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 #if defined(__i386__)
  50 /*ARGSUSED*/
  51 int
  52 sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
  53 {
  54 #pragma unused(eax)
  55         uintptr_t stack0 = 0, stack1 = 0, stack2 = 0, stack3 = 0, stack4 = 0;
  56         sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
  57
  58         for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
  59                 if ((uintptr_t)sdt->sdp_patchpoint == addr) {
  60                         uintptr_t *stacktop;
  61                         if (CPU_ON_INTR(CPU))
  62                                 stacktop = (uintptr_t *)dtrace_get_cpu_int_stack_top();
  63                         else
  64                                 stacktop = (uintptr_t *)(dtrace_get_kernel_stack(current_thread()) + kernel_stack_size);
  65
  66             if (stack <= stacktop)
  67                 stack0 = *stack++;
  68             if (stack <= stacktop)
  69                 stack1 = *stack++;
  70             if (stack <= stacktop)
  71                 stack2 = *stack++;
  72             if (stack <= stacktop)
  73                 stack3 = *stack++;
  74             if (stack <= stacktop)
  75                 stack4 = *stack++;
  76
  77                         dtrace_probe(sdt->sdp_id, stack0, stack1, stack2, stack3, stack4);
  78
  79                         return (DTRACE_INVOP_NOP);
  80                 }
  81         }
  82
  83         return (0);
  84 }
  85 #elif defined(__x86_64__)
  86 /*ARGSUSED*/
  87 int
  88 sdt_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
  89 {
  90 #pragma unused(eax)
  91         sdt_probe_t *sdt = sdt_probetab[SDT_ADDR2NDX(addr)];
  92
  93         for (; sdt != NULL; sdt = sdt->sdp_hashnext) {
  94                 if ((uintptr_t)sdt->sdp_patchpoint == addr) {
  95                         x86_saved_state64_t *regs = (x86_saved_state64_t *)stack;
  96
  97                         dtrace_probe(sdt->sdp_id, regs->rdi, regs->rsi, regs->rdx, regs->rcx, regs->r8);
  98
  99                         return (DTRACE_INVOP_NOP);
 100                 }
 101         }
 102
 103         return (0);
 104 }
 105 #else
 106 #error Unknown arch
 107 #endif
 108
 109
 110 struct frame {
 111     struct frame *backchain;
 112     uintptr_t retaddr;
 113 };
 114
 115 /*ARGSUSED*/
 116 uint64_t
 117 sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
 118 {
 119 #pragma unused(arg, id, parg)
 120         uint64_t val;
 121         struct frame *fp = (struct frame *)__builtin_frame_address(0);
 122         uintptr_t *stack;
 123         uintptr_t pc;
 124         int i;
 125
 126 #if defined(__x86_64__)
 127     /*
 128      * A total of 6 arguments are passed via registers; any argument with
 129      * index of 5 or lower is therefore in a register.
 130      */
 131     int inreg = 5;
 132 #endif
 133
 134         for (i = 1; i <= aframes; i++) {
 135                 fp = fp->backchain;
 136                 pc = fp->retaddr;
 137
 138                 if (dtrace_invop_callsite_pre != NULL
 139                         && pc  >  (uintptr_t)dtrace_invop_callsite_pre
 140                         && pc  <= (uintptr_t)dtrace_invop_callsite_post) {
 141 #if defined(__i386__)
 142                         /*
 143                          * If we pass through the invalid op handler, we will
 144                          * use the pointer that it passed to the stack as the
 145                          * second argument to dtrace_invop() as the pointer to
 146                          * the frame we're hunting for.
 147                          */
 148
 149                         stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
 150                         fp = (struct frame *)stack[1]; /* Grab *second* argument */
 151                         stack = (uintptr_t *)&fp[0]; /* Find marshalled arguments */
 152 #elif defined(__x86_64__)
 153                         /*
 154                          * In the case of x86_64, we will use the pointer to the
 155                          * save area structure that was pushed when we took the
 156                          * trap.  To get this structure, we must increment
 157                          * beyond the frame structure. If the
 158                          * argument that we're seeking is passed on the stack,
 159                          * we'll pull the true stack pointer out of the saved
 160                          * registers and decrement our argument by the number
 161                          * of arguments passed in registers; if the argument
 162                          * we're seeking is passed in regsiters, we can just
 163                          * load it directly.
 164                          */
 165
 166                         /* fp points to frame of dtrace_invop() activation. */
 167                         fp = fp->backchain; /* to fbt_perfcallback() activation. */
 168                         fp = fp->backchain; /* to kernel_trap() activation. */
 169                         fp = fp->backchain; /* to trap_from_kernel() activation. */
 170
 171                         x86_saved_state_t   *tagged_regs = (x86_saved_state_t *)&fp[1];
 172                         x86_saved_state64_t *saved_state = saved_state64(tagged_regs);
 173
 174                         if (argno <= inreg) {
 175                                 stack = (uintptr_t *)&saved_state->rdi;
 176                         } else {
 177                                 fp = (struct frame *)(saved_state->isf.rsp);
 178                                 stack = (uintptr_t *)&fp[0]; /* Find marshalled
 179                                                                 arguments */
 180                                 argno -= (inreg +1);
 181                         }
 182 #else
 183 #error Unknown arch
 184 #endif
 185                         goto load;
 186                 }
 187         }
 188
 189         /*
 190          * We know that we did not come through a trap to get into
 191          * dtrace_probe() --  We arrive here when the provider has
 192          * called dtrace_probe() directly.
 193          * The probe ID is the first argument to dtrace_probe().
 194          * We must advance beyond that to get the argX.
 195          */
 196         argno++; /* Advance past probeID */
 197
 198 #if defined(__x86_64__)
 199         if (argno <= inreg) {
 200                 /*
 201                  * This shouldn't happen.  If the argument is passed in a
 202                  * register then it should have been, well, passed in a
 203                  * register...
 204                  */
 205                 DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
 206                 return (0);
 207         }
 208
 209         argno -= (inreg + 1);
 210 #endif
 211         stack = (uintptr_t *)&fp[1]; /* Find marshalled arguments */
 212
 213 load:
 214         DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
 215         /* dtrace_probe arguments arg0 ... arg4 are 64bits wide */
 216         val = (uint64_t)(*(((uintptr_t *)stack) + argno));
 217         DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
 218
 219         return (val);
 220 }
 221