Source of /osfmk/kdp/ml/x86_64/kdp_machdep.c (From xnu-11215.1.10)

/*
 * Copyright (c) 2000-2006 Apple Computer, 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.
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#include <mach_kdp.h>
#include <mach/mach_types.h>
#include <mach/machine.h>
#include <mach/exception_types.h>
#include <kern/cpu_data.h>
#include <i386/trap.h>
#include <i386/mp.h>
#include <kdp/kdp_internal.h>
#include <mach-o/loader.h>
#include <mach-o/nlist.h>
#include <IOKit/IOPlatformExpert.h> /* for PE_halt_restart */
#include <kern/machine.h> /* for halt_all_cpus */
#include <libkern/OSAtomic.h>

#include <kern/thread.h>
#include <i386/thread.h>
#include <i386/trap_internal.h>
#include <vm/vm_map.h>
#include <i386/pmap.h>

#define KDP_TEST_HARNESS 0
#if KDP_TEST_HARNESS
#define dprintf(x) printf x
#else
#define dprintf(x)
#endif

extern cpu_type_t cpuid_cputype(void);
extern cpu_subtype_t cpuid_cpusubtype(void);

void            print_saved_state(void *);
void            kdp_call(void);
int             kdp_getc(void);
void            kdp_getstate(x86_thread_state64_t *);
void            kdp_setstate(x86_thread_state64_t *);
unsigned machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len);
int machine_trace_thread64(thread_t thread, char * tracepos, char * tracebound,
    int nframes, uint32_t * thread_trace_flags);

void
kdp_exception(
	unsigned char       *pkt,
	int *len,
	unsigned short      *remote_port,
	unsigned int        exception,
	unsigned int        code,
	unsigned int        subcode
	)
{
	kdp_exception_t     *rq = (kdp_exception_t *)pkt;

	rq->hdr.request = KDP_EXCEPTION;
	rq->hdr.is_reply = 0;
	rq->hdr.seq = kdp.exception_seq;
	rq->hdr.key = 0;
	rq->hdr.len = sizeof(*rq);

	rq->n_exc_info = 1;
	rq->exc_info[0].cpu = 0;
	rq->exc_info[0].exception = exception;
	rq->exc_info[0].code = code;
	rq->exc_info[0].subcode = subcode;

	rq->hdr.len += rq->n_exc_info * sizeof(kdp_exc_info_t);

	bcopy((char *)rq, (char *)pkt, rq->hdr.len);

	kdp.exception_ack_needed = TRUE;

	*remote_port = kdp.exception_port;
	*len = rq->hdr.len;
}

boolean_t
kdp_exception_ack(
	unsigned char       *pkt,
	int                 len
	)
{
	kdp_exception_ack_t *rq = (kdp_exception_ack_t *)pkt;

	if (((unsigned int) len) < sizeof(*rq)) {
		return FALSE;
	}

	if (!rq->hdr.is_reply || rq->hdr.request != KDP_EXCEPTION) {
		return FALSE;
	}

	dprintf(("kdp_exception_ack seq %x %x\n", rq->hdr.seq, kdp.exception_seq));

	if (rq->hdr.seq == kdp.exception_seq) {
		kdp.exception_ack_needed = FALSE;
		kdp.exception_seq++;
	}
	return TRUE;
}

void
kdp_getstate(
	x86_thread_state64_t        *state
	)
{
	x86_saved_state64_t *saved_state;

	saved_state = (x86_saved_state64_t *)kdp.saved_state;

	state->rax = saved_state->rax;
	state->rbx = saved_state->rbx;
	state->rcx = saved_state->rcx;
	state->rdx = saved_state->rdx;
	state->rdi = saved_state->rdi;
	state->rsi = saved_state->rsi;
	state->rbp = saved_state->rbp;

	state->r8  = saved_state->r8;
	state->r9  = saved_state->r9;
	state->r10 = saved_state->r10;
	state->r11 = saved_state->r11;
	state->r12 = saved_state->r12;
	state->r13 = saved_state->r13;
	state->r14 = saved_state->r14;
	state->r15 = saved_state->r15;

	state->rsp = saved_state->isf.rsp;
	state->rflags = saved_state->isf.rflags;
	state->rip = saved_state->isf.rip;

	state->cs = saved_state->isf.cs;
	state->fs = saved_state->fs;
	state->gs = saved_state->gs;
}


void
kdp_setstate(
	x86_thread_state64_t        *state
	)
{
	x86_saved_state64_t         *saved_state;

	saved_state = (x86_saved_state64_t *)kdp.saved_state;
	saved_state->rax = state->rax;
	saved_state->rbx = state->rbx;
	saved_state->rcx = state->rcx;
	saved_state->rdx = state->rdx;
	saved_state->rdi = state->rdi;
	saved_state->rsi = state->rsi;
	saved_state->rbp = state->rbp;
	saved_state->r8  = state->r8;
	saved_state->r9  = state->r9;
	saved_state->r10 = state->r10;
	saved_state->r11 = state->r11;
	saved_state->r12 = state->r12;
	saved_state->r13 = state->r13;
	saved_state->r14 = state->r14;
	saved_state->r15 = state->r15;

