嵌入式Linux

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Unix_Linux

scall_o32.S：源码内容
							/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995 - 2000, 2001 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 *
 * Hairy, the userspace application uses a different argument passing
 * convention than the kernel, so we have to translate things from o32
 * to ABI64 calling convention.  64-bit syscalls are also processed
 * here for now.
 */
#include <asm/asm.h>
#include <linux/errno.h>
#include <asm/current.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/unistd.h>
#include <asm/sysmips.h>
/* This duplicates the definition from <linux/sched.h> */
#define PT_TRACESYS	0x00000002	/* tracing system calls */
/* This duplicates the definition from <asm/signal.h> */
#define SIGILL		4		/* Illegal instruction (ANSI).  */
/* Highest syscall used of any syscall flavour */
#define MAX_SYSCALL_NO	__NR_Linux32 + __NR_Linux32_syscalls
	.align  5
NESTED(handle_sys, PT_SIZE, sp)
	.set	noat
	SAVE_SOME
	STI
	.set	at
	ld	t1, PT_EPC(sp)		# skip syscall on return
	subu	t0, v0, __NR_Linux32	# check syscall number
	sltiu	t0, t0, __NR_Linux32_syscalls + 1
	daddiu	t1, 4			# skip to next instruction
	beqz	t0, not_o32_scall
	sd	t1, PT_EPC(sp)
	/* XXX Put both in one cacheline, should save a bit. */
	dsll	t0, v0, 3		# offset into table
	ld	t2, (sys_call_table - (__NR_Linux32 * 8))(t0) # syscall routine
	lbu	t3, (sys_narg_table - __NR_Linux32)(v0)	# number of arguments
	subu	t0, t3, 5		# 5 or more arguments?
	sd	a3, PT_R26(sp)		# save a3 for syscall restarting
	bgez	t0, stackargs
stack_done:
		ld	t0, TASK_PTRACE($28)	# syscall tracing enabled?
		andi	t0, PT_TRACESYS
		bnez	t0, trace_a_syscall
		jalr	t2			# Do The Real Thing (TM)
		li	t0, -EMAXERRNO - 1	# error?
		sltu	t0, t0, v0
		sd	t0, PT_R7(sp)		# set error flag
		beqz	t0, 1f
		negu	v0			# error
		sd	v0, PT_R0(sp)		# flag for syscall restarting
1:		sd	v0, PT_R2(sp)		# result
FEXPORT(o32_ret_from_sys_call)
		mfc0	t0, CP0_STATUS	# need_resched and signals atomic test
		ori	t0, t0, 1
		xori	t0, t0, 1
		mtc0	t0, CP0_STATUS
		ld	t2, TASK_NEED_RESCHED($28)
		bnez	t2, o32_reschedule
		lw	v0, TASK_SIGPENDING($28)
		bnez	v0, signal_return
restore_all:	RESTORE_SOME
		RESTORE_SP
		.set	mips3
		eret
		.set	mips0
signal_return:	mfc0	t0, CP0_STATUS	# need_resched and signals atomic test
		ori	t0, t0, 1
		mtc0	t0, CP0_STATUS
		move	a0, zero
		move	a1, sp
		SAVE_STATIC
		jal	do_signal
o32_reschedule:
		SAVE_STATIC
		jal	schedule
		b	o32_ret_from_sys_call
/* ------------------------------------------------------------------------ */
trace_a_syscall:
	SAVE_STATIC
	sd	a4, PT_R8(sp)
	sd	a5, PT_R9(sp)
	sd	a6, PT_R10(sp)
	sd	a7, PT_R11(sp)
	sd	t2,PT_R1(sp)
	jal	syscall_trace
	ld	t2,PT_R1(sp)
	ld	a0, PT_R4(sp)		# Restore argument registers
	ld	a1, PT_R5(sp)
	ld	a2, PT_R6(sp)
	ld	a3, PT_R7(sp)
	ld	a4, PT_R8(sp)
	ld	a5, PT_R9(sp)
	jalr	t2
	li	t0, -EMAXERRNO - 1	# error?
	sltu	t0, t0, v0
	sd	t0, PT_R7(sp)		# set error flag
	beqz	t0, 1f
	negu	v0			# error
	sd	v0, PT_R0(sp)		# set flag for syscall restarting
1:	sd	v0, PT_R2(sp)		# result
	jal	syscall_trace
	j	o32_ret_from_sys_call
/* ------------------------------------------------------------------------ */
	/*
	 * More than four arguments.  Try to deal with it by copying the
	 * stack arguments from the user stack to the kernel stack.
