1 /*
2  * Copyright (c) 1983, 1993, 1998
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 #include "gprof.h"
30 #include "search_list.h"
31 #include "source.h"
32 #include "symtab.h"
33 #include "cg_arcs.h"
34 #include "corefile.h"
35 #include "hist.h"
36 
37 /*
38  * Opcodes of the call instructions:
39  */
40 #define OP_Jxx      0x1aU
41 #define   OP_BSR    0x34U
42 
43 #define Jxx_FUNC_JMP                    0U
44 #define Jxx_FUNC_JSR                    1U
45 #define Jxx_FUNC_RET                    2U
46 #define Jxx_FUNC_JSR_COROUTINE          3U
47 
48 /* *INDENT-OFF* */
49 /* Here to document only.  We can't use this when cross compiling as
50    the bitfield layout might not be the same as native.
51 
52    typedef union
53      {
54        struct
55          {
56              unsigned other:26;
57              unsigned op_code:6;
58          }
59        a;                               -- any format
60        struct
61          {
62              int disp:21;
63              unsigned ra:5;
64              unsigned op_code:6;
65          }
66        b;                               -- branch format
67        struct
68          {
69              int hint:14;
70              unsigned func:2;
71              unsigned rb:5;
72              unsigned ra:5;
73              unsigned op_code:6;
74          }
75        j;                               -- jump format
76      }
77     alpha_Instruction;
78 */
79 /* *INDENT-ON* */
80 
81 static Sym indirect_child;
82 
83 void alpha_find_call (Sym *, bfd_vma, bfd_vma);
84 
85 /*
86  * On the Alpha we can only detect PC relative calls, which are
87  * usually generated for calls to functions within the same
88  * object file only.  This is still better than nothing, however.
89  * (In particular it should be possible to find functions that
90  *  potentially call integer division routines, for example.)
91  */
92 void
alpha_find_call(Sym * parent,bfd_vma p_lowpc,bfd_vma p_highpc)93 alpha_find_call (Sym *parent, bfd_vma p_lowpc, bfd_vma p_highpc)
94 {
95   bfd_vma pc, dest_pc;
96   unsigned int insn;
97   Sym *child;
98 
99   if (indirect_child.name == NULL)
100     {
101       sym_init (&indirect_child);
102       indirect_child.name = _("<indirect child>");
103       indirect_child.cg.prop.fract = 1.0;
104       indirect_child.cg.cyc.head = &indirect_child;
105     }
106 
107   DBG (CALLDEBUG, printf (_("[find_call] %s: 0x%lx to 0x%lx\n"),
108                                 parent->name, (unsigned long) p_lowpc,
109                                 (unsigned long) p_highpc));
110   p_lowpc = (p_lowpc + 3) & ~3;
111   p_highpc &= ~3;
112   for (pc = p_lowpc; pc < p_highpc; pc += 4)
113     {
114       insn = bfd_get_32 (core_bfd, ((unsigned char *) core_text_space
115                                             + pc - core_text_sect->vma));
116       switch (insn & (0x3fU << 26))
117           {
118           case OP_Jxx << 26:
119             /*
120              * There is no simple and reliable way to determine the
121              * target of a jsr (the hint bits help, but there aren't
122              * enough bits to get a satisfactory hit rate).  Instead,
123              * for any indirect jump we simply add an arc from PARENT
124              * to INDIRECT_CHILD---that way the user it at least able
125              * to see that there are other calls as well.
126              */
127             if ((insn & (3 << 14)) == Jxx_FUNC_JSR << 14
128                 || (insn & (3 << 14)) == Jxx_FUNC_JSR_COROUTINE << 14)
129               {
130                 DBG (CALLDEBUG,
131                        printf (_("[find_call] 0x%lx: jsr%s <indirect_child>\n"),
132                                  (unsigned long) pc,
133                                  ((insn & (3 << 14)) == Jxx_FUNC_JSR << 14
134                                   ? "" : "_coroutine")));
135                 arc_add (parent, &indirect_child, (unsigned long) 0);
136               }
137             break;
138 
139           case OP_BSR << 26:
140             DBG (CALLDEBUG,
141                  printf (_("[find_call] 0x%lx: bsr"), (unsigned long) pc));
142             /*
143              * Regular PC relative addressing.  Check that this is the
144              * address of a function.  The linker sometimes redirects
145              * the entry point by 8 bytes to skip loading the global
146              * pointer, so we allow for either address:
147              */
148             dest_pc = pc + 4 + (((bfd_signed_vma) (insn & 0x1fffff)
149                                      ^ 0x100000) - 0x100000);
150             if (hist_check_address (dest_pc))
151               {
152                 child = sym_lookup (&symtab, dest_pc);
153               if (child)
154                 {
155                     DBG (CALLDEBUG,
156                            printf (" 0x%lx\t; name=%s, addr=0x%lx",
157                                      (unsigned long) dest_pc, child->name,
158                                      (unsigned long) child->addr));
159                     if (child->addr == dest_pc || child->addr == dest_pc - 8)
160                         {
161                           DBG (CALLDEBUG, printf ("\n"));
162                           /* a hit:  */
163                           arc_add (parent, child, (unsigned long) 0);
164                           continue;
165                         }
166                 }
167               }
168             /*
169              * Something funny going on.
170              */
171             DBG (CALLDEBUG, printf ("\tbut it's a botch\n"));
172             break;
173 
174           default:
175             break;
176           }
177     }
178 }
179