219 lines
7.8 KiB
Diff
219 lines
7.8 KiB
Diff
From e61177a6feca143d431be190d4758bda23f6174d Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Mon, 28 Aug 2017 08:47:22 +0200
|
|
Subject: [PATCH 026/241] x86/traps: Simplify pagefault tracing logic
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
CVE-2017-5754
|
|
|
|
Make use of the new irqvector tracing static key and remove the duplicated
|
|
trace_do_pagefault() implementation.
|
|
|
|
If irq vector tracing is disabled, then the overhead of this is a single
|
|
NOP5, which is a reasonable tradeoff to avoid duplicated code and the
|
|
unholy macro mess.
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Cc: Andy Lutomirski <luto@kernel.org>
|
|
Cc: Borislav Petkov <bp@alien8.de>
|
|
Cc: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Cc: Peter Zijlstra <peterz@infradead.org>
|
|
Cc: Steven Rostedt <rostedt@goodmis.org>
|
|
Link: http://lkml.kernel.org/r/20170828064956.672965407@linutronix.de
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
(cherry picked from commit 11a7ffb01703c3bbb1e9b968893f4487a1b0b5a8)
|
|
Signed-off-by: Andy Whitcroft <apw@canonical.com>
|
|
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
|
|
(cherry picked from commit 8478bb5608747fd64c9fd4a2f5422fb4af756a50)
|
|
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
|
|
---
|
|
arch/x86/include/asm/traps.h | 10 +--------
|
|
arch/x86/kernel/kvm.c | 2 +-
|
|
arch/x86/mm/fault.c | 49 ++++++++++++--------------------------------
|
|
arch/x86/entry/entry_32.S | 8 --------
|
|
arch/x86/entry/entry_64.S | 13 +-----------
|
|
5 files changed, 16 insertions(+), 66 deletions(-)
|
|
|
|
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
|
|
index 01fd0a7f48cd..b4f322d6c95f 100644
|
|
--- a/arch/x86/include/asm/traps.h
|
|
+++ b/arch/x86/include/asm/traps.h
|
|
@@ -39,7 +39,6 @@ asmlinkage void machine_check(void);
|
|
asmlinkage void simd_coprocessor_error(void);
|
|
|
|
#ifdef CONFIG_TRACING
|
|
-asmlinkage void trace_page_fault(void);
|
|
#define trace_stack_segment stack_segment
|
|
#define trace_divide_error divide_error
|
|
#define trace_bounds bounds
|
|
@@ -54,6 +53,7 @@ asmlinkage void trace_page_fault(void);
|
|
#define trace_alignment_check alignment_check
|
|
#define trace_simd_coprocessor_error simd_coprocessor_error
|
|
#define trace_async_page_fault async_page_fault
|
|
+#define trace_page_fault page_fault
|
|
#endif
|
|
|
|
dotraplinkage void do_divide_error(struct pt_regs *, long);
|
|
@@ -74,14 +74,6 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *);
|
|
#endif
|
|
dotraplinkage void do_general_protection(struct pt_regs *, long);
|
|
dotraplinkage void do_page_fault(struct pt_regs *, unsigned long);
|
|
-#ifdef CONFIG_TRACING
|
|
-dotraplinkage void trace_do_page_fault(struct pt_regs *, unsigned long);
|
|
-#else
|
|
-static inline void trace_do_page_fault(struct pt_regs *regs, unsigned long error)
|
|
-{
|
|
- do_page_fault(regs, error);
|
|
-}
|
|
-#endif
|
|
dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *, long);
|
|
dotraplinkage void do_coprocessor_error(struct pt_regs *, long);
|
|
dotraplinkage void do_alignment_check(struct pt_regs *, long);
|
|
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
|
|
index e5e4306e4546..9e3798b00e40 100644
|
|
--- a/arch/x86/kernel/kvm.c
|
|
+++ b/arch/x86/kernel/kvm.c
|
|
@@ -270,7 +270,7 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
|
|
|
|
switch (kvm_read_and_reset_pf_reason()) {
|
|
default:
|
|
- trace_do_page_fault(regs, error_code);
|
|
+ do_page_fault(regs, error_code);
|
|
break;
|
|
case KVM_PV_REASON_PAGE_NOT_PRESENT:
|
|
/* page is swapped out by the host. */
|
|
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
|
|
index 955be01dd9cc..4ee9eb916826 100644
|
|
--- a/arch/x86/mm/fault.c
|
|
+++ b/arch/x86/mm/fault.c
|
|
@@ -1253,10 +1253,6 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs)
|
|
* This routine handles page faults. It determines the address,
|
|
* and the problem, and then passes it off to one of the appropriate
|
|
* routines.
|
|
- *
|
|
- * This function must have noinline because both callers
|
|
- * {,trace_}do_page_fault() have notrace on. Having this an actual function
|
|
- * guarantees there's a function trace entry.
