arch/mips/kernel/syscall.c - linux - Git at Google

 /*
  * 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, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  * Copyright (C) 2001 MIPS Technologies, Inc.
  */
 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/fs.h>
 #include <linux/smp.h>
 #include <linux/ptrace.h>
 #include <linux/string.h>
 #include <linux/syscalls.h>
 #include <linux/file.h>
 #include <linux/utsname.h>
 #include <linux/unistd.h>
 #include <linux/sem.h>
 #include <linux/msg.h>
 #include <linux/shm.h>
 #include <linux/compiler.h>
 #include <linux/ipc.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 #include <linux/elf.h>

 #include <asm/asm.h>
 #include <asm/branch.h>
 #include <asm/cachectl.h>
 #include <asm/cacheflush.h>
 #include <asm/asm-offsets.h>
 #include <asm/signal.h>
 #include <asm/sim.h>
 #include <asm/shmparam.h>
 #include <asm/sysmips.h>
 #include <asm/uaccess.h>
 #include <asm/switch_to.h>

 /*
  * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
  * convention.  It returns results in registers $v0 / $v1 which means there
  * is no need for it to do verify the validity of a userspace pointer
  * argument.  Historically that used to be expensive in Linux.  These days
  * the performance advantage is negligible.
  */
 asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
 {
 	int fd[2];
 	int error, res;

 	error = do_pipe_flags(fd, 0);
 	if (error) {
 		res = error;
 		goto out;
 	}
 	regs.regs[3] = fd[1];
 	res = fd[0];
 out:
 	return res;
 }

 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags, unsigned long,
 	fd, off_t, offset)
 {
 	unsigned long result;

 	result = -EINVAL;
 	if (offset & ~PAGE_MASK)
 		goto out;

 	result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

 out:
 	return result;
 }

 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags, unsigned long, fd,
 	unsigned long, pgoff)
 {
 	if (pgoff & (~PAGE_MASK >> 12))
 		return -EINVAL;

 	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
 }

 save_static_function(sys_fork);
 static int __used noinline
 _sys_fork(nabi_no_regargs struct pt_regs regs)
 {
 	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
 }

 save_static_function(sys_clone);
 static int __used noinline
 _sys_clone(nabi_no_regargs struct pt_regs regs)
 {
 	unsigned long clone_flags;
 	unsigned long newsp;
 	int __user *parent_tidptr, *child_tidptr;

 	clone_flags = regs.regs[4];
 	newsp = regs.regs[5];
 	if (!newsp)
 		newsp = regs.regs[29];
 	parent_tidptr = (int __user *) regs.regs[6];
 #ifdef CONFIG_32BIT
 	/* We need to fetch the fifth argument off the stack.  */
 	child_tidptr = NULL;
 	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
 		int __user *__user *usp = (int __user *__user *) regs.regs[29];
 		if (regs.regs[2] == __NR_syscall) {
 			if (get_user (child_tidptr, &usp[5]))
 				return -EFAULT;
 		}
 		else if (get_user (child_tidptr, &usp[4]))
 			return -EFAULT;
 	}
 #else
 	child_tidptr = (int __user *) regs.regs[8];
 #endif
 	return do_fork(clone_flags, newsp, &regs, 0,
 	               parent_tidptr, child_tidptr);
 }

 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
 {
 	struct thread_info *ti = task_thread_info(current);

 	ti->tp_value = addr;
 	if (cpu_has_userlocal)
 		write_c0_userlocal(addr);

 	return 0;
 }

 static inline int mips_atomic_set(struct pt_regs *regs,
 	unsigned long addr, unsigned long new)
 {
 	unsigned long old, tmp;
 	unsigned int err;

 	if (unlikely(addr & 3))
 		return -EINVAL;

 	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
 		return -EINVAL;

