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#ifdef LISP_FEATURE_SB_THREAD
#include <architecture/i386/table.h>
#include <i386/user_ldt.h>
#include <mach/mach_init.h>
#endif
#include "thread.h"
#include "validate.h"
#include "runtime.h"
#include "interrupt.h"
#include "x86-64-darwin-os.h"
#include "genesis/fdefn.h"
#include <mach/mach.h>
#include <mach/mach_error.h>
#include <mach/mach_types.h>
#include <mach/sync_policy.h>
#include <mach/machine/thread_state.h>
#include <mach/machine/thread_status.h>
#include <sys/_types.h>
#include <sys/ucontext.h>
#include <pthread.h>
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#if __DARWIN_UNIX03
#include <sys/_structs.h>
#endif
#if __DARWIN_UNIX03
typedef struct __darwin_ucontext darwin_ucontext;
typedef struct __darwin_mcontext64 darwin_mcontext;
#define rip __rip
#define rsp __rsp
#define rbp __rbp
#define rax __rax
#define rbx __rbx
#define rcx __rcx
#define rdx __rdx
#define rsi __rsi
#define rdi __rdi
#define r8 __r8
#define r9 __r9
#define faultvaddr __faultvaddr
#define ss __ss
#define es __es
#define fs __fs
#define fpu_fcw __fpu_fcw
#define fpu_mxcsr __fpu_mxcsr
#else
typedef struct ucontext darwin_ucontext;
typedef struct mcontext darwin_mcontext;
#endif
#ifdef LISP_FEATURE_SB_THREAD
pthread_mutex_t mach_exception_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
kern_return_t mach_thread_init(mach_port_t thread_exception_port);
void sigill_handler(int signal, siginfo_t *siginfo, os_context_t *context);
void sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context);
void memory_fault_handler(int signal, siginfo_t *siginfo,
os_context_t *context);
/* This executes in the faulting thread as part of the signal
* emulation. It is passed a context with the uc_mcontext field
* pointing to a valid block of memory. */
void build_fake_signal_context(darwin_ucontext *context,
x86_thread_state64_t *thread_state,
x86_float_state64_t *float_state) {
pthread_sigmask(0, NULL, &context->uc_sigmask);
context->uc_mcontext->ss = *thread_state;
context->uc_mcontext->fs = *float_state;
}
/* This executes in the faulting thread as part of the signal
* emulation. It is effectively the inverse operation from above. */
void update_thread_state_from_context(x86_thread_state64_t *thread_state,
x86_float_state64_t *float_state,
darwin_ucontext *context) {
*thread_state = context->uc_mcontext->ss;
*float_state = context->uc_mcontext->fs;
pthread_sigmask(SIG_SETMASK, &context->uc_sigmask, NULL);
}
/* Modify a context to push new data on its stack. */
void push_context(u64 data, x86_thread_state64_t *context)
{
u64 *stack_pointer;
stack_pointer = (u64*) context->rsp;
*(--stack_pointer) = data;
context->rsp = (u64) stack_pointer;
}
void align_context_stack(x86_thread_state64_t *context)
{
/* 16byte align the stack (provided that the stack is, as it
* should be, 8byte aligned. */
while (context->rsp & 15) push_context(0, context);
}
/* Stack allocation starts with a context that has a mod-4 ESP value
* and needs to leave a context with a mod-16 ESP that will restore
* the old ESP value and other register state when activated. The
* first part of this is the recovery trampoline, which loads ESP from
* EBP, pops EBP, and returns. */
asm(".globl _stack_allocation_recover; \
.align 4; \
_stack_allocation_recover: \
lea -48(%rbp), %rsp; \
pop %rsi; \
pop %rdi; \
pop %rdx; \
pop %rcx; \
pop %r8; \
pop %r9; \
pop %rbp; \
ret;");
void open_stack_allocation(x86_thread_state64_t *context)
{
void stack_allocation_recover(void);
push_context(context->rip, context);
push_context(context->rbp, context);
context->rbp = context->rsp;
push_context(context->r9, context);
push_context(context->r8, context);
push_context(context->rcx, context);
push_context(context->rdx, context);
push_context(context->rsi, context);
push_context(context->rdi, context);
context->rip = (u64) stack_allocation_recover;
align_context_stack(context);
}
/* Stack allocation of data starts with a context with a mod-16 ESP
* value and reserves some space on it by manipulating the ESP
* register. */
void *stack_allocate(x86_thread_state64_t *context, size_t size)
{
/* round up size to 16byte multiple */
size = (size + 15) & -16;
context->rsp = ((u64)context->rsp) - size;
return (void *)context->rsp;
}
/* Arranging to invoke a C function is tricky, as we have to assume
* cdecl calling conventions (caller removes args) and x86/darwin
* alignment requirements. The simplest way to arrange this,
* actually, is to open a new stack allocation.
