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[apple/xnu.git] / bsd / dev / arm / dtrace_isa.c
diff --git a/bsd/dev/arm/dtrace_isa.c b/bsd/dev/arm/dtrace_isa.c
new file mode 100644 (file)
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--- /dev/null
@@ -0,0 +1,631 @@
+/*
+ * Copyright (c) 2005-2008 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.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#define MACH__POSIX_C_SOURCE_PRIVATE 1 /* pulls in suitable savearea from
+                                        * mach/ppc/thread_status.h */
+#include <arm/proc_reg.h>
+
+#include <kern/thread.h>
+#include <mach/thread_status.h>
+
+#include <stdarg.h>
+#include <string.h>
+#include <sys/malloc.h>
+#include <sys/time.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/proc_internal.h>
+#include <sys/kauth.h>
+#include <sys/dtrace.h>
+#include <sys/dtrace_impl.h>
+#include <libkern/OSAtomic.h>
+#include <kern/simple_lock.h>
+#include <kern/sched_prim.h>           /* for thread_wakeup() */
+#include <kern/thread_call.h>
+#include <kern/task.h>
+#include <miscfs/devfs/devfs.h>
+#include <mach/vm_param.h>
+
+extern struct arm_saved_state *find_kern_regs(thread_t);
+
+extern dtrace_id_t      dtrace_probeid_error;   /* special ERROR probe */
+typedef arm_saved_state_t savearea_t;
+
+extern lck_attr_t      *dtrace_lck_attr;
+extern lck_grp_t       *dtrace_lck_grp;
+
+int dtrace_arm_condition_true(int condition, int cpsr);
+
+/*
+ * Atomicity and synchronization
+ */
+inline void
+dtrace_membar_producer(void)
+{
+#if __ARM_SMP__
+       __asm__ volatile("dmb ish" : : : "memory");
+#else
+       __asm__ volatile("nop" : : : "memory");
+#endif
+}
+
+inline void
+dtrace_membar_consumer(void)
+{
+#if __ARM_SMP__
+       __asm__ volatile("dmb ish" : : : "memory");
+#else
+       __asm__ volatile("nop" : : : "memory");
+#endif
+}
+
+/*
+ * Interrupt manipulation
+ * XXX dtrace_getipl() can be called from probe context.
+ */
+int
+dtrace_getipl(void)
+{
+       /*
+        * XXX Drat, get_interrupt_level is MACH_KERNEL_PRIVATE
+        * in osfmk/kern/cpu_data.h
+        */
+       /* return get_interrupt_level(); */
+       return (ml_at_interrupt_context() ? 1 : 0);
+}
+
+#if __ARM_SMP__
+/*
+ * MP coordination
+ */
+
+decl_lck_mtx_data(static, dt_xc_lock);
+static uint32_t dt_xc_sync;
+
+typedef struct xcArg {
+       processorid_t   cpu;
+       dtrace_xcall_t  f;
+       void           *arg;
+} xcArg_t;
+
+static void
+xcRemote(void *foo)
+{
+       xcArg_t *pArg = (xcArg_t *) foo;
+
+       if (pArg->cpu == CPU->cpu_id || pArg->cpu == DTRACE_CPUALL)
+               (pArg->f) (pArg->arg);
+
+       if (hw_atomic_sub(&dt_xc_sync, 1) == 0)
+               thread_wakeup((event_t) &dt_xc_sync);
+}
+#endif
+
+/*
+ * dtrace_xcall() is not called from probe context.
