diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 25 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64.S | 35 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_para.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/traps.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/kvm.c | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 6 | ||||
| -rw-r--r-- | arch/x86/mm/fault.c | 30 |
7 files changed, 59 insertions, 51 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 4d4b6100f0e8..2bb986f305ac 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1443,9 +1443,28 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR, ENTRY(page_fault) ASM_CLAC - pushl $do_page_fault - ALIGN - jmp common_exception + pushl $0; /* %gs's slot on the stack */ + + SAVE_ALL switch_stacks=1 skip_gs=1 + + ENCODE_FRAME_POINTER + UNWIND_ESPFIX_STACK + + /* fixup %gs */ + GS_TO_REG %ecx + REG_TO_PTGS %ecx + SET_KERNEL_GS %ecx + + GET_CR2_INTO(%ecx) # might clobber %eax + + /* fixup orig %eax */ + movl PT_ORIG_EAX(%esp), %edx # get the error code + movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart + + TRACE_IRQS_OFF + movl %esp, %eax # pt_regs pointer + call do_page_fault + jmp ret_from_exception END(page_fault) common_exception: diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 95ae05f0edf2..7cb2e1f1ec09 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -864,7 +864,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt */ #define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + (x) * 8) -.macro idtentry_part do_sym, has_error_code:req, paranoid:req, shift_ist=-1, ist_offset=0 +.macro idtentry_part do_sym, has_error_code:req, read_cr2:req, paranoid:req, shift_ist=-1, ist_offset=0 .if \paranoid call paranoid_entry @@ -874,12 +874,21 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt .endif UNWIND_HINT_REGS - .if \paranoid + .if \read_cr2 + GET_CR2_INTO(%rdx); /* can clobber %rax */ + .endif + .if \shift_ist != -1 TRACE_IRQS_OFF_DEBUG /* reload IDT in case of recursion */ .else TRACE_IRQS_OFF .endif + + .if \paranoid == 0 + testb $3, CS(%rsp) + jz .Lfrom_kernel_no_context_tracking_\@ + CALL_enter_from_user_mode +.Lfrom_kernel_no_context_tracking_\@: .endif movq %rsp, %rdi /* pt_regs pointer */ @@ -923,6 +932,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt * fresh stack. (This is for #DB, which has a nasty habit * of recursing.) * @create_gap: create a 6-word stack gap when coming from kernel mode. + * @read_cr2: load CR2 into the 3rd argument; done before calling any C code * * idtentry generates an IDT stub that sets up a usable kernel context, * creates struct pt_regs, and calls @do_sym. The stub has the following @@ -947,7 +957,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt * @paranoid == 2 is special: the stub will never switch stacks. This is for * #DF: if the thread stack is somehow unusable, we'll still get a useful OOPS. */ -.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0 create_gap=0 +.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 ist_offset=0 create_gap=0 read_cr2=0 ENTRY(\sym) UNWIND_HINT_IRET_REGS offset=\has_error_code*8 @@ -985,7 +995,7 @@ ENTRY(\sym) .Lfrom_usermode_no_gap_\@: .endif - idtentry_part \do_sym, \has_error_code, \paranoid, \shift_ist, \ist_offset + idtentry_part \do_sym, \has_error_code, \read_cr2, \paranoid, \shift_ist, \ist_offset .if \paranoid == 1 /* @@ -994,7 +1004,7 @@ ENTRY(\sym) * run in real process context if user_mode(regs). */ .Lfrom_usermode_switch_stack_\@: - idtentry_part \do_sym, \has_error_code, paranoid=0 + idtentry_part \do_sym, \has_error_code, \read_cr2, paranoid=0 .endif _ASM_NOKPROBE(\sym) @@ -1006,7 +1016,7 @@ idtentry overflow do_overflow has_error_code=0 idtentry bounds do_bounds has_error_code=0 idtentry invalid_op do_invalid_op has_error_code=0 idtentry device_not_available do_device_not_available has_error_code=0 -idtentry double_fault do_double_fault has_error_code=1 paranoid=2 +idtentry double_fault do_double_fault has_error_code=1 paranoid=2 read_cr2=1 idtentry coprocessor_segment_overrun do_coprocessor_segment_overrun has_error_code=0 idtentry invalid_TSS do_invalid_TSS has_error_code=1 idtentry segment_not_present do_segment_not_present has_error_code=1 @@ -1179,10 +1189,10 @@ idtentry xenint3 do_int3 has_error_code=0 #endif idtentry general_protection do_general_protection has_error_code=1 -idtentry page_fault do_page_fault has_error_code=1 +idtentry page_fault do_page_fault has_error_code=1 read_cr2=1 #ifdef CONFIG_KVM_GUEST -idtentry async_page_fault do_async_page_fault has_error_code=1 +idtentry async_page_fault do_async_page_fault has_error_code=1 read_cr2=1 #endif #ifdef CONFIG_X86_MCE @@ -1281,18 +1291,9 @@ ENTRY(error_entry) movq %rax, %rsp /* switch stack */ ENCODE_FRAME_POINTER pushq %r12 - - /* - * We need to tell lockdep that IRQs are off. We can't do this until - * we fix gsbase, and we should do it before enter_from_user_mode - * (which can take