	 * This Sucks (TM).
	 */
stackargs:
	ld	t0, PT_R29(sp)		# get old user stack pointer
	subu	t3, 4
	sll	t1, t3, 2		# stack valid?
	addu	t1, t0			# end address
	or	t0, t1
	bltz	t0, bad_stack		# -> sp is bad
	ld	t0, PT_R29(sp)		# get old user stack pointer
	la	t1, 3f			# copy 1 to 2 arguments
	sll	t3, t3, 2
	subu	t1, t3
	jr	t1
	/* Ok, copy the args from the luser stack to the kernel stack */
1:	lw	a5, 20(t0)		# argument #6 from usp
2:	lw	a4, 16(t0)		# argument #5 from usp
3:	j	stack_done		# go back
	.section __ex_table,"a"
	PTR	1b, bad_stack
	PTR	2b, bad_stack
	.previous
	/*
	 * The stackpointer for a call with more than 4 arguments is bad.
	 */
bad_stack:
	negu	v0				# error
	sd	v0, PT_R0(sp)
	sd	v0, PT_R2(sp)
	li	t0, 1				# set error flag
	sd	t0, PT_R7(sp)
	j	ret_from_sys_call
not_o32_scall:
	/* This is not an 32-bit compatibility syscall, pass it on to
	   the 64-bit syscall handlers.  */
	j	handle_sys64
illegal_syscall:
	/* This also isn't a 64-bit syscall, throw an error.  */
	li	v0, ENOSYS			# error
	sd	v0, PT_R2(sp)
	li	t0, 1				# set error flag
	sd	t0, PT_R7(sp)
	j	ret_from_sys_call
	END(handle_sys)
	LEAF(mips_atomic_set)
	ld	v1, THREAD_CURDS($28)
	daddiu	a0, a1, 4
	or	a0, a0, a1
	li	v0, -EFAULT
	and	a0, a0, v1
	bltz	a0, 9f
	/* Ok, this is the ll/sc case.  World is sane :-)  */
1:	ll	v0, (a1)
	move	a0, a2
2:	sc	a0, (a1)
	beqz	a0, 1b
	.section __ex_table,"a"
	PTR	1b, bad_stack
	PTR	2b, bad_stack
	.previous
1:	sd	v0, PT_R2(sp)		# result
	/* Success, so skip usual error handling garbage.  */
	ld	t0, TASK_PTRACE($28)	# syscall tracing enabled?
	andi	t0, PT_TRACESYS
	bnez	t0, 1f
	b	o32_ret_from_sys_call
1:	SAVE_STATIC
	jal	syscall_trace
	li	a3, 0			# success
	j	ret_from_sys_call
9:	li	v0, -EFAULT
	jr	ra
	END(mips_atomic_set)
	LEAF(sys_sysmips)
	beq	a0, MIPS_ATOMIC_SET, mips_atomic_set
	j	_sys_sysmips
	END(sys_sysmips)
	.macro	syscalltable
	sys	sys_syscall	0			/* 4000 */
	sys	sys_exit	1
	sys	sys_fork	0
	sys	sys_read	3
	sys	sys_write	3
	sys	sys_open	3			/* 4005 */
	sys	sys_close	1
	sys	sys_waitpid	3
	sys	sys_creat	2
	sys	sys_link	2
	sys	sys_unlink	1			/* 4010 */
	sys	sys32_execve	0
	sys	sys_chdir	1
	sys	sys_time	1
	sys	sys_mknod	3
	sys	sys_chmod	2			/* 4015 */
	sys	sys_lchown	3
	sys	sys_ni_syscall	0
	sys	sys_stat	2
	sys	sys_lseek	3
	sys	sys_getpid	0			/* 4020 */
	sys	sys_mount	5
	sys	sys_oldumount	1
	sys	sys_setuid	1
	sys	sys_getuid	0
	sys	sys_stime	1			/* 4025 */
	sys	sys32_ptrace	4
	sys	sys32_alarm	1
