2 * Compatibility mode system call entry point for x86-64.
4 * Copyright 2000-2002 Andi Kleen, SuSE Labs.
7 #include <asm/dwarf2.h>
8 #include <asm/calling.h>
9 #include <asm/asm-offsets.h>
10 #include <asm/current.h>
11 #include <asm/errno.h>
12 #include <asm/ia32_unistd.h>
13 #include <asm/thread_info.h>
14 #include <asm/segment.h>
15 #include <asm/irqflags.h>
16 #include <linux/linkage.h>
18 /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
19 #include <linux/elf-em.h>
20 #define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
21 #define __AUDIT_ARCH_LE 0x40000000
23 #ifndef CONFIG_AUDITSYSCALL
24 #define sysexit_audit int_ret_from_sys_call
25 #define sysretl_audit int_ret_from_sys_call
28 #define IA32_NR_syscalls ((ia32_syscall_end - ia32_sys_call_table)/8)
30 .macro IA32_ARG_FIXUP noebp=0
38 movl %edx,%edx /* zero extension */
42 .macro CLEAR_RREGS _r9=rax
51 * Reload arg registers from stack in case ptrace changed them.
52 * We don't reload %eax because syscall_trace_enter() returned
53 * the value it wants us to use in the table lookup.
55 .macro LOAD_ARGS32 offset, _r9=0
57 movl \offset+16(%rsp),%r9d
59 movl \offset+40(%rsp),%ecx
60 movl \offset+48(%rsp),%edx
61 movl \offset+56(%rsp),%esi
62 movl \offset+64(%rsp),%edi
65 .macro CFI_STARTPROC32 simple
77 #ifdef CONFIG_PARAVIRT
78 ENTRY(native_usergs_sysret32)
81 ENDPROC(native_usergs_sysret32)
83 ENTRY(native_irq_enable_sysexit)
87 ENDPROC(native_irq_enable_sysexit)
91 * 32bit SYSENTER instruction entry.
94 * %eax System call number.
105 * This is purely a fast path. For anything complicated we use the int 0x80
106 * path below. Set up a complete hardware stack frame to share code
107 * with the int 0x80 path.
109 ENTRY(ia32_sysenter_target)
110 CFI_STARTPROC32 simple
115 movq PER_CPU_VAR(kernel_stack), %rsp
116 addq $(KERNEL_STACK_OFFSET),%rsp
118 * No need to follow this irqs on/off section: the syscall
119 * disabled irqs, here we enable it straight after entry:
121 ENABLE_INTERRUPTS(CLBR_NONE)
122 movl %ebp,%ebp /* zero extension */
124 CFI_ADJUST_CFA_OFFSET 8
125 /*CFI_REL_OFFSET ss,0*/
127 CFI_ADJUST_CFA_OFFSET 8
130 CFI_ADJUST_CFA_OFFSET 8
131 /*CFI_REL_OFFSET rflags,0*/
132 movl 8*3-THREAD_SIZE+TI_sysenter_return(%rsp), %r10d
135 CFI_ADJUST_CFA_OFFSET 8
136 /*CFI_REL_OFFSET cs,0*/
139 CFI_ADJUST_CFA_OFFSET 8
142 CFI_ADJUST_CFA_OFFSET 8
145 /* no need to do an access_ok check here because rbp has been
146 32bit zero extended */
148 .section __ex_table,"a"
151 GET_THREAD_INFO(%r10)
152 orl $TS_COMPAT,TI_status(%r10)
153 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
155 jnz sysenter_tracesys
156 cmpl $(IA32_NR_syscalls-1),%eax
161 call *ia32_sys_call_table(,%rax,8)
162 movq %rax,RAX-ARGOFFSET(%rsp)
163 GET_THREAD_INFO(%r10)
164 DISABLE_INTERRUPTS(CLBR_NONE)
166 testl $_TIF_ALLWORK_MASK,TI_flags(%r10)
168 sysexit_from_sys_call:
169 andl $~TS_COMPAT,TI_status(%r10)
170 /* clear IF, that popfq doesn't enable interrupts early */
171 andl $~0x200,EFLAGS-R11(%rsp)
172 movl RIP-R11(%rsp),%edx /* User %eip */
174 RESTORE_ARGS 1,24,1,1,1,1
176 CFI_ADJUST_CFA_OFFSET -8
177 /*CFI_RESTORE rflags*/
178 popq %rcx /* User %esp */
179 CFI_ADJUST_CFA_OFFSET -8
182 ENABLE_INTERRUPTS_SYSEXIT32
184 #ifdef CONFIG_AUDITSYSCALL
185 .macro auditsys_entry_common
186 movl %esi,%r9d /* 6th arg: 4th syscall arg */
187 movl %edx,%r8d /* 5th arg: 3rd syscall arg */
188 /* (already in %ecx) 4th arg: 2nd syscall arg */
189 movl %ebx,%edx /* 3rd arg: 1st syscall arg */
190 movl %eax,%esi /* 2nd arg: syscall number */
191 movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */
192 call audit_syscall_entry
193 movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */
194 cmpl $(IA32_NR_syscalls-1),%eax
196 movl %ebx,%edi /* reload 1st syscall arg */
197 movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */
198 movl RDX-ARGOFFSET(%rsp),%edx /* reload 3rd syscall arg */
199 movl RSI-ARGOFFSET(%rsp),%ecx /* reload 4th syscall arg */