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		__asm__ __volatile__ (
 		"	.set	mips3					\n"
 		"	li	%[err], 0				\n"
 		"1:	ll	%[old], (%[addr])			\n"
 		"	move	%[tmp], %[new]				\n"
 		"2:	sc	%[tmp], (%[addr])			\n"
 		"	beqzl	%[tmp], 1b				\n"
 		"3:							\n"
 		"	.section .fixup,\"ax\"				\n"
 		"4:	li	%[err], %[efault]			\n"
 		"	j	3b					\n"
 		"	.previous					\n"
 		"	.section __ex_table,\"a\"			\n"
 		"	"STR(PTR)"	1b, 4b				\n"
 		"	"STR(PTR)"	2b, 4b				\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: [old] "=&r" (old),
 		  [err] "=&r" (err),
 		  [tmp] "=&r" (tmp)
 		: [addr] "r" (addr),
 		  [new] "r" (new),
 		  [efault] "i" (-EFAULT)
 		: "memory");
 	} else if (cpu_has_llsc) {
 		__asm__ __volatile__ (
 		"	.set	mips3					\n"
 		"	li	%[err], 0				\n"
 		"1:	ll	%[old], (%[addr])			\n"
 		"	move	%[tmp], %[new]				\n"
 		"2:	sc	%[tmp], (%[addr])			\n"
 		"	bnez	%[tmp], 4f				\n"
 		"3:							\n"
 		"	.subsection 2					\n"
 		"4:	b	1b					\n"
 		"	.previous					\n"
 		"							\n"
 		"	.section .fixup,\"ax\"				\n"
 		"5:	li	%[err], %[efault]			\n"
 		"	j	3b					\n"
 		"	.previous					\n"
 		"	.section __ex_table,\"a\"			\n"
 		"	"STR(PTR)"	1b, 5b				\n"
 		"	"STR(PTR)"	2b, 5b				\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: [old] "=&r" (old),
 		  [err] "=&r" (err),
 		  [tmp] "=&r" (tmp)
 		: [addr] "r" (addr),
 		  [new] "r" (new),
 		  [efault] "i" (-EFAULT)
 		: "memory");
 	} else {
 		do {
 			preempt_disable();
 			ll_bit = 1;
 			ll_task = current;
 			preempt_enable();

 			err = __get_user(old, (unsigned int *) addr);
 			err |= __put_user(new, (unsigned int *) addr);
 			if (err)
 				break;
 			rmb();
 		} while (!ll_bit);
 	}

 	if (unlikely(err))
 		return err;

 	regs->regs[2] = old;
 	regs->regs[7] = 0;	/* No error */

 	/*
 	 * Don't let your children do this ...
 	 */
 	__asm__ __volatile__(
 	"	move	$29, %0						\n"
 	"	j	syscall_exit					\n"
 	: /* no outputs */
 	: "r" (regs));

 	/* unreached.  Honestly.  */
 	while (1);
 }

 save_static_function(sys_sysmips);
 static int __used noinline
 _sys_sysmips(nabi_no_regargs struct pt_regs regs)
 {
 	long cmd, arg1, arg2;

 	cmd = regs.regs[4];
 	arg1 = regs.regs[5];
 	arg2 = regs.regs[6];

 	switch (cmd) {
 	case MIPS_ATOMIC_SET:
 		return mips_atomic_set(&regs, arg1, arg2);

 	case MIPS_FIXADE:
 		if (arg1 & ~3)
 			return -EINVAL;

 		if (arg1 & 1)
 			set_thread_flag(TIF_FIXADE);
 		else
 			clear_thread_flag(TIF_FIXADE);
 		if (arg1 & 2)
 			set_thread_flag(TIF_LOGADE);
 		else
 			clear_thread_flag(TIF_LOGADE);

 		return 0;

 	case FLUSH_CACHE:
 		__flush_cache_all();
 		return 0;
 	}

 	return -EINVAL;
 }

 /*
  * No implemented yet ...
  */
 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
 {
 	return -ENOSYS;
 }

