a0f7ab8a6a
cherry-pick from upstream 4.14
436 lines
15 KiB
Diff
436 lines
15 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Juergen Gross <jgross@suse.com>
|
|
Date: Thu, 31 Aug 2017 19:42:49 +0200
|
|
Subject: [PATCH] x86/xen: Get rid of paravirt op adjust_exception_frame
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
CVE-2017-5754
|
|
|
|
When running as Xen pv-guest the exception frame on the stack contains
|
|
%r11 and %rcx additional to the other data pushed by the processor.
|
|
|
|
Instead of having a paravirt op being called for each exception type
|
|
prepend the Xen specific code to each exception entry. When running as
|
|
Xen pv-guest just use the exception entry with prepended instructions,
|
|
otherwise use the entry without the Xen specific code.
|
|
|
|
[ tglx: Merged through tip to avoid ugly merge conflict ]
|
|
|
|
Signed-off-by: Juergen Gross <jgross@suse.com>
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Cc: xen-devel@lists.xenproject.org
|
|
Cc: boris.ostrovsky@oracle.com
|
|
Cc: luto@amacapital.net
|
|
Link: http://lkml.kernel.org/r/20170831174249.26853-1-jg@pfupf.net
|
|
(backported from commit 5878d5d6fdef6447d73b0acc121ba445bef37f53)
|
|
Signed-off-by: Andy Whitcroft <apw@canonical.com>
|
|
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
|
|
(cherry picked from commit 9a6fb927deb3ebbe831741ca82081714637181a7)
|
|
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
|
|
---
|
|
arch/x86/include/asm/paravirt.h | 5 --
|
|
arch/x86/include/asm/paravirt_types.h | 3 --
|
|
arch/x86/include/asm/proto.h | 3 ++
|
|
arch/x86/include/asm/traps.h | 28 ++++++++--
|
|
arch/x86/xen/xen-ops.h | 1 -
|
|
arch/x86/kernel/asm-offsets_64.c | 1 -
|
|
arch/x86/kernel/paravirt.c | 3 --
|
|
arch/x86/xen/enlighten_pv.c | 98 +++++++++++++++++++++++------------
|
|
arch/x86/xen/irq.c | 3 --
|
|
arch/x86/entry/entry_64.S | 23 ++------
|
|
arch/x86/entry/entry_64_compat.S | 1 -
|
|
arch/x86/xen/xen-asm_64.S | 41 +++++++++++++--
|
|
12 files changed, 133 insertions(+), 77 deletions(-)
|
|
|
|
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
|
|
index 9ccac1926587..c25dd22f7c70 100644
|
|
--- a/arch/x86/include/asm/paravirt.h
|
|
+++ b/arch/x86/include/asm/paravirt.h
|
|
@@ -960,11 +960,6 @@ extern void default_banner(void);
|
|
#define GET_CR2_INTO_RAX \
|
|
call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
|
|
|
|
-#define PARAVIRT_ADJUST_EXCEPTION_FRAME \
|
|
- PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \
|
|
- CLBR_NONE, \
|
|
- call PARA_INDIRECT(pv_irq_ops+PV_IRQ_adjust_exception_frame))
|
|
-
|
|
#define USERGS_SYSRET64 \
|
|
PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64), \
|
|
CLBR_NONE, \
|
|
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
|
|
index 9ffc36bfe4cd..6b64fc6367f2 100644
|
|
--- a/arch/x86/include/asm/paravirt_types.h
|
|
+++ b/arch/x86/include/asm/paravirt_types.h
|
|
@@ -196,9 +196,6 @@ struct pv_irq_ops {
|
|
void (*safe_halt)(void);
|
|
void (*halt)(void);
|
|
|
|
-#ifdef CONFIG_X86_64
|
|
- void (*adjust_exception_frame)(void);