200 movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th syscall arg */
203 .macro auditsys_exit exit,ebpsave=RBP
204 testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
205 jnz int_ret_from_sys_call
208 movl %eax,%esi /* second arg, syscall return value */
209 cmpl $0,%eax /* is it < 0? */
210 setl %al /* 1 if so, 0 if not */
211 movzbl %al,%edi /* zero-extend that into %edi */
212 inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
213 call audit_syscall_exit
214 GET_THREAD_INFO(%r10)
215 movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall return value */
216 movl \ebpsave-ARGOFFSET(%rsp),%ebp /* reload user register value */
217 movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
220 testl %edi,TI_flags(%r10)
227 auditsys_entry_common
228 movl %ebp,%r9d /* reload 6th syscall arg */
229 jmp sysenter_dispatch
232 auditsys_exit sysexit_from_sys_call
236 #ifdef CONFIG_AUDITSYSCALL
237 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
242 movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
243 movq %rsp,%rdi /* &pt_regs -> arg1 */
244 call syscall_trace_enter
245 LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
247 cmpl $(IA32_NR_syscalls-1),%eax
248 ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
251 ENDPROC(ia32_sysenter_target)
254 * 32bit SYSCALL instruction entry.
257 * %eax System call number.
263 * %ebp Arg2 [note: not saved in the stack frame, should not be touched]
269 * This is purely a fast path. For anything complicated we use the int 0x80
270 * path below. Set up a complete hardware stack frame to share code
271 * with the int 0x80 path.
273 ENTRY(ia32_cstar_target)
274 CFI_STARTPROC32 simple
276 CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
278 /*CFI_REGISTER rflags,r11*/
282 movq PER_CPU_VAR(kernel_stack),%rsp
284 * No need to follow this irqs on/off section: the syscall
285 * disabled irqs and here we enable it straight after entry:
287 ENABLE_INTERRUPTS(CLBR_NONE)
289 movl %eax,%eax /* zero extension */
290 movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
291 movq %rcx,RIP-ARGOFFSET(%rsp)
292 CFI_REL_OFFSET rip,RIP-ARGOFFSET
293 movq %rbp,RCX-ARGOFFSET(%rsp) /* this lies slightly to ptrace */
295 movq $__USER32_CS,CS-ARGOFFSET(%rsp)
296 movq $__USER32_DS,SS-ARGOFFSET(%rsp)
297 movq %r11,EFLAGS-ARGOFFSET(%rsp)
298 /*CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
299 movq %r8,RSP-ARGOFFSET(%rsp)
300 CFI_REL_OFFSET rsp,RSP-ARGOFFSET
301 /* no need to do an access_ok check here because r8 has been
302 32bit zero extended */
303 /* hardware stack frame is complete now */
305 .section __ex_table,"a"
308 GET_THREAD_INFO(%r10)
309 orl $TS_COMPAT,TI_status(%r10)
310 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
313 cmpl $IA32_NR_syscalls-1,%eax
318 call *ia32_sys_call_table(,%rax,8)
319 movq %rax,RAX-ARGOFFSET(%rsp)
320 GET_THREAD_INFO(%r10)
321 DISABLE_INTERRUPTS(CLBR_NONE)
323 testl $_TIF_ALLWORK_MASK,TI_flags(%r10)
325 sysretl_from_sys_call:
326 andl $~TS_COMPAT,TI_status(%r10)
327 RESTORE_ARGS 1,-ARG_SKIP,1,1,1
328 movl RIP-ARGOFFSET(%rsp),%ecx
330 movl EFLAGS-ARGOFFSET(%rsp),%r11d
331 /*CFI_REGISTER rflags,r11*/
333 movl RSP-ARGOFFSET(%rsp),%esp
337 #ifdef CONFIG_AUDITSYSCALL
340 movl %r9d,R9-ARGOFFSET(%rsp) /* register to be clobbered by call */
341 auditsys_entry_common
342 movl R9-ARGOFFSET(%rsp),%r9d /* reload 6th syscall arg */
346 auditsys_exit sysretl_from_sys_call, RCX /* user %ebp in RCX slot */
350 #ifdef CONFIG_AUDITSYSCALL
351 testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%r10)
357 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
358 movq %rsp,%rdi /* &pt_regs -> arg1 */
359 call syscall_trace_enter
360 LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */
363 cmpl $(IA32_NR_syscalls-1),%eax
364 ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
366 END(ia32_cstar_target)
374 * Emulated IA32 system calls via int 0x80.