	saved_state->isf.rflags = state->rflags;
	saved_state->isf.rsp = state->rsp;
	saved_state->isf.rip = state->rip;

	saved_state->fs = (uint32_t)state->fs;
	saved_state->gs = (uint32_t)state->gs;
}


kdp_error_t
kdp_machine_read_regs(
	__unused unsigned int cpu,
	unsigned int flavor,
	char *data,
	int *size
	)
{
	static x86_float_state64_t  null_fpstate;

	switch (flavor) {
	case x86_THREAD_STATE64:
		dprintf(("kdp_readregs THREAD_STATE64\n"));
		kdp_getstate((x86_thread_state64_t *)data);
		*size = sizeof(x86_thread_state64_t);
		return KDPERR_NO_ERROR;

	case x86_FLOAT_STATE64:
		dprintf(("kdp_readregs THREAD_FPSTATE64\n"));
		*(x86_float_state64_t *)data = null_fpstate;
		*size = sizeof(x86_float_state64_t);
		return KDPERR_NO_ERROR;

	default:
		dprintf(("kdp_readregs bad flavor %d\n", flavor));
		*size = 0;
		return KDPERR_BADFLAVOR;
	}
}

kdp_error_t
kdp_machine_write_regs(
	__unused unsigned int cpu,
	unsigned int flavor,
	char *data,
	__unused int *size
	)
{
	switch (flavor) {
	case x86_THREAD_STATE64:
		dprintf(("kdp_writeregs THREAD_STATE64\n"));
		kdp_setstate((x86_thread_state64_t *)data);
		return KDPERR_NO_ERROR;

	case x86_FLOAT_STATE64:
		dprintf(("kdp_writeregs THREAD_FPSTATE64\n"));
		return KDPERR_NO_ERROR;

	default:
		dprintf(("kdp_writeregs bad flavor %d\n", flavor));
		return KDPERR_BADFLAVOR;
	}
}



void
kdp_machine_hostinfo(
	kdp_hostinfo_t *hostinfo
	)
{
	int                 i;

	hostinfo->cpus_mask = 0;

	for (i = 0; i < machine_info.max_cpus; i++) {
		if (cpu_data_ptr[i] == NULL) {
			continue;
		}

		hostinfo->cpus_mask |= (1 << i);
	}

	hostinfo->cpu_type = cpuid_cputype() | CPU_ARCH_ABI64;
	hostinfo->cpu_subtype = cpuid_cpusubtype();
}

void
kdp_panic(
	const char          *fmt,
	...
	)
{
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wformat-nonliteral"
	char kdp_fmt[256];
	va_list args;

	va_start(args, fmt);
	(void) snprintf(kdp_fmt, sizeof(kdp_fmt), "kdp panic: %s", fmt);
	vprintf(kdp_fmt, args);
	va_end(args);

	__asm__ volatile ("hlt");
#pragma clang diagnostic pop
}

int
kdp_intr_disbl(void)
{
	return splhigh();
}

void
kdp_intr_enbl(int s)
{
	splx(s);
}

int
kdp_getc(void)
{
	return console_try_read_char();
}

void
kdp_us_spin(int usec)
{
	delay(usec / 100);
}

void
print_saved_state(void *state)
{
	x86_saved_state64_t         *saved_state;

	saved_state = state;

	kprintf("pc = 0x%llx\n", saved_state->isf.rip);
	kprintf("cr2= 0x%llx\n", saved_state->cr2);
	kprintf("rp = TODO FIXME\n");
	kprintf("sp = %p\n", saved_state);
}

void
kdp_sync_cache(void)
{
	return; /* No op here. */
}

void
kdp_call(void)
{
	__asm__ volatile ("int	$3");   /* Let the processor do the work */
}


typedef struct _cframe_t {
	struct _cframe_t    *prev;
	unsigned            caller;
	unsigned            args[0];
} cframe_t;

boolean_t
kdp_i386_trap(
	unsigned int                trapno,
	x86_saved_state64_t *saved_state,
	kern_return_t       result,
	vm_offset_t         va
	)
{
	unsigned int exception, code, subcode = 0;
	boolean_t prev_interrupts_state;

	if (trapno != T_INT3 && trapno != T_DEBUG) {
		kprintf("Debugger: Unexpected kernel trap number: "
		    "0x%x, RIP: 0x%llx, CR2: 0x%llx\n",
		    trapno, saved_state->isf.rip, saved_state->cr2);
		if (!kdp.is_conn) {
			return FALSE;
		}
	}

	prev_interrupts_state = ml_set_interrupts_enabled(FALSE);
	disable_preemption();

	if (saved_state->isf.rflags & EFL_TF) {
		enable_preemption_no_check();
	}

	switch (trapno) {
	case T_DIVIDE_ERROR:
		exception = EXC_ARITHMETIC;
		code = EXC_I386_DIVERR;
		break;

