diff options
Diffstat (limited to 'arch/x86/kernel/entry_32.S')
| -rw-r--r-- | arch/x86/kernel/entry_32.S | 455 |
1 files changed, 290 insertions, 165 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 4646902..899e893 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -30,12 +30,13 @@ * 1C(%esp) - %ds * 20(%esp) - %es * 24(%esp) - %fs - * 28(%esp) - orig_eax - * 2C(%esp) - %eip - * 30(%esp) - %cs - * 34(%esp) - %eflags - * 38(%esp) - %oldesp - * 3C(%esp) - %oldss + * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS + * 2C(%esp) - orig_eax + * 30(%esp) - %eip + * 34(%esp) - %cs + * 38(%esp) - %eflags + * 3C(%esp) - %oldesp + * 40(%esp) - %oldss * * "current" is in register %ebx during any slow entries. */ @@ -46,7 +47,7 @@ #include <asm/errno.h> #include <asm/segment.h> #include <asm/smp.h> -#include <asm/page.h> +#include <asm/page_types.h> #include <asm/desc.h> #include <asm/percpu.h> #include <asm/dwarf2.h> @@ -101,121 +102,221 @@ #define resume_userspace_sig resume_userspace #endif -#define SAVE_ALL \ - cld; \ - pushl %fs; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET fs, 0;*/\ - pushl %es; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET es, 0;*/\ - pushl %ds; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET ds, 0;*/\ - pushl %eax; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET eax, 0;\ - pushl %ebp; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ebp, 0;\ - pushl %edi; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET edi, 0;\ - pushl %esi; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET esi, 0;\ - pushl %edx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET edx, 0;\ - pushl %ecx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ecx, 0;\ - pushl %ebx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ebx, 0;\ - movl $(__USER_DS), %edx; \ - movl %edx, %ds; \ - movl %edx, %es; \ - movl $(__KERNEL_PERCPU), %edx; \ +/* + * User gs save/restore + * + * %gs is used for userland TLS and kernel only uses it for stack + * canary which is required to be at %gs:20 by gcc. Read the comment + * at the top of stackprotector.h for more info. + * + * Local labels 98 and 99 are used. + */ +#ifdef CONFIG_X86_32_LAZY_GS + + /* unfortunately push/pop can't be no-op */ +.macro PUSH_GS + pushl $0 + CFI_ADJUST_CFA_OFFSET 4 +.endm +.macro POP_GS pop=0 + addl $(4 + \pop), %esp + CFI_ADJUST_CFA_OFFSET -(4 + \pop) +.endm +.macro POP_GS_EX +.endm + + /* all the rest are no-op */ +.macro PTGS_TO_GS +.endm +.macro PTGS_TO_GS_EX +.endm +.macro GS_TO_REG reg +.endm +.macro REG_TO_PTGS reg +.endm +.macro SET_KERNEL_GS reg +.endm + +#else /* CONFIG_X86_32_LAZY_GS */ + +.macro PUSH_GS + pushl %gs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET gs, 0*/ +.endm + +.macro POP_GS pop=0 +98: popl %gs + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE gs*/ + .if \pop <> 0 + add $\pop, %esp + CFI_ADJUST_CFA_OFFSET -\pop + .endif +.endm +.macro POP_GS_EX +.pushsection .fixup, "ax" +99: movl $0, (%esp) + jmp 98b +.section __ex_table, "a" + .align 4 + .long 98b, 99b +.popsection +.endm + +.macro PTGS_TO_GS +98: mov PT_GS(%esp), %gs +.endm +.macro PTGS_TO_GS_EX +.pushsection .fixup, "ax" +99: movl $0, PT_GS(%esp) + jmp 98b +.section __ex_table, "a" + .align 4 + .long 98b, 99b +.popsection +.endm + +.macro GS_TO_REG reg + movl %gs, \reg + /*CFI_REGISTER gs, \reg*/ +.endm +.macro REG_TO_PTGS reg + movl \reg, PT_GS(%esp) + /*CFI_REL_OFFSET gs, PT_GS*/ +.endm +.macro SET_KERNEL_GS reg + movl $(__KERNEL_STACK_CANARY), \reg + movl \reg, %gs +.endm + +#endif /* CONFIG_X86_32_LAZY_GS */ + +.macro SAVE_ALL + cld + PUSH_GS + pushl %fs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET fs, 0;*/ + pushl %es + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET es, 0;*/ + pushl %ds + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET ds, 0;*/ + pushl %eax + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET eax, 0 + pushl %ebp + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ebp, 0 + pushl %edi + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edi, 0 + pushl %esi + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET esi, 0 + pushl %edx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edx, 0 + pushl %ecx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ecx, 0 + pushl %ebx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ebx, 0 + movl $(__USER_DS), %edx + movl %edx, %ds + movl %edx, %es + movl $(__KERNEL_PERCPU), %edx movl %edx, %fs + SET_KERNEL_GS %edx +.endm -#define RESTORE_INT_REGS \ - popl %ebx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ebx;\ - popl %ecx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ecx;\ - popl %edx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE edx;\ - popl %esi; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE esi;\ - popl %edi; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE edi;\ - popl %ebp; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ebp;\ - popl %eax; \ - CFI_ADJUST_CFA_OFFSET -4;\ +.macro RESTORE_INT_REGS + popl %ebx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ebx + popl %ecx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ecx + popl %edx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE edx + popl %esi + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE esi + popl %edi + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE edi + popl %ebp + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ebp + popl %eax + CFI_ADJUST_CFA_OFFSET -4 CFI_RESTORE eax +.endm -#define RESTORE_REGS \ - RESTORE_INT_REGS; \ -1: popl %ds; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE ds;*/\ -2: popl %es; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE es;*/\ -3: popl %fs; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE fs;*/\ -.pushsection .fixup,"ax"; \ -4: movl $0,(%esp); \ - jmp 1b; \ -5: movl $0,(%esp); \ - jmp 2b; \ -6: movl $0,(%esp); \ - jmp 3b; \ -.section __ex_table,"a";\ - .align 4; \ - .long 1b,4b; \ - .long 2b,5b; \ - .long 3b,6b; \ +.macro RESTORE_REGS pop=0 + RESTORE_INT_REGS +1: popl %ds + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE ds;*/ +2: popl %es + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE es;*/ +3: popl %fs + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE fs;*/ + POP_GS \pop +.pushsection .fixup, "ax" +4: movl $0, (%esp) + jmp 1b +5: movl $0, (%esp) + jmp 2b +6: movl $0, (%esp) + jmp 3b +.section __ex_table, "a" + .align 4 + .long 1b, 4b + .long 2b, 5b + .long 3b, 6b .popsection + POP_GS_EX +.endm -#define RING0_INT_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, 3*4;\ - /*CFI_OFFSET cs, -2*4;*/\ +.macro RING0_INT_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, 3*4 + /*CFI_OFFSET cs, -2*4;*/ CFI_OFFSET eip, -3*4 +.endm -#define RING0_EC_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, 4*4;\ - /*CFI_OFFSET cs, -2*4;*/\ +.macro