +++++++++++++++++++++++------------
42 arch/x86/xen/irq.c | 3 --
43 arch/x86/entry/entry_64.S | 23 ++------
44 arch/x86/entry/entry_64_compat.S | 1 -
45 arch/x86/xen/xen-asm_64.S | 41 +++++++++++++--
46 12 files changed, 133 insertions(+), 77 deletions(-)
47
48diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
49index 9ccac1926587..c25dd22f7c70 100644
50--- a/arch/x86/include/asm/paravirt.h
51+++ b/arch/x86/include/asm/paravirt.h
52@@ -960,11 +960,6 @@ extern void default_banner(void);
53 #define GET_CR2_INTO_RAX \
54 call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
55
56-#define PARAVIRT_ADJUST_EXCEPTION_FRAME \
57- PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \
58- CLBR_NONE, \
59- call PARA_INDIRECT(pv_irq_ops+PV_IRQ_adjust_exception_frame))
60-
61 #define USERGS_SYSRET64 \
62 PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64), \
63 CLBR_NONE, \
64diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
65index 9ffc36bfe4cd..6b64fc6367f2 100644
66--- a/arch/x86/include/asm/paravirt_types.h
67+++ b/arch/x86/include/asm/paravirt_types.h
68@@ -196,9 +196,6 @@ struct pv_irq_ops {
69 void (*safe_halt)(void);
70 void (*halt)(void);
71
72-#ifdef CONFIG_X86_64
73- void (*adjust_exception_frame)(void);
74-#endif
75 } __no_randomize_layout;
76
77 struct pv_mmu_ops {
78diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
79index 8d3964fc5f91..b408b1886195 100644
80--- a/arch/x86/include/asm/proto.h
81+++ b/arch/x86/include/asm/proto.h
82@@ -24,6 +24,9 @@ void entry_SYSENTER_compat(void);
83 void __end_entry_SYSENTER_compat(void);
84 void entry_SYSCALL_compat(void);
85 void entry_INT80_compat(void);
86+#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
87+void xen_entry_INT80_compat(void);
88+#endif
89 #endif
90
91 void x86_configure_nx(void);
92diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
93index b4f322d6c95f..feb89dbe359d 100644
94--- a/arch/x86/include/asm/traps.h
95+++ b/arch/x86/include/asm/traps.h
96@@ -13,9 +13,6 @@ asmlinkage void divide_error(void);
97 asmlinkage void debug(void);
98 asmlinkage void nmi(void);
99 asmlinkage void int3(void);
100-asmlinkage void xen_debug(void);
101-asmlinkage void xen_int3(void);
102-asmlinkage void xen_stack_segment(void);
103 asmlinkage void overflow(void);
104 asmlinkage void bounds(void);
105 asmlinkage void invalid_op(void);
106@@ -56,6 +53,31 @@ asmlinkage void simd_coprocessor_error(void);
107 #define trace_page_fault page_fault
108 #endif
109
110+#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
111+asmlinkage void xen_divide_error(void);
112+asmlinkage void xen_xendebug(void);
113+asmlinkage void xen_xenint3(void);
114+asmlinkage void xen_nmi(void);
115+asmlinkage void xen_overflow(void);
116+asmlinkage void xen_bounds(void);
117+asmlinkage void xen_invalid_op(void);
118+asmlinkage void xen_device_not_available(void);
119+asmlinkage void xen_double_fault(void);
120+asmlinkage void xen_coprocessor_segment_overrun(void);
121+asmlinkage void xen_invalid_TSS(void);
122+asmlinkage void xen_segment_not_present(void);
123+asmlinkage void xen_stack_segment(void);
124+asmlinkage void xen_general_protection(void);
125+asmlinkage void xen_page_fault(void);
126+asmlinkage void xen_spurious_interrupt_bug(void);
127+asmlinkage void xen_coprocessor_error(void);
128+asmlinkage void xen_alignment_check(void);
129+#ifdef CONFIG_X86_MCE
130+asmlinkage void xen_machine_check(void);
131+#endif /* CONFIG_X86_MCE */
132+asmlinkage void xen_simd_coprocessor_error(void);
