[apple/xnu.git] / osfmk / arm64 / bsd_arm64.c

/*
 * Copyright (c) 2019 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#ifdef  MACH_BSD
#include <mach_debug.h>
#include <mach_ldebug.h>

#include <mach/kern_return.h>
#include <mach/mach_traps.h>
#include <mach/vm_param.h>

#include <kern/counters.h>
#include <kern/cpu_data.h>
#include <arm/cpu_data_internal.h>
#include <kern/mach_param.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/sched_prim.h>
#include <kern/misc_protos.h>
#include <kern/assert.h>
#include <kern/spl.h>
#include <kern/syscall_sw.h>
#include <ipc/ipc_port.h>
#include <vm/vm_kern.h>
#include <mach/thread_status.h>
#include <vm/pmap.h>

#include <sys/kdebug.h>

#include <sys/syscall.h>

extern void throttle_lowpri_io(int);
void mach_syscall(struct arm_saved_state*);
typedef kern_return_t (*mach_call_t)(void *);

struct mach_call_args {
	syscall_arg_t arg1;
	syscall_arg_t arg2;
	syscall_arg_t arg3;
	syscall_arg_t arg4;
	syscall_arg_t arg5;
	syscall_arg_t arg6;
	syscall_arg_t arg7;
	syscall_arg_t arg8;
	syscall_arg_t arg9;
};

static void
arm_set_mach_syscall_ret(struct arm_saved_state *state, int retval)
{
	if (is_saved_state32(state)) {
		saved_state32(state)->r[0] = retval;
	} else {
		saved_state64(state)->x[0] = retval;
	}
}

static kern_return_t
arm_get_mach_syscall_args(struct arm_saved_state *state, struct mach_call_args *dest, const mach_trap_t *trapp)
{
	uint32_t reg_count;

	if (is_saved_state32(state)) {
		/* The trap table entry defines the number of 32-bit words to be copied in from userspace. */
		reg_count = trapp->mach_trap_u32_words;

		/*
		 * We get 7 contiguous words; r0-r6, hop over r7
		 * (frame pointer), optionally r8
		 */
		if (reg_count <= 7) {
			bcopy((char*)saved_state32(state), (char*)dest, sizeof(uint32_t) * reg_count);
		} else if (reg_count <= 9) {
			bcopy((char*)saved_state32(state), (char*)dest, sizeof(uint32_t) * 7);
			bcopy((char*)&saved_state32(state)->r[8], ((char*)dest) + sizeof(uint32_t) * 7,
			    reg_count - 7);
		} else {
			panic("Trap with %d words of args? We only support 9.", reg_count);
		}

#if CONFIG_REQUIRES_U32_MUNGING
		trapp->mach_trap_arg_munge32(dest);
#else
#error U32 mach traps on ARM64 kernel requires munging
#endif
	} else {
		assert(is_saved_state64(state));
		bcopy((char*)saved_state64(state), (char*)dest, trapp->mach_trap_arg_count * sizeof(uint64_t));
	}

	return KERN_SUCCESS;
}

kern_return_t
thread_setsinglestep(__unused thread_t thread, __unused int on)
{
	return KERN_FAILURE; /* XXX TODO */
}

#if CONFIG_DTRACE

vm_offset_t dtrace_get_cpu_int_stack_top(void);

vm_offset_t
dtrace_get_cpu_int_stack_top(void)
{
	return getCpuDatap()->intstack_top;
}
#endif /* CONFIG_DTRACE */
extern const char *mach_syscall_name_table[];

