diff options
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 196 |
1 files changed, 75 insertions, 121 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index a57b3387ec7d5..e8372e08f8c25 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -26,12 +26,6 @@ * Some macro usage: * - CFI macros are used to generate dwarf2 unwind information for better * backtraces. They don't change any code. - * - SAVE_ALL/RESTORE_ALL - Save/restore all registers - * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. - * There are unfortunately lots of special cases where some registers - * not touched. The macro is a big mess that should be cleaned up. - * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. - * Gives a full stack frame. * - ENTRY/END Define functions in the symbol table. * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack * frame that is otherwise undefined after a SYSCALL @@ -190,9 +184,9 @@ ENDPROC(native_usergs_sysret64) .endm /* - * frame that enables calling into C. + * frame that enables passing a complete pt_regs to a C function. */ - .macro PARTIAL_FRAME start=1 offset=0 + .macro DEFAULT_FRAME start=1 offset=0 XCPT_FRAME \start, ORIG_RAX+\offset-ARGOFFSET CFI_REL_OFFSET rdi, RDI+\offset-ARGOFFSET CFI_REL_OFFSET rsi, RSI+\offset-ARGOFFSET @@ -203,13 +197,6 @@ ENDPROC(native_usergs_sysret64) CFI_REL_OFFSET r9, R9+\offset-ARGOFFSET CFI_REL_OFFSET r10, R10+\offset-ARGOFFSET CFI_REL_OFFSET r11, R11+\offset-ARGOFFSET - .endm - -/* - * frame that enables passing a complete pt_regs to a C function. - */ - .macro DEFAULT_FRAME start=1 offset=0 - PARTIAL_FRAME \start, R11+\offset-R15 CFI_REL_OFFSET rbx, RBX+\offset CFI_REL_OFFSET rbp, RBP+\offset CFI_REL_OFFSET r12, R12+\offset @@ -221,21 +208,8 @@ ENDPROC(native_usergs_sysret64) ENTRY(save_paranoid) XCPT_FRAME 1 RDI+8 cld - movq %rdi, RDI+8(%rsp) - movq %rsi, RSI+8(%rsp) - movq_cfi rdx, RDX+8 - movq_cfi rcx, RCX+8 - movq_cfi rax, RAX+8 - movq %r8, R8+8(%rsp) - movq %r9, R9+8(%rsp) - movq %r10, R10+8(%rsp) - movq %r11, R11+8(%rsp) - movq_cfi rbx, RBX+8 - movq %rbp, RBP+8(%rsp) - movq %r12, R12+8(%rsp) - movq %r13, R13+8(%rsp) - movq %r14, R14+8(%rsp) - movq %r15, R15+8(%rsp) + SAVE_C_REGS 8 + SAVE_EXTRA_REGS 8 movl $1,%ebx movl $MSR_GS_BASE,%ecx rdmsr @@ -264,7 +238,7 @@ ENTRY(ret_from_fork) GET_THREAD_INFO(%rcx) - RESTORE_REST + RESTORE_EXTRA_REGS testl $3, CS-ARGOFFSET(%rsp) # from kernel_thread? jz 1f @@ -276,12 +250,10 @@ ENTRY(ret_from_fork) jmp ret_from_sys_call # go to the SYSRET fastpath 1: - subq $REST_SKIP, %rsp # leave space for volatiles - CFI_ADJUST_CFA_OFFSET REST_SKIP movq %rbp, %rdi call *%rbx movl $0, RAX(%rsp) - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(ret_from_fork) @@ -339,9 +311,11 @@ GLOBAL(system_call_after_swapgs) * and short: */ ENABLE_INTERRUPTS(CLBR_NONE) - SAVE_ARGS 8, 0, rax_enosys=1 + ALLOC_PT_GPREGS_ON_STACK 8 + SAVE_C_REGS_EXCEPT_RAX_RCX + movq $-ENOSYS,RAX-ARGOFFSET(%rsp) movq_cfi rax,(ORIG_RAX-ARGOFFSET) - movq %rcx,RIP-ARGOFFSET(%rsp) + movq %rcx,RIP-ARGOFFSET(%rsp) CFI_REL_OFFSET rip,RIP-ARGOFFSET testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) jnz tracesys @@ -372,9 +346,9 @@ ret_from_sys_call: * sysretq will re-enable interrupts: */ TRACE_IRQS_ON + RESTORE_C_REGS_EXCEPT_RCX movq RIP-ARGOFFSET(%rsp),%rcx CFI_REGISTER rip,rcx - RESTORE_ARGS 1,-ARG_SKIP,0 /*CFI_REGISTER rflags,r11*/ movq PER_CPU_VAR(old_rsp), %rsp USERGS_SYSRET64 @@ -387,16 +361,17 @@ int_ret_from_sys_call_fixup: /* Do syscall tracing */ tracesys: - leaq -REST_SKIP(%rsp), %rdi + movq %rsp, %rdi movq $AUDIT_ARCH_X86_64, %rsi call syscall_trace_enter_phase1 test %rax, %rax jnz tracesys_phase2 /* if needed, run the slow path */ - LOAD_ARGS 0 /* else restore clobbered regs */ + RESTORE_C_REGS_EXCEPT_RAX /* else restore clobbered regs */ + movq ORIG_RAX-ARGOFFSET(%rsp), %rax jmp system_call_fastpath /* and return to the fast path */ tracesys_phase2: - SAVE_REST + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %rdi movq %rsp, %rdi movq $AUDIT_ARCH_X86_64, %rsi @@ -408,8 +383,8 @@ tracesys_phase2: * We don't reload %rax because syscall_trace_entry_phase2() returned * the value it wants us to use in the table lookup. */ - LOAD_ARGS ARGOFFSET, 1 - RESTORE_REST + RESTORE_C_REGS_EXCEPT_RAX + RESTORE_EXTRA_REGS #if __SYSCALL_MASK == ~0 cmpq $__NR_syscall_max,%rax #else @@ -460,7 +435,7 @@ int_very_careful: TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_NONE) int_check_syscall_exit_work: - SAVE_REST + SAVE_EXTRA_REGS /* Check for syscall exit trace */ testl $_TIF_WORK_SYSCALL_EXIT,%edx jz int_signal @@ -479,7 +454,7 @@ int_signal: call do_notify_resume 1: movl $_TIF_WORK_MASK,%edi int_restore_rest: - RESTORE_REST + RESTORE_EXTRA_REGS DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF jmp int_with_check @@ -489,15 +464,12 @@ END(system_call) .macro FORK_LIKE func ENTRY(stub_\func) CFI_STARTPROC - popq %r11 /* save return address */ - PARTIAL_FRAME 0 - SAVE_REST - pushq %r11 /* put it back on stack */ + DEFAULT_FRAME 0, 8 /* offset 8: return address */ + SAVE_EXTRA_REGS 8 FIXUP_TOP_OF_STACK %r11, 8 - DEFAULT_FRAME 0 8 /* offset 8: return address */ call sys_\func RESTORE_TOP_OF_STACK %r11, 8 - ret $REST_SKIP /* pop extended registers */ + ret CFI_ENDPROC END(stub_\func) .endm @@ -505,7 +477,7 @@ END(stub_\func) .macro FIXED_FRAME label,func ENTRY(\label) CFI_STARTPROC - PARTIAL_FRAME 0 8 /* offset 8: return address */ + DEFAULT_FRAME 0, 8 /* offset 8: return address */ FIXUP_TOP_OF_STACK %r11, 8-ARGOFFSET call \func RESTORE_TOP_OF_STACK %r11, 8-ARGOFFSET @@ -522,12 +494,12 @@ END(\label) ENTRY(stub_execve) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call sys_execve movq %rax,RAX(%rsp) - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_execve) @@ -535,13 +507,13 @@ END(stub_execve) ENTRY(stub_execveat) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call