diff options
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 300 |
1 files changed, 166 insertions, 134 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index dbf06a0ef3d5..5a12432ccdf9 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -242,6 +242,78 @@ ENTRY(native_usergs_sysret64) CFI_REL_OFFSET rsp,RSP /*CFI_REL_OFFSET ss,SS*/ .endm + +/* + * initial frame state for interrupts and exceptions + */ + .macro _frame ref + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA rsp,SS+8-\ref + /*CFI_REL_OFFSET ss,SS-\ref*/ + CFI_REL_OFFSET rsp,RSP-\ref + /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/ + /*CFI_REL_OFFSET cs,CS-\ref*/ + CFI_REL_OFFSET rip,RIP-\ref + .endm + +/* + * initial frame state for interrupts (and exceptions without error code) + */ +#define INTR_FRAME _frame RIP +/* + * initial frame state for exceptions with error code (and interrupts + * with vector already pushed) + */ +#define XCPT_FRAME _frame ORIG_RAX + +/* save partial stack frame */ +ENTRY(save_args) + XCPT_FRAME + cld + movq %rdi, 8*8+16(%rsp) + CFI_REL_OFFSET rdi, 8*8+16 + movq %rsi, 7*8+16(%rsp) + CFI_REL_OFFSET rsi, 7*8+16 + movq %rdx, 6*8+16(%rsp) + CFI_REL_OFFSET rdx, 6*8+16 + movq %rcx, 5*8+16(%rsp) + CFI_REL_OFFSET rcx, 5*8+16 + movq %rax, 4*8+16(%rsp) + CFI_REL_OFFSET rax, 4*8+16 + movq %r8, 3*8+16(%rsp) + CFI_REL_OFFSET r8, 3*8+16 + movq %r9, 2*8+16(%rsp) + CFI_REL_OFFSET r9, 2*8+16 + movq %r10, 1*8+16(%rsp) + CFI_REL_OFFSET r10, 1*8+16 + movq %r11, 0*8+16(%rsp) + CFI_REL_OFFSET r11, 0*8+16 + leaq -ARGOFFSET+16(%rsp),%rdi /* arg1 for handler */ + movq %rbp, 8(%rsp) /* push %rbp */ + leaq 8(%rsp), %rbp /* mov %rsp, %ebp */ + testl $3, CS(%rdi) + je 1f + SWAPGS + /* + * irqcount 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 %gs:pda_irqcount + jne 2f + pop %rax /* move return address... */ + mov %gs:pda_irqstackptr,%rsp + push %rax /* ... to the new stack */ + /* + * We entered an interrupt context - irqs are off: + */ +2: TRACE_IRQS_OFF + ret + CFI_ENDPROC +END(save_args) + /* * A newly forked process directly context switches into this. */ @@ -608,26 +680,6 @@ ENTRY(stub_rt_sigreturn) END(stub_rt_sigreturn) /* - * initial frame state for interrupts and exceptions - */ - .macro _frame ref - CFI_STARTPROC simple - CFI_SIGNAL_FRAME - CFI_DEF_CFA rsp,SS+8-\ref - /*CFI_REL_OFFSET ss,SS-\ref*/ - CFI_REL_OFFSET rsp,RSP-\ref - /*CFI_REL_OFFSET rflags,EFLAGS-\ref*/ - /*CFI_REL_OFFSET cs,CS-\ref*/ - CFI_REL_OFFSET rip,RIP-\ref - .endm - -/* initial frame state for interrupts (and exceptions without error code) */ -#define INTR_FRAME _frame RIP -/* initial frame state for exceptions with error code (and interrupts with - vector already pushed) */ -#define XCPT_FRAME _frame ORIG_RAX - -/* * Build the entry stubs and pointer table with some assembler magic. * We pack 7 stubs into a single 32-byte chunk, which will fit in a * single cache line on all modern x86 implementations. @@ -667,46 +719,19 @@ END(irq_entries_start) END(interrupt) .previous -/* +/* * Interrupt entry/exit. * * Interrupt entry points save only callee clobbered registers in fast path. - * - * Entry runs with interrupts off. - */ + * + * Entry runs with