+ */
+void
+dtrace_xcall(processorid_t cpu, dtrace_xcall_t f, void *arg)
+{
+#if __ARM_SMP__
+       /* Only one dtrace_xcall in flight allowed */
+       lck_mtx_lock(&dt_xc_lock);
+
+       xcArg_t xcArg;
+
+       xcArg.cpu = cpu;
+       xcArg.f = f;
+       xcArg.arg = arg;
+
+       cpu_broadcast_xcall(&dt_xc_sync, TRUE, xcRemote, (void*) &xcArg);
+
+       lck_mtx_unlock(&dt_xc_lock);
+       return;
+#else
+#pragma unused(cpu)
+       /* On uniprocessor systems, the cpu should always be either ourselves or all */
+       ASSERT(cpu == CPU->cpu_id || cpu == DTRACE_CPUALL);
+
+       (*f)(arg);
+       return;
+#endif
+}
+
+/*
+ * Initialization
+ */
+void
+dtrace_isa_init(void)
+{
+#if __ARM_SMP__
+       lck_mtx_init(&dt_xc_lock, dtrace_lck_grp, dtrace_lck_attr);
+#endif
+       return;
+}
+
+/*
+ * Runtime and ABI
+ */
+uint64_t
+dtrace_getreg(struct regs * savearea, uint_t reg)
+{
+       struct arm_saved_state *regs = (struct arm_saved_state *) savearea;
+       
+       /* beyond register limit? */
+       if (reg > ARM_SAVED_STATE32_COUNT - 1) {
+               DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
+               return (0);
+       }
+       return (uint64_t) ((unsigned int *) (&(regs->r)))[reg];
+}
+
+#define RETURN_OFFSET 4
+
+static int
+dtrace_getustack_common(uint64_t * pcstack, int pcstack_limit, user_addr_t pc,
+                       user_addr_t sp)
+{
+       int ret = 0;
+       
+       ASSERT(pcstack == NULL || pcstack_limit > 0);
+
+       while (pc != 0) {
+               ret++;
+               if (pcstack != NULL) {
+                       *pcstack++ = (uint64_t) pc;
+                       pcstack_limit--;
+                       if (pcstack_limit <= 0)
+                               break;
+               }
+
+               if (sp == 0)
+                       break;
+
+               pc = dtrace_fuword32((sp + RETURN_OFFSET));
+               sp = dtrace_fuword32(sp);
+       }
+
+       return (ret);
+}
+
+void
+dtrace_getupcstack(uint64_t * pcstack, int pcstack_limit)
+{
+       thread_t        thread = current_thread();
+       savearea_t     *regs;
+       user_addr_t     pc, sp;
+       volatile uint16_t *flags = (volatile uint16_t *) & cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
+       int n;
+
+       if (*flags & CPU_DTRACE_FAULT)
+               return;
+
+       if (pcstack_limit <= 0)
+               return;
+
+       /*
+        * If there's no user context we still need to zero the stack.
+        */
+       if (thread == NULL)
+               goto zero;
+
+       regs = (savearea_t *) find_user_regs(thread);
+       if (regs == NULL)
+               goto zero;
+
+       *pcstack++ = (uint64_t)dtrace_proc_selfpid();
+       pcstack_limit--;
+
+       if (pcstack_limit <= 0)
+               return;
+
+       pc = regs->pc;
+       sp = regs->sp;
+
+       if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
+               *pcstack++ = (uint64_t) pc;
+               pcstack_limit--;
+               if (pcstack_limit <= 0)
+                       return;
+
+               pc = regs->lr;
+       }
+
+       n = dtrace_getustack_common(pcstack, pcstack_limit, pc, regs->r[7]);
+
+       ASSERT(n >= 0);
+       ASSERT(n <= pcstack_limit);
+
+       pcstack += n;
+       pcstack_limit -= n;
+
+zero:
+       while (pcstack_limit-- > 0)
+               *pcstack++ = 0ULL;
+}
+
+int
+dtrace_getustackdepth(void)
+{
+       thread_t        thread = current_thread();
+       savearea_t     *regs;
+       user_addr_t     pc, sp;
+       int             n = 0;
+
+       if (thread == NULL)
+               return 0;
+
+       if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_FAULT))
+               return (-1);
+
+       regs = (savearea_t *) find_user_regs(thread);
+       if (regs == NULL)
+               return 0;
+
+       pc = regs->pc;
+       sp = regs->sp;
+
+       if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
+               n++;
+               pc = regs->lr;
+       }
+
+               /*
+        * Note that unlike ppc, the arm code does not use
+        * CPU_DTRACE_USTACK_FP. This is because arm always
+        * traces from the sp, even in syscall/profile/fbt
+        * providers.
