osfmk/kperf/callstack.c

   1 /*
   2  * Copyright (c) 2011 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /* Collect kernel callstacks */
  30
  31 #include <mach/mach_types.h>
  32 #include <machine/machine_routines.h>  /* XXX: remove me */
  33 #include <kern/thread.h>
  34
  35 #include <chud/chud_xnu.h>
  36
  37 #include <kperf/buffer.h>
  38 #include <kperf/context.h>
  39 #include <kperf/callstack.h>
  40 #include <kperf/ast.h>
  41
  42 static void
  43 callstack_sample( struct callstack *cs,
  44                   struct kperf_context *context,
  45                   uint32_t is_user )
  46 {
  47         kern_return_t kr;
  48         mach_msg_type_number_t nframes; /* WTF with the type? */
  49         uint32_t code;
  50
  51         if( is_user )
  52                 code = PERF_CS_USAMPLE;
  53         else
  54                 code = PERF_CS_KSAMPLE;
  55
  56         BUF_INFO1( code, (uintptr_t)context->cur_thread );
  57
  58         /* fill out known flags */
  59         cs->flags = 0;
  60         if( !is_user )
  61         {
  62                 cs->flags |= CALLSTACK_KERNEL;
  63 #ifdef __LP64__
  64                 cs->flags |= CALLSTACK_64BIT;
  65 #endif
  66         }
  67         else
  68         {
  69                 /* FIXME: detect 32 vs 64-bit? */
  70         }
  71
  72         /* collect the callstack */
  73         nframes = MAX_CALLSTACK_FRAMES;
  74         kr = chudxnu_thread_get_callstack64_kperf( context->cur_thread,
  75                                                    cs->frames,
  76                                                    &nframes,
  77                                                    is_user );
  78
  79         /* check for overflow */
  80         if( kr == KERN_SUCCESS )
  81         {
  82                 cs->flags |= CALLSTACK_VALID;
  83                 cs->nframes = nframes;
  84         }
  85         else if( kr == KERN_RESOURCE_SHORTAGE )
  86         {
  87                 /* FIXME: more here */
  88                 cs->flags |= CALLSTACK_TRUNCATED;
  89                 cs->flags |= CALLSTACK_VALID;
  90                 cs->nframes = nframes;
  91         }
  92         else
  93         {
  94                 BUF_INFO2(PERF_CS_ERROR, ERR_GETSTACK, kr);
  95                 cs->nframes = 0;
  96         }
  97
  98         if( cs->nframes >= MAX_CALLSTACK_FRAMES )
  99         {
 100                 /* necessary? */
 101                 BUF_INFO1(PERF_CS_ERROR, ERR_FRAMES);
 102                 cs->nframes = 0;
 103         }
 104
 105 }
 106
 107 void
 108 kperf_kcallstack_sample( struct callstack *cs, struct kperf_context *context )
 109 {
 110         callstack_sample( cs, context, 0 );
 111 }
 112
 113 void
 114 kperf_ucallstack_sample( struct callstack *cs, struct kperf_context *context )
 115 {
 116         callstack_sample( cs, context, 1 );
 117 }
 118
 119 static void
 120 callstack_log( struct callstack *cs, uint32_t hcode, uint32_t dcode )
 121 {
 122         unsigned int i, j, n, of = 4;
 123
 124         /* Header on the stack */
 125         BUF_DATA2( hcode, cs->flags, cs->nframes );
 126
 127         /* look for how many batches of 4 */
 128         n  = cs->nframes / 4;
 129         of = cs->nframes % 4;
 130         if( of != 0 )
 131                 n++;
 132
 133         /* print all the stack data, and zero the overflow */
 134         for( i = 0; i < n; i++ )
 135         {
 136 #define SCRUB_FRAME(x) (((x)<cs->nframes)?cs->frames[x]:0)
 137                 j = i * 4;
 138                 BUF_DATA ( dcode,
 139                            SCRUB_FRAME(j+0),
 140                            SCRUB_FRAME(j+1),
 141                            SCRUB_FRAME(j+2),
 142                            SCRUB_FRAME(j+3) );
 143 #undef SCRUB_FRAME
 144         }
 145 }
 146
 147 void
 148 kperf_kcallstack_log( struct callstack *cs )
 149 {
 150         callstack_log( cs, PERF_CS_KHDR, PERF_CS_KDATA );
 151 }
 152
 153 void
 154 kperf_ucallstack_log( struct callstack *cs )
 155 {
 156         callstack_log( cs, PERF_CS_UHDR, PERF_CS_UDATA );
 157 }
 158
 159 int
 160 kperf_ucallstack_pend( struct kperf_context * context )
 161 {
 162         return kperf_ast_pend( context->cur_thread, T_AST_CALLSTACK,
 163                                T_AST_CALLSTACK );
 164 }
 165
 166 //      kr = chudxnu_thread_get_callstack(context->generic->threadID,
 167 //              (uint32_t*)frames, &frameCount, !collectingSupervisorStack);