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 #include <kern/cpu_data.h>
  27 #include <kern/debug.h>
  28 #include <kern/thread.h>
  29 #include <mach/thread_status.h>
  30 #include <mach/vm_param.h>
  31
  32 #include <sys/dtrace.h>
  33 #include <sys/dtrace_impl.h>
  34
  35 #include <sys/dtrace_glue.h>
  36
  37 #include <sys/sdt_impl.h>
  38
  39 extern sdt_probe_t      **sdt_probetab;
  40
  41 int
  42 sdt_invop(__unused uintptr_t addr, __unused uintptr_t *stack, __unused uintptr_t eax)
  43 {
  44 #pragma unused(eax)
  45         sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
  46
  47         for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
  48                 if ((uintptr_t) sdt->sdp_patchpoint == addr) {
  49                         struct arm_saved_state* regs = (struct arm_saved_state*) stack;
  50
  51                         dtrace_probe(sdt->sdp_id, get_saved_state_reg(regs, 0), get_saved_state_reg(regs, 1),
  52                             get_saved_state_reg(regs, 2), get_saved_state_reg(regs, 3), get_saved_state_reg(regs, 4));
  53
  54                         return DTRACE_INVOP_NOP;
  55                 }
  56         }
  57
  58         return 0;
  59 }
  60
  61 struct frame {
  62         struct frame *backchain;
  63         uintptr_t retaddr;
  64 };
  65
  66 /*ARGSUSED*/
  67 uint64_t
  68 sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
  69 {
  70 #pragma unused(arg,id,parg)     /* __APPLE__ */
  71
  72         uint64_t val = 0;
  73         struct frame *fp = (struct frame *)__builtin_frame_address(0);
  74         uintptr_t *stack;
  75         uintptr_t pc;
  76         int i;
  77
  78         /*
  79          * A total of eight arguments are passed via registers;  any argument
  80          * with an index of 7 or lower is therefore in a register.
  81          */
  82
  83         int inreg = 7;
  84
  85         for (i = 1; i <= aframes; i++) {
  86                 fp = fp->backchain;
  87                 pc = fp->retaddr;
  88
  89                 if (dtrace_invop_callsite_pre != NULL
  90                     && pc > (uintptr_t)dtrace_invop_callsite_pre
  91                     && pc <= (uintptr_t)dtrace_invop_callsite_post) {
  92                         /*
  93                          * When we pass through the invalid op handler,
  94                          * we expect to find the save area structure,
  95                          * pushed on the stack where we took the trap.
  96                          * If the argument we seek is passed in a register, then
  97                          * we can load it directly from this saved area.
  98                          * If the argument we seek is passed on the stack, then
  99                          * we increment the frame pointer further, to find the
 100                          * pushed args
 101                          */
 102
 103                         /* fp points to the dtrace_invop activation */
 104                         fp = fp->backchain; /* fbt_perfCallback  */
 105                         fp = fp->backchain; /* sleh_synchronous */
 106                         fp = fp->backchain; /* fleh_synchronous */
 107
 108                         arm_saved_state_t *tagged_regs = (arm_saved_state_t *)((uintptr_t *)&fp[1]);
 109                         arm_saved_state64_t *saved_state = saved_state64(tagged_regs);
 110
 111                         if (argno <= inreg) {
 112                                 /* The argument will be in a register */
 113                                 stack = (uintptr_t *)&saved_state->x[0];
 114                         } else {
 115                                 /* The argument will be found on the stack */
 116                                 fp = (struct frame *)(saved_state->sp);
 117                                 stack = (uintptr_t *)&fp[0]; /* Find marshalled arguments */
 118                                 argno -= (inreg + 1);
 119                         }
 120                         goto load;
 121                 }
 122         }
 123
 124         /*
 125          * We know that we did not come through a trap to get into
 126          * dtrace_probe() --  We arrive here when the provider has
 127          * called dtrace_probe() directly.
 128          * The probe ID is the first argument to dtrace_probe().
 129          * We must advance beyond that to get the argX.
 130          */
 131         argno++; /* Advance past probeID */
 132
 133         if (argno <= inreg) {
 134                 /*
 135                  * This shouldn't happen.  If the argument is passed in a
 136                  * register then it should have been, well, passed in a
 137                  * register...
 138                  */
 139                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
 140                 return 0;
 141         }
 142
 143         argno -= (inreg + 1);
 144         stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
 145
 146 load:
 147         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
 148         /* dtrace_probe arguments arg0 .. arg4 are 64bits wide */
 149         val = (uint64_t)(*(((uintptr_t *)stack) + argno));
 150         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
 151         return val;
 152 }