* WARNING!!! THIS DOES NOT PRESERVE REGISTERS! */
void call_c_function_in_context(x86_thread_state64_t *context,
void *function,
int nargs,
...)
{
va_list ap;
int i;
u64 *stack_pointer;
/* Set up to restore stack on exit. */
open_stack_allocation(context);
/* Have to keep stack 16byte aligned on x86/darwin. */
for (i = (1 & -nargs); i; i--) {
push_context(0, context);
}
context->rsp = ((u64)context->rsp) - nargs * 8;
stack_pointer = (u64 *)context->rsp;
va_start(ap, nargs);
if (nargs > 0) context->rdi = va_arg(ap, u64);
if (nargs > 1) context->rsi = va_arg(ap, u64);
if (nargs > 2) context->rdx = va_arg(ap, u64);
if (nargs > 3) context->rcx = va_arg(ap, u64);
if (nargs > 4) context->r8 = va_arg(ap, u64);
if (nargs > 5) context->r9 = va_arg(ap, u64);
for (i = 6; i < nargs; i++) {
stack_pointer[i] = va_arg(ap, u64);
}
va_end(ap);
push_context(context->rip, context);
context->rip = (u64) function;
}
void signal_emulation_wrapper(x86_thread_state64_t *thread_state,
x86_float_state64_t *float_state,
int signal,
siginfo_t *siginfo,
void (*handler)(int, siginfo_t *, void *))
{
/* CLH: FIXME **NOTE: HACK ALERT!** Ideally, we would allocate
* context and regs on the stack as local variables, but this
* causes problems for the lisp debugger. When it walks the stack
* for a back trace, it sees the 1) address of the local variable
* on the stack and thinks that is a frame pointer to a lisp
* frame, and, 2) the address of the sap that we alloc'ed in
* dynamic space and thinks that is a return address, so it,
* heuristicly (and wrongly), chooses that this should be
* interpreted as a lisp frame instead of as a C frame.
* We can work around this in this case by os_validating the
* context (and regs just for symmetry).
*/
darwin_ucontext *context;
darwin_mcontext *regs;
context = (darwin_ucontext *) os_validate(0, sizeof(darwin_ucontext));
regs = (darwin_mcontext*) os_validate(0, sizeof(darwin_mcontext));
context->uc_mcontext = regs;
/* when BSD signals are fired, they mask they signals in sa_mask
which always seem to be the blockable_sigset, for us, so we
need to:
1) save the current sigmask
2) block blockable signals
3) call the signal handler
4) restore the sigmask */
build_fake_signal_context(context, thread_state, float_state);
block_blockable_signals(0, 0);
handler(signal, siginfo, context);
update_thread_state_from_context(thread_state, float_state, context);
os_invalidate((os_vm_address_t)context, sizeof(darwin_ucontext));
os_invalidate((os_vm_address_t)regs, sizeof(darwin_mcontext));
/* Trap to restore the signal context. */
asm volatile ("mov %0, %%rax; mov %1, %%rbx; .quad 0xffffffffffff0b0f"
: : "r" (thread_state), "r" (float_state));
}
#if defined DUMP_CONTEXT
void dump_context(x86_thread_state64_t *context)
{
int i;
u64 *stack_pointer;
printf("rax: %08lx rcx: %08lx rdx: %08lx rbx: %08lx\n",
context->rax, context->rcx, context->rdx, context->rbx);
printf("rsp: %08lx rbp: %08lx rsi: %08lx rdi: %08lx\n",
context->rsp, context->rbp, context->rsi, context->rdi);
printf("rip: %08lx eflags: %08lx\n",
context->rip, context->rflags);
printf("cs: %04hx ds: %04hx es: %04hx "
"ss: %04hx fs: %04hx gs: %04hx\n",
context->cs, context->ds, context->rs,
context->ss, context->fs, context->gs);
stack_pointer = (u64 *)context->rsp;
for (i = 0; i < 48; i+=4) {
printf("%08x: %08x %08x %08x %08x\n",
context->rsp + (i * 4),
stack_pointer[i],
stack_pointer[i+1],
stack_pointer[i+2],
stack_pointer[i+3]);
}
}
#endif
void
control_stack_exhausted_handler(int signal, siginfo_t *siginfo,
os_context_t *context) {
unblock_signals_in_context_and_maybe_warn(context);
arrange_return_to_lisp_function
(context, StaticSymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
}
void
undefined_alien_handler(int signal, siginfo_t *siginfo, os_context_t *context) {
arrange_return_to_lisp_function
(context, StaticSymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
}
kern_return_t
catch_exception_raise(mach_port_t exception_port,
mach_port_t thread,
mach_port_t task,
exception_type_t exception,
exception_data_t code_vector,
mach_msg_type_number_t code_count)
{