|
|
-#endif
|
|
} __no_randomize_layout;
|
|
|
|
struct pv_mmu_ops {
|
|
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
|
|
index 8d3964fc5f91..b408b1886195 100644
|
|
--- a/arch/x86/include/asm/proto.h
|
|
+++ b/arch/x86/include/asm/proto.h
|
|
@@ -24,6 +24,9 @@ void entry_SYSENTER_compat(void);
|
|
void __end_entry_SYSENTER_compat(void);
|
|
void entry_SYSCALL_compat(void);
|
|
void entry_INT80_compat(void);
|
|
+#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
|
|
+void xen_entry_INT80_compat(void);
|
|
+#endif
|
|
#endif
|
|
|
|
void x86_configure_nx(void);
|
|
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
|
|
index b4f322d6c95f..feb89dbe359d 100644
|
|
--- a/arch/x86/include/asm/traps.h
|
|
+++ b/arch/x86/include/asm/traps.h
|
|
@@ -13,9 +13,6 @@ asmlinkage void divide_error(void);
|
|
asmlinkage void debug(void);
|
|
asmlinkage void nmi(void);
|
|
asmlinkage void int3(void);
|
|
-asmlinkage void xen_debug(void);
|
|
-asmlinkage void xen_int3(void);
|
|
-asmlinkage void xen_stack_segment(void);
|
|
asmlinkage void overflow(void);
|
|
asmlinkage void bounds(void);
|
|
asmlinkage void invalid_op(void);
|
|
@@ -56,6 +53,31 @@ asmlinkage void simd_coprocessor_error(void);
|
|
#define trace_page_fault page_fault
|
|
#endif
|
|
|
|
+#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
|
|
+asmlinkage void xen_divide_error(void);
|
|
+asmlinkage void xen_xendebug(void);
|
|
+asmlinkage void xen_xenint3(void);
|
|
+asmlinkage void xen_nmi(void);
|
|
+asmlinkage void xen_overflow(void);
|
|
+asmlinkage void xen_bounds(void);
|
|
+asmlinkage void xen_invalid_op(void);
|
|
+asmlinkage void xen_device_not_available(void);
|
|
+asmlinkage void xen_double_fault(void);
|
|
+asmlinkage void xen_coprocessor_segment_overrun(void);
|
|
+asmlinkage void xen_invalid_TSS(void);
|
|
+asmlinkage void xen_segment_not_present(void);
|
|
+asmlinkage void xen_stack_segment(void);
|
|
+asmlinkage void xen_general_protection(void);
|
|
+asmlinkage void xen_page_fault(void);
|
|
+asmlinkage void xen_spurious_interrupt_bug(void);
|
|
+asmlinkage void xen_coprocessor_error(void);
|
|
+asmlinkage void xen_alignment_check(void);
|
|
+#ifdef CONFIG_X86_MCE
|
|
+asmlinkage void xen_machine_check(void);
|
|
+#endif /* CONFIG_X86_MCE */
|
|
+asmlinkage void xen_simd_coprocessor_error(void);
|
|
+#endif
|
|
+
|
|
dotraplinkage void do_divide_error(struct pt_regs *, long);
|
|
dotraplinkage void do_debug(struct pt_regs *, long);
|
|
dotraplinkage void do_nmi(struct pt_regs *, long);
|
|
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
|
|
index 70301ac0d414..c8a6d224f7ed 100644
|
|
--- a/arch/x86/xen/xen-ops.h
|
|
+++ b/arch/x86/xen/xen-ops.h
|
|
@@ -138,7 +138,6 @@ __visible void xen_restore_fl_direct(unsigned long);
|
|
__visible void xen_iret(void);
|
|
__visible void xen_sysret32(void);
|
|
__visible void xen_sysret64(void);
|
|
-__visible void xen_adjust_exception_frame(void);
|
|
|
|
extern int xen_panic_handler_init(void);
|
|
|
|
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
|
|
