[mirror_ubuntu-eoan-kernel.git] / arch / mips / kernel / syscall.c

/*
 * 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 <linux/sched/task_stack.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/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(void)
{
	int fd[2];
	int error = do_pipe_flags(fd, 0);
	if (error)
		return error;
	current_pt_regs()->regs[3] = fd[1];
	return fd[0];
}

SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long,
	fd, off_t, offset)
{
	if (offset & ~PAGE_MASK)
		return -EINVAL;
	return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
}

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);
save_static_function(sys_clone);

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(unsigned long addr, unsigned long new)
{
	unsigned long old, tmp;
	struct pt_regs *regs;
	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	arch=r4000				\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"
		"	.insn						\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	"MIPS_ISA_ARCH_LEVEL"			\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"
		"	.insn						\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 = current_pt_regs();
	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.  */
	unreachable();
}

SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
{
	switch (cmd) {
	case MIPS_ATOMIC_SET:
		return mips_atomic_set(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);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
	7	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	8	* Copyright (C) 2001 MIPS Technologies, Inc.
	9	*/
a9415644	10	#include <linux/capability.h>
1da177e4 LT	11	#include <linux/errno.h>
1da177e4 LT	12	#include <linux/linkage.h>
4e950f6f	13	#include <linux/fs.h>
1da177e4	14	#include <linux/smp.h>
1da177e4	15	#include <linux/ptrace.h>
1da177e4 LT	16	#include <linux/string.h>
	17	#include <linux/syscalls.h>
	18	#include <linux/file.h>
1da177e4 LT	19	#include <linux/utsname.h>
	20	#include <linux/unistd.h>
	21	#include <linux/sem.h>
	22	#include <linux/msg.h>
	23	#include <linux/shm.h>
	24	#include <linux/compiler.h>
cba4fbbf	25	#include <linux/ipc.h>
f1e39a4a	26	#include <linux/uaccess.h>
5a0e3ad6	27	#include <linux/slab.h>
652b14aa	28	#include <linux/elf.h>
68db0cf1	29	#include <linux/sched/task_stack.h>
1da177e4	30
f1e39a4a	31	#include <asm/asm.h>
1da177e4 LT	32	#include <asm/branch.h>
	33	#include <asm/cachectl.h>
	34	#include <asm/cacheflush.h>
048eb582	35	#include <asm/asm-offsets.h>
1da177e4 LT	36	#include <asm/signal.h>
	37	#include <asm/sim.h>
	38	#include <asm/shmparam.h>
	39	#include <asm/sysmips.h>
b81947c6	40	#include <asm/switch_to.h>
1da177e4	41
8213bbf9 RB	42	/*
8213bbf9 RB	43	* For historic reasons the pipe(2) syscall on MIPS has an unusual calling
70342287	44	* convention. It returns results in registers $v0 / $v1 which means there
8213bbf9	45	* is no need for it to do verify the validity of a userspace pointer
70342287	46	* argument. Historically that used to be expensive in Linux. These days
8213bbf9 RB	47	* the performance advantage is negligible.
8213bbf9 RB	48	*/
974fdb3c	49	asmlinkage int sysm_pipe(void)
1da177e4 LT	50	{
1da177e4 LT	51	int fd[2];
974fdb3c AV	52	int error = do_pipe_flags(fd, 0);
	53	if (error)
	54	return error;
	55	current_pt_regs()->regs[3] = fd[1];
	56	return fd[0];
1da177e4 LT	57	}
1da177e4 LT	58
dbda6ac0 RB	59	SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
	60	unsigned long, prot, unsigned long, flags, unsigned long,
	61	fd, off_t, offset)
1da177e4	62	{
1da177e4	63	if (offset & ~PAGE_MASK)
c9d3fdf3 ME	64	return -EINVAL;
c9d3fdf3 ME	65	return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
1da177e4 LT	66	}
1da177e4 LT	67
dbda6ac0 RB	68	SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
	69	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	70	unsigned long, pgoff)
1da177e4	71	{
947df17c PA	72	if (pgoff & (~PAGE_MASK >> 12))
	73	return -EINVAL;
	74
f8b72560	75	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
1da177e4 LT	76	}
	77
	78	save_static_function(sys_fork);
1da177e4	79	save_static_function(sys_clone);
