mirror of
https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable.git
synced 2025-10-30 22:47:06 +10:00
a0d14b8909
Despite the current efforts to read CR2 before tracing happens there still
exist a number of possible holes:
idtentry page_fault do_page_fault has_error_code=1
call error_entry
TRACE_IRQS_OFF
call trace_hardirqs_off*
#PF // modifies CR2
CALL_enter_from_user_mode
__context_tracking_exit()
trace_user_exit(0)
#PF // modifies CR2
call do_page_fault
address = read_cr2(); /* whoopsie */
And similar for i386.
Fix it by pulling the CR2 read into the entry code, before any of that
stuff gets a chance to run and ruin things.
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: jgross@suse.com
Cc: joel@joelfernandes.org
Link: https://lkml.kernel.org/r/20190711114336.116812491@infradead.org
Debugged-by: Steven Rostedt <rostedt@goodmis.org>
136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_X86_KVM_PARA_H
|
|
#define _ASM_X86_KVM_PARA_H
|
|
|
|
#include <asm/processor.h>
|
|
#include <asm/alternative.h>
|
|
#include <uapi/asm/kvm_para.h>
|
|
|
|
extern void kvmclock_init(void);
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
bool kvm_check_and_clear_guest_paused(void);
|
|
#else
|
|
static inline bool kvm_check_and_clear_guest_paused(void)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_KVM_GUEST */
|
|
|
|
#define KVM_HYPERCALL \
|
|
ALTERNATIVE(".byte 0x0f,0x01,0xc1", ".byte 0x0f,0x01,0xd9", X86_FEATURE_VMMCALL)
|
|
|
|
/* For KVM hypercalls, a three-byte sequence of either the vmcall or the vmmcall
|
|
* instruction. The hypervisor may replace it with something else but only the
|
|
* instructions are guaranteed to be supported.
|
|
*
|
|
* Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
|
|
* The hypercall number should be placed in rax and the return value will be
|
|
* placed in rax. No other registers will be clobbered unless explicitly
|
|
* noted by the particular hypercall.
|
|
*/
|
|
|
|
static inline long kvm_hypercall0(unsigned int nr)
|
|
{
|
|
long ret;
|
|
asm volatile(KVM_HYPERCALL
|
|
: "=a"(ret)
|
|
: "a"(nr)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
|
|
{
|
|
long ret;
|
|
asm volatile(KVM_HYPERCALL
|
|
: "=a"(ret)
|
|
: "a"(nr), "b"(p1)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
|
|
unsigned long p2)
|
|
{
|
|
long ret;
|
|
asm volatile(KVM_HYPERCALL
|
|
: "=a"(ret)
|
|
: "a"(nr), "b"(p1), "c"(p2)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
|
|
unsigned long p2, unsigned long p3)
|
|
{
|
|
long ret;
|
|
asm volatile(KVM_HYPERCALL
|
|
: "=a"(ret)
|
|
: "a"(nr), "b"(p1), "c"(p2), "d"(p3)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
|
|
unsigned long p2, unsigned long p3,
|
|
unsigned long p4)
|
|
{
|
|
long ret;
|
|
asm volatile(KVM_HYPERCALL
|
|
: "=a"(ret)
|
|
: "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
|
|
: "memory");
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
bool kvm_para_available(void);
|
|
unsigned int kvm_arch_para_features(void);
|
|
unsigned int kvm_arch_para_hints(void);
|
|
void kvm_async_pf_task_wait(u32 token, int interrupt_kernel);
|
|
void kvm_async_pf_task_wake(u32 token);
|
|
u32 kvm_read_and_reset_pf_reason(void);
|
|
extern void kvm_disable_steal_time(void);
|
|
void do_async_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address);
|
|
|
|
#ifdef CONFIG_PARAVIRT_SPINLOCKS
|
|
void __init kvm_spinlock_init(void);
|
|
#else /* !CONFIG_PARAVIRT_SPINLOCKS */
|
|
static inline void kvm_spinlock_init(void)
|
|
{
|
|
}
|
|
#endif /* CONFIG_PARAVIRT_SPINLOCKS */
|
|
|
|
#else /* CONFIG_KVM_GUEST */
|
|
#define kvm_async_pf_task_wait(T, I) do {} while(0)
|
|
#define kvm_async_pf_task_wake(T) do {} while(0)
|
|
|
|
static inline bool kvm_para_available(void)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline unsigned int kvm_arch_para_features(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned int kvm_arch_para_hints(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline u32 kvm_read_and_reset_pf_reason(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void kvm_disable_steal_time(void)
|
|
{
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
#endif /* _ASM_X86_KVM_PARA_H */
|