index 99332f550c48..cf42206926af 100644
|
|
--- a/arch/x86/kernel/asm-offsets_64.c
|
|
+++ b/arch/x86/kernel/asm-offsets_64.c
|
|
@@ -20,7 +20,6 @@ static char syscalls_ia32[] = {
|
|
int main(void)
|
|
{
|
|
#ifdef CONFIG_PARAVIRT
|
|
- OFFSET(PV_IRQ_adjust_exception_frame, pv_irq_ops, adjust_exception_frame);
|
|
OFFSET(PV_CPU_usergs_sysret64, pv_cpu_ops, usergs_sysret64);
|
|
OFFSET(PV_CPU_swapgs, pv_cpu_ops, swapgs);
|
|
BLANK();
|
|
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
|
|
index bc0a849589bb..a14df9eecfed 100644
|
|
--- a/arch/x86/kernel/paravirt.c
|
|
+++ b/arch/x86/kernel/paravirt.c
|
|
@@ -319,9 +319,6 @@ __visible struct pv_irq_ops pv_irq_ops = {
|
|
.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
|
|
.safe_halt = native_safe_halt,
|
|
.halt = native_halt,
|
|
-#ifdef CONFIG_X86_64
|
|
- .adjust_exception_frame = paravirt_nop,
|
|
-#endif
|
|
};
|
|
|
|
__visible struct pv_cpu_ops pv_cpu_ops = {
|
|
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
|
|
index c76f5ff4d0d7..ae2a2e2d6362 100644
|
|
--- a/arch/x86/xen/enlighten_pv.c
|
|
+++ b/arch/x86/xen/enlighten_pv.c
|
|
@@ -586,6 +586,70 @@ static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
|
|
preempt_enable();
|
|
}
|
|
|
|
+#ifdef CONFIG_X86_64
|
|
+struct trap_array_entry {
|
|
+ void (*orig)(void);
|
|
+ void (*xen)(void);
|
|
+ bool ist_okay;
|
|
+};
|
|
+
|
|
+static struct trap_array_entry trap_array[] = {
|
|
+ { debug, xen_xendebug, true },
|
|
+ { int3, xen_xenint3, true },
|
|
+ { double_fault, xen_double_fault, true },
|
|
+#ifdef CONFIG_X86_MCE
|
|
+ { machine_check, xen_machine_check, true },
|
|
+#endif
|
|
+ { nmi, xen_nmi, true },
|
|
+ { overflow, xen_overflow, false },
|
|
+#ifdef CONFIG_IA32_EMULATION
|
|
+ { entry_INT80_compat, xen_entry_INT80_compat, false },
|
|
+#endif
|
|
+ { page_fault, xen_page_fault, false },
|
|
+ { divide_error, xen_divide_error, false },
|
|
+ { bounds, xen_bounds, false },
|
|
+ { invalid_op, xen_invalid_op, false },
|
|
+ { device_not_available, xen_device_not_available, false },
|
|
+ { coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false },
|
|
+ { invalid_TSS, xen_invalid_TSS, false },
|
|
+ { segment_not_present, xen_segment_not_present, false },
|
|
+ { stack_segment, xen_stack_segment, false },
|
|
+ { general_protection, xen_general_protection, false },
|
|
+ { spurious_interrupt_bug, xen_spurious_interrupt_bug, false },
|
|
+ { coprocessor_error, xen_coprocessor_error, false },
|
|
+ { alignment_check, xen_alignment_check, false },
|
|
+ { simd_coprocessor_error, xen_simd_coprocessor_error, false },
|
|
+};
|
|
+
|
|
+static bool get_trap_addr(void **addr, unsigned int ist)
|
|
+{
|
|
+ unsigned int nr;
|
|
+ bool ist_okay = false;
|
|
+
|
|
+ /*
|
|
+ * Replace trap handler addresses by Xen specific ones.
|
|
+ * Check for known traps using IST and whitelist them.
|
|
+ * The debugger ones are the only ones we care about.
|
|
+ * Xen will handle faults like double_fault, * so we should never see
|
|
+ * them. Warn if there's an unexpected IST-using fault handler.