1da177e4	80
dbda6ac0	81	SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
3c37026d	82	{
dc8f6029	83	struct thread_info *ti = task_thread_info(current);
3c37026d RB	84
3c37026d RB	85	ti->tp_value = addr;
a3692020 RB	86	if (cpu_has_userlocal)
a3692020 RB	87	write_c0_userlocal(addr);
06be375b RB	88
06be375b RB	89	return 0;
3c37026d RB	90	}
3c37026d RB	91
12890d0f	92	static inline int mips_atomic_set(unsigned long addr, unsigned long new)
1da177e4	93	{
f1e39a4a	94	unsigned long old, tmp;
12890d0f	95	struct pt_regs *regs;
f1e39a4a RB	96	unsigned int err;
	97
	98	if (unlikely(addr & 3))
	99	return -EINVAL;
	100
	101	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
	102	return -EINVAL;
	103
	104	if (cpu_has_llsc && R10000_LLSC_WAR) {
	105	__asm__ __volatile__ (
a809d460	106	" .set arch=r4000 \n"
f1e39a4a RB	107	" li %[err], 0 \n"
	108	"1: ll %[old], (%[addr]) \n"
	109	" move %[tmp], %[new] \n"
	110	"2: sc %[tmp], (%[addr]) \n"
	111	" beqzl %[tmp], 1b \n"
	112	"3: \n"
0e525e48	113	" .insn \n"
f1e39a4a RB	114	" .section .fixup,\"ax\" \n"
	115	"4: li %[err], %[efault] \n"
	116	" j 3b \n"
	117	" .previous \n"
	118	" .section __ex_table,\"a\" \n"
	119	" "STR(PTR)" 1b, 4b \n"
	120	" "STR(PTR)" 2b, 4b \n"
	121	" .previous \n"
a91be9ee	122	" .set mips0 \n"
f1e39a4a RB	123	: [old] "=&r" (old),
	124	[err] "=&r" (err),
	125	[tmp] "=&r" (tmp)
	126	: [addr] "r" (addr),
	127	[new] "r" (new),
	128	[efault] "i" (-EFAULT)
	129	: "memory");
	130	} else if (cpu_has_llsc) {
	131	__asm__ __volatile__ (
fee313d4	132	" .set "MIPS_ISA_ARCH_LEVEL" \n"
f1e39a4a RB	133	" li %[err], 0 \n"
	134	"1: ll %[old], (%[addr]) \n"
	135	" move %[tmp], %[new] \n"
	136	"2: sc %[tmp], (%[addr]) \n"
	137	" bnez %[tmp], 4f \n"
	138	"3: \n"
0e525e48	139	" .insn \n"
f1e39a4a RB	140	" .subsection 2 \n"
	141	"4: b 1b \n"
	142	" .previous \n"
	143	" \n"
	144	" .section .fixup,\"ax\" \n"
	145	"5: li %[err], %[efault] \n"
	146	" j 3b \n"
	147	" .previous \n"
	148	" .section __ex_table,\"a\" \n"
	149	" "STR(PTR)" 1b, 5b \n"
	150	" "STR(PTR)" 2b, 5b \n"
	151	" .previous \n"
a91be9ee	152	" .set mips0 \n"
f1e39a4a RB	153	: [old] "=&r" (old),
	154	[err] "=&r" (err),
	155	[tmp] "=&r" (tmp)
	156	: [addr] "r" (addr),
	157	[new] "r" (new),
	158	[efault] "i" (-EFAULT)
	159	: "memory");
	160	} else {
	161	do {
	162	preempt_disable();
	163	ll_bit = 1;
	164	ll_task = current;
	165	preempt_enable();
	166
	167	err = __get_user(old, (unsigned int *) addr);
	168	err \|= __put_user(new, (unsigned int *) addr);
	169	if (err)
	170	break;
	171	rmb();
	172	} while (!ll_bit);
	173	}
	174
	175	if (unlikely(err))
	176	return err;
	177
12890d0f	178	regs = current_pt_regs();
f1e39a4a RB	179	regs->regs[2] = old;
	180	regs->regs[7] = 0; /* No error */
	181
	182	/*
	183	* Don't let your children do this ...
	184	*/
	185	__asm__ __volatile__(
	186	" move $29, %0 \n"
	187	" j syscall_exit \n"
	188	: /* no outputs */
	189	: "r" (regs));
	190
	191	/* unreached. Honestly. */
f2ace931	192	unreachable();
f1e39a4a RB	193	}
f1e39a4a RB	194
12890d0f	195	SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
f1e39a4a	196	{
293c5bd1	197	switch (cmd) {
1da177e4	198	case MIPS_ATOMIC_SET:
12890d0f	199	return mips_atomic_set(arg1, arg2);
1da177e4 LT	200
1da177e4 LT	201	case MIPS_FIXADE:
293c5bd1 RB	202	if (arg1 & ~3)
	203	return -EINVAL;
	204
	205	if (arg1 & 1)
	206	set_thread_flag(TIF_FIXADE);
	207	else
	208	clear_thread_flag(TIF_FIXADE);
	209	if (arg1 & 2)
	210	set_thread_flag(TIF_LOGADE);
	211	else
e56293b1	212	clear_thread_flag(TIF_LOGADE);
293c5bd1	213
1da177e4 LT	214	return 0;
	215
	216	case FLUSH_CACHE:
	217	__flush_cache_all();
	218	return 0;
1da177e4 LT	219	}
	220
	221	return -EINVAL;
	222	}
	223
1da177e4 LT	224	/*
	225	* No implemented yet ...
	226	*/
dbda6ac0	227	SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
1da177e4 LT	228	{
	229	return -ENOSYS;
	230	}
	231
	232	/*
	233	* If we ever come here the user sp is bad. Zap the process right away.
	234	* Due to the bad stack signaling wouldn't work.
	235	*/
	236	asmlinkage void bad_stack(void)
	237	{
	238	do_exit(SIGSEGV);
	239	}