377 * %eax System call number.
383 * %ebp Arg6 [note: not saved in the stack frame, should not be touched]
386 * Uses the same stack frame as the x86-64 version.
387 * All registers except %eax must be saved (but ptrace may violate that)
388 * Arguments are zero extended. For system calls that want sign extension and
389 * take long arguments a wrapper is needed. Most calls can just be called
391 * Assumes it is only called from user space and entered with interrupts off.
395 CFI_STARTPROC32 simple
397 CFI_DEF_CFA rsp,SS+8-RIP
398 /*CFI_REL_OFFSET ss,SS-RIP*/
399 CFI_REL_OFFSET rsp,RSP-RIP
400 /*CFI_REL_OFFSET rflags,EFLAGS-RIP*/
401 /*CFI_REL_OFFSET cs,CS-RIP*/
402 CFI_REL_OFFSET rip,RIP-RIP
403 PARAVIRT_ADJUST_EXCEPTION_FRAME
406 * No need to follow this irqs on/off section: the syscall
407 * disabled irqs and here we enable it straight after entry:
409 ENABLE_INTERRUPTS(CLBR_NONE)
412 CFI_ADJUST_CFA_OFFSET 8
414 /* note the registers are not zero extended to the sf.
415 this could be a problem. */
417 GET_THREAD_INFO(%r10)
418 orl $TS_COMPAT,TI_status(%r10)
419 testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10)
421 cmpl $(IA32_NR_syscalls-1),%eax
425 call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
427 movq %rax,RAX-ARGOFFSET(%rsp)
428 jmp int_ret_from_sys_call
433 movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
434 movq %rsp,%rdi /* &pt_regs -> arg1 */
435 call syscall_trace_enter
436 LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */
438 cmpl $(IA32_NR_syscalls-1),%eax
439 ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
444 movq $0,ORIG_RAX-ARGOFFSET(%rsp)
445 movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
446 jmp int_ret_from_sys_call
453 .macro PTREGSCALL label, func, arg
456 leaq \func(%rip),%rax
457 leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */
458 jmp ia32_ptregs_common
463 PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi
464 PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi
465 PTREGSCALL stub32_sigaltstack, sys32_sigaltstack, %rdx
466 PTREGSCALL stub32_execve, sys32_execve, %rcx
467 PTREGSCALL stub32_fork, sys_fork, %rdi
468 PTREGSCALL stub32_clone, sys32_clone, %rdx
469 PTREGSCALL stub32_vfork, sys_vfork, %rdi
470 PTREGSCALL stub32_iopl, sys_iopl, %rsi
472 ENTRY(ia32_ptregs_common)
475 CFI_STARTPROC32 simple
477 CFI_DEF_CFA rsp,SS+8-ARGOFFSET
478 CFI_REL_OFFSET rax,RAX-ARGOFFSET
479 CFI_REL_OFFSET rcx,RCX-ARGOFFSET
480 CFI_REL_OFFSET rdx,RDX-ARGOFFSET
481 CFI_REL_OFFSET rsi,RSI-ARGOFFSET
482 CFI_REL_OFFSET rdi,RDI-ARGOFFSET
483 CFI_REL_OFFSET rip,RIP-ARGOFFSET
484 /* CFI_REL_OFFSET cs,CS-ARGOFFSET*/
485 /* CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
486 CFI_REL_OFFSET rsp,RSP-ARGOFFSET
487 /* CFI_REL_OFFSET ss,SS-ARGOFFSET*/
491 jmp ia32_sysret /* misbalances the return cache */
493 END(ia32_ptregs_common)
498 .quad sys_restart_syscall
503 .quad compat_sys_open /* 5 */
508 .quad sys_unlink /* 10 */
511 .quad compat_sys_time
513 .quad sys_chmod /* 15 */
515 .quad quiet_ni_syscall /* old break syscall holder */
518 .quad sys_getpid /* 20 */
519 .quad compat_sys_mount /* mount */
520 .quad sys_oldumount /* old_umount */
523 .quad compat_sys_stime /* stime */ /* 25 */
524 .quad compat_sys_ptrace /* ptrace */
526 .quad sys_fstat /* (old)fstat */