kern_return_t ret, dealloc_ret;
int signal;
siginfo_t* siginfo;
#ifdef LISP_FEATURE_SB_THREAD
thread_mutex_lock(&mach_exception_lock);
#endif
x86_thread_state64_t thread_state;
mach_msg_type_number_t thread_state_count = x86_THREAD_STATE64_COUNT;
x86_float_state64_t float_state;
mach_msg_type_number_t float_state_count = x86_FLOAT_STATE64_COUNT;
x86_exception_state64_t exception_state;
mach_msg_type_number_t exception_state_count = x86_EXCEPTION_STATE64_COUNT;
x86_thread_state64_t backup_thread_state;
x86_thread_state64_t *target_thread_state;
x86_float_state64_t *target_float_state;
os_vm_address_t addr;
struct thread *th = (struct thread*) exception_port;
FSHOW((stderr,"/entering catch_exception_raise with exception: %d\n", exception));
switch (exception) {
case EXC_BAD_ACCESS:
signal = SIGBUS;
ret = thread_get_state(thread,
x86_THREAD_STATE64,
(thread_state_t)&thread_state,
&thread_state_count);
ret = thread_get_state(thread,
x86_FLOAT_STATE64,
(thread_state_t)&float_state,
&float_state_count);
ret = thread_get_state(thread,
x86_EXCEPTION_STATE64,
(thread_state_t)&exception_state,
&exception_state_count);
addr = (void*)exception_state.faultvaddr;
/* note the os_context hackery here. When the signal handler returns,
* it won't go back to what it was doing ... */
if(addr >= CONTROL_STACK_GUARD_PAGE(th) &&
addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
/* We hit the end of the control stack: disable guard page
* protection so the error handler has some headroom, protect the
* previous page so that we can catch returns from the guard page
* and restore it. */
lower_thread_control_stack_guard_page(th);
backup_thread_state = thread_state;
open_stack_allocation(&thread_state);
/* Reserve a 256 byte zone for signal handlers
* to use on the interrupted thread stack.
*/
stack_allocate(&thread_state, 256);
/* Save thread state */
target_thread_state =
stack_allocate(&thread_state, sizeof(*target_thread_state));
(*target_thread_state) = backup_thread_state;
/* Save float state */
target_float_state =
stack_allocate(&thread_state, sizeof(*target_float_state));
(*target_float_state) = float_state;
/* Set up siginfo */
siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
/* what do we need to put in our fake siginfo? It looks like
* the x86 code only uses si_signo and si_adrr. */
siginfo->si_signo = signal;
siginfo->si_addr = (void*)exception_state.faultvaddr;
call_c_function_in_context(&thread_state,
signal_emulation_wrapper,
5,
target_thread_state,
target_float_state,
signal,
siginfo,
control_stack_exhausted_handler);
}
else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
/* We're returning from the guard page: reprotect it, and
* unprotect this one. This works even if we somehow missed
* the return-guard-page, and hit it on our way to new
* exhaustion instead. */
reset_thread_control_stack_guard_page(th);
}
else if (addr >= undefined_alien_address &&
addr < undefined_alien_address + os_vm_page_size) {
backup_thread_state = thread_state;
open_stack_allocation(&thread_state);
stack_allocate(&thread_state, 256);
/* Save thread state */
target_thread_state =
stack_allocate(&thread_state, sizeof(*target_thread_state));
(*target_thread_state) = backup_thread_state;
target_float_state =
stack_allocate(&thread_state, sizeof(*target_float_state));
(*target_float_state) = float_state;
/* Set up siginfo */
siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
/* what do we need to put in our fake siginfo? It looks like
* the x86 code only uses si_signo and si_adrr. */
siginfo->si_signo = signal;
siginfo->si_addr = (void*)exception_state.faultvaddr;
call_c_function_in_context(&thread_state,
signal_emulation_wrapper,
5,
target_thread_state,
target_float_state,
signal,
siginfo,
undefined_alien_handler);
} else {
backup_thread_state = thread_state;
open_stack_allocation(&thread_state);
stack_allocate(&thread_state, 256);
/* Save thread state */
target_thread_state =
stack_allocate(&thread_state, sizeof(*target_thread_state));
(*target_thread_state) = backup_thread_state;
target_float_state =
stack_allocate(&thread_state, sizeof(*target_float_state));