133+#endif
134+
135 dotraplinkage void do_divide_error(struct pt_regs *, long);
136 dotraplinkage void do_debug(struct pt_regs *, long);
137 dotraplinkage void do_nmi(struct pt_regs *, long);
138diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
139index 70301ac0d414..c8a6d224f7ed 100644
140--- a/arch/x86/xen/xen-ops.h
141+++ b/arch/x86/xen/xen-ops.h
142@@ -138,7 +138,6 @@ __visible void xen_restore_fl_direct(unsigned long);
143 __visible void xen_iret(void);
144 __visible void xen_sysret32(void);
145 __visible void xen_sysret64(void);
146-__visible void xen_adjust_exception_frame(void);
147
148 extern int xen_panic_handler_init(void);
149
150diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
151index 99332f550c48..cf42206926af 100644
152--- a/arch/x86/kernel/asm-offsets_64.c
153+++ b/arch/x86/kernel/asm-offsets_64.c
154@@ -20,7 +20,6 @@ static char syscalls_ia32[] = {
155 int main(void)
156 {
157 #ifdef CONFIG_PARAVIRT
158- OFFSET(PV_IRQ_adjust_exception_frame, pv_irq_ops, adjust_exception_frame);
159 OFFSET(PV_CPU_usergs_sysret64, pv_cpu_ops, usergs_sysret64);
160 OFFSET(PV_CPU_swapgs, pv_cpu_ops, swapgs);
161 BLANK();
162diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
163index bc0a849589bb..a14df9eecfed 100644
164--- a/arch/x86/kernel/paravirt.c
165+++ b/arch/x86/kernel/paravirt.c
166@@ -319,9 +319,6 @@ __visible struct pv_irq_ops pv_irq_ops = {
167 .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
168 .safe_halt = native_safe_halt,
169 .halt = native_halt,
170-#ifdef CONFIG_X86_64
171- .adjust_exception_frame = paravirt_nop,
172-#endif
173 };
174
175 __visible struct pv_cpu_ops pv_cpu_ops = {
176diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
177index c76f5ff4d0d7..ae2a2e2d6362 100644
178--- a/arch/x86/xen/enlighten_pv.c
179+++ b/arch/x86/xen/enlighten_pv.c
180@@ -586,6 +586,70 @@ static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
181 preempt_enable();
182 }
183
184+#ifdef CONFIG_X86_64
185+struct trap_array_entry {
186+ void (*orig)(void);
187+ void (*xen)(void);
188+ bool ist_okay;
189+};
190+
191+static struct trap_array_entry trap_array[] = {
192+ { debug, xen_xendebug, true },
193+ { int3, xen_xenint3, true },
194+ { double_fault, xen_double_fault, true },
195+#ifdef CONFIG_X86_MCE
196+ { machine_check, xen_machine_check, true },
197+#endif
198+ { nmi, xen_nmi, true },
199+ { overflow, xen_overflow, false },
200+#ifdef CONFIG_IA32_EMULATION
201+ { entry_INT80_compat, xen_entry_INT80_compat, false },
202+#endif
203+ { page_fault, xen_page_fault, false },
204+ { divide_error, xen_divide_error, false },
205+ { bounds, xen_bounds, false },
206+ { invalid_op, xen_invalid_op, false },
207+ { device_not_available, xen_device_not_available, false },
208+ { coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false },
209+ { invalid_TSS, xen_invalid_TSS, false },
210+ { segment_not_present, xen_segment_not_present, false },
211+ { stack_segment, xen_stack_segment, false },
212+ { general_protection, xen_general_protection, false },
213+ { spurious_interrupt_bug, xen_spurious_interrupt_bug, false },
214+ { coprocessor_error, xen_coprocessor_error, false },
215+ { alignment_check, xen_alignment_check, false },
216+ { simd_coprocessor_error, xen_simd_coprocessor_error, false },
217+};
218+
219+static bool get_trap_addr(void **addr, unsigned int ist)
220+{
221+ unsigned int nr;
222+ bool ist_okay = false;
223+
224+ /*
225+ * Replace trap handler addresses by Xen specific ones.