528 .quad compat_sys_utime /* 30 */
529 .quad quiet_ni_syscall /* old stty syscall holder */
530 .quad quiet_ni_syscall /* old gtty syscall holder */
533 .quad quiet_ni_syscall /* 35 */ /* old ftime syscall holder */
538 .quad sys_rmdir /* 40 */
541 .quad compat_sys_times
542 .quad quiet_ni_syscall /* old prof syscall holder */
543 .quad sys_brk /* 45 */
548 .quad sys_getegid16 /* 50 */
550 .quad sys_umount /* new_umount */
551 .quad quiet_ni_syscall /* old lock syscall holder */
552 .quad compat_sys_ioctl
553 .quad compat_sys_fcntl64 /* 55 */
554 .quad quiet_ni_syscall /* old mpx syscall holder */
556 .quad quiet_ni_syscall /* old ulimit syscall holder */
558 .quad sys_umask /* 60 */
560 .quad compat_sys_ustat
563 .quad sys_getpgrp /* 65 */
565 .quad sys32_sigaction
568 .quad sys_setreuid16 /* 70 */
570 .quad sys32_sigsuspend
571 .quad compat_sys_sigpending
572 .quad sys_sethostname
573 .quad compat_sys_setrlimit /* 75 */
574 .quad compat_sys_old_getrlimit /* old_getrlimit */
575 .quad compat_sys_getrusage
576 .quad compat_sys_gettimeofday
577 .quad compat_sys_settimeofday
578 .quad sys_getgroups16 /* 80 */
579 .quad sys_setgroups16
580 .quad sys32_old_select
583 .quad sys_readlink /* 85 */
587 .quad compat_sys_old_readdir
588 .quad sys32_mmap /* 90 */
593 .quad sys_fchown16 /* 95 */
594 .quad sys_getpriority
595 .quad sys_setpriority
596 .quad quiet_ni_syscall /* old profil syscall holder */
597 .quad compat_sys_statfs
598 .quad compat_sys_fstatfs /* 100 */
600 .quad compat_sys_socketcall
602 .quad compat_sys_setitimer
603 .quad compat_sys_getitimer /* 105 */
604 .quad compat_sys_newstat
605 .quad compat_sys_newlstat
606 .quad compat_sys_newfstat
608 .quad stub32_iopl /* 110 */
610 .quad quiet_ni_syscall /* old "idle" system call */
611 .quad sys32_vm86_warning /* vm86old */
612 .quad compat_sys_wait4
613 .quad sys_swapoff /* 115 */
614 .quad compat_sys_sysinfo
617 .quad stub32_sigreturn
618 .quad stub32_clone /* 120 */
619 .quad sys_setdomainname
622 .quad compat_sys_adjtimex
623 .quad sys32_mprotect /* 125 */
624 .quad compat_sys_sigprocmask
625 .quad quiet_ni_syscall /* create_module */
626 .quad sys_init_module
627 .quad sys_delete_module
628 .quad quiet_ni_syscall /* 130 get_kernel_syms */
632 .quad quiet_ni_syscall /* bdflush */
633 .quad sys_sysfs /* 135 */
634 .quad sys_personality
635 .quad quiet_ni_syscall /* for afs_syscall */
638 .quad sys_llseek /* 140 */
639 .quad compat_sys_getdents
640 .quad compat_sys_select
643 .quad compat_sys_readv /* 145 */
644 .quad compat_sys_writev
647 .quad sys32_sysctl /* sysctl */
648 .quad sys_mlock /* 150 */
652 .quad sys_sched_setparam
653 .quad sys_sched_getparam /* 155 */
654 .quad sys_sched_setscheduler
655 .quad sys_sched_getscheduler
656 .quad sys_sched_yield
657 .quad sys_sched_get_priority_max
658 .quad sys_sched_get_priority_min /* 160 */
659 .quad sys32_sched_rr_get_interval
660 .quad compat_sys_nanosleep
662 .quad sys_setresuid16
663 .quad sys_getresuid16 /* 165 */
664 .quad sys32_vm86_warning /* vm86 */
665 .quad quiet_ni_syscall /* query_module */
667 .quad compat_sys_nfsservctl
668 .quad sys_setresgid16 /* 170 */
669 .quad sys_getresgid16
671 .quad stub32_rt_sigreturn
672 .quad sys32_rt_sigaction
673 .quad sys32_rt_sigprocmask /* 175 */
674 .quad sys32_rt_sigpending