+        */
+
+       n += dtrace_getustack_common(NULL, 0, pc, regs->r[7]);
+
+       return (n);
+}
+
+void
+dtrace_getufpstack(uint64_t * pcstack, uint64_t * fpstack, int pcstack_limit)
+{
+       /* XXX ARMTODO 64vs32 */
+       thread_t        thread = current_thread();
+       savearea_t      *regs;
+       user_addr_t     pc, sp;
+       
+       volatile        uint16_t  *flags = (volatile uint16_t *) & cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
+
+#if 0
+       uintptr_t oldcontext;
+       size_t          s1, s2;
+#endif
+
+       if (*flags & CPU_DTRACE_FAULT)
+               return;
+
+       if (pcstack_limit <= 0)
+               return;
+
+        /*
+        * If there's no user context we still need to zero the stack.
+        */
+       if (thread == NULL)
+               goto zero;
+
+       regs = (savearea_t *) find_user_regs(thread);
+       if (regs == NULL)
+               goto zero;
+       
+       *pcstack++ = (uint64_t)dtrace_proc_selfpid();
+       pcstack_limit--;
+
+       if (pcstack_limit <= 0)
+               return;
+       
+       pc = regs->pc;
+       sp = regs->sp;
+
+#if 0                          /* XXX signal stack crawl */
+       oldcontext = lwp->lwp_oldcontext;
+
+       if (p->p_model == DATAMODEL_NATIVE) {
+               s1 = sizeof(struct frame) + 2 * sizeof(long);
+               s2 = s1 + sizeof(siginfo_t);
+       } else {
+               s1 = sizeof(struct frame32) + 3 * sizeof(int);
+               s2 = s1 + sizeof(siginfo32_t);
+       }
+#endif
+
+       if (DTRACE_CPUFLAG_ISSET(CPU_DTRACE_ENTRY)) {
+               *pcstack++ = (uint64_t) pc;
+               *fpstack++ = 0;
+               pcstack_limit--;
+               if (pcstack_limit <= 0)
+                       return;
+
+               pc = dtrace_fuword32(sp);
+       }
+       while (pc != 0 && sp != 0) {
+               *pcstack++ = (uint64_t) pc;
+               *fpstack++ = sp;
+               pcstack_limit--;
+               if (pcstack_limit <= 0)
+                       break;
+
+#if 0                          /* XXX signal stack crawl */
+               if (oldcontext == sp + s1 || oldcontext == sp + s2) {
+                       if (p->p_model == DATAMODEL_NATIVE) {
+                               ucontext_t     *ucp = (ucontext_t *) oldcontext;
+                               greg_t         *gregs = ucp->uc_mcontext.gregs;
+
+                               sp = dtrace_fulword(&gregs[REG_FP]);
+                               pc = dtrace_fulword(&gregs[REG_PC]);
+
+                               oldcontext = dtrace_fulword(&ucp->uc_link);
+                       } else {
+                               ucontext_t     *ucp = (ucontext_t *) oldcontext;
+                               greg_t         *gregs = ucp->uc_mcontext.gregs;
+
+                               sp = dtrace_fuword32(&gregs[EBP]);
+                               pc = dtrace_fuword32(&gregs[EIP]);
+
+                               oldcontext = dtrace_fuword32(&ucp->uc_link);
+                       }
+               } else
+#endif
+               {
+                       pc = dtrace_fuword32((sp + RETURN_OFFSET));
+                       sp = dtrace_fuword32(sp);
+               }
+
+#if 0
+               /* XXX ARMTODO*/
+               /*
+                * This is totally bogus:  if we faulted, we're going to clear
+                * the fault and break.  This is to deal with the apparently
+                * broken Java stacks on x86.