/* ARM64_TODO: remove this. still TODO?*/
extern struct proc* current_proc(void);
extern int proc_pid(struct proc*);

void
mach_syscall(struct arm_saved_state *state)
{
	kern_return_t retval;
	mach_call_t mach_call;
	struct mach_call_args args = {
		.arg1 = 0,
		.arg2 = 0,
		.arg3 = 0,
		.arg4 = 0,
		.arg5 = 0,
		.arg6 = 0,
		.arg7 = 0,
		.arg8 = 0,
		.arg9 = 0
	};
	int call_number = get_saved_state_svc_number(state);
	int64_t exc_code;
	int argc;

	struct uthread *ut = get_bsdthread_info(current_thread());
	uthread_reset_proc_refcount(ut);

	assert(call_number < 0); /* Otherwise it would be a Unix syscall */
	call_number = -call_number;

	if (call_number >= MACH_TRAP_TABLE_COUNT) {
		goto bad;
	}

	DEBUG_KPRINT_SYSCALL_MACH(
		"mach_syscall: code=%d(%s) (pid %d, tid %lld)\n",
		call_number, mach_syscall_name_table[call_number],
		proc_pid(current_proc()), thread_tid(current_thread()));

#if DEBUG_TRACE
	kprintf("mach_syscall(0x%08x) code=%d\n", state, call_number);
#endif

	mach_call = (mach_call_t)mach_trap_table[call_number].mach_trap_function;

	if (mach_call == (mach_call_t)kern_invalid) {
		DEBUG_KPRINT_SYSCALL_MACH(
			"mach_syscall: kern_invalid 0x%x\n", call_number);
		goto bad;
	}

	argc = mach_trap_table[call_number].mach_trap_arg_count;
	if (argc) {
		retval = arm_get_mach_syscall_args(state, &args, &mach_trap_table[call_number]);
		if (retval != KERN_SUCCESS) {
			arm_set_mach_syscall_ret(state, retval);

			DEBUG_KPRINT_SYSCALL_MACH(
				"mach_syscall: retval=0x%x\n", retval);
			return;
		}
	}

	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
	    MACHDBG_CODE(DBG_MACH_EXCP_SC, (call_number)) | DBG_FUNC_START,
	    args.arg1, args.arg2, args.arg3, args.arg4, 0);

	retval = mach_call(&args);

	DEBUG_KPRINT_SYSCALL_MACH("mach_syscall: retval=0x%x (pid %d, tid %lld)\n", retval,
	    proc_pid(current_proc()), thread_tid(current_thread()));

	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
	    MACHDBG_CODE(DBG_MACH_EXCP_SC, (call_number)) | DBG_FUNC_END,
	    retval, 0, 0, 0, 0);

	arm_set_mach_syscall_ret(state, retval);

	throttle_lowpri_io(1);

#if DEBUG || DEVELOPMENT
	kern_allocation_name_t
	prior __assert_only = thread_get_kernel_state(current_thread())->allocation_name;
	assertf(prior == NULL, "thread_set_allocation_name(\"%s\") not cleared", kern_allocation_get_name(prior));
#endif /* DEBUG || DEVELOPMENT */

#if PROC_REF_DEBUG
	if (__improbable(uthread_get_proc_refcount(ut) != 0)) {
		panic("system call returned with uu_proc_refcount != 0");
	}
#endif

	return;