	case T_OVERFLOW:
		exception = EXC_SOFTWARE;
		code = EXC_I386_INTOFLT;
		break;

	case T_OUT_OF_BOUNDS:
		exception = EXC_ARITHMETIC;
		code = EXC_I386_BOUNDFLT;
		break;

	case T_INVALID_OPCODE:
		exception = EXC_BAD_INSTRUCTION;
		code = EXC_I386_INVOPFLT;
		break;

	case T_SEGMENT_NOT_PRESENT:
		exception = EXC_BAD_INSTRUCTION;
		code = EXC_I386_SEGNPFLT;
		subcode = (unsigned int)saved_state->isf.err;
		break;

	case T_STACK_FAULT:
		exception = EXC_BAD_INSTRUCTION;
		code = EXC_I386_STKFLT;
		subcode = (unsigned int)saved_state->isf.err;
		break;

	case T_GENERAL_PROTECTION:
		exception = EXC_BAD_INSTRUCTION;
		code = EXC_I386_GPFLT;
		subcode = (unsigned int)saved_state->isf.err;
		break;

	case T_PAGE_FAULT:
		exception = EXC_BAD_ACCESS;
		code = result;
		subcode = (unsigned int)va;
		break;

	case T_WATCHPOINT:
		exception = EXC_SOFTWARE;
		code = EXC_I386_ALIGNFLT;
		break;

	case T_DEBUG:
	case T_INT3:
		exception = EXC_BREAKPOINT;
		code = EXC_I386_BPTFLT;
		break;

	default:
		exception = EXC_BAD_INSTRUCTION;
		code = trapno;
		break;
	}

	if (current_cpu_datap()->cpu_fatal_trap_state) {
		current_cpu_datap()->cpu_post_fatal_trap_state = saved_state;
		saved_state = current_cpu_datap()->cpu_fatal_trap_state;
	}

	handle_debugger_trap(exception, code, subcode, saved_state);

	enable_preemption();
	ml_set_interrupts_enabled(prev_interrupts_state);

	/* If the instruction single step bit is set, disable kernel preemption
	 */
	if (saved_state->isf.rflags & EFL_TF) {
		disable_preemption();
	}

	return TRUE;
}

void
kdp_machine_get_breakinsn(
	uint8_t *bytes,
	uint32_t *size
	)
{
	bytes[0] = 0xcc;
	*size = 1;
}

#define RETURN_OFFSET64 8
/* Routine to encapsulate the 64-bit address read hack*/
unsigned
machine_read64(addr64_t srcaddr, caddr_t dstaddr, uint32_t len)
{
	return (unsigned)kdp_machine_vm_read(srcaddr, dstaddr, len);
}

int
machine_trace_thread64(thread_t thread,
    char * tracepos,
    char * tracebound,
    int nframes,
    uint32_t * thread_trace_flags)
{
	extern bool machine_trace_thread_validate_kva(vm_offset_t addr);

	uint64_t * tracebuf = (uint64_t *)tracepos;
	unsigned framesize  = sizeof(addr64_t);

	uint32_t fence             = 0;
	int framecount             = 0;
	addr64_t prev_rip          = 0;
	addr64_t prevsp            = 0;
	vm_offset_t kern_virt_addr = 0;

	nframes = (tracebound > tracepos) ? MIN(nframes, (int)((tracebound - tracepos) / framesize)) : 0;

	addr64_t stackptr = STACK_IKS(thread->kernel_stack)->k_rbp;
	prev_rip = STACK_IKS(thread->kernel_stack)->k_rip;
	prev_rip = VM_KERNEL_UNSLIDE(prev_rip);

	for (framecount = 0; framecount < nframes; framecount++) {
		*tracebuf++ = prev_rip;

		if (!stackptr || (stackptr == fence)) {
			break;
		}
		if (stackptr & 0x0000007) {
			break;
		}
		if (stackptr <= prevsp) {
			break;
		}

		kern_virt_addr = stackptr + RETURN_OFFSET64;
		bool ok = machine_trace_thread_validate_kva(kern_virt_addr);
		if (!ok) {
			if (thread_trace_flags) {
				*thread_trace_flags |= kThreadTruncatedBT;
			}
			break;
		}

		prev_rip = VM_KERNEL_UNSLIDE(*(uint64_t *)kern_virt_addr);
		prevsp = stackptr;

		kern_virt_addr = stackptr;
		ok = machine_trace_thread_validate_kva(kern_virt_addr);
		if (!ok) {
			if (thread_trace_flags) {
				*thread_trace_flags |= kThreadTruncatedBT;
			}
			break;
		}
		stackptr = *(uint64_t *)kern_virt_addr;
	}

	return (uint32_t) (((char *) tracebuf) - tracepos);
}

void
kdp_ml_enter_debugger(void)
{
	__asm__ __volatile__ ("int3");
}