RING0_EC_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, 4*4 + /*CFI_OFFSET cs, -2*4;*/ CFI_OFFSET eip, -3*4 +.endm -#define RING0_PTREGS_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\ - /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\ - CFI_OFFSET eip, PT_EIP-PT_OLDESP;\ - /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\ - /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\ - CFI_OFFSET eax, PT_EAX-PT_OLDESP;\ - CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\ - CFI_OFFSET edi, PT_EDI-PT_OLDESP;\ - CFI_OFFSET esi, PT_ESI-PT_OLDESP;\ - CFI_OFFSET edx, PT_EDX-PT_OLDESP;\ - CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\ +.macro RING0_PTREGS_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, PT_OLDESP-PT_EBX + /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/ + CFI_OFFSET eip, PT_EIP-PT_OLDESP + /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/ + /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/ + CFI_OFFSET eax, PT_EAX-PT_OLDESP + CFI_OFFSET ebp, PT_EBP-PT_OLDESP + CFI_OFFSET edi, PT_EDI-PT_OLDESP + CFI_OFFSET esi, PT_ESI-PT_OLDESP + CFI_OFFSET edx, PT_EDX-PT_OLDESP + CFI_OFFSET ecx, PT_ECX-PT_OLDESP CFI_OFFSET ebx, PT_EBX-PT_OLDESP +.endm ENTRY(ret_from_fork) CFI_STARTPROC @@ -362,6 +463,7 @@ sysenter_exit: xorl %ebp,%ebp TRACE_IRQS_ON 1: mov PT_FS(%esp), %fs + PTGS_TO_GS ENABLE_INTERRUPTS_SYSEXIT #ifdef CONFIG_AUDITSYSCALL @@ -410,6 +512,7 @@ sysexit_audit: .align 4 .long 1b,2b .popsection + PTGS_TO_GS_EX ENDPROC(ia32_sysenter_target) # system call handler stub @@ -452,8 +555,7 @@ restore_all: restore_nocheck: TRACE_IRQS_IRET restore_nocheck_notrace: - RESTORE_REGS - addl $4, %esp # skip orig_eax/error_code + RESTORE_REGS 4 # skip orig_eax/error_code CFI_ADJUST_CFA_OFFSET -4 irq_return: INTERRUPT_RETURN @@ -595,28 +697,50 @@ syscall_badsys: END(syscall_badsys) CFI_ENDPROC -#define FIXUP_ESPFIX_STACK \ - /* since we are on a wrong stack, we cant make it a C code :( */ \ - PER_CPU(gdt_page, %ebx); \ - GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \ - addl %esp, %eax; \ - pushl $__KERNEL_DS; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl %eax; \ - CFI_ADJUST_CFA_OFFSET 4; \ - lss (%esp), %esp; \ - CFI_ADJUST_CFA_OFFSET -8; -#define UNWIND_ESPFIX_STACK \ - movl %ss, %eax; \ - /* see if on espfix stack */ \ - cmpw $__ESPFIX_SS, %ax; \ - jne 27f; \ - movl $__KERNEL_DS, %eax; \ - movl %eax, %ds; \ - movl %eax, %es; \ - /* switch to normal stack */ \ - FIXUP_ESPFIX_STACK; \ -27:; +/* + * System calls that need a pt_regs pointer. + */ +#define PTREGSCALL(name) \ + ALIGN; \ +ptregs_##name: \ + leal 4(%esp),%eax; \ + jmp sys_##name; + +PTREGSCALL(iopl) +PTREGSCALL(fork) +PTREGSCALL(clone) +PTREGSCALL(vfork) +PTREGSCALL(execve) +PTREGSCALL(sigaltstack) +PTREGSCALL(sigreturn) +PTREGSCALL(rt_sigreturn) +PTREGSCALL(vm86) +PTREGSCALL(vm86old) + +.macro FIXUP_ESPFIX_STACK + /* since we are on a wrong stack, we cant make it a C code :( */ + PER_CPU(gdt_page, %ebx) + GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah) + addl %esp, %eax + pushl $__KERNEL_DS + CFI_ADJUST_CFA_OFFSET 4 + pushl %eax + CFI_ADJUST_CFA_OFFSET 4 + lss (%esp), %esp + CFI_ADJUST_CFA_OFFSET -8 +.endm +.macro UNWIND_ESPFIX_STACK + movl %ss, %eax + /* see if on espfix stack */ + cmpw $__ESPFIX_SS, %ax + jne 27f + movl $__KERNEL_DS, %eax + movl %eax, %ds + movl %eax, %es + /* switch to normal stack */ + FIXUP_ESPFIX_STACK +27: +.endm /* * Build the