	sys	sys_fstat	2
	sys	sys_pause	0
	sys	sys32_utime	2			/* 4030 */
	sys	sys_ni_syscall	0
	sys	sys_ni_syscall	0
	sys	sys_access	2
	sys	sys_nice	1
	sys	sys_ni_syscall	0			/* 4035 */
	sys	sys_sync	0
	sys	sys_kill	2
	sys	sys_rename	2
	sys	sys_mkdir	2
	sys	sys_rmdir	1			/* 4040 */
	sys	sys_dup		1
	sys	sys_pipe	0
	sys	sys32_times	1
	sys	sys_ni_syscall	0
	sys	sys_brk		1			/* 4045 */
	sys	sys_setgid	1
	sys	sys_getgid	0
	sys	sys_ni_syscall	0	/* was signal	2 */
	sys	sys_geteuid	0
	sys	sys_getegid	0			/* 4050 */
	sys	sys_acct	0
	sys	sys_umount	2
	sys	sys_ni_syscall	0
	sys	sys32_ioctl	3
	sys	sys32_fcntl	3			/* 4055 */
	sys	sys_ni_syscall	2
	sys	sys_setpgid	2
	sys	sys_ni_syscall, 0
	sys	sys_ni_syscall	0	/* was sys_olduname  */
	sys	sys_umask	1			/* 4060 */
	sys	sys_chroot	1
	sys	sys_ustat	2
	sys	sys_dup2	2
	sys	sys_getppid	0
	sys	sys_getpgrp	0			/* 4065 */
	sys	sys_setsid	0
	sys	sys32_sigaction	3
	sys	sys_sgetmask	0
	sys	sys_ssetmask	1
	sys	sys_setreuid	2			/* 4070 */
	sys	sys_setregid	2
	sys	sys32_sigsuspend	0
	sys	sys32_sigpending	1
	sys	sys_sethostname	2
	sys	sys32_setrlimit	2			/* 4075 */
	sys	sys32_getrlimit	2
	sys	sys32_getrusage	2
	sys	sys32_gettimeofday 2
	sys	sys32_settimeofday 2
	sys	sys_getgroups	2			/* 4080 */
	sys	sys_setgroups	2
	sys	sys_ni_syscall	0 /* old_select */
	sys	sys_symlink	2
	sys	sys_lstat	2
	sys	sys_readlink	3			/* 4085 */
	sys	sys_uselib	1
	sys	sys_swapon	2
	sys	sys_reboot	3
	sys	sys32_readdir	3
	sys	sys_mmap	6			/* 4090 */
	sys	sys_munmap	2
	sys	sys_truncate	2
	sys	sys_ftruncate	2
	sys	sys_fchmod	2
	sys	sys_fchown	3			/* 4095 */
	sys	sys_getpriority	2
	sys	sys_setpriority	3
	sys	sys_ni_syscall	0
	sys	sys32_statfs	2
	sys	sys32_fstatfs	2			/* 4100 */
	sys	sys_ni_syscall	0	/* sys_ioperm */
	sys	sys_socketcall	2
	sys	sys_syslog	3
	sys	sys32_setitimer	3
	sys	sys32_getitimer	2			/* 4105 */
	sys	sys32_newstat	2
	sys	sys32_newlstat	2
	sys	sys32_newfstat	2
	sys	sys_ni_syscall	0	/* was sys_uname */
	sys	sys_ni_syscall	0	/* sys_ioperm  *//* 4110 */
	sys	sys_vhangup	0
	sys	sys_ni_syscall	0	/* was sys_idle	 */
	sys	sys_ni_syscall	0	/* sys_vm86 */
	sys	sys32_wait4	4
	sys	sys_swapoff	1			/* 4115 */
	sys	sys_sysinfo	1
	sys	sys32_ipc		6
	sys	sys_fsync	1
	sys	sys32_sigreturn	0
	sys	sys_clone	0			/* 4120 */
	sys	sys_setdomainname 2
	sys	sys32_newuname	1
	sys	sys_ni_syscall	0	/* sys_modify_ldt */
	sys	sys32_adjtimex	1
	sys	sys_mprotect	3			/* 4125 */
	sys	sys32_sigprocmask	3
	sys	sys_create_module 2