 /*
  * If we ever come here the user sp is bad.  Zap the process right away.
  * Due to the bad stack signaling wouldn't work.
  */
 asmlinkage void bad_stack(void)
 {
 	do_exit(SIGSEGV);
 }
	/*
	* 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, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	* Copyright (C) 2001 MIPS Technologies, Inc.
	*/
	#include <linux/capability.h>
	#include <linux/errno.h>
	#include <linux/linkage.h>
	#include <linux/fs.h>
	#include <linux/smp.h>
	#include <linux/ptrace.h>
	#include <linux/string.h>
	#include <linux/syscalls.h>
	#include <linux/file.h>
	#include <linux/utsname.h>
	#include <linux/unistd.h>
	#include <linux/sem.h>
	#include <linux/msg.h>
	#include <linux/shm.h>
	#include <linux/compiler.h>
	#include <linux/ipc.h>
	#include <linux/uaccess.h>
	#include <linux/slab.h>
	#include <linux/elf.h>

	#include <asm/asm.h>
	#include <asm/branch.h>
	#include <asm/cachectl.h>
	#include <asm/cacheflush.h>
	#include <asm/asm-offsets.h>
	#include <asm/signal.h>
	#include <asm/sim.h>
	#include <asm/shmparam.h>
	#include <asm/sysmips.h>
	#include <asm/uaccess.h>
	#include <asm/switch_to.h>

	/*
	* For historic reasons the pipe(2) syscall on MIPS has an unusual calling
	* convention. It returns results in registers $v0 / $v1 which means there
	* is no need for it to do verify the validity of a userspace pointer
	* argument. Historically that used to be expensive in Linux. These days
	* the performance advantage is negligible.
	*/
	asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
	{
	int fd[2];
	int error, res;

	error = do_pipe_flags(fd, 0);
	if (error) {
	res = error;
	goto out;
	}
	regs.regs[3] = fd[1];
	res = fd[0];
	out:
	return res;
	}

	SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long,
	fd, off_t, offset)
	{
	unsigned long result;

	result = -EINVAL;
	if (offset & ~PAGE_MASK)
	goto out;

	result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

	out:
	return result;
	}

	SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	unsigned long, pgoff)
	{
	if (pgoff & (~PAGE_MASK >> 12))
	return -EINVAL;

	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
	}

	save_static_function(sys_fork);
	static int __used noinline
	_sys_fork(nabi_no_regargs struct pt_regs regs)
	{
	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
	}

	save_static_function(sys_clone);
	static int __used noinline
	_sys_clone(nabi_no_regargs struct pt_regs regs)
	{
	unsigned long clone_flags;
	unsigned long newsp;
	int __user parent_tidptr, child_tidptr;

	clone_flags = regs.regs[4];
	newsp = regs.regs[5];
	if (!newsp)
	newsp = regs.regs[29];
	parent_tidptr = (int __user *) regs.regs[6];
	#ifdef CONFIG_32BIT
	/* We need to fetch the fifth argument off the stack. */
	child_tidptr = NULL;
	if (clone_flags & (CLONE_CHILD_SETTID \| CLONE_CHILD_CLEARTID)) {
	int __user __user usp = (int __user __user ) regs.regs[29];
	if (regs.regs[2] == __NR_syscall) {
	if (get_user (child_tidptr, &usp[5]))
	return -EFAULT;
	}
	else if (get_user (child_tidptr, &usp[4]))
	return -EFAULT;
	}
	#else
	child_tidptr = (int __user *) regs.regs[8];
	#endif
	return do_fork(clone_flags, newsp, &regs, 0,
	parent_tidptr, child_tidptr);
	}

	SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
	{
	struct thread_info *ti = task_thread_info(current);

	ti->tp_value = addr;
	if (cpu_has_userlocal)
	write_c0_userlocal(addr);

	return 0;
	}

	static inline int mips_atomic_set(struct pt_regs *regs,
	unsigned long addr, unsigned long new)
	{
	unsigned long old, tmp;
	unsigned int err;

	if (unlikely(addr & 3))
	return -EINVAL;