interrupts off. + */ /* 0(%rsp): ~(interrupt number) */ .macro interrupt func - cld - SAVE_ARGS - leaq -ARGOFFSET(%rsp),%rdi /* arg1 for handler */ - pushq %rbp - /* - * Save rbp twice: One is for marking the stack frame, as usual, and the - * other, to fill pt_regs properly. This is because bx comes right - * before the last saved register in that structure, and not bp. If the - * base pointer were in the place bx is today, this would not be needed. - */ - movq %rbp, -8(%rsp) - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rbp, 0 - movq %rsp,%rbp - CFI_DEF_CFA_REGISTER rbp - testl $3,CS(%rdi) - je 1f - SWAPGS - /* irqcount 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 %gs:pda_irqcount - cmoveq %gs:pda_irqstackptr,%rsp - push %rbp # backlink for old unwinder - /* - * We entered an interrupt context - irqs are off: - */ - TRACE_IRQS_OFF + subq $10*8, %rsp + CFI_ADJUST_CFA_OFFSET 10*8 + call save_args call \func .endm @@ -852,6 +877,8 @@ END(common_interrupt) /* * APIC interrupts. */ + .p2align 5 + .macro apicinterrupt num,func INTR_FRAME pushq $~(\num) @@ -922,24 +949,29 @@ END(spurious_interrupt) .macro zeroentry sym INTR_FRAME PARAVIRT_ADJUST_EXCEPTION_FRAME - pushq $0 /* push error code/oldrax */ + pushq $-1 /* ORIG_RAX: no syscall to restart */ CFI_ADJUST_CFA_OFFSET 8 - pushq %rax /* push real oldrax to the rdi slot */ - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rax,0 - leaq \sym(%rip),%rax - jmp error_entry + subq $15*8,%rsp + CFI_ADJUST_CFA_OFFSET 15*8 + call error_entry + movq %rsp,%rdi /* pt_regs pointer */ + xorl %esi,%esi /* no error code */ + call \sym + jmp error_exit /* %ebx: no swapgs flag */ CFI_ENDPROC .endm .macro errorentry sym XCPT_FRAME PARAVIRT_ADJUST_EXCEPTION_FRAME - pushq %rax - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rax,0 - leaq \sym(%rip),%rax - jmp error_entry + subq $15*8,%rsp + CFI_ADJUST_CFA_OFFSET 15*8 + call error_entry + movq %rsp,%rdi /* pt_regs pointer */ + movq ORIG_RAX(%rsp),%rsi /* get error code */ + movq $-1,ORIG_RAX(%rsp) /* no syscall to restart */ + call \sym + jmp error_exit /* %ebx: no swapgs flag */ CFI_ENDPROC .endm @@ -1043,93 +1075,93 @@ paranoid_schedule\trace: .endm /* - * Exception entry point. This expects an error code/orig_rax on the stack - * and the exception handler in %rax. + * Exception entry point. This expects an error code/orig_rax on the stack. + * returns in "no swapgs flag" in %ebx. */ KPROBE_ENTRY(error_entry) _frame RDI - CFI_REL_OFFSET rax,0 - /* rdi slot contains rax, oldrax contains error code */ + CFI_ADJUST_CFA_OFFSET 15*8 + /* oldrax contains error code */ cld - subq $14*8,%rsp - CFI_ADJUST_CFA_OFFSET (14*8) - movq %rsi,13*8(%rsp) - CFI_REL_OFFSET rsi,RSI - movq 14*8(%rsp),%rsi /* load rax from rdi slot */ - CFI_REGISTER rax,rsi - movq %rdx,12*8(%rsp) - CFI_REL_OFFSET rdx,RDX - movq %rcx,11*8(%rsp) - CFI_REL_OFFSET rcx,RCX - movq %rsi,10*8(%rsp) /* store rax */ - CFI_REL_OFFSET rax,RAX - movq %r8, 9*8(%rsp) - CFI_REL_OFFSET r8,R8 - movq %r9, 8*8(%rsp) - CFI_REL_OFFSET r9,R9 - movq %r10,7*8(%rsp) - CFI_REL_OFFSET r10,R10 - movq %r11,6*8(%rsp) - CFI_REL_OFFSET r11,R11 - movq %rbx,5*8(%rsp) - CFI_REL_OFFSET rbx,RBX - movq %rbp,4*8(%rsp) - CFI_REL_OFFSET rbp,RBP - movq %r12,3*8(%rsp) - CFI_REL_OFFSET r12,R12 - movq %r13,2*8(%rsp) - CFI_REL_OFFSET r13,R13 - movq %r14,1*8(%rsp) - CFI_REL_OFFSET r14,R14 - movq %r15,(%rsp) - CFI_REL_OFFSET r15,R15 + movq %rdi,14*8+8(%rsp) + CFI_REL_OFFSET rdi,RDI+8 + movq %rsi,13*8+8(%rsp) + CFI_REL_OFFSET rsi,RSI+8 + movq %rdx,12*8+8(%rsp) + CFI_REL_OFFSET rdx,RDX+8 + movq %rcx,11*8+8(%rsp) + CFI_REL_OFFSET rcx,RCX+8 + movq %rax,10*8+8(%rsp) + CFI_REL_OFFSET rax,RAX+8 + movq %r8, 9*8+8(%rsp) + CFI_REL_OFFSET r8,R8+8 + movq %r9, 8*8+8(%rsp) + CFI_REL_OFFSET r9,R9+8 + movq %r10,7*8+8(%rsp) + CFI_REL_OFFSET r10,R10+8 + movq %r11,6*8+8(%rsp) + CFI_REL_OFFSET r11,R11+8 + movq %rbx,5*8+8(%rsp) + CFI_REL_OFFSET rbx,RBX+8 + movq %rbp,4*8+8(%rsp) + CFI_REL_OFFSET rbp,RBP+8 + movq %r12,3*8+8(%rsp) + CFI_REL_OFFSET r12,R12+8 + movq %r13,2*8+8(%rsp) + CFI_REL_OFFSET r13,R13+8 + movq %r14,1*8+8(%rsp) + CFI_REL_OFFSET r14,R14+8 + movq %r15,0*8+8(%rsp) + CFI_REL_OFFSET r15,R15+8 xorl %ebx,%ebx - testl $3,CS(%rsp) - je error_kernelspace + testl $3,CS+8(%rsp) + je error_kernelspace error_swapgs: SWAPGS error_sti: TRACE_IRQS_OFF - movq %rdi,RDI(%rsp) - CFI_REL_OFFSET rdi,RDI - movq %rsp,%rdi - movq ORIG_RAX(%rsp),%rsi /* get error code */ - movq $-1,ORIG_RAX(%rsp) - call *%rax - /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ -error_exit: + ret + CFI_ENDPROC + +/* + * There are two places in the kernel that can potentially fault with + * usergs. Handle them here. The exception handlers after iret run with + * kernel gs again, so don't set the user space flag. B stepping K8s + * sometimes report an truncated RIP for IRET exceptions returning to + * compat mode. Check for these here too. + */ +error_kernelspace: + incl %ebx + leaq irq_return(%rip),%rcx + cmpq %rcx,RIP+8(%rsp) + je error_swapgs + movl %ecx,%ecx /* zero extend */ + cmpq %rcx,RIP+8(%rsp) + je error_swapgs + cmpq $gs_change,RIP+8(%rsp) + je error_swapgs + jmp error_sti +KPROBE_END(error_entry) + + +/* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ +KPROBE_ENTRY(error_exit) + _frame R15 movl %ebx,%eax RESTORE_REST DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF GET_THREAD_INFO(%rcx) testl %eax,%eax - jne retint_kernel + jne retint_kernel LOCKDEP_SYS_EXIT_IRQ - movl TI_flags(%rcx),%edx - movl $_TIF_WORK_MASK,%edi - andl %edi,%edx - jnz retint_careful + movl TI_flags(%rcx),%edx + movl $_TIF_WORK_MASK,%edi + andl %edi,%edx + jnz retint_careful jmp retint_swapgs CFI_ENDPROC - -error_kernelspace: - incl %ebx - /* There are two places in the kernel that can potentially fault with - usergs. Handle them here. The exception handlers after - iret run with kernel gs again, so don't set the user space flag. - B stepping K8s sometimes report an truncated RIP for IRET - exceptions returning to compat mode. Check for these here too. */ - leaq irq_return(%rip),%rcx - cmpq %rcx,RIP(%rsp) - je error_swapgs - movl %ecx,%ecx /* zero extend */ - cmpq %rcx,RIP(%rsp) - je error_swapgs - cmpq $gs_change,RIP(%rsp) - je error_swapgs - jmp error_sti -KPROBE_END(error_entry) +KPROBE_END(error_exit) /* Reload gs selector with exception handling */ /* edi: new selector */ |