bsd/dev/i386/sdt_x86.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 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* #pragma ident        "@(#)sdt.c      1.9     08/07/01 SMI" */
  27
  28 #ifdef KERNEL
  29 #ifndef _KERNEL
  30 #define _KERNEL /* Solaris vs. Darwin */
  31 #endif
  32 #endif
  33
  34 #define MACH__POSIX_C_SOURCE_PRIVATE 1 /* pulls in suitable savearea from mach/ppc/thread_status.h */
  35 #include <kern/cpu_data.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 /*ARGSUSED*/
  50 int
  51 sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
  52 {
  53 #pragma unused(eax)
  54         sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
  55
  56         for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
  57                 if ((uintptr_t)sdt->sdp_patchpoint == addr) {
  58                         x86_saved_state64_t *regs = (x86_saved_state64_t *)stack;
  59
  60                         dtrace_probe(sdt->sdp_id, regs->rdi, regs->rsi, regs->rdx, regs->rcx, regs->r8);
  61
  62                         return (DTRACE_INVOP_NOP);
  63                 }
  64         }
  65
  66         return (0);
  67 }
  68
  69
  70 struct frame {
  71     struct frame *backchain;
  72     uintptr_t retaddr;
  73 };
  74
  75 /*ARGSUSED*/
  76 uint64_t
  77 sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
  78 {
  79 #pragma unused(arg, id, parg)
  80         uint64_t val;
  81         struct frame *fp = (struct frame *)__builtin_frame_address(0);
  82         uintptr_t *stack;
  83         uintptr_t pc;
  84         int i;
  85
  86     /*
  87      * A total of 6 arguments are passed via registers; any argument with
  88      * index of 5 or lower is therefore in a register.
  89      */
  90     int inreg = 5;
  91
  92         for (i = 1; i <= aframes; i++) {
  93                 fp = fp->backchain;
  94                 pc = fp->retaddr;
  95
  96                 if (dtrace_invop_callsite_pre != NULL
  97                         && pc  >  (uintptr_t)dtrace_invop_callsite_pre
  98                         && pc  <= (uintptr_t)dtrace_invop_callsite_post) {
  99                         /*
 100                          * In the case of x86_64, we will use the pointer to the
 101                          * save area structure that was pushed when we took the
 102                          * trap.  To get this structure, we must increment
 103                          * beyond the frame structure. If the
 104                          * argument that we're seeking is passed on the stack,
 105                          * we'll pull the true stack pointer out of the saved
 106                          * registers and decrement our argument by the number
 107                          * of arguments passed in registers; if the argument
 108                          * we're seeking is passed in regsiters, we can just
 109                          * load it directly.
 110                          */
 111
 112                         /* fp points to frame of dtrace_invop() activation. */
 113                         fp = fp->backchain; /* to fbt_perfcallback() activation. */
 114                         fp = fp->backchain; /* to kernel_trap() activation. */
 115                         fp = fp->backchain; /* to trap_from_kernel() activation. */
 116
 117                         x86_saved_state_t   *tagged_regs = (x86_saved_state_t *)&fp[1];
 118                         x86_saved_state64_t *saved_state = saved_state64(tagged_regs);
 119
 120                         if (argno <= inreg) {
 121                                 stack = (uintptr_t *)(void*)&saved_state->rdi;
 122                         } else {
 123                                 fp = (struct frame *)(saved_state->isf.rsp);
 124                                 stack = (uintptr_t *)&fp[0]; /* Find marshalled
 125                                                                 arguments */
 126                                 argno -= (inreg +1);
 127                         }
 128                         goto load;
 129                 }
 130         }
 131
 132         /*
 133          * We know that we did not come through a trap to get into
 134          * dtrace_probe() --  We arrive here when the provider has
 135          * called dtrace_probe() directly.
 136          * The probe ID is the first argument to dtrace_probe().
 137          * We must advance beyond that to get the argX.
 138          */
 139         argno++; /* Advance past probeID */
 140
 141         if (argno <= inreg) {
 142                 /*
 143                  * This shouldn't happen.  If the argument is passed in a
 144                  * register then it should have been, well, passed in a
 145                  * register...
 146                  */
 147                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
 148                 return (0);
 149         }
 150
 151         argno -= (inreg + 1);
 152         stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
 153
 154 load:
 155         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
 156         /* dtrace_probe arguments arg0 ... arg4 are 64bits wide */
 157         val = (uint64_t)(*(((uintptr_t *)stack) + argno));
 158         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
 159
 160         return (val);
 161 }
 162