bad:
	exc_code = call_number;
	exception_triage(EXC_SYSCALL, &exc_code, 1);
	/* NOTREACHED */
	panic("Returned from exception_triage()?\n");
}
#endif /* MACH_BSD */
Commit	Line	Data
5ba3f43e	1	/*
cb323159	2	* Copyright (c) 2019 Apple Inc. All rights reserved.
5ba3f43e A	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
0a7de745	29	#ifdef MACH_BSD
5ba3f43e A	30	#include <mach_debug.h>
	31	#include <mach_ldebug.h>
	32
	33	#include <mach/kern_return.h>
	34	#include <mach/mach_traps.h>
	35	#include <mach/vm_param.h>
	36
	37	#include <kern/counters.h>
	38	#include <kern/cpu_data.h>
	39	#include <arm/cpu_data_internal.h>
	40	#include <kern/mach_param.h>
	41	#include <kern/task.h>
	42	#include <kern/thread.h>
	43	#include <kern/sched_prim.h>
	44	#include <kern/misc_protos.h>
	45	#include <kern/assert.h>
	46	#include <kern/spl.h>
	47	#include <kern/syscall_sw.h>
	48	#include <ipc/ipc_port.h>
	49	#include <vm/vm_kern.h>
	50	#include <mach/thread_status.h>
	51	#include <vm/pmap.h>
	52
	53	#include <sys/kdebug.h>
	54
	55	#include <sys/syscall.h>
	56
	57	extern void throttle_lowpri_io(int);
	58	void mach_syscall(struct arm_saved_state*);
	59	typedef kern_return_t (mach_call_t)(void );
	60
	61	struct mach_call_args {
	62	syscall_arg_t arg1;
	63	syscall_arg_t arg2;
	64	syscall_arg_t arg3;
	65	syscall_arg_t arg4;
	66	syscall_arg_t arg5;
	67	syscall_arg_t arg6;
	68	syscall_arg_t arg7;
	69	syscall_arg_t arg8;
	70	syscall_arg_t arg9;
	71	};
	72
	73	static void
0a7de745	74	arm_set_mach_syscall_ret(struct arm_saved_state *state, int retval)
5ba3f43e A	75	{
	76	if (is_saved_state32(state)) {
	77	saved_state32(state)->r[0] = retval;
	78	} else {
	79	saved_state64(state)->x[0] = retval;
	80	}
	81	}
	82
	83	static kern_return_t
	84	arm_get_mach_syscall_args(struct arm_saved_state state, struct mach_call_args dest, const mach_trap_t *trapp)
	85	{
	86	uint32_t reg_count;
	87
	88	if (is_saved_state32(state)) {
	89	/* The trap table entry defines the number of 32-bit words to be copied in from userspace. */
	90	reg_count = trapp->mach_trap_u32_words;
0a7de745 A	91
	92	/*
	93	* We get 7 contiguous words; r0-r6, hop over r7
	94	* (frame pointer), optionally r8
5ba3f43e A	95	*/
	96	if (reg_count <= 7) {
	97	bcopy((char)saved_state32(state), (char)dest, sizeof(uint32_t) * reg_count);
	98	} else if (reg_count <= 9) {
	99	bcopy((char)saved_state32(state), (char)dest, sizeof(uint32_t) * 7);
0a7de745 A	100	bcopy((char)&saved_state32(state)->r[8], ((char)dest) + sizeof(uint32_t) * 7,
0a7de745 A	101	reg_count - 7);
5ba3f43e A	102	} else {
	103	panic("Trap with %d words of args? We only support 9.", reg_count);
	104	}
	105
	106	#if CONFIG_REQUIRES_U32_MUNGING
	107	trapp->mach_trap_arg_munge32(dest);
	108	#else
	109	#error U32 mach traps on ARM64 kernel requires munging
	110	#endif
0a7de745	111	} else {
5ba3f43e A	112	assert(is_saved_state64(state));
	113	bcopy((char)saved_state64(state), (char)dest, trapp->mach_trap_arg_count * sizeof(uint64_t));
	114	}
	115
	116	return KERN_SUCCESS;
	117	}
	118
	119	kern_return_t
	120	thread_setsinglestep(__unused thread_t thread, __unused int on)
	121	{
0a7de745	122	return KERN_FAILURE; /* XXX TODO */
5ba3f43e A	123	}
	124
	125	#if CONFIG_DTRACE
	126
	127	vm_offset_t dtrace_get_cpu_int_stack_top(void);
	128
	129	vm_offset_t
	130	dtrace_get_cpu_int_stack_top(void)
	131	{
