bsd/dev/arm64/sdt_arm.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* #pragma ident        "@(#)sdt.c      1.6     06/03/24 SMI" */
  27
  28 #ifdef KERNEL
  29 #ifndef _KERNEL
  30 #define _KERNEL /* Solaris vs. Darwin */
  31 #endif
  32 #endif
  33
  34 #include <kern/cpu_data.h>
  35 #include <kern/debug.h>
  36 #include <kern/thread.h>
  37 #include <mach/thread_status.h>
  38 #include <mach/vm_param.h>
  39
  40 #include <sys/dtrace.h>
  41 #include <sys/dtrace_impl.h>
  42
  43 #include <sys/dtrace_glue.h>
  44
  45 #include <sys/sdt_impl.h>
  46
  47 extern sdt_probe_t      **sdt_probetab;
  48
  49 int
  50 sdt_invop(__unused uintptr_t addr, __unused uintptr_t *stack, __unused uintptr_t eax)
  51 {
  52 #pragma unused(eax)
  53         sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
  54
  55         for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
  56                 if ((uintptr_t) sdt->sdp_patchpoint == addr) {
  57                         struct arm_saved_state* regs = (struct arm_saved_state*) stack;
  58
  59                         dtrace_probe(sdt->sdp_id, get_saved_state_reg(regs, 0), get_saved_state_reg(regs, 1),
  60                             get_saved_state_reg(regs, 2), get_saved_state_reg(regs, 3),get_saved_state_reg(regs, 4));
  61
  62                         return (DTRACE_INVOP_NOP);
  63                 }
  64         }
  65
  66         return (0);
  67 }
  68
  69 struct frame {
  70         struct frame *backchain;
  71         uintptr_t retaddr;
  72 };
  73
  74 /*ARGSUSED*/
  75 uint64_t
  76 sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
  77 {
  78
  79 #pragma unused(arg,id,parg)     /* __APPLE__ */
  80
  81         uint64_t val = 0;
  82         struct frame *fp = (struct frame *)__builtin_frame_address(0);
  83         uintptr_t *stack;
  84         uintptr_t pc;
  85         int i;
  86
  87         /*
  88          * A total of eight arguments are passed via registers;  any argument
  89          * with an index of 7 or lower is therefore in a register.
  90          */
  91
  92         int inreg = 7;
  93
  94         for (i = 1; i <= aframes; i++) {
  95                 fp = fp->backchain;
  96                 pc = fp->retaddr;
  97
  98                 if (dtrace_invop_callsite_pre != NULL
  99                         && pc  >  (uintptr_t)dtrace_invop_callsite_pre
 100                         && pc  <= (uintptr_t)dtrace_invop_callsite_post) {
 101
 102                         /*
 103                          * When we pass through the invalid op handler,
 104                          * we expect to find the save area structure,
 105                          * pushed on the stack where we took the trap.
 106                          * If the argument we seek is passed in a register, then
 107                          * we can load it directly from this saved area.
 108                          * If the argument we seek is passed on the stack, then
 109                          * we increment the frame pointer further, to find the
 110                          * pushed args
 111                          */
 112
 113                         /* fp points to the dtrace_invop activation */
 114                         fp = fp->backchain; /* fbt_perfCallback  */
 115                         fp = fp->backchain; /* sleh_synchronous */
 116                         fp = fp->backchain; /* fleh_synchronous */
 117
 118                         arm_saved_state_t *tagged_regs = (arm_saved_state_t *)((uintptr_t *)&fp[1]);
 119                         arm_saved_state64_t *saved_state = saved_state64(tagged_regs);
 120
 121                         if (argno <= inreg) {
 122                                 /* The argument will be in a register */
 123                                 stack = (uintptr_t *)&saved_state->x[0];
 124                         } else {
 125                                 /* The argument will be found on the stack */
 126                                 fp = (struct frame *)(saved_state->sp);
 127                                 stack = (uintptr_t *)&fp[0]; /* Find marshalled arguments */
 128                                 argno -= (inreg + 1);
 129                         }
 130                         goto load;
 131                 }
 132         }
 133
 134         /*
 135          * We know that we did not come through a trap to get into
 136          * dtrace_probe() --  We arrive here when the provider has
 137          * called dtrace_probe() directly.
 138          * The probe ID is the first argument to dtrace_probe().
 139          * We must advance beyond that to get the argX.
 140          */
 141         argno++; /* Advance past probeID */
 142
 143         if (argno <= inreg) {
 144                 /*
 145                  * This shouldn't happen.  If the argument is passed in a
 146                  * register then it should have been, well, passed in a
 147                  * register...
 148                  */
 149                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
 150                 return (0);
 151         }
 152
 153         argno -= (inreg + 1);
 154         stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
 155
 156 load:
 157         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
 158         /* dtrace_probe arguments arg0 .. arg4 are 64bits wide */
 159         val = (uint64_t)(*(((uintptr_t *)stack) + argno));
 160         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
 161         return (val);
 162 }