|
|
+ */
|
|
+ for (nr = 0; nr < ARRAY_SIZE(trap_array); nr++) {
|
|
+ struct trap_array_entry *entry = trap_array + nr;
|
|
+
|
|
+ if (*addr == entry->orig) {
|
|
+ *addr = entry->xen;
|
|
+ ist_okay = entry->ist_okay;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ if (WARN_ON(ist != 0 && !ist_okay))
|
|
+ return false;
|
|
+
|
|
+ return true;
|
|
+}
|
|
+#endif
|
|
+
|
|
static int cvt_gate_to_trap(int vector, const gate_desc *val,
|
|
struct trap_info *info)
|
|
{
|
|
@@ -598,40 +662,8 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val,
|
|
|
|
addr = gate_offset(val);
|
|
#ifdef CONFIG_X86_64
|
|
- /*
|
|
- * Look for known traps using IST, and substitute them
|
|
- * appropriately. The debugger ones are the only ones we care
|
|
- * about. Xen will handle faults like double_fault,
|
|
- * so we should never see them. Warn if
|
|
- * there's an unexpected IST-using fault handler.
|
|
- */
|
|
- if (addr == (unsigned long)debug)
|
|
- addr = (unsigned long)xen_debug;
|
|
- else if (addr == (unsigned long)int3)
|
|
- addr = (unsigned long)xen_int3;
|
|
- else if (addr == (unsigned long)stack_segment)
|
|
- addr = (unsigned long)xen_stack_segment;
|
|
- else if (addr == (unsigned long)double_fault) {
|
|
- /* Don't need to handle these */
|
|
+ if (!get_trap_addr((void **)&addr, val->bits.ist))
|
|
return 0;
|
|
-#ifdef CONFIG_X86_MCE
|
|
- } else if (addr == (unsigned long)machine_check) {
|
|
- /*
|
|
- * when xen hypervisor inject vMCE to guest,
|
|
- * use native mce handler to handle it
|
|
- */
|
|
- ;
|
|
-#endif
|
|
- } else if (addr == (unsigned long)nmi)
|
|
- /*
|
|
- * Use the native version as well.
|
|
- */
|
|
- ;
|
|
- else {
|
|
- /* Some other trap using IST? */
|
|
- if (WARN_ON(val->bits.ist != 0))
|
|
- return 0;
|
|
- }
|
|
#endif /* CONFIG_X86_64 */
|
|
info->address = addr;
|
|
|
|
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
|
|
index 33e92955e09d..d4eff5676cfa 100644
|
|
--- a/arch/x86/xen/irq.c
|
|
+++ b/arch/x86/xen/irq.c
|
|
@@ -123,9 +123,6 @@ static const struct pv_irq_ops xen_irq_ops __initconst = {
|
|
|
|
.safe_halt = xen_safe_halt,
|
|
.halt = xen_halt,
|
|
-#ifdef CONFIG_X86_64
|
|
- .adjust_exception_frame = xen_adjust_exception_frame,
|
|
-#endif
|
|
};
|
|
|
|
void __init xen_init_irq_ops(void)
|
|
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
|
|
index dfabcbf8e813..c12260ef3e4b 100644
|
|
--- a/arch/x86/entry/entry_64.S
|
|
+++ b/arch/x86/entry/entry_64.S
|
|
@@ -829,7 +829,6 @@ ENTRY(\sym)
|
|
.endif
|
|
|
|
ASM_CLAC
|
|
- PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
|
|
.ifeq \has_error_code
|
|
pushq $-1 /* ORIG_RAX: no syscall to restart */
|
|
@@ -975,7 +974,7 @@ ENTRY(do_softirq_own_stack)
|
|
ENDPROC(do_softirq_own_stack)
|
|
|
|
#ifdef CONFIG_XEN
|
|
-idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
|
|
+idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0
|
|
|
|
/*
|
|
* A note on the "critical region" in our callback handler.
