1.0.1.1:
[sbcl.git] / src / runtime / x86-darwin-os.c
index fa924d5..feec962 100644 (file)
@@ -7,7 +7,23 @@
 #endif
 
 #include "thread.h"
+#include "validate.h"
+#include "runtime.h"
+#include "interrupt.h"
 #include "x86-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>
 
 #ifdef LISP_FEATURE_SB_THREAD
 
@@ -28,6 +44,10 @@ void set_data_desc_addr(data_desc_t* desc, void* addr)
 
 #endif
 
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+kern_return_t mach_thread_init(mach_port_t thread_exception_port);
+#endif
+
 int arch_os_thread_init(struct thread *thread) {
 #ifdef LISP_FEATURE_SB_THREAD
     int n;
@@ -36,7 +56,7 @@ int arch_os_thread_init(struct thread *thread) {
     data_desc_t ldt_entry = { 0, 0, 0, DESC_DATA_WRITE,
                               3, 1, 0, DESC_DATA_32B, DESC_GRAN_BYTE, 0 };
 
-    set_data_desc_addr(&ldt_entry, (unsigned long) thread);
+    set_data_desc_addr(&ldt_entry, thread);
     set_data_desc_size(&ldt_entry, dynamic_values_bytes);
 
     thread_mutex_lock(&modify_ldt_lock);
@@ -58,6 +78,9 @@ int arch_os_thread_init(struct thread *thread) {
     thread->tls_cookie=n;
     pthread_setspecific(specials,thread);
 #endif
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+    mach_thread_init(THREAD_STRUCT_TO_EXCEPTION_PORT(thread));
+#endif
 
 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
     stack_t sigstack;
@@ -90,3 +113,589 @@ int arch_os_thread_cleanup(struct thread *thread) {
     return 1;                  /* success */
 }
 