226+ * Check for known traps using IST and whitelist them.
227+ * The debugger ones are the only ones we care about.
228+ * Xen will handle faults like double_fault, * so we should never see
229+ * them. Warn if there's an unexpected IST-using fault handler.
230+ */
231+ for (nr = 0; nr < ARRAY_SIZE(trap_array); nr++) {
232+ struct trap_array_entry *entry = trap_array + nr;
233+
234+ if (*addr == entry->orig) {
235+ *addr = entry->xen;
236+ ist_okay = entry->ist_okay;
237+ break;
238+ }
239+ }
240+
241+ if (WARN_ON(ist != 0 && !ist_okay))
242+ return false;
243+
244+ return true;
245+}
246+#endif
247+
248 static int cvt_gate_to_trap(int vector, const gate_desc *val,
249 struct trap_info *info)
250 {
251@@ -598,40 +662,8 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val,
252
253 addr = gate_offset(val);
254 #ifdef CONFIG_X86_64
255- /*
256- * Look for known traps using IST, and substitute them
257- * appropriately. The debugger ones are the only ones we care
258- * about. Xen will handle faults like double_fault,
259- * so we should never see them. Warn if
260- * there's an unexpected IST-using fault handler.
261- */
262- if (addr == (unsigned long)debug)
263- addr = (unsigned long)xen_debug;
264- else if (addr == (unsigned long)int3)
265- addr = (unsigned long)xen_int3;
266- else if (addr == (unsigned long)stack_segment)
267- addr = (unsigned long)xen_stack_segment;
268- else if (addr == (unsigned long)double_fault) {
269- /* Don't need to handle these */
270+ if (!get_trap_addr((void **)&addr, val->bits.ist))
271 return 0;
272-#ifdef CONFIG_X86_MCE
273- } else if (addr == (unsigned long)machine_check) {
274- /*
275- * when xen hypervisor inject vMCE to guest,
276- * use native mce handler to handle it
277- */
278- ;
279-#endif
280- } else if (addr == (unsigned long)nmi)
281- /*
282- * Use the native version as well.
283- */
284- ;
285- else {
286- /* Some other trap using IST? */
287- if (WARN_ON(val->bits.ist != 0))
288- return 0;
289- }
290 #endif /* CONFIG_X86_64 */
291 info->address = addr;
292
293diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
294index 33e92955e09d..d4eff5676cfa 100644
295--- a/arch/x86/xen/irq.c
296+++ b/arch/x86/xen/irq.c
297@@ -123,9 +123,6 @@ static const struct pv_irq_ops xen_irq_ops __initconst = {
298
299 .safe_halt = xen_safe_halt,
300 .halt = xen_halt,
301-#ifdef CONFIG_X86_64
302- .adjust_exception_frame = xen_adjust_exception_frame,
303-#endif
304 };
305
306 void __init xen_init_irq_ops(void)
307diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
308index dfabcbf8e813..c12260ef3e4b 100644
309--- a/arch/x86/entry/entry_64.S
310+++ b/arch/x86/entry/entry_64.S
311@@ -829,7 +829,6 @@ ENTRY(\sym)
312 .endif
313
314 ASM_CLAC
315- PARAVIRT_ADJUST_EXCEPTION_FRAME
316
317 .ifeq \has_error_code
318 pushq $-1 /* ORIG_RAX: no syscall to restart */
319@@ -975,7 +974,7 @@ ENTRY(do_softirq_own_stack)
320 ENDPROC(do_softirq_own_stack)
321
322 #ifdef CONFIG_XEN
323-idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
324+idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0
325
326 /*
327 * A note on the "critical region" in our callback handler.