|
|
@@ -1042,8 +1041,6 @@ ENTRY(xen_failsafe_callback)
|
|
movq 8(%rsp), %r11
|
|
addq $0x30, %rsp
|
|
pushq $0 /* RIP */
|
|
- pushq %r11
|
|
- pushq %rcx
|
|
UNWIND_HINT_IRET_REGS offset=8
|
|
jmp general_protection
|
|
1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
|
|
@@ -1074,9 +1071,8 @@ idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
|
|
idtentry stack_segment do_stack_segment has_error_code=1
|
|
|
|
#ifdef CONFIG_XEN
|
|
-idtentry xen_debug do_debug has_error_code=0
|
|
-idtentry xen_int3 do_int3 has_error_code=0
|
|
-idtentry xen_stack_segment do_stack_segment has_error_code=1
|
|
+idtentry xendebug do_debug has_error_code=0
|
|
+idtentry xenint3 do_int3 has_error_code=0
|
|
#endif
|
|
|
|
idtentry general_protection do_general_protection has_error_code=1
|
|
@@ -1240,20 +1236,9 @@ ENTRY(error_exit)
|
|
END(error_exit)
|
|
|
|
/* Runs on exception stack */
|
|
+/* XXX: broken on Xen PV */
|
|
ENTRY(nmi)
|
|
UNWIND_HINT_IRET_REGS
|
|
- /*
|
|
- * Fix up the exception frame if we're on Xen.
|
|
- * PARAVIRT_ADJUST_EXCEPTION_FRAME is guaranteed to push at most
|
|
- * one value to the stack on native, so it may clobber the rdx
|
|
- * scratch slot, but it won't clobber any of the important
|
|
- * slots past it.
|
|
- *
|
|
- * Xen is a different story, because the Xen frame itself overlaps
|
|
- * the "NMI executing" variable.
|
|
- */
|
|
- PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
-
|
|
/*
|
|
* We allow breakpoints in NMIs. If a breakpoint occurs, then
|
|
* the iretq it performs will take us out of NMI context.
|
|
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
|
|
index 5314d7b8e5ad..d8468ba24be0 100644
|
|
--- a/arch/x86/entry/entry_64_compat.S
|
|
+++ b/arch/x86/entry/entry_64_compat.S
|
|
@@ -293,7 +293,6 @@ ENTRY(entry_INT80_compat)
|
|
/*
|
|
* Interrupts are off on entry.
|
|
*/
|
|
- PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
ASM_CLAC /* Do this early to minimize exposure */
|
|
SWAPGS
|
|
|
|
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
|
|
index 3a3b6a211584..dae2cc33afb5 100644
|
|
--- a/arch/x86/xen/xen-asm_64.S
|
|
+++ b/arch/x86/xen/xen-asm_64.S
|
|
@@ -16,11 +16,42 @@
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
-ENTRY(xen_adjust_exception_frame)
|
|
- mov 8+0(%rsp), %rcx
|
|
- mov 8+8(%rsp), %r11
|
|
- ret $16
|
|
-ENDPROC(xen_adjust_exception_frame)
|
|
+.macro xen_pv_trap name
|
|
+ENTRY(xen_\name)
|
|
+ pop %rcx
|
|
+ pop %r11
|
|
+ jmp \name
|
|
+END(xen_\name)
|
|
+.endm
|
|
+
|
|
+xen_pv_trap divide_error
|
|
+xen_pv_trap debug
|
|
+xen_pv_trap xendebug
|
|
+xen_pv_trap int3
|
|
+xen_pv_trap xenint3
|
|
+xen_pv_trap nmi
|
|
+xen_pv_trap overflow
|
|
+xen_pv_trap bounds
|
|
+xen_pv_trap invalid_op
|
|
+xen_pv_trap device_not_available
|
|
+xen_pv_trap double_fault
|
|
+xen_pv_trap coprocessor_segment_overrun
|
|
+xen_pv_trap invalid_TSS
|
|
+xen_pv_trap segment_not_present
|
|
+xen_pv_trap stack_segment
|
|
+xen_pv_trap general_protection
|
|
+xen_pv_trap page_fault
|
|
+xen_pv_trap spurious_interrupt_bug
|
|
+xen_pv_trap coprocessor_error
|
|
+xen_pv_trap alignment_check
|
|
+#ifdef CONFIG_X86_MCE
|
|
+xen_pv_trap machine_check
|
|
+#endif /* CONFIG_X86_MCE */
|
|
+xen_pv_trap simd_coprocessor_error
|
|
+#ifdef CONFIG_IA32_EMULATION
|
|
+xen_pv_trap entry_INT80_compat
|
|
+#endif
|
|
+xen_pv_trap hypervisor_callback
|
|
|
|
hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
|
|
/*
|
|
--
|
|
2.14.2
|
|
|