+                */
+               if (*flags & CPU_DTRACE_FAULT) {
+                       *flags &= ~CPU_DTRACE_FAULT;
+                       break;
+               }
+#endif
+       }
+
+zero:
+       while (pcstack_limit-- > 0)
+               *pcstack++ = 0ULL;
+}
+
+void
+dtrace_getpcstack(pc_t * pcstack, int pcstack_limit, int aframes,
+                 uint32_t * intrpc)
+{
+       struct frame   *fp = (struct frame *) __builtin_frame_address(0);
+       struct frame   *nextfp, *minfp, *stacktop;
+       int             depth = 0;
+       int             on_intr;
+       int             last = 0;
+       uintptr_t       pc;
+       uintptr_t       caller = CPU->cpu_dtrace_caller;
+
+       if ((on_intr = CPU_ON_INTR(CPU)) != 0)
+               stacktop = (struct frame *) dtrace_get_cpu_int_stack_top();
+       else
+               stacktop = (struct frame *) (dtrace_get_kernel_stack(current_thread()) + kernel_stack_size);
+
+       minfp = fp;
+
+       aframes++;
+
+       if (intrpc != NULL && depth < pcstack_limit)
+               pcstack[depth++] = (pc_t) intrpc;
+
+       while (depth < pcstack_limit) {
+               nextfp = *(struct frame **) fp;
+               pc = *(uintptr_t *) (((uint32_t) fp) + RETURN_OFFSET);
+
+               if (nextfp <= minfp || nextfp >= stacktop) {
+                       if (on_intr) {
+                               /*
+                                * Hop from interrupt stack to thread stack.
+                                */
+                               arm_saved_state_t *arm_kern_regs = (arm_saved_state_t *) find_kern_regs(current_thread());
+                               if (arm_kern_regs) {
+                                       nextfp = (struct frame *)arm_kern_regs->r[7];
+
+                                       vm_offset_t kstack_base = dtrace_get_kernel_stack(current_thread());
+
+                                       minfp = (struct frame *)kstack_base;
+                                       stacktop = (struct frame *)(kstack_base + kernel_stack_size);
+
+                                       on_intr = 0;
+
+                                       if (nextfp <= minfp || nextfp >= stacktop) {
+                                               last = 1;
+                                       }
+                               } else {
+                                       /*
+                                        * If this thread was on the interrupt stack, but did not
+                                        * take an interrupt (i.e, the idle thread), there is no
+                                        * explicit saved state for us to use.
+                                        */
+                                       last = 1;
+                               }
+                       } else {
+                               /*
+                                * This is the last frame we can process; indicate
+                                * that we should return after processing this frame.
+                                */
+                               last = 1;
+                       }
+               }
+               if (aframes > 0) {
+                       if (--aframes == 0 && caller != (uintptr_t)NULL) {
+                               /*
+                                * We've just run out of artificial frames,
+                                * and we have a valid caller -- fill it in
+                                * now.