|
|
*/
|
|
static noinline void
|
|
__do_page_fault(struct pt_regs *regs, unsigned long error_code,
|
|
@@ -1491,27 +1487,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
|
|
}
|
|
NOKPROBE_SYMBOL(__do_page_fault);
|
|
|
|
-dotraplinkage void notrace
|
|
-do_page_fault(struct pt_regs *regs, unsigned long error_code)
|
|
-{
|
|
- unsigned long address = read_cr2(); /* Get the faulting address */
|
|
- enum ctx_state prev_state;
|
|
-
|
|
- /*
|
|
- * We must have this function tagged with __kprobes, notrace and call
|
|
- * read_cr2() before calling anything else. To avoid calling any kind
|
|
- * of tracing machinery before we've observed the CR2 value.
|
|
- *
|
|
- * exception_{enter,exit}() contain all sorts of tracepoints.
|
|
- */
|
|
-
|
|
- prev_state = exception_enter();
|
|
- __do_page_fault(regs, error_code, address);
|
|
- exception_exit(prev_state);
|
|
-}
|
|
-NOKPROBE_SYMBOL(do_page_fault);
|
|
-
|
|
-#ifdef CONFIG_TRACING
|
|
static nokprobe_inline void
|
|
trace_page_fault_entries(unsigned long address, struct pt_regs *regs,
|
|
unsigned long error_code)
|
|
@@ -1522,22 +1497,24 @@ trace_page_fault_entries(unsigned long address, struct pt_regs *regs,
|
|
trace_page_fault_kernel(address, regs, error_code);
|
|
}
|
|
|
|
+/*
|
|
+ * We must have this function blacklisted from kprobes, tagged with notrace
|
|
+ * and call read_cr2() before calling anything else. To avoid calling any
|
|
+ * kind of tracing machinery before we've observed the CR2 value.
|
|
+ *
|
|
+ * exception_{enter,exit}() contains all sorts of tracepoints.
|
|
+ */
|
|
dotraplinkage void notrace
|
|
-trace_do_page_fault(struct pt_regs *regs, unsigned long error_code)
|
|
+do_page_fault(struct pt_regs *regs, unsigned long error_code)
|
|
{
|
|
- /*
|
|
- * The exception_enter and tracepoint processing could
|
|
- * trigger another page faults (user space callchain
|
|
- * reading) and destroy the original cr2 value, so read
|
|
- * the faulting address now.
|
|
- */
|
|
- unsigned long address = read_cr2();
|
|
+ unsigned long address = read_cr2(); /* Get the faulting address */
|
|
enum ctx_state prev_state;
|
|
|
|
prev_state = exception_enter();
|
|
- trace_page_fault_entries(address, regs, error_code);
|
|
+ if (trace_irqvectors_enabled())
|
|
+ trace_page_fault_entries(address, regs, error_code);
|
|
+
|
|
__do_page_fault(regs, error_code, address);
|
|
exception_exit(prev_state);
|
|
}
|
|
-NOKPROBE_SYMBOL(trace_do_page_fault);
|
|
-#endif /* CONFIG_TRACING */
|
|
+NOKPROBE_SYMBOL(do_page_fault);
|
|
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
|
|
index 48ef7bb32c42..0092da1c056f 100644
|
|
--- a/arch/x86/entry/entry_32.S
|
|
+++ b/arch/x86/entry/entry_32.S
|
|
@@ -891,14 +891,6 @@ BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR,
|
|
|
|
#endif /* CONFIG_HYPERV */
|
|
|
|
-#ifdef CONFIG_TRACING
|
|
-ENTRY(trace_page_fault)
|
|
- ASM_CLAC
|
|
- pushl $trace_do_page_fault
|
|
- jmp common_exception
|
|
-END(trace_page_fault)
|
|
-#endif
|
|
-
|
|
ENTRY(page_fault)
|
|
ASM_CLAC
|
|
pushl $do_page_fault
|
|
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
|
|
index ca0b250eefc4..dfabcbf8e813 100644
|
|
--- a/arch/x86/entry/entry_64.S
|
|
+++ b/arch/x86/entry/entry_64.S
|
|
@@ -913,17 +913,6 @@ ENTRY(\sym)
|
|
END(\sym)
|
|
.endm
|
|
|
|
-#ifdef CONFIG_TRACING
|
|
-.macro trace_idtentry sym do_sym has_error_code:req
|
|
-idtentry trace(\sym) trace(\do_sym) has_error_code=\has_error_code
|
|
-idtentry \sym \do_sym has_error_code=\has_error_code
|
|
-.endm
|
|
-#else
|
|
-.macro trace_idtentry sym do_sym has_error_code:req
|
|
-idtentry \sym \do_sym has_error_code=\has_error_code
|
|
-.endm
|
|
-#endif
|
|
-
|
|
idtentry divide_error do_divide_error has_error_code=0
|
|
idtentry overflow do_overflow has_error_code=0
|
|
idtentry bounds do_bounds has_error_code=0
|
|
@@ -1091,7 +1080,7 @@ idtentry xen_stack_segment do_stack_segment has_error_code=1
|
|
#endif
|
|
|
|
idtentry general_protection do_general_protection has_error_code=1
|
|
-trace_idtentry page_fault do_page_fault has_error_code=1
|
|
+idtentry page_fault do_page_fault has_error_code=1
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
idtentry async_page_fault do_async_page_fault has_error_code=1
|
|
--
|
|
2.14.2
|
|
|