328@@ -1042,8 +1041,6 @@ ENTRY(xen_failsafe_callback)
329 movq 8(%rsp), %r11
330 addq $0x30, %rsp
331 pushq $0 /* RIP */
332- pushq %r11
333- pushq %rcx
334 UNWIND_HINT_IRET_REGS offset=8
335 jmp general_protection
336 1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
337@@ -1074,9 +1071,8 @@ idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
338 idtentry stack_segment do_stack_segment has_error_code=1
339
340 #ifdef CONFIG_XEN
341-idtentry xen_debug do_debug has_error_code=0
342-idtentry xen_int3 do_int3 has_error_code=0
343-idtentry xen_stack_segment do_stack_segment has_error_code=1
344+idtentry xendebug do_debug has_error_code=0
345+idtentry xenint3 do_int3 has_error_code=0
346 #endif
347
348 idtentry general_protection do_general_protection has_error_code=1
349@@ -1240,20 +1236,9 @@ ENTRY(error_exit)
350 END(error_exit)
351
352 /* Runs on exception stack */
353+/* XXX: broken on Xen PV */
354 ENTRY(nmi)
355 UNWIND_HINT_IRET_REGS
356- /*
357- * Fix up the exception frame if we're on Xen.
358- * PARAVIRT_ADJUST_EXCEPTION_FRAME is guaranteed to push at most
359- * one value to the stack on native, so it may clobber the rdx
360- * scratch slot, but it won't clobber any of the important
361- * slots past it.
362- *
363- * Xen is a different story, because the Xen frame itself overlaps
364- * the "NMI executing" variable.
365- */
366- PARAVIRT_ADJUST_EXCEPTION_FRAME
367-
368 /*
369 * We allow breakpoints in NMIs. If a breakpoint occurs, then
370 * the iretq it performs will take us out of NMI context.
371diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
372index 5314d7b8e5ad..d8468ba24be0 100644
373--- a/arch/x86/entry/entry_64_compat.S
374+++ b/arch/x86/entry/entry_64_compat.S
375@@ -293,7 +293,6 @@ ENTRY(entry_INT80_compat)
376 /*
377 * Interrupts are off on entry.
378 */
379- PARAVIRT_ADJUST_EXCEPTION_FRAME
380 ASM_CLAC /* Do this early to minimize exposure */
381 SWAPGS
382
383diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
384index 3a3b6a211584..dae2cc33afb5 100644
385--- a/arch/x86/xen/xen-asm_64.S
386+++ b/arch/x86/xen/xen-asm_64.S
387@@ -16,11 +16,42 @@
388
389 #include <linux/linkage.h>
390
391-ENTRY(xen_adjust_exception_frame)
392- mov 8+0(%rsp), %rcx
393- mov 8+8(%rsp), %r11
394- ret $16
395-ENDPROC(xen_adjust_exception_frame)
396+.macro xen_pv_trap name
397+ENTRY(xen_\name)
398+ pop %rcx
399+ pop %r11
400+ jmp \name
401+END(xen_\name)
402+.endm
403+
404+xen_pv_trap divide_error
405+xen_pv_trap debug
406+xen_pv_trap xendebug
407+xen_pv_trap int3
408+xen_pv_trap xenint3
409+xen_pv_trap nmi
410+xen_pv_trap overflow
411+xen_pv_trap bounds
412+xen_pv_trap invalid_op
413+xen_pv_trap device_not_available
414+xen_pv_trap double_fault
415+xen_pv_trap coprocessor_segment_overrun
416+xen_pv_trap invalid_TSS
417+xen_pv_trap segment_not_present
418+xen_pv_trap stack_segment
419+xen_pv_trap general_protection
420+xen_pv_trap page_fault
421+xen_pv_trap spurious_interrupt_bug
422+xen_pv_trap coprocessor_error
423+xen_pv_trap alignment_check
424+#ifdef CONFIG_X86_MCE
425+xen_pv_trap machine_check
426+#endif /* CONFIG_X86_MCE */
427+xen_pv_trap simd_coprocessor_error
428+#ifdef CONFIG_IA32_EMULATION
429+xen_pv_trap entry_INT80_compat
430+#endif
431+xen_pv_trap hypervisor_callback
432
433 hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
434 /*
435--
4362.14.2
437
Linux Kernel for Proxmox projects