+                                */
+                               ASSERT(depth < pcstack_limit);
+                               pcstack[depth++] = (pc_t) caller;
+                               caller = (uintptr_t)NULL;
+                       }
+               } else {
+                       if (depth < pcstack_limit)
+                               pcstack[depth++] = (pc_t) pc;
+               }
+
+               if (last) {
+                       while (depth < pcstack_limit)
+                               pcstack[depth++] = (pc_t) NULL;
+                       return;
+               }
+               fp = nextfp;
+               minfp = fp;
+       }
+}
+
+int
+dtrace_instr_size(uint32_t instr, int thumb_mode)
+{
+       if (thumb_mode) {
+               uint16_t instr16 = *(uint16_t*) &instr;
+               if (((instr16 >> 11) & 0x1F) > 0x1C)
+                       return 4;
+               else
+                       return 2;
+       } else {
+               return 4;
+       }
+}
+
+uint64_t
+dtrace_getarg(int arg, int aframes, dtrace_mstate_t *mstate, dtrace_vstate_t *vstate)
+{
+#pragma unused(arg, aframes, mstate, vstate)
+#if 0
+       /* XXX ARMTODO */
+       uint64_t val;
+       uintptr_t *fp = (uintptr_t *)__builtin_frame_address(0);
+       uintptr_t *stack;
+       uintptr_t pc;
+       int i;
+
+       for (i = 1; i <= aframes; i++) {
+               fp = fp[0];
+               pc = fp[1];
+
+               if (dtrace_invop_callsite_pre != NULL
+                       && pc  >  (uintptr_t)dtrace_invop_callsite_pre
+                       && pc  <= (uintptr_t)dtrace_invop_callsite_post) {
+                       /*
+                        * If we pass through the invalid op handler, we will
+                        * use the pointer that it passed to the stack as the
+                        * second argument to dtrace_invop() as the pointer to
+                        * the frame we're hunting for.
+                        */
+
+                       stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
+                       fp = (struct frame *)stack[1]; /* Grab *second* argument */
+                       stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
+                       DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
+                       val = (uint64_t)(stack[arg]);
+                       DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
+                       return val;
+               }
+       }
+
+       /*
+        * Arrive here when provider has called dtrace_probe directly.
+        */
+       stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
+       stack++; /* Advance past probeID */
+
+       DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
+       val = *(((uint64_t *)stack) + arg); /* dtrace_probe arguments arg0 .. arg4 are 64bits wide */
+       DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
+       return (val);
+#endif
+       return 0xfeedfacedeafbeadLL;
+}
+
+void
+dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which,
+               int fltoffs, int fault, uint64_t illval)
+{
+       /* XXX ARMTODO */
+       /*
+        * For the case of the error probe firing lets
+        * stash away "illval" here, and special-case retrieving it in DIF_VARIABLE_ARG.
+        */
+       state->dts_arg_error_illval = illval;
+       dtrace_probe( dtrace_probeid_error, (uint64_t)(uintptr_t)state, epid, which, fltoffs, fault );
+}
+
+void
+dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
+{
+       /* XXX ARMTODO check copied from ppc/x86*/
+       /*
+        * "base" is the smallest toxic address in the range, "limit" is the first
+        * VALID address greater than "base".
+        */ 
+       func(0x0, VM_MIN_KERNEL_ADDRESS);
+       if (VM_MAX_KERNEL_ADDRESS < ~(uintptr_t)0)
+                       func(VM_MAX_KERNEL_ADDRESS + 1, ~(uintptr_t)0);
+}
+
+int
+dtrace_arm_condition_true(int cond, int cpsr)
+{
+       int taken = 0;
+       int zf = (cpsr & PSR_ZF) ? 1 : 0,
+           nf = (cpsr & PSR_NF) ? 1 : 0,
+           cf = (cpsr & PSR_CF) ? 1 : 0,
+           vf = (cpsr & PSR_VF) ? 1 : 0;
+
+       switch(cond) {
+               case 0: taken = zf; break;
+               case 1: taken = !zf; break;
+               case 2: taken = cf; break;
+               case 3: taken = !cf; break;
+               case 4: taken = nf; break;
+               case 5: taken = !nf; break;
+               case 6: taken = vf; break;
+               case 7: taken = !vf; break;
+               case 8: taken = (cf && !zf); break;
+               case 9: taken = (!cf || zf); break;
+               case 10: taken = (nf == vf); break;
+               case 11: taken = (nf != vf); break;
+               case 12: taken = (!zf && (nf == vf)); break;
+               case 13: taken = (zf || (nf != vf)); break;
+               case 14: taken = 1; break;
+               case 15: taken = 1; break; /* always "true" for ARM, unpredictable for THUMB. */
+       }
+
+       return taken;
+}