diff options
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 197 |
1 files changed, 53 insertions, 144 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 8cb3e438f21e..d3033183ed70 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -33,7 +33,6 @@ #include <asm/paravirt.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> @@ -229,6 +228,11 @@ entry_SYSCALL_64_fastpath: */ USERGS_SYSRET64 +GLOBAL(int_ret_from_sys_call_irqs_off) + TRACE_IRQS_ON + ENABLE_INTERRUPTS(CLBR_NONE) + jmp int_ret_from_sys_call + /* Do syscall entry tracing */ tracesys: movq %rsp, %rdi @@ -272,69 +276,11 @@ tracesys_phase2: * Has correct iret frame. */ GLOBAL(int_ret_from_sys_call) - DISABLE_INTERRUPTS(CLBR_NONE) -int_ret_from_sys_call_irqs_off: /* jumps come here from the irqs-off SYSRET path */ - TRACE_IRQS_OFF - movl $_TIF_ALLWORK_MASK, %edi - /* edi: mask to check */ -GLOBAL(int_with_check) - LOCKDEP_SYS_EXIT_IRQ - GET_THREAD_INFO(%rcx) - movl TI_flags(%rcx), %edx - andl %edi, %edx - jnz int_careful - andl $~TS_COMPAT, TI_status(%rcx) - jmp syscall_return - - /* - * Either reschedule or signal or syscall exit tracking needed. - * First do a reschedule test. - * edx: work, edi: workmask - */ -int_careful: - bt $TIF_NEED_RESCHED, %edx - jnc int_very_careful - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_NONE) - pushq %rdi - SCHEDULE_USER - popq %rdi - DISABLE_INTERRUPTS(CLBR_NONE) - TRACE_IRQS_OFF - jmp int_with_check - - /* handle signals and tracing -- both require a full pt_regs */ -int_very_careful: - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_NONE) SAVE_EXTRA_REGS - /* Check for syscall exit trace */ - testl $_TIF_WORK_SYSCALL_EXIT, %edx - jz int_signal - pushq %rdi - leaq 8(%rsp), %rdi /* &ptregs -> arg1 */ - call syscall_trace_leave - popq %rdi - andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU), %edi - jmp int_restore_rest - -int_signal: - testl $_TIF_DO_NOTIFY_MASK, %edx - jz 1f - movq %rsp, %rdi /* &ptregs -> arg1 */ - xorl %esi, %esi /* oldset -> arg2 */ - call do_notify_resume -1: movl $_TIF_WORK_MASK, %edi -int_restore_rest: + movq %rsp, %rdi + call syscall_return_slowpath /* returns with IRQs disabled */ RESTORE_EXTRA_REGS - DISABLE_INTERRUPTS(CLBR_NONE) - TRACE_IRQS_OFF - jmp int_with_check - -syscall_return: - /* The IRETQ could re-enable interrupts: */ - DISABLE_INTERRUPTS(CLBR_ANY) - TRACE_IRQS_IRETQ + TRACE_IRQS_IRETQ /* we're about to change IF */ /* * Try to use SYSRET instead of IRET if we're returning to @@ -555,23 +501,22 @@ END(irq_entries_start) /* 0(%rsp): ~(interrupt number) */ .macro interrupt func cld - /* - * Since nothing in interrupt handling code touches r12...r15 members - * of "struct pt_regs", and since interrupts can nest, we can save - * four stack slots and simultaneously provide - * an unwind-friendly stack layout by saving "truncated" pt_regs - * exactly up to rbp slot, without these members. - */ - 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) */ + ALLOC_PT_GPREGS_ON_STACK + SAVE_C_REGS + SAVE_EXTRA_REGS - testb $3, CS-RBP(%rsp) + testb $3, CS(%rsp) jz 1f + + /* + * IRQ from user mode. Switch to kernel gsbase and inform context + * tracking that we're in kernel mode. + */ SWAPGS +#ifdef CONFIG_CONTEXT_TRACKING + call enter_from_user_mode +#endif + 1: /* * Save previous stack pointer, optionally switch to interrupt stack. @@ -580,14 +525,14 @@ END(irq_entries_start) * a little cheaper to use a separate counter in the PDA (short of * moving irq_enter into assembly, which would be too much work) */ - movq %rsp, %rsi + movq %rsp, %rdi incl PER_CPU_VAR(irq_count) cmovzq PER_CPU_VAR(irq_stack_ptr), %rsp - pushq %rsi + pushq %rdi /* We entered an interrupt context - irqs are off: */ TRACE_IRQS_OFF - call \func + call \func /* rdi points to pt_regs */ .endm /* @@ -606,34 +551,19 @@ ret_from_intr: decl PER_CPU_VAR(irq_count) /* Restore saved previous stack */ - popq %rsi - /* return code expects complete pt_regs - adjust rsp accordingly: */ - leaq -RBP(%rsi), %rsp + popq %rsp testb $3, CS(%rsp) jz retint_kernel - /* Interrupt came from user space */ -retint_user: - GET_THREAD_INFO(%rcx) - /* %rcx: thread info. Interrupts are off. */ -retint_with_reschedule: - movl $_TIF_WORK_MASK, %edi -retint_check: + /* Interrupt came from user space */ LOCKDEP_SYS_EXIT_IRQ - movl TI_flags(%rcx), %edx - andl %edi, %edx - jnz retint_careful - -retint_swapgs: /* return to user-space */ - /* - * The iretq could re-enable interrupts: - */ - DISABLE_INTERRUPTS(CLBR_ANY) +GLOBAL(retint_user) + mov %rsp,%rdi + call prepare_exit_to_usermode TRACE_IRQS_IRETQ - SWAPGS - jmp restore_c_regs_and_iret + jmp restore_regs_and_iret /* Returning to kernel space */ retint_kernel: @@ -657,6 +587,8 @@ retint_kernel: * At this label, code paths which return to kernel and to user, * which come from interrupts/exception and from syscalls, merge. */ +restore_regs_and_iret: + RESTORE_EXTRA_REGS restore_c_regs_and_iret: RESTORE_C_REGS REMOVE_PT_GPREGS_FROM_STACK 8 @@ -707,37 +639,6 @@ native_irq_return_ldt: popq %rax jmp native_irq_return_iret #endif - - /* edi: workmask, edx: work */ -retint_careful: - bt $TIF_NEED_RESCHED, %edx - jnc retint_signal - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_NONE) - pushq %rdi - SCHEDULE_USER - popq %rdi - GET_THREAD_INFO(%rcx) - DISABLE_INTERRUPTS(CLBR_NONE) - TRACE_IRQS_OFF - jmp retint_check - -retint_signal: - testl $_TIF_DO_NOTIFY_MASK, %edx - jz retint_swapgs - TRACE_IRQS_ON - ENABLE_INTERRUPTS(CLBR_NONE) - SAVE_EXTRA_REGS - movq $-1, ORIG_RAX(%rsp) - xorl %esi, %esi /* oldset */ - movq %rsp, %rdi /* &pt_regs */ - call do_notify_resume - RESTORE_EXTRA_REGS - DISABLE_INTERRUPTS(CLBR_NONE) - TRACE_IRQS_OFF - GET_THREAD_INFO(%rcx) - jmp retint_with_reschedule - END(common_interrupt) /* @@ -1143,12 +1044,22 @@ ENTRY(error_entry) SAVE_EXTRA_REGS 8 xorl %ebx, %ebx testb $3, CS+8(%rsp) - jz error_kernelspace + jz .Lerror_kernelspace - /* We entered from user mode */ +.Lerror_entry_from_usermode_swapgs: + /* + * We entered from user mode or we're pretending to have entered + * from user mode due to an IRET fault. + */ SWAPGS -error_entry_done: +.Lerror_entry_from_usermode_after_swapgs: +#ifdef CONFIG_CONTEXT_TRACKING + call enter_from_user_mode +#endif + +.Lerror_entry_done: + TRACE_IRQS_OFF ret @@ -1158,31 +1069,30 @@ error_entry_done: * truncated RIP for IRET exceptions returning to compat mode. Check * for these here too. */ -error_kernelspace: +.Lerror_kernelspace: incl %ebx leaq native_irq_return_iret(%rip), %rcx cmpq %rcx, RIP+8(%rsp) - je error_bad_iret + je .Lerror_bad_iret movl %ecx, %eax /* zero extend */ cmpq %rax, RIP+8(%rsp) - je bstep_iret + je .Lbstep_iret cmpq $gs_change, RIP+8(%rsp) - jne error_entry_done + jne .Lerror_entry_done /* * hack: gs_change can fail with user gsbase. If this happens, fix up * gsbase and proceed. We'll fix up the exception and land in * gs_change's error handler with kernel gsbase. */ - SWAPGS - jmp error_entry_done + jmp .Lerror_entry_from_usermode_swapgs -bstep_iret: +.Lbstep_iret: /* Fix truncated RIP */ movq %rcx, RIP+8(%rsp) /* fall through */ -error_bad_iret: +.Lerror_bad_iret: /* * We came from an IRET to user mode, so we have user gsbase. * Switch to kernel gsbase: @@ -1198,7 +1108,7 @@ error_bad_iret: call fixup_bad_iret mov %rax, %rsp decl %ebx - jmp error_entry_done + jmp .Lerror_entry_from_usermode_after_swapgs END(error_entry) @@ -1209,7 +1119,6 @@ END(error_entry) */ ENTRY(error_exit) movl %ebx, %eax - RESTORE_EXTRA_REGS DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF testl %eax, %eax |