diff options
Diffstat (limited to 'arch/x86/ia32/ia32entry.S')
| -rw-r--r-- | arch/x86/ia32/ia32entry.S | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S new file mode 100644 index 00000000..e3e73400 --- /dev/null +++ b/arch/x86/ia32/ia32entry.S @@ -0,0 +1,493 @@ +/* + * Compatibility mode system call entry point for x86-64. + * + * Copyright 2000-2002 Andi Kleen, SuSE Labs. + */ + +#include <asm/dwarf2.h> +#include <asm/calling.h> +#include <asm/asm-offsets.h> +#include <asm/current.h> +#include <asm/errno.h> +#include <asm/ia32_unistd.h> +#include <asm/thread_info.h> +#include <asm/segment.h> +#include <asm/irqflags.h> +#include <linux/linkage.h> +#include <linux/err.h> + +/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ +#include <linux/elf-em.h> +#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE) +#define __AUDIT_ARCH_LE 0x40000000 + +#ifndef CONFIG_AUDITSYSCALL +#define sysexit_audit ia32_ret_from_sys_call +#define sysretl_audit ia32_ret_from_sys_call +#endif + + .section .entry.text, "ax" + + .macro IA32_ARG_FIXUP noebp=0 + movl %edi,%r8d + .if \noebp + .else + movl %ebp,%r9d + .endif + xchg %ecx,%esi + movl %ebx,%edi + movl %edx,%edx /* zero extension */ + .endm + + /* clobbers %eax */ + .macro CLEAR_RREGS offset=0, _r9=rax + xorl %eax,%eax + movq %rax,\offset+R11(%rsp) + movq %rax,\offset+R10(%rsp) + movq %\_r9,\offset+R9(%rsp) + movq %rax,\offset+R8(%rsp) + .endm + + /* + * Reload arg registers from stack in case ptrace changed them. + * We don't reload %eax because syscall_trace_enter() returned + * the %rax value we should see. Instead, we just truncate that + * value to 32 bits again as we did on entry from user mode. + * If it's a new value set by user_regset during entry tracing, + * this matches the normal truncation of the user-mode value. + * If it's -1 to make us punt the syscall, then (u32)-1 is still + * an appropriately invalid value. + */ + .macro LOAD_ARGS32 offset, _r9=0 + .if \_r9 + movl \offset+16(%rsp),%r9d + .endif + movl \offset+40(%rsp),%ecx + movl \offset+48(%rsp),%edx + movl \offset+56(%rsp),%esi + movl \offset+64(%rsp),%edi + movl %eax,%eax /* zero extension */ + .endm + + .macro CFI_STARTPROC32 simple + CFI_STARTPROC \simple + CFI_UNDEFINED r8 + CFI_UNDEFINED r9 + CFI_UNDEFINED r10 + CFI_UNDEFINED r11 + CFI_UNDEFINED r12 + CFI_UNDEFINED r13 + CFI_UNDEFINED r14 + CFI_UNDEFINED r15 + .endm + +#ifdef CONFIG_PARAVIRT +ENTRY(native_usergs_sysret32) + swapgs + sysretl +ENDPROC(native_usergs_sysret32) + +ENTRY(native_irq_enable_sysexit) + swapgs + sti + sysexit +ENDPROC(native_irq_enable_sysexit) +#endif + +/* + * 32bit SYSENTER instruction entry. + * + * Arguments: + * %eax System call number. + * %ebx Arg1 + * %ecx Arg2 + * %edx Arg3 + * %esi Arg4 + * %edi Arg5 + * %ebp user stack + * 0(%ebp) Arg6 + * + * Interrupts off. + * + * This is purely a fast path. For anything complicated we use the int 0x80 + * path below. Set up a complete hardware stack frame to share code + * with the int 0x80 path. + */ +ENTRY(ia32_sysenter_target) + CFI_STARTPROC32 simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA rsp,0 + CFI_REGISTER rsp,rbp + SWAPGS_UNSAFE_STACK + movq PER_CPU_VAR(kernel_stack), %rsp + addq $(KERNEL_STACK_OFFSET),%rsp + /* + * No need to follow this irqs on/off section: the syscall + * disabled irqs, here we enable it straight after entry: + */ + ENABLE_INTERRUPTS(CLBR_NONE) + movl %ebp,%ebp /* zero extension */ + pushq_cfi $__USER32_DS + /*CFI_REL_OFFSET ss,0*/ + pushq_cfi %rbp + CFI_REL_OFFSET rsp,0 + pushfq_cfi + /*CFI_REL_OFFSET rflags,0*/ + movl TI_sysenter_return+THREAD_INFO(%rsp,3*8-KERNEL_STACK_OFFSET),%r10d + CFI_REGISTER rip,r10 + pushq_cfi $__USER32_CS + /*CFI_REL_OFFSET cs,0*/ + movl %eax, %eax + pushq_cfi %r10 + CFI_REL_OFFSET rip,0 + pushq_cfi %rax + cld + SAVE_ARGS 0,1,0 + /* no need to do an access_ok check here because rbp has been + 32bit zero extended */ +1: movl (%rbp),%ebp + .section __ex_table,"a" + .quad 1b,ia32_badarg + .previous + orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + CFI_REMEMBER_STATE + jnz sysenter_tracesys + cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys +sysenter_do_call: + IA32_ARG_FIXUP +sysenter_dispatch: + call *ia32_sys_call_table(,%rax,8) + movq %rax,RAX-ARGOFFSET(%rsp) + DISABLE_INTERRUPTS(CLBR_NONE) + TRACE_IRQS_OFF + testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jnz sysexit_audit +sysexit_from_sys_call: + andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) + /* clear IF, that popfq doesn't enable interrupts early */ + andl $~0x200,EFLAGS-R11(%rsp) + movl RIP-R11(%rsp),%edx /* User %eip */ + CFI_REGISTER rip,rdx + RESTORE_ARGS 0,24,0,0,0,0 + xorq %r8,%r8 + xorq %r9,%r9 + xorq %r10,%r10 + xorq %r11,%r11 + popfq_cfi + /*CFI_RESTORE rflags*/ + popq_cfi %rcx /* User %esp */ + CFI_REGISTER rsp,rcx + TRACE_IRQS_ON + ENABLE_INTERRUPTS_SYSEXIT32 + +#ifdef CONFIG_AUDITSYSCALL + .macro auditsys_entry_common + movl %esi,%r9d /* 6th arg: 4th syscall arg */ + movl %edx,%r8d /* 5th arg: 3rd syscall arg */ + /* (already in %ecx) 4th arg: 2nd syscall arg */ + movl %ebx,%edx /* 3rd arg: 1st syscall arg */ + movl %eax,%esi /* 2nd arg: syscall number */ + movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */ + call __audit_syscall_entry + movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */ + cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys + movl %ebx,%edi /* reload 1st syscall arg */ + movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */ + movl RDX-ARGOFFSET(%rsp),%edx /* reload 3rd syscall arg */ + movl RSI-ARGOFFSET(%rsp),%ecx /* reload 4th syscall arg */ + movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th syscall arg */ + .endm + + .macro auditsys_exit exit + testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jnz ia32_ret_from_sys_call + TRACE_IRQS_ON + sti + movl %eax,%esi /* second arg, syscall return value */ + cmpl $-MAX_ERRNO,%eax /* is it an error ? */ + jbe 1f + movslq %eax, %rsi /* if error sign extend to 64 bits */ +1: setbe %al /* 1 if error, 0 if not */ + movzbl %al,%edi /* zero-extend that into %edi */ + call __audit_syscall_exit + movq RAX-ARGOFFSET(%rsp),%rax /* reload syscall return value */ + movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi + cli + TRACE_IRQS_OFF + testl %edi,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jz \exit + CLEAR_RREGS -ARGOFFSET + jmp int_with_check + .endm + +sysenter_auditsys: + CFI_RESTORE_STATE + auditsys_entry_common + movl %ebp,%r9d /* reload 6th syscall arg */ + jmp sysenter_dispatch + +sysexit_audit: + auditsys_exit sysexit_from_sys_call +#endif + +sysenter_tracesys: +#ifdef CONFIG_AUDITSYSCALL + testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jz sysenter_auditsys +#endif + SAVE_REST + CLEAR_RREGS + movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */ + movq %rsp,%rdi /* &pt_regs -> arg1 */ + call syscall_trace_enter + LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ + RESTORE_REST + cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */ + jmp sysenter_do_call + CFI_ENDPROC +ENDPROC(ia32_sysenter_target) + +/* + * 32bit SYSCALL instruction entry. + * + * Arguments: + * %eax System call number. + * %ebx Arg1 + * %ecx return EIP + * %edx Arg3 + * %esi Arg4 + * %edi Arg5 + * %ebp Arg2 [note: not saved in the stack frame, should not be touched] + * %esp user stack + * 0(%esp) Arg6 + * + * Interrupts off. + * + * This is purely a fast path. For anything complicated we use the int 0x80 + * path below. Set up a complete hardware stack frame to share code + * with the int 0x80 path. + */ +ENTRY(ia32_cstar_target) + CFI_STARTPROC32 simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET + CFI_REGISTER rip,rcx + /*CFI_REGISTER rflags,r11*/ + SWAPGS_UNSAFE_STACK + movl %esp,%r8d + CFI_REGISTER rsp,r8 + movq PER_CPU_VAR(kernel_stack),%rsp + /* + * No need to follow this irqs on/off section: the syscall + * disabled irqs and here we enable it straight after entry: + */ + ENABLE_INTERRUPTS(CLBR_NONE) + SAVE_ARGS 8,0,0 + movl %eax,%eax /* zero extension */ + movq %rax,ORIG_RAX-ARGOFFSET(%rsp) + movq %rcx,RIP-ARGOFFSET(%rsp) + CFI_REL_OFFSET rip,RIP-ARGOFFSET + movq %rbp,RCX-ARGOFFSET(%rsp) /* this lies slightly to ptrace */ + movl %ebp,%ecx + movq $__USER32_CS,CS-ARGOFFSET(%rsp) + movq $__USER32_DS,SS-ARGOFFSET(%rsp) + movq %r11,EFLAGS-ARGOFFSET(%rsp) + /*CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/ + movq %r8,RSP-ARGOFFSET(%rsp) + CFI_REL_OFFSET rsp,RSP-ARGOFFSET + /* no need to do an access_ok check here because r8 has been + 32bit zero extended */ + /* hardware stack frame is complete now */ +1: movl (%r8),%r9d + .section __ex_table,"a" + .quad 1b,ia32_badarg + .previous + orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + CFI_REMEMBER_STATE + jnz cstar_tracesys + cmpq $IA32_NR_syscalls-1,%rax + ja ia32_badsys +cstar_do_call: + IA32_ARG_FIXUP 1 +cstar_dispatch: + call *ia32_sys_call_table(,%rax,8) + movq %rax,RAX-ARGOFFSET(%rsp) + DISABLE_INTERRUPTS(CLBR_NONE) + TRACE_IRQS_OFF + testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jnz sysretl_audit +sysretl_from_sys_call: + andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) + RESTORE_ARGS 0,-ARG_SKIP,0,0,0 + movl RIP-ARGOFFSET(%rsp),%ecx + CFI_REGISTER rip,rcx + movl EFLAGS-ARGOFFSET(%rsp),%r11d + /*CFI_REGISTER rflags,r11*/ + xorq %r10,%r10 + xorq %r9,%r9 + xorq %r8,%r8 + TRACE_IRQS_ON + movl RSP-ARGOFFSET(%rsp),%esp + CFI_RESTORE rsp + USERGS_SYSRET32 + +#ifdef CONFIG_AUDITSYSCALL +cstar_auditsys: + CFI_RESTORE_STATE + movl %r9d,R9-ARGOFFSET(%rsp) /* register to be clobbered by call */ + auditsys_entry_common + movl R9-ARGOFFSET(%rsp),%r9d /* reload 6th syscall arg */ + jmp cstar_dispatch + +sysretl_audit: + auditsys_exit sysretl_from_sys_call +#endif + +cstar_tracesys: +#ifdef CONFIG_AUDITSYSCALL + testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jz cstar_auditsys +#endif + xchgl %r9d,%ebp + SAVE_REST + CLEAR_RREGS 0, r9 + movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ + movq %rsp,%rdi /* &pt_regs -> arg1 */ + call syscall_trace_enter + LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */ + RESTORE_REST + xchgl %ebp,%r9d + cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */ + jmp cstar_do_call +END(ia32_cstar_target) + +ia32_badarg: + movq $-EFAULT,%rax + jmp ia32_sysret + CFI_ENDPROC + +/* + * Emulated IA32 system calls via int 0x80. + * + * Arguments: + * %eax System call number. + * %ebx Arg1 + * %ecx Arg2 + * %edx Arg3 + * %esi Arg4 + * %edi Arg5 + * %ebp Arg6 [note: not saved in the stack frame, should not be touched] + * + * Notes: + * Uses the same stack frame as the x86-64 version. + * All registers except %eax must be saved (but ptrace may violate that) + * Arguments are zero extended. For system calls that want sign extension and + * take long arguments a wrapper is needed. Most calls can just be called + * directly. + * Assumes it is only called from user space and entered with interrupts off. + */ + +ENTRY(ia32_syscall) + CFI_STARTPROC32 simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA rsp,SS+8-RIP + /*CFI_REL_OFFSET ss,SS-RIP*/ + CFI_REL_OFFSET rsp,RSP-RIP + /*CFI_REL_OFFSET rflags,EFLAGS-RIP*/ + /*CFI_REL_OFFSET cs,CS-RIP*/ + CFI_REL_OFFSET rip,RIP-RIP + PARAVIRT_ADJUST_EXCEPTION_FRAME + SWAPGS + /* + * No need to follow this irqs on/off section: the syscall + * disabled irqs and here we enable it straight after entry: + */ + ENABLE_INTERRUPTS(CLBR_NONE) + movl %eax,%eax + pushq_cfi %rax + cld + /* note the registers are not zero extended to the sf. + this could be a problem. */ + SAVE_ARGS 0,1,0 + orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) + jnz ia32_tracesys + cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys +ia32_do_call: + IA32_ARG_FIXUP + call *ia32_sys_call_table(,%rax,8) # xxx: rip relative +ia32_sysret: + movq %rax,RAX-ARGOFFSET(%rsp) +ia32_ret_from_sys_call: + CLEAR_RREGS -ARGOFFSET + jmp int_ret_from_sys_call + +ia32_tracesys: + SAVE_REST + CLEAR_RREGS + movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ + movq %rsp,%rdi /* &pt_regs -> arg1 */ + call syscall_trace_enter + LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ + RESTORE_REST + cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */ + jmp ia32_do_call +END(ia32_syscall) + +ia32_badsys: + movq $0,ORIG_RAX-ARGOFFSET(%rsp) + movq $-ENOSYS,%rax + jmp ia32_sysret + + CFI_ENDPROC + + .macro PTREGSCALL label, func, arg + ALIGN +GLOBAL(\label) + leaq \func(%rip),%rax + leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */ + jmp ia32_ptregs_common + .endm + + CFI_STARTPROC32 + + PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi + PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi + PTREGSCALL stub32_sigaltstack, sys32_sigaltstack, %rdx + PTREGSCALL stub32_execve, sys32_execve, %rcx + PTREGSCALL stub32_fork, sys_fork, %rdi + PTREGSCALL stub32_clone, sys32_clone, %rdx + PTREGSCALL stub32_vfork, sys_vfork, %rdi + PTREGSCALL stub32_iopl, sys_iopl, %rsi + + ALIGN +ia32_ptregs_common: + popq %r11 + CFI_ENDPROC + CFI_STARTPROC32 simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA rsp,SS+8-ARGOFFSET + CFI_REL_OFFSET rax,RAX-ARGOFFSET + CFI_REL_OFFSET rcx,RCX-ARGOFFSET + CFI_REL_OFFSET rdx,RDX-ARGOFFSET + CFI_REL_OFFSET rsi,RSI-ARGOFFSET + CFI_REL_OFFSET rdi,RDI-ARGOFFSET + CFI_REL_OFFSET rip,RIP-ARGOFFSET +/* CFI_REL_OFFSET cs,CS-ARGOFFSET*/ +/* CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/ + CFI_REL_OFFSET rsp,RSP-ARGOFFSET +/* CFI_REL_OFFSET ss,SS-ARGOFFSET*/ + SAVE_REST + call *%rax + RESTORE_REST + jmp ia32_sysret /* misbalances the return cache */ + CFI_ENDPROC +END(ia32_ptregs_common) |