	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
	return -EINVAL;

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	__asm__ __volatile__ (
	" .set mips3 \n"
	" li %[err], 0 \n"
	"1: ll %[old], (%[addr]) \n"
	" move %[tmp], %[new] \n"
	"2: sc %[tmp], (%[addr]) \n"
	" beqzl %[tmp], 1b \n"
	"3: \n"
	" .section .fixup,\"ax\" \n"
	"4: li %[err], %[efault] \n"
	" j 3b \n"
	" .previous \n"
	" .section __ex_table,\"a\" \n"
	" "STR(PTR)" 1b, 4b \n"
	" "STR(PTR)" 2b, 4b \n"
	" .previous \n"
	" .set mips0 \n"
	: [old] "=&r" (old),
	[err] "=&r" (err),
	[tmp] "=&r" (tmp)
	: [addr] "r" (addr),
	[new] "r" (new),
	[efault] "i" (-EFAULT)
	: "memory");
	} else if (cpu_has_llsc) {
	__asm__ __volatile__ (
	" .set mips3 \n"
	" li %[err], 0 \n"
	"1: ll %[old], (%[addr]) \n"
	" move %[tmp], %[new] \n"
	"2: sc %[tmp], (%[addr]) \n"
	" bnez %[tmp], 4f \n"
	"3: \n"
	" .subsection 2 \n"
	"4: b 1b \n"
	" .previous \n"
	" \n"
	" .section .fixup,\"ax\" \n"
	"5: li %[err], %[efault] \n"
	" j 3b \n"
	" .previous \n"
	" .section __ex_table,\"a\" \n"
	" "STR(PTR)" 1b, 5b \n"
	" "STR(PTR)" 2b, 5b \n"
	" .previous \n"
	" .set mips0 \n"
	: [old] "=&r" (old),
	[err] "=&r" (err),
	[tmp] "=&r" (tmp)
	: [addr] "r" (addr),
	[new] "r" (new),
	[efault] "i" (-EFAULT)
	: "memory");
	} else {
	do {
	preempt_disable();
	ll_bit = 1;
	ll_task = current;
	preempt_enable();

	err = __get_user(old, (unsigned int *) addr);
	err \|= __put_user(new, (unsigned int *) addr);
	if (err)
	break;
	rmb();
	} while (!ll_bit);
	}

	if (unlikely(err))
	return err;

	regs->regs[2] = old;
	regs->regs[7] = 0; /* No error */

	/*
	* Don't let your children do this ...
	*/
	__asm__ __volatile__(
	" move $29, %0 \n"
	" j syscall_exit \n"
	: /* no outputs */
	: "r" (regs));

	/* unreached. Honestly. */
	while (1);
	}

	save_static_function(sys_sysmips);
	static int __used noinline
	_sys_sysmips(nabi_no_regargs struct pt_regs regs)
	{
	long cmd, arg1, arg2;

	cmd = regs.regs[4];
	arg1 = regs.regs[5];
	arg2 = regs.regs[6];

	switch (cmd) {
	case MIPS_ATOMIC_SET:
	return mips_atomic_set(&regs, arg1, arg2);

	case MIPS_FIXADE:
	if (arg1 & ~3)
	return -EINVAL;

	if (arg1 & 1)
	set_thread_flag(TIF_FIXADE);
	else
	clear_thread_flag(TIF_FIXADE);
	if (arg1 & 2)
	set_thread_flag(TIF_LOGADE);
	else
	clear_thread_flag(TIF_LOGADE);

	return 0;

	case FLUSH_CACHE:
	__flush_cache_all();
	return 0;
	}

	return -EINVAL;
	}

	/*
	* No implemented yet ...
	*/
	SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
	{
	return -ENOSYS;
	}

	/*
	* If we ever come here the user sp is bad. Zap the process right away.
	* Due to the bad stack signaling wouldn't work.
	*/
	asmlinkage void bad_stack(void)
	{
	do_exit(SIGSEGV);
	}