sys_execveat RESTORE_TOP_OF_STACK %r11 movq %rax,RAX(%rsp) - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_execveat) @@ -553,12 +525,12 @@ END(stub_execveat) ENTRY(stub_rt_sigreturn) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call sys_rt_sigreturn movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_rt_sigreturn) @@ -567,12 +539,12 @@ END(stub_rt_sigreturn) ENTRY(stub_x32_rt_sigreturn) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call sys32_x32_rt_sigreturn movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_x32_rt_sigreturn) @@ -580,13 +552,13 @@ END(stub_x32_rt_sigreturn) ENTRY(stub_x32_execve) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call compat_sys_execve RESTORE_TOP_OF_STACK %r11 movq %rax,RAX(%rsp) - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_x32_execve) @@ -594,13 +566,13 @@ END(stub_x32_execve) ENTRY(stub_x32_execveat) CFI_STARTPROC addq $8, %rsp - PARTIAL_FRAME 0 - SAVE_REST + DEFAULT_FRAME 0 + SAVE_EXTRA_REGS FIXUP_TOP_OF_STACK %r11 call compat_sys_execveat RESTORE_TOP_OF_STACK %r11 movq %rax,RAX(%rsp) - RESTORE_REST + RESTORE_EXTRA_REGS jmp int_ret_from_sys_call CFI_ENDPROC END(stub_x32_execveat) @@ -656,42 +628,28 @@ END(interrupt) /* 0(%rsp): ~(interrupt number) */ .macro interrupt func - /* reserve pt_regs for scratch regs and rbp */ - subq $ORIG_RAX-RBP, %rsp - CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP cld - /* start from rbp in pt_regs and jump over */ - movq_cfi rdi, (RDI-RBP) - movq_cfi rsi, (RSI-RBP) - movq_cfi rdx, (RDX-RBP) - movq_cfi rcx, (RCX-RBP) - movq_cfi rax, (RAX-RBP) - movq_cfi r8, (R8-RBP) - movq_cfi r9, (R9-RBP) - movq_cfi r10, (R10-RBP) - movq_cfi r11, (R11-RBP) - - /* Save rbp so that we can unwind from get_irq_regs() */ - movq_cfi rbp, 0 - - /* Save previous stack value */ - movq %rsp, %rsi + ALLOC_PT_GPREGS_ON_STACK -RBP + SAVE_C_REGS -RBP + /* this goes to 0(%rsp) for unwinder, not for saving the value: */ + SAVE_EXTRA_REGS_RBP -RBP + + leaq -RBP(%rsp),%rdi /* arg1 for \func (pointer to pt_regs) */ - leaq -RBP(%rsp),%rdi /* arg1 for handler */ - testl $3, CS-RBP(%rsi) + testl $3, CS-RBP(%rsp) je 1f SWAPGS +1: /* * irq_count is used to check if a CPU is already on an interrupt stack * or not. While this is essentially redundant with preempt_count it is * a little cheaper to use a separate counter in the PDA (short of * moving irq_enter into assembly, which would be too much work) */ -1: incl PER_CPU_VAR(irq_count) + movq %rsp, %rsi + incl PER_CPU_VAR(irq_count) cmovzq PER_CPU_VAR(irq_stack_ptr),%rsp CFI_DEF_CFA_REGISTER rsi - - /* Store previous stack value */ pushq %rsi CFI_ESCAPE 0x0f /* DW_CFA_def_cfa_expression */, 6, \ 0x77 /* DW_OP_breg7 */, 0, \ @@ -800,7 +758,8 @@ retint_swapgs: /* return to user-space */ */ irq_return_via_sysret: CFI_REMEMBER_STATE - RESTORE_ARGS 1,8,1 + RESTORE_C_REGS + REMOVE_PT_GPREGS_FROM_STACK 8 movq (RSP-RIP)(%rsp),%rsp USERGS_SYSRET64 CFI_RESTORE_STATE @@ -816,7 +775,8 @@ retint_restore_args: /* return to kernel space */ */ TRACE_IRQS_IRETQ restore_args: - RESTORE_ARGS 1,8,1 + RESTORE_C_REGS + REMOVE_PT_GPREGS_FROM_STACK 8 irq_return: INTERRUPT_RETURN @@ -887,12 +847,12 @@ retint_signal: jz retint_swapgs TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_NONE) - SAVE_REST + SAVE_EXTRA_REGS movq $-1,ORIG_RAX(%rsp) xorl %esi,%esi # oldset movq %rsp,%rdi # &pt_regs call do_notify_resume - RESTORE_REST + RESTORE_EXTRA_REGS DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF GET_THREAD_INFO(%rcx) @@ -1019,8 +979,7 @@ ENTRY(\sym) pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ .endif - subq $ORIG_RAX-R15, %rsp - CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 + ALLOC_PT_GPREGS_ON_STACK .if \paranoid .if \paranoid == 1 @@ -1269,7 +1228,9 @@ ENTRY(xen_failsafe_callback) addq $0x30,%rsp CFI_ADJUST_CFA_OFFSET -0x30 pushq_cfi $-1 /* orig_ax = -1 => not a system call */ - SAVE_ALL + ALLOC_PT_GPREGS_ON_STACK + SAVE_C_REGS + SAVE_EXTRA_REGS jmp error_exit CFI_ENDPROC END(xen_failsafe_callback) @@ -1321,11 +1282,15 @@ ENTRY(paranoid_exit) jnz paranoid_restore TRACE_IRQS_IRETQ 0 SWAPGS_UNSAFE_STACK - RESTORE_ALL 8 + RESTORE_EXTRA_REGS + RESTORE_C_REGS + REMOVE_PT_GPREGS_FROM_STACK 8 INTERRUPT_RETURN paranoid_restore: TRACE_IRQS_IRETQ_DEBUG 0 - RESTORE_ALL 8 + RESTORE_EXTRA_REGS + RESTORE_C_REGS + REMOVE_PT_GPREGS_FROM_STACK 8 INTERRUPT_RETURN CFI_ENDPROC END(paranoid_exit) @@ -1339,21 +1304,8 @@ ENTRY(error_entry) CFI_ADJUST_CFA_OFFSET 15*8 /* oldrax contains error code */ cld - movq %rdi, RDI+8(%rsp) - movq %rsi, RSI+8(%rsp) - movq %rdx, RDX+8(%rsp) - movq %rcx, RCX+8(%rsp) - movq %rax, RAX+8(%rsp) - movq %r8, R8+8(%rsp) - movq %r9, R9+8(%rsp) - movq %r10, R10+8(%rsp) - movq %r11, R11+8(%rsp) - movq_cfi rbx, RBX+8 - movq %rbp, RBP+8(%rsp) - movq %r12, R12+8(%rsp) - movq %r13, R13+8(%rsp) - movq %r14, R14+8(%rsp) - movq %r15, R15+8(%rsp) + SAVE_C_REGS 8 + SAVE_EXTRA_REGS 8 xorl %ebx,%ebx testl $3,CS+8(%rsp) je error_kernelspace @@ -1402,7 +1354,7 @@ END(error_entry) ENTRY(error_exit) DEFAULT_FRAME movl %ebx,%eax - RESTORE_REST + RESTORE_EXTRA_REGS DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF GET_THREAD_INFO(%rcx) @@ -1621,8 +1573,8 @@ end_repeat_nmi: * so that we repeat another NMI. */ pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */ - subq $ORIG_RAX-R15, %rsp - CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15 + ALLOC_PT_GPREGS_ON_STACK + /* * Use save_paranoid to handle SWAPGS, but no need to use paranoid_exit * as we should not be calling schedule in NMI context. @@ -1661,8 +1613,10 @@ end_repeat_nmi: nmi_swapgs: SWAPGS_UNSAFE_STACK nmi_restore: + RESTORE_EXTRA_REGS + RESTORE_C_REGS /* Pop the extra iret frame at once */ - RESTORE_ALL 6*8 + REMOVE_PT_GPREGS_FROM_STACK 6*8 /* Clear the NMI executing stack variable */ movq $0, 5*8(%rsp) |