	132	return getCpuDatap()->intstack_top;
	133	}
	134	#endif /* CONFIG_DTRACE */
	135	extern const char *mach_syscall_name_table[];
	136
	137	/* ARM64_TODO: remove this. still TODO?*/
	138	extern struct proc* current_proc(void);
	139	extern int proc_pid(struct proc*);
	140
	141	void
	142	mach_syscall(struct arm_saved_state *state)
	143	{
	144	kern_return_t retval;
	145	mach_call_t mach_call;
cb323159 A	146	struct mach_call_args args = {
	147	.arg1 = 0,
	148	.arg2 = 0,
	149	.arg3 = 0,
	150	.arg4 = 0,
	151	.arg5 = 0,
	152	.arg6 = 0,
	153	.arg7 = 0,
	154	.arg8 = 0,
	155	.arg9 = 0
	156	};
5ba3f43e A	157	int call_number = get_saved_state_svc_number(state);
	158	int64_t exc_code;
	159	int argc;
	160
	161	struct uthread *ut = get_bsdthread_info(current_thread());
	162	uthread_reset_proc_refcount(ut);
	163
	164	assert(call_number < 0); /* Otherwise it would be a Unix syscall */
	165	call_number = -call_number;
	166
	167	if (call_number >= MACH_TRAP_TABLE_COUNT) {
	168	goto bad;
	169	}
	170
	171	DEBUG_KPRINT_SYSCALL_MACH(
	172	"mach_syscall: code=%d(%s) (pid %d, tid %lld)\n",
0a7de745	173	call_number, mach_syscall_name_table[call_number],
5ba3f43e A	174	proc_pid(current_proc()), thread_tid(current_thread()));
	175
	176	#if DEBUG_TRACE
	177	kprintf("mach_syscall(0x%08x) code=%d\n", state, call_number);
	178	#endif
	179
	180	mach_call = (mach_call_t)mach_trap_table[call_number].mach_trap_function;
	181
	182	if (mach_call == (mach_call_t)kern_invalid) {
	183	DEBUG_KPRINT_SYSCALL_MACH(
	184	"mach_syscall: kern_invalid 0x%x\n", call_number);
	185	goto bad;
	186	}
	187
	188	argc = mach_trap_table[call_number].mach_trap_arg_count;
	189	if (argc) {
	190	retval = arm_get_mach_syscall_args(state, &args, &mach_trap_table[call_number]);
	191	if (retval != KERN_SUCCESS) {
	192	arm_set_mach_syscall_ret(state, retval);
	193
	194	DEBUG_KPRINT_SYSCALL_MACH(
	195	"mach_syscall: retval=0x%x\n", retval);
	196	return;
	197	}
	198	}
	199
	200	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
0a7de745 A	201	MACHDBG_CODE(DBG_MACH_EXCP_SC, (call_number)) \| DBG_FUNC_START,
0a7de745 A	202	args.arg1, args.arg2, args.arg3, args.arg4, 0);
5ba3f43e A	203
	204	retval = mach_call(&args);
	205
	206	DEBUG_KPRINT_SYSCALL_MACH("mach_syscall: retval=0x%x (pid %d, tid %lld)\n", retval,
0a7de745	207	proc_pid(current_proc()), thread_tid(current_thread()));
5ba3f43e A	208
5ba3f43e A	209	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
0a7de745 A	210	MACHDBG_CODE(DBG_MACH_EXCP_SC, (call_number)) \| DBG_FUNC_END,
0a7de745 A	211	retval, 0, 0, 0, 0);
5ba3f43e A	212
	213	arm_set_mach_syscall_ret(state, retval);
	214
	215	throttle_lowpri_io(1);
	216
	217	#if DEBUG \|\| DEVELOPMENT
	218	kern_allocation_name_t
	219	prior __assert_only = thread_get_kernel_state(current_thread())->allocation_name;
	220	assertf(prior == NULL, "thread_set_allocation_name(\"%s\") not cleared", kern_allocation_get_name(prior));
	221	#endif /* DEBUG \|\| DEVELOPMENT */
	222
	223	#if PROC_REF_DEBUG
	224	if (__improbable(uthread_get_proc_refcount(ut) != 0)) {
	225	panic("system call returned with uu_proc_refcount != 0");
	226	}
	227	#endif
	228
	229	return;
	230
	231	bad:
	232	exc_code = call_number;
	233	exception_triage(EXC_SYSCALL, &exc_code, 1);
	234	/* NOTREACHED */
	235	panic("Returned from exception_triage()?\n");
	236	}
	237	#endif /* MACH_BSD */