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+
+void sigill_handler(int signal, siginfo_t *siginfo, void *void_context);
+void sigtrap_handler(int signal, siginfo_t *siginfo, void *void_context);
+void memory_fault_handler(int signal, siginfo_t *siginfo, void *void_context);
+
+/* exc_server handles mach exception messages from the kernel and
+ * calls catch exception raise. We use the system-provided
+ * mach_msg_server, which, I assume, calls exc_server in a loop.
+ *
+ */
+extern boolean_t exc_server();
+
+/* 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(struct ucontext *context,
+                               x86_thread_state32_t *thread_state,
+                               x86_float_state32_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_state32_t *thread_state,
+                                      x86_float_state32_t *float_state,
+                                      struct 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(u32 data, x86_thread_state32_t *context)
+{
+    u32 *stack_pointer;
+
+    stack_pointer = (u32*) context->esp;
+    *(--stack_pointer) = data;
+    context->esp = (unsigned int) stack_pointer;
+}
+
+void align_context_stack(x86_thread_state32_t *context)
+{
+    /* 16byte align the stack (provided that the stack is, as it
+     * should be, 4byte aligned. */
+    while (context->esp & 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("_stack_allocation_recover: movl %ebp, %esp; popl %ebp; ret;");
+
+void open_stack_allocation(x86_thread_state32_t *context)
+{
+    void stack_allocation_recover(void);
+
+    push_context(context->eip, context);
+    push_context(context->ebp, context);
+    context->ebp = context->esp;
+    context->eip = (unsigned int) 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_state32_t *context, size_t size)
+{
+    /* round up size to 16byte multiple */
+    size = (size + 15) & -16;
+
+    context->esp = ((u32)context->esp) - size;
+
+    return (void *)context->esp;
+}
+
+/* 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_state32_t *context,
+                                void *function,
+                                int nargs,
+                                ...)
+{
+    va_list ap;
+    int i;
+    u32 *stack_pointer;
+
+    /* Set up to restore stack on exit. */
+    open_stack_allocation(context);
+
+    /* Have to keep stack 16byte aligned on x86/darwin. */
+    for (i = (3 & -nargs); i; i--) {
+        push_context(0, context);
+    }
+
+    context->esp = ((u32)context->esp) - nargs * 4;
+    stack_pointer = (u32 *)context->esp;
+
+    va_start(ap, nargs);
+    for (i = 0; i < nargs; i++) {
+        //push_context(va_arg(ap, u32), context);
+        stack_pointer[i] = va_arg(ap, u32);
+    }
+    va_end(ap);
+
+    push_context(context->eip, context);
+    context->eip = (unsigned int) function;
+}
+
+void signal_emulation_wrapper(x86_thread_state32_t *thread_state,
+                              x86_float_state32_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).
+     */
+
+    struct ucontext *context;
+    struct mcontext *regs;
+    sigset_t sigmask;
+
+    context = (struct ucontext*) os_validate(0, sizeof(struct ucontext));
+    regs = (struct mcontext*) os_validate(0, sizeof(struct 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 */
+
+    pthread_sigmask(0, NULL, &sigmask);
+    block_blockable_signals();
+
+    build_fake_signal_context(context, thread_state, float_state);
+
+    handler(signal, siginfo, context);
+
+    update_thread_state_from_context(thread_state, float_state, context);
+
+    pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
+
+    os_invalidate((os_vm_address_t)context, sizeof(struct ucontext));
+    os_invalidate((os_vm_address_t)regs, sizeof(struct mcontext));
+
+    /* Trap to restore the signal context. */
+    asm volatile ("movl %0, %%eax; .long 0xffff0b0f": : "r" (thread_state));
+}
+
+#if defined DUMP_CONTEXT
+void dump_context(x86_thread_state32_t *context)
+{
+    int i;
+    u32 *stack_pointer;
+
+    printf("eax: %08lx  ecx: %08lx  edx: %08lx  ebx: %08lx\n",
+           context->eax, context->ecx, context->edx, context->ebx);
+    printf("esp: %08lx  ebp: %08lx  esi: %08lx  edi: %08lx\n",
+           context->esp, context->ebp, context->esi, context->edi);
+    printf("eip: %08lx  eflags: %08lx\n",
+           context->eip, context->eflags);
+    printf("cs: %04hx  ds: %04hx  es: %04hx  "
+           "ss: %04hx  fs: %04hx  gs: %04hx\n",
+           context->cs, context->ds, context->es,
+           context->ss, context->fs, context->gs);
+
+    stack_pointer = (u32 *)context->esp;
+    for (i = 0; i < 48; i+=4) {
+        printf("%08x:  %08x %08x %08x %08x\n",
+               context->esp + (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, void *void_context) {
+    os_context_t *context = arch_os_get_context(&void_context);
+
+    arrange_return_to_lisp_function
+        (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
+}
+
+void
+undefined_alien_handler(int signal, siginfo_t *siginfo, void *void_context) {
+    os_context_t *context = arch_os_get_context(&void_context);
+
+    arrange_return_to_lisp_function
+        (context, SymbolFunction(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;
+    int signal;
+    siginfo_t* siginfo;
+
+    x86_thread_state32_t thread_state;
+    mach_msg_type_number_t thread_state_count = x86_THREAD_STATE32_COUNT;
+
+    x86_float_state32_t float_state;
+    mach_msg_type_number_t float_state_count = x86_FLOAT_STATE32_COUNT;
+
+    x86_exception_state32_t exception_state;
+    mach_msg_type_number_t exception_state_count = x86_EXCEPTION_STATE32_COUNT;
+
+    x86_thread_state32_t backup_thread_state;
+    x86_thread_state32_t *target_thread_state;
+    x86_float_state32_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_STATE32,
+                               (thread_state_t)&thread_state,
+                               &thread_state_count);
+        ret = thread_get_state(thread,
+                               x86_FLOAT_STATE32,
+                               (thread_state_t)&float_state,
+                               &float_state_count);
+        ret = thread_get_state(thread,
+                               x86_EXCEPTION_STATE32,
+                               (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. */
+            protect_control_stack_guard_page_thread(0, th);
+            protect_control_stack_return_guard_page_thread(1, th);
+
+            backup_thread_state = thread_state;
