diff options
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 316 |
1 files changed, 82 insertions, 234 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 1e96c3628bf2..da4098ee928f 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -53,11 +53,11 @@ #include <asm/page_types.h> #include <asm/irqflags.h> #include <asm/paravirt.h> -#include <asm/ftrace.h> #include <asm/percpu.h> #include <asm/asm.h> #include <asm/context_tracking.h> #include <asm/smap.h> +#include <asm/pgtable_types.h> #include <linux/err.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ @@ -69,209 +69,6 @@ .code64 .section .entry.text, "ax" -#ifdef CONFIG_FUNCTION_TRACER - -#ifdef CC_USING_FENTRY -# define function_hook __fentry__ -#else -# define function_hook mcount -#endif - -#ifdef CONFIG_DYNAMIC_FTRACE - -ENTRY(function_hook) - retq -END(function_hook) - -/* skip is set if stack has been adjusted */ -.macro ftrace_caller_setup skip=0 - MCOUNT_SAVE_FRAME \skip - - /* Load the ftrace_ops into the 3rd parameter */ - movq function_trace_op(%rip), %rdx - - /* Load ip into the first parameter */ - movq RIP(%rsp), %rdi - subq $MCOUNT_INSN_SIZE, %rdi - /* Load the parent_ip into the second parameter */ -#ifdef CC_USING_FENTRY - movq SS+16(%rsp), %rsi -#else - movq 8(%rbp), %rsi -#endif -.endm - -ENTRY(ftrace_caller) - /* Check if tracing was disabled (quick check) */ - cmpl $0, function_trace_stop - jne ftrace_stub - - ftrace_caller_setup - /* regs go into 4th parameter (but make it NULL) */ - movq $0, %rcx - -GLOBAL(ftrace_call) - call ftrace_stub - - MCOUNT_RESTORE_FRAME -ftrace_return: - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -GLOBAL(ftrace_graph_call) - jmp ftrace_stub -#endif - -GLOBAL(ftrace_stub) - retq -END(ftrace_caller) - -ENTRY(ftrace_regs_caller) - /* Save the current flags before compare (in SS location)*/ - pushfq - - /* Check if tracing was disabled (quick check) */ - cmpl $0, function_trace_stop - jne ftrace_restore_flags - - /* skip=8 to skip flags saved in SS */ - ftrace_caller_setup 8 - - /* Save the rest of pt_regs */ - movq %r15, R15(%rsp) - movq %r14, R14(%rsp) - movq %r13, R13(%rsp) - movq %r12, R12(%rsp) - movq %r11, R11(%rsp) - movq %r10, R10(%rsp) - movq %rbp, RBP(%rsp) - movq %rbx, RBX(%rsp) - /* Copy saved flags */ - movq SS(%rsp), %rcx - movq %rcx, EFLAGS(%rsp) - /* Kernel segments */ - movq $__KERNEL_DS, %rcx - movq %rcx, SS(%rsp) - movq $__KERNEL_CS, %rcx - movq %rcx, CS(%rsp) - /* Stack - skipping return address */ - leaq SS+16(%rsp), %rcx - movq %rcx, RSP(%rsp) - - /* regs go into 4th parameter */ - leaq (%rsp), %rcx - -GLOBAL(ftrace_regs_call) - call ftrace_stub - - /* Copy flags back to SS, to restore them */ - movq EFLAGS(%rsp), %rax - movq %rax, SS(%rsp) - - /* Handlers can change the RIP */ - movq RIP(%rsp), %rax - movq %rax, SS+8(%rsp) - - /* restore the rest of pt_regs */ - movq R15(%rsp), %r15 - movq R14(%rsp), %r14 - movq R13(%rsp), %r13 - movq R12(%rsp), %r12 - movq R10(%rsp), %r10 - movq RBP(%rsp), %rbp - movq RBX(%rsp), %rbx - - /* skip=8 to skip flags saved in SS */ - MCOUNT_RESTORE_FRAME 8 - - /* Restore flags */ - popfq - - jmp ftrace_return -ftrace_restore_flags: - popfq - jmp ftrace_stub - -END(ftrace_regs_caller) - - -#else /* ! CONFIG_DYNAMIC_FTRACE */ - -ENTRY(function_hook) - cmpl $0, function_trace_stop - jne ftrace_stub - - cmpq $ftrace_stub, ftrace_trace_function - jnz trace - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - cmpq $ftrace_stub, ftrace_graph_return - jnz ftrace_graph_caller - - cmpq $ftrace_graph_entry_stub, ftrace_graph_entry - jnz ftrace_graph_caller -#endif - -GLOBAL(ftrace_stub) - retq - -trace: - MCOUNT_SAVE_FRAME - - movq RIP(%rsp), %rdi -#ifdef CC_USING_FENTRY - movq SS+16(%rsp), %rsi -#else - movq 8(%rbp), %rsi -#endif - subq $MCOUNT_INSN_SIZE, %rdi - - call *ftrace_trace_function - - MCOUNT_RESTORE_FRAME - - jmp ftrace_stub -END(function_hook) -#endif /* CONFIG_DYNAMIC_FTRACE */ -#endif /* CONFIG_FUNCTION_TRACER */ - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -ENTRY(ftrace_graph_caller) - MCOUNT_SAVE_FRAME - -#ifdef CC_USING_FENTRY - leaq SS+16(%rsp), %rdi - movq $0, %rdx /* No framepointers needed */ -#else - leaq 8(%rbp), %rdi - movq (%rbp), %rdx -#endif - movq RIP(%rsp), %rsi - subq $MCOUNT_INSN_SIZE, %rsi - - call prepare_ftrace_return - - MCOUNT_RESTORE_FRAME - - retq -END(ftrace_graph_caller) - -GLOBAL(return_to_handler) - subq $24, %rsp - - /* Save the return values */ - movq %rax, (%rsp) - movq %rdx, 8(%rsp) - movq %rbp, %rdi - - call ftrace_return_to_handler - - movq %rax, %rdi - movq 8(%rsp), %rdx - movq (%rsp), %rax - addq $24, %rsp - jmp *%rdi -#endif - #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args @@ -487,8 +284,6 @@ ENDPROC(native_usergs_sysret64) TRACE_IRQS_OFF .endm -/* save complete stack frame */ - .pushsection .kprobes.text, "ax" ENTRY(save_paranoid) XCPT_FRAME 1 RDI+8 cld @@ -517,7 +312,6 @@ ENTRY(save_paranoid) 1: ret CFI_ENDPROC END(save_paranoid) - .popsection /* * A newly forked process directly context switches into this address. @@ -694,12 +488,11 @@ badsys: * jump back to the normal fast path. */ auditsys: - movq %r10,%r9 /* 6th arg: 4th syscall arg */ - movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ - movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ - movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ - movq %rax,%rsi /* 2nd arg: syscall number */ - movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ + movq %r10,%r8 /* 5th arg: 4th syscall arg */ + movq %rdx,%rcx /* 4th arg: 3rd syscall arg */ + movq %rsi,%rdx /* 3rd arg: 2nd syscall arg */ + movq %rdi,%rsi /* 2nd arg: 1st syscall arg */ + movq %rax,%rdi /* 1st arg: syscall number */ call __audit_syscall_entry LOAD_ARGS 0 /* reload call-clobbered registers */ jmp system_call_fastpath @@ -975,10 +768,6 @@ END(interrupt) call \func .endm -/* - * Interrupt entry/exit should be protected against kprobes - */ - .pushsection .kprobes.text, "ax" /* * The interrupt stubs push (~vector+0x80) onto the stack and * then jump to common_interrupt. @@ -1040,8 +829,18 @@ restore_args: RESTORE_ARGS 1,8,1 irq_return: + /* + * Are we returning to a stack segment from the LDT? Note: in + * 64-bit mode SS:RSP on the exception stack is always valid. + */ +#ifdef CONFIG_X86_ESPFIX64 + testb $4,(SS-RIP)(%rsp) + jnz irq_return_ldt +#endif + +irq_return_iret: INTERRUPT_RETURN - _ASM_EXTABLE(irq_return, bad_iret) + _ASM_EXTABLE(irq_return_iret, bad_iret) #ifdef CONFIG_PARAVIRT ENTRY(native_iret) @@ -1049,6 +848,32 @@ ENTRY(native_iret) _ASM_EXTABLE(native_iret, bad_iret) #endif +#ifdef CONFIG_X86_ESPFIX64 +irq_return_ldt: + pushq_cfi %rax + pushq_cfi %rdi + SWAPGS + movq PER_CPU_VAR(espfix_waddr),%rdi + movq %rax,(0*8)(%rdi) /* RAX */ + movq (2*8)(%rsp),%rax /* RIP */ + movq %rax,(1*8)(%rdi) + movq (3*8)(%rsp),%rax /* CS */ + movq %rax,(2*8)(%rdi) + movq (4*8)(%rsp),%rax /* RFLAGS */ + movq %rax,(3*8)(%rdi) + movq (6*8)(%rsp),%rax /* SS */ + movq %rax,(5*8)(%rdi) + movq (5*8)(%rsp),%rax /* RSP */ + movq %rax,(4*8)(%rdi) + andl $0xffff0000,%eax + popq_cfi %rdi + orq PER_CPU_VAR(espfix_stack),%rax + SWAPGS + movq %rax,%rsp + popq_cfi %rax + jmp irq_return_iret +#endif + .section .fixup,"ax" bad_iret: /* @@ -1110,13 +935,45 @@ ENTRY(retint_kernel) call preempt_schedule_irq jmp exit_intr #endif - CFI_ENDPROC END(common_interrupt) -/* - * End of kprobes section - */ - .popsection + + /* + * If IRET takes a fault on the espfix stack, then we + * end up promoting it to a doublefault. In that case, + * modify the stack to make it look like we just entered + * the #GP handler from user space, similar to bad_iret. + */ +#ifdef CONFIG_X86_ESPFIX64 + ALIGN +__do_double_fault: + XCPT_FRAME 1 RDI+8 + movq RSP(%rdi),%rax /* Trap on the espfix stack? */ + sarq $PGDIR_SHIFT,%rax + cmpl $ESPFIX_PGD_ENTRY,%eax + jne do_double_fault /* No, just deliver the fault */ + cmpl $__KERNEL_CS,CS(%rdi) + jne do_double_fault + movq RIP(%rdi),%rax + cmpq $irq_return_iret,%rax +#ifdef CONFIG_PARAVIRT + je 1f + cmpq $native_iret,%rax +#endif + jne do_double_fault /* This shouldn't happen... */ +1: + movq PER_CPU_VAR(kernel_stack),%rax + subq $(6*8-KERNEL_STACK_OFFSET),%rax /* Reset to original stack */ + movq %rax,RSP(%rdi) + movq $0,(%rax) /* Missing (lost) #GP error code */ + movq $general_protection,RIP(%rdi) + retq + CFI_ENDPROC +END(__do_double_fault) +#else +# define __do_double_fault do_double_fault +#endif + /* * APIC interrupts. @@ -1314,7 +1171,7 @@ zeroentry overflow do_overflow zeroentry bounds do_bounds zeroentry invalid_op do_invalid_op zeroentry device_not_available do_device_not_available -paranoiderrorentry double_fault do_double_fault +paranoiderrorentry double_fault __do_double_fault zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun errorentry invalid_TSS do_invalid_TSS errorentry segment_not_present do_segment_not_present @@ -1477,11 +1334,6 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \ hyperv_callback_vector hyperv_vector_handler #endif /* CONFIG_HYPERV */ -/* - * Some functions should be protected against kprobes - */ - .pushsection .kprobes.text, "ax" - paranoidzeroentry_ist debug do_debug DEBUG_STACK paranoidzeroentry_ist int3 do_int3 DEBUG_STACK paranoiderrorentry stack_segment do_stack_segment @@ -1601,7 +1453,7 @@ error_sti: */ error_kernelspace: incl %ebx - leaq irq_return(%rip),%rcx + leaq irq_return_iret(%rip),%rcx cmpq %rcx,RIP+8(%rsp) je error_swapgs movl %ecx,%eax /* zero extend */ @@ -1898,7 +1750,3 @@ ENTRY(ignore_sysret) CFI_ENDPROC END(ignore_sysret) -/* - * End of kprobes section - */ - .popsection |