	sys	sys_init_module	5
	sys	sys_delete_module 1
	sys	sys_get_kernel_syms 1			/* 4130 */
	sys	sys_quotactl	0
	sys	sys_getpgid	1
	sys	sys_fchdir	1
	sys	sys_bdflush	2
	sys	sys_sysfs	3			/* 4135 */
	sys	sys32_personality	1
	sys	sys_ni_syscall	0 /* for afs_syscall */
	sys	sys_setfsuid	1
	sys	sys_setfsgid	1
	sys	sys32_llseek	5			/* 4140 */
	sys	sys32_getdents	3
	sys	sys32_select	5
	sys	sys_flock	2
	sys	sys_msync	3
	sys	sys32_readv	3			/* 4145 */
	sys	sys32_writev	3
	sys	sys_cacheflush	3
	sys	sys_cachectl	3
	sys	sys_sysmips	4
	sys	sys_ni_syscall	0			/* 4150 */
	sys	sys_getsid	1
	sys	sys_fdatasync	0
	sys	sys32_sysctl	1
	sys	sys_mlock	2
	sys	sys_munlock	2			/* 4155 */
	sys	sys_mlockall	1
	sys	sys_munlockall	0
	sys	sys_sched_setparam 2
	sys	sys_sched_getparam 2
	sys	sys_sched_setscheduler 3		/* 4160 */
	sys	sys_sched_getscheduler 1
	sys	sys_sched_yield	0
	sys	sys_sched_get_priority_max 1
	sys	sys_sched_get_priority_min 1
	sys	sys32_sched_rr_get_interval 2		/* 4165 */
	sys	sys32_nanosleep	2
	sys	sys_mremap	4
	sys	sys_accept	3
	sys	sys_bind	3
	sys	sys_connect	3			/* 4170 */
	sys	sys_getpeername	3
	sys	sys_getsockname	3
	sys	sys_getsockopt	5
	sys	sys_listen	2
	sys	sys_recv	4			/* 4175 */
	sys	sys_recvfrom	6
	sys	sys32_recvmsg	3
	sys	sys_send	4
	sys	sys32_sendmsg	3
	sys	sys_sendto	6			/* 4180 */
	sys	sys32_setsockopt	5
	sys	sys_shutdown	2
	sys	sys_socket	3
	sys	sys_socketpair	4
	sys	sys_setresuid	3			/* 4185 */
	sys	sys_getresuid	3
	sys	sys_query_module 5
	sys	sys_poll	3
	sys	sys_nfsservctl	3
	sys	sys_setresgid	3			/* 4190 */
	sys	sys_getresgid	3
	sys	sys_prctl	5
	sys	sys32_rt_sigreturn 0
	sys	sys32_rt_sigaction 4
	sys	sys32_rt_sigprocmask 4			/* 4195 */
	sys	sys32_rt_sigpending 2
	sys	sys32_rt_sigtimedwait 4
	sys	sys32_rt_sigqueueinfo 3
	sys	sys32_rt_sigsuspend 0
	sys	sys32_pread	6			/* 4200 */
	sys	sys32_pwrite	6
	sys	sys_chown	3
	sys	sys_getcwd	2
	sys	sys_capget	2
	sys	sys_capset	2			/* 4205 */
	sys	sys32_sigaltstack	0
	sys	sys_sendfile	3
	sys	sys_ni_syscall	0
	sys	sys_ni_syscall	0
	sys	sys_mmap2	6			/* 4210 */
	sys	sys_truncate64	2
	sys	sys_ftruncate64	2
	sys	sys_newstat	2
	sys	sys_newlstat	2
	sys	sys_newfstat	2			/* 4215 */
	sys	sys_pivot_root	2
	sys	sys_mincore	3
	sys	sys_madvise	3
	sys	sys_getdents64	3
	sys	sys32_fcntl64	3			/* 4220 */
	.endm
	.macro	sys function, nargs
	PTR	function
	.endm
sys_call_table:
	syscalltable
	.macro	sys function, nargs
	.byte	nargs
	.endm
sys_narg_table:
	syscalltable

						