675 .quad compat_sys_rt_sigtimedwait
676 .quad sys32_rt_sigqueueinfo
677 .quad sys_rt_sigsuspend
678 .quad sys32_pread /* 180 */
684 .quad stub32_sigaltstack
686 .quad quiet_ni_syscall /* streams1 */
687 .quad quiet_ni_syscall /* streams2 */
688 .quad stub32_vfork /* 190 */
689 .quad compat_sys_getrlimit
691 .quad sys32_truncate64
692 .quad sys32_ftruncate64
693 .quad sys32_stat64 /* 195 */
698 .quad sys_getgid /* 200 */
703 .quad sys_getgroups /* 205 */
708 .quad sys_setresgid /* 210 */
713 .quad sys_setfsuid /* 215 */
718 .quad compat_sys_getdents64 /* 220 getdents64 */
719 .quad compat_sys_fcntl64
720 .quad quiet_ni_syscall /* tux */
721 .quad quiet_ni_syscall /* security */
723 .quad sys32_readahead /* 225 */
728 .quad sys_lgetxattr /* 230 */
733 .quad sys_removexattr /* 235 */
734 .quad sys_lremovexattr
735 .quad sys_fremovexattr
738 .quad compat_sys_futex /* 240 */
739 .quad compat_sys_sched_setaffinity
740 .quad compat_sys_sched_getaffinity
741 .quad sys_set_thread_area
742 .quad sys_get_thread_area
743 .quad compat_sys_io_setup /* 245 */
745 .quad compat_sys_io_getevents
746 .quad compat_sys_io_submit
748 .quad sys32_fadvise64 /* 250 */
749 .quad quiet_ni_syscall /* free_huge_pages */
751 .quad sys32_lookup_dcookie
752 .quad sys_epoll_create
753 .quad sys_epoll_ctl /* 255 */
755 .quad sys_remap_file_pages
756 .quad sys_set_tid_address
757 .quad compat_sys_timer_create
758 .quad compat_sys_timer_settime /* 260 */
759 .quad compat_sys_timer_gettime
760 .quad sys_timer_getoverrun
761 .quad sys_timer_delete
762 .quad compat_sys_clock_settime
763 .quad compat_sys_clock_gettime /* 265 */
764 .quad compat_sys_clock_getres
765 .quad compat_sys_clock_nanosleep
766 .quad compat_sys_statfs64
767 .quad compat_sys_fstatfs64
768 .quad sys_tgkill /* 270 */
769 .quad compat_sys_utimes
770 .quad sys32_fadvise64_64
771 .quad quiet_ni_syscall /* sys_vserver */
773 .quad compat_sys_get_mempolicy /* 275 */
774 .quad sys_set_mempolicy
775 .quad compat_sys_mq_open
777 .quad compat_sys_mq_timedsend
778 .quad compat_sys_mq_timedreceive /* 280 */
779 .quad compat_sys_mq_notify
780 .quad compat_sys_mq_getsetattr
781 .quad compat_sys_kexec_load /* reserved for kexec */
782 .quad compat_sys_waitid
783 .quad quiet_ni_syscall /* 285: sys_altroot */
785 .quad sys_request_key
788 .quad sys_ioprio_get /* 290 */
789 .quad sys_inotify_init
790 .quad sys_inotify_add_watch
791 .quad sys_inotify_rm_watch
792 .quad sys_migrate_pages
793 .quad compat_sys_openat /* 295 */
797 .quad compat_sys_futimesat
798 .quad sys32_fstatat /* 300 */
803 .quad sys_readlinkat /* 305 */
806 .quad compat_sys_pselect6
807 .quad compat_sys_ppoll
808 .quad sys_unshare /* 310 */
809 .quad compat_sys_set_robust_list
810 .quad compat_sys_get_robust_list
812 .quad sys32_sync_file_range
813 .quad sys_tee /* 315 */
814 .quad compat_sys_vmsplice
815 .quad compat_sys_move_pages
817 .quad sys_epoll_pwait
818 .quad compat_sys_utimensat /* 320 */
819 .quad compat_sys_signalfd
820 .quad sys_timerfd_create
822 .quad sys32_fallocate
823 .quad compat_sys_timerfd_settime /* 325 */
824 .quad compat_sys_timerfd_gettime
825 .quad compat_sys_signalfd4
827 .quad sys_epoll_create1
828 .quad sys_dup3 /* 330 */
830 .quad sys_inotify_init1
831 .quad compat_sys_preadv
832 .quad compat_sys_pwritev