locks). - */ - TRACE_IRQS_OFF - CALL_enter_from_user_mode ret .Lerror_entry_done: - TRACE_IRQS_OFF ret /* diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 5ed3cf1c3934..9b4df6eaa11a 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -92,7 +92,7 @@ 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); +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); diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 7d6f3f3fad78..5dd1674ddf4c 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -74,14 +74,14 @@ dotraplinkage void do_invalid_TSS(struct pt_regs *regs, long error_code); dotraplinkage void do_segment_not_present(struct pt_regs *regs, long error_code); dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code); #ifdef CONFIG_X86_64 -dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code); +dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long address); asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs); asmlinkage __visible notrace struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s); void __init trap_init(void); #endif dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code); -dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code); +dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address); dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code); dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code); dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code); diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 82caf01b63dd..3231440d6253 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -242,23 +242,23 @@ EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason); NOKPROBE_SYMBOL(kvm_read_and_reset_pf_reason); dotraplinkage void -do_async_page_fault(struct pt_regs *regs, unsigned long error_code) +do_async_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address) { enum ctx_state prev_state; switch (kvm_read_and_reset_pf_reason()) { default: - do_page_fault(regs, error_code); + do_page_fault(regs, error_code, address); break; case KVM_PV_REASON_PAGE_NOT_PRESENT: /* page is swapped out by the host. */ prev_state = exception_enter(); - kvm_async_pf_task_wait((u32)read_cr2(), !user_mode(regs)); + kvm_async_pf_task_wait((u32)address, !user_mode(regs)); exception_exit(prev_state); break; case KVM_PV_REASON_PAGE_READY: rcu_irq_enter(); - kvm_async_pf_task_wake((u32)read_cr2()); + kvm_async_pf_task_wake((u32)address); rcu_irq_exit(); break; } diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 87095a477154..4bb0f8447112 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -313,13 +313,10 @@ __visible void __noreturn handle_stack_overflow(const char *message, #ifdef CONFIG_X86_64 /* Runs on IST stack */ -dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) +dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2) { static const char str[] = "double fault"; struct task_struct *tsk = current; -#ifdef CONFIG_VMAP_STACK - unsigned long cr2; -#endif #ifdef CONFIG_X86_ESPFIX64 extern unsigned char native_irq_return_iret[]; @@ -415,7 +412,6 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) * stack even if the actual trigger for the double fault was * something else. */ - cr2 = read_cr2(); if ((unsigned long)task_stack_page(tsk) - 1 - cr2 < PAGE_SIZE) handle_stack_overflow("kernel stack overflow (double-fault)", regs, cr2); #endif diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 794f364cb882..0799cc79efd3 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1507,9 +1507,8 @@ good_area: NOKPROBE_SYMBOL(do_user_addr_fault); /* - * This routine handles page faults. It determines the address, - * and the problem, and then passes it off to one of the appropriate - * routines. + * Explicitly marked noinline such that the function tracer sees this as the + * page_fault entry point. */ static noinline void __do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, @@ -1528,33 +1527,26 @@ __do_page_fault(struct pt_regs *regs, unsigned long hw_error_code, } NOKPROBE_SYMBOL(__do_page_fault); -static nokprobe_inline void -trace_page_fault_entries(unsigned long address, struct pt_regs *regs, - unsigned long error_code) +static __always_inline void +trace_page_fault_entries(struct pt_regs *regs, unsigned long error_code, + unsigned long address) { + if (!trace_pagefault_enabled()) + return; + if (user_mode(regs)) trace_page_fault_user(address, regs, error_code); else 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 -do_page_fault(struct pt_regs *regs, unsigned long error_code) +dotraplinkage void +do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address) { - unsigned long address = read_cr2(); /* Get the faulting address */ enum ctx_state prev_state; prev_state = exception_enter(); - if (trace_pagefault_enabled()) - trace_page_fault_entries(address, regs, error_code); - + trace_page_fault_entries(regs, error_code, address); __do_page_fault(regs, error_code, address); exception_exit(prev_state); } |