entry stubs and pointer table with some assembler magic. @@ -672,7 +796,7 @@ common_interrupt: ENDPROC(common_interrupt) CFI_ENDPROC -#define BUILD_INTERRUPT(name, nr) \ +#define BUILD_INTERRUPT3(name, nr, fn) \ ENTRY(name) \ RING0_INT_FRAME; \ pushl $~(nr); \ @@ -680,13 +804,15 @@ ENTRY(name) \ SAVE_ALL; \ TRACE_IRQS_OFF \ movl %esp,%eax; \ - call smp_##name; \ + call fn; \ jmp ret_from_intr; \ CFI_ENDPROC; \ ENDPROC(name) +#define BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(name, nr, smp_##name) + /* The include is where all of the SMP etc. interrupts come from */ -#include "entry_arch.h" +#include <asm/entry_arch.h> ENTRY(coprocessor_error) RING0_INT_FRAME @@ -1068,7 +1194,10 @@ ENTRY(page_fault) CFI_ADJUST_CFA_OFFSET 4 ALIGN error_code: - /* the function address is in %fs's slot on the stack */ + /* the function address is in %gs's slot on the stack */ + pushl %fs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET fs, 0*/ pushl %es CFI_ADJUST_CFA_OFFSET 4 /*CFI_REL_OFFSET es, 0*/ @@ -1097,20 +1226,15 @@ error_code: CFI_ADJUST_CFA_OFFSET 4 CFI_REL_OFFSET ebx, 0 cld - pushl %fs - CFI_ADJUST_CFA_OFFSET 4 - /*CFI_REL_OFFSET fs, 0*/ movl $(__KERNEL_PERCPU), %ecx movl %ecx, %fs UNWIND_ESPFIX_STACK - popl %ecx - CFI_ADJUST_CFA_OFFSET -4 - /*CFI_REGISTER es, ecx*/ - movl PT_FS(%esp), %edi # get the function address + GS_TO_REG %ecx + movl PT_GS(%esp), %edi # get the function address movl PT_ORIG_EAX(%esp), %edx # get the error code movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart - mov %ecx, PT_FS(%esp) - /*CFI_REL_OFFSET fs, ES*/ + REG_TO_PTGS %ecx + SET_KERNEL_GS %ecx movl $(__USER_DS), %ecx movl %ecx, %ds movl %ecx, %es @@ -1134,26 +1258,27 @@ END(page_fault) * by hand onto the new stack - while updating the return eip past * the instruction that would have done it for sysenter. */ -#define FIX_STACK(offset, ok, label) \ - cmpw $__KERNEL_CS,4(%esp); \ - jne ok; \ -label: \ - movl TSS_sysenter_sp0+offset(%esp),%esp; \ - CFI_DEF_CFA esp, 0; \ - CFI_UNDEFINED eip; \ - pushfl; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl $__KERNEL_CS; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl $sysenter_past_esp; \ - CFI_ADJUST_CFA_OFFSET 4; \ +.macro FIX_STACK offset ok label + cmpw $__KERNEL_CS, 4(%esp) + jne \ok +\label: + movl TSS_sysenter_sp0 + \offset(%esp), %esp + CFI_DEF_CFA esp, 0 + CFI_UNDEFINED eip + pushfl + CFI_ADJUST_CFA_OFFSET 4 + pushl $__KERNEL_CS + CFI_ADJUST_CFA_OFFSET 4 + pushl $sysenter_past_esp + CFI_ADJUST_CFA_OFFSET 4 CFI_REL_OFFSET eip, 0 +.endm ENTRY(debug) RING0_INT_FRAME cmpl $ia32_sysenter_target,(%esp) jne debug_stack_correct - FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn) + FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn debug_stack_correct: pushl $-1 # mark this as an int CFI_ADJUST_CFA_OFFSET 4 @@ -1211,7 +1336,7 @@ nmi_stack_correct: nmi_stack_fixup: RING0_INT_FRAME - FIX_STACK(12,nmi_stack_correct, 1) + FIX_STACK 12, nmi_stack_correct, 1 jmp nmi_stack_correct nmi_debug_stack_check: @@ -1222,7 +1347,7 @@ nmi_debug_stack_check: jb nmi_stack_correct cmpl $debug_esp_fix_insn,(%esp) ja nmi_stack_correct - FIX_STACK(24,nmi_stack_correct, 1) + FIX_STACK 24, nmi_stack_correct, 1 jmp nmi_stack_correct nmi_espfix_stack: @@ -1234,7 +1359,7 @@ nmi_espfix_stack: CFI_ADJUST_CFA_OFFSET 4 pushl %esp CFI_ADJUST_CFA_OFFSET 4 - addw $4, (%esp) + addl $4, (%esp) /* copy the iret frame of 12 bytes */ .rept 3 pushl 16(%esp) |