(*target_float_state) = float_state;
/* Set up siginfo */
siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
/* what do we need to put in our fake siginfo? It looks like
* the x86 code only uses si_signo and si_adrr. */
siginfo->si_signo = signal;
siginfo->si_addr = (void*)exception_state.faultvaddr;
call_c_function_in_context(&thread_state,
signal_emulation_wrapper,
5,
target_thread_state,
target_float_state,
signal,
siginfo,
memory_fault_handler);
}
ret = thread_set_state(thread,
x86_THREAD_STATE64,
(thread_state_t)&thread_state,
thread_state_count);
ret = thread_set_state(thread,
x86_FLOAT_STATE64,
(thread_state_t)&float_state,
float_state_count);
#ifdef LISP_FEATURE_SB_THREAD
thread_mutex_unlock(&mach_exception_lock);
#endif
ret = KERN_SUCCESS;
break;
case EXC_BAD_INSTRUCTION:
ret = thread_get_state(thread,
x86_THREAD_STATE64,
(thread_state_t)&thread_state,
&thread_state_count);
ret = thread_get_state(thread,
x86_FLOAT_STATE64,
(thread_state_t)&float_state,
&float_state_count);
ret = thread_get_state(thread,
x86_EXCEPTION_STATE64,
(thread_state_t)&exception_state,
&exception_state_count);
if (0xffffffffffff0b0f == *((u64 *)thread_state.rip)) {
/* fake sigreturn. */
/* When we get here, thread_state.rax is a pointer to a
* thread_state to restore. */
/* thread_state = *((thread_state_t *)thread_state.rax); */
ret = thread_set_state(thread,
x86_THREAD_STATE64,
(thread_state_t) thread_state.rax,
/* &thread_state, */
thread_state_count);
ret = thread_set_state(thread,
x86_FLOAT_STATE64,
(thread_state_t) thread_state.rbx,
/* &thread_state, */
float_state_count);
} else {
backup_thread_state = thread_state;
open_stack_allocation(&thread_state);
stack_allocate(&thread_state, 256);
/* Save thread state */
target_thread_state =
stack_allocate(&thread_state, sizeof(*target_thread_state));
(*target_thread_state) = backup_thread_state;
target_float_state =
stack_allocate(&thread_state, sizeof(*target_float_state));
(*target_float_state) = float_state;
/* Set up siginfo */
siginfo = stack_allocate(&thread_state, sizeof(*siginfo));
/* what do we need to put in our fake siginfo? It looks like
* the x86 code only uses si_signo and si_adrr. */
if (*((unsigned short *)target_thread_state->rip) == 0x0b0f) {
signal = SIGTRAP;
siginfo->si_signo = signal;
siginfo->si_addr = (void*)exception_state.faultvaddr;
target_thread_state->rip += 2;
call_c_function_in_context(&thread_state,
signal_emulation_wrapper,
5,
target_thread_state,
target_float_state,
signal,
siginfo,
sigtrap_handler);
} else {
signal = SIGILL;
siginfo->si_signo = signal;
siginfo->si_addr = (void*)exception_state.faultvaddr;
call_c_function_in_context(&thread_state,
signal_emulation_wrapper,
5,
target_thread_state,
target_float_state,
signal,
siginfo,
sigill_handler);
}
ret = thread_set_state(thread,
x86_THREAD_STATE64,
(thread_state_t)&thread_state,
thread_state_count);
ret = thread_set_state(thread,
x86_FLOAT_STATE64,
(thread_state_t)&float_state,
float_state_count);
}
#ifdef LISP_FEATURE_SB_THREAD
thread_mutex_unlock(&mach_exception_lock);
#endif
ret = KERN_SUCCESS;
break;
default:
#ifdef LISP_FEATURE_SB_THREAD
thread_mutex_unlock(&mach_exception_lock);
#endif
ret = KERN_INVALID_RIGHT;
}
dealloc_ret = mach_port_deallocate (current_mach_task, thread);
if (dealloc_ret) {
lose("mach_port_deallocate (thread) failed with return_code %d\n", dealloc_ret);
}
dealloc_ret = mach_port_deallocate (current_mach_task, task);
if (dealloc_ret) {
lose("mach_port_deallocate (task) failed with return_code %d\n", dealloc_ret);
}
return ret;
}
void
os_restore_fp_control(os_context_t *context)
{
/* KLUDGE: The x87 FPU control word is some nasty bitfield struct
* thing. Rather than deal with that, just grab it as a 16-bit
* integer. */
unsigned short fpu_control_word =
*((unsigned short *)&context->uc_mcontext->fs.fpu_fcw);
/* reset exception flags and restore control flags on SSE2 FPU */
unsigned int temp = (context->uc_mcontext->fs.fpu_mxcsr) & ~0x3F;
asm ("ldmxcsr %0" : : "m" (temp));
/* same for x87 FPU. */
asm ("fldcw %0" : : "m" (fpu_control_word));
}
#endif