/* * Compatibility mode system call entry point for x86-64. * * Copyright 2000-2002 Andi Kleen, SuSE Labs. */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* Avoid __ASSEMBLER__'ifying just for this. */ #include #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 */ ASM_STAC 1: movl (%rbp),%ebp _ASM_EXTABLE(1b,ia32_badarg) ASM_CLAC /* * Sysenter doesn't filter flags, so we need to clear NT * ourselves. To save a few cycles, we can check whether * NT was set instead of doing an unconditional popfq. */ testl $X86_EFLAGS_NT,EFLAGS-ARGOFFSET(%rsp) jnz sysenter_fix_flags sysenter_flags_fixed: 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 CFI_RESTORE_STATE #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 ENABLE_INTERRUPTS(CLBR_NONE) 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 DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF testl %edi,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET) jz \exit CLEAR_RREGS -ARGOFFSET jmp int_with_check .endm sysenter_auditsys: auditsys_entry_common movl %ebp,%r9d /* reload 6th syscall arg */ jmp sysenter_dispatch sysexit_audit: auditsys_exit sysexit_from_sys_call #endif sysenter_fix_flags: pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED) popfq_cfi jmp sysenter_flags_fixed 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 */ ASM_STAC 1: movl (%r8),%r9d _ASM_EXTABLE(1b,ia32_badarg) ASM_CLAC 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: ASM_CLAC 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 ALIGN GLOBAL(\label) leaq \func(%rip),%rax jmp ia32_ptregs_common .endm CFI_STARTPROC32 PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn PTREGSCALL stub32_sigreturn, sys32_sigreturn PTREGSCALL stub32_execve, compat_sys_execve PTREGSCALL stub32_fork, sys_fork PTREGSCALL stub32_vfork, sys_vfork ALIGN GLOBAL(stub32_clone) leaq sys_clone(%rip),%rax mov %r8, %rcx jmp ia32_ptregs_common 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)