+            open_stack_allocation(&thread_state);
+
+            /* 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. */
+            protect_control_stack_guard_page_thread(1, th);
+            protect_control_stack_return_guard_page_thread(0, 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);
+
+            /* 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);
+
+            /* 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_STATE32,
+                               (thread_state_t)&thread_state,
+                               thread_state_count);
+
+        ret = thread_set_state(thread,
+                               x86_FLOAT_STATE32,
+                               (thread_state_t)&float_state,
+                               float_state_count);
+        return KERN_SUCCESS;
+
+    case EXC_BAD_INSTRUCTION:
+
+        ret = thread_get_state(thread,
+                               x86_THREAD_STATE32,
+                               (thread_state_t)&thread_state,
+                               &thread_state_count);
+        ret = thread_get_state(thread,
+                               x86_FLOAT_STATE32,
+                               (thread_state_t)&float_state,
+                               &float_state_count);
+        ret = thread_get_state(thread,
+                               x86_EXCEPTION_STATE32,
+                               (thread_state_t)&exception_state,
+                               &exception_state_count);
+        if (0xffff0b0f == *((u32 *)thread_state.eip)) {
+            /* fake sigreturn. */
+
+            /* When we get here, thread_state.eax is a pointer to a
+             * thread_state to restore. */
+            /* thread_state = *((thread_state_t *)thread_state.eax); */
+
+            ret = thread_set_state(thread,
+                                   x86_THREAD_STATE32,
+                                   (thread_state_t) thread_state.eax,
+                                   /* &thread_state, */
+                                   thread_state_count);
+        } else {
+
+            backup_thread_state = thread_state;
+            open_stack_allocation(&thread_state);
+
+            /* 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->eip) == 0x0b0f) {
+                signal = SIGTRAP;
+                siginfo->si_signo = signal;
+                siginfo->si_addr = (void*)exception_state.faultvaddr;
+                target_thread_state->eip += 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_STATE32,
+                                   (thread_state_t)&thread_state,
+                                   thread_state_count);
+            ret = thread_set_state(thread,
+                                   x86_FLOAT_STATE32,
+                                   (thread_state_t)&float_state,
+                                   float_state_count);
+        }
+        return KERN_SUCCESS;
+
+    default:
+        return KERN_INVALID_RIGHT;
+    }
+}
+
+void *
+mach_exception_handler(void *port)
+{
+  mach_msg_server(exc_server, 2048, (mach_port_t) port, 0);
+  /* mach_msg_server should never return, but it should dispatch mach
+   * exceptions to our catch_exception_raise function
+   */
+  abort();
+}
+
+#endif
+
+#ifdef LISP_FEATURE_MACH_EXCEPTION_HANDLER
+
+/* Sets up the thread that will listen for mach exceptions. note that
+   the exception handlers will be run on this thread. This is
+   different from the BSD-style signal handling situation in which the
+   signal handlers run in the relevant thread directly. */
+
+mach_port_t mach_exception_handler_port_set = MACH_PORT_NULL;
+
+pthread_t
+setup_mach_exception_handling_thread()
+{
+    kern_return_t ret;
+    pthread_t mach_exception_handling_thread = NULL;
+    pthread_attr_t attr;
+
+    /* allocate a mach_port for this process */
+    ret = mach_port_allocate(mach_task_self(),
+                             MACH_PORT_RIGHT_PORT_SET,
+                             &mach_exception_handler_port_set);
+
+    /* create the thread that will receive the mach exceptions */
+
+    FSHOW((stderr, "Creating mach_exception_handler thread!\n"));
+
+    pthread_attr_init(&attr);
+    pthread_create(&mach_exception_handling_thread,
+                   &attr,
+                   mach_exception_handler,
+                   (void*) mach_exception_handler_port_set);
+    pthread_attr_destroy(&attr);
+
+    return mach_exception_handling_thread;
+}
+
+/* tell the kernel that we want EXC_BAD_ACCESS exceptions sent to the
+   exception port (which is being listened to do by the mach
+   exception handling thread). */
+kern_return_t
+mach_thread_init(mach_port_t thread_exception_port)
+{
+    kern_return_t ret;
+    /* allocate a named port for the thread */
+
+    FSHOW((stderr, "Allocating mach port %x\n", thread_exception_port));
+
+    ret = mach_port_allocate_name(mach_task_self(),
+                                  MACH_PORT_RIGHT_RECEIVE,
+                                  thread_exception_port);
+    if (ret) {
+        lose("mach_port_allocate_name failed with return_code %d\n", ret);
+    }
+
+    /* establish the right for the thread_exception_port to send messages */
+    ret = mach_port_insert_right(mach_task_self(),
+                                 thread_exception_port,
+                                 thread_exception_port,
+                                 MACH_MSG_TYPE_MAKE_SEND);
+    if (ret) {
+        lose("mach_port_insert_right failed with return_code %d\n", ret);
+    }
+
+    ret = thread_set_exception_ports(mach_thread_self(),
+                                     EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION,
+                                     thread_exception_port,
+                                     EXCEPTION_DEFAULT,
+                                     THREAD_STATE_NONE);
+    if (ret) {
+        lose("thread_set_exception_port failed with return_code %d\n", ret);
+    }
+
+    ret = mach_port_move_member(mach_task_self(),
+                                thread_exception_port,
+                                mach_exception_handler_port_set);
+    if (ret) {
+        lose("mach_port_ failed with return_code %d\n", ret);
+    }
+
+    return ret;
+}
+
+void
+setup_mach_exceptions() {
+    setup_mach_exception_handling_thread();
+    mach_thread_init(THREAD_STRUCT_TO_EXCEPTION_PORT(all_threads));
+}
+
+pid_t
+mach_fork() {
+    pid_t pid = fork();
+    if (pid == 0) {
+        setup_mach_exceptions();
+        return pid;
+    } else {
+        return pid;
+    }
+}
+
+#endif