src/gallium/drivers/radeon/radeon_elf_util.c

   1 /*
   2  * Copyright 2014 Advanced Micro Devices, Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  *
  23  * Authors: Tom Stellard <thomas.stellard@amd.com>
  24  *
  25  */
  26
  27 #include "radeon_elf_util.h"
  28 #include "r600_pipe_common.h"
  29
  30 #include "util/u_memory.h"
  31
  32 #include <gelf.h>
  33 #include <libelf.h>
  34 #include <stdio.h>
  35
  36 static void parse_symbol_table(Elf_Data *symbol_table_data,
  37                                 const GElf_Shdr *symbol_table_header,
  38                                 struct radeon_shader_binary *binary)
  39 {
  40         GElf_Sym symbol;
  41         unsigned i = 0;
  42         unsigned symbol_count =
  43                 symbol_table_header->sh_size / symbol_table_header->sh_entsize;
  44
  45         /* We are over allocating this list, because symbol_count gives the
  46          * total number of symbols, and we will only be filling the list
  47          * with offsets of global symbols.  The memory savings from
  48          * allocating the correct size of this list will be small, and
  49          * I don't think it is worth the cost of pre-computing the number
  50          * of global symbols.
  51          */
  52         binary->global_symbol_offsets = CALLOC(symbol_count, sizeof(uint64_t));
  53
  54         while (gelf_getsym(symbol_table_data, i++, &symbol)) {
  55                 unsigned i;
  56                 if (GELF_ST_BIND(symbol.st_info) != STB_GLOBAL ||
  57                     symbol.st_shndx == 0 /* Undefined symbol */) {
  58                         continue;
  59                 }
  60
  61                 binary->global_symbol_offsets[binary->global_symbol_count] =
  62                                         symbol.st_value;
  63
  64                 /* Sort the list using bubble sort.  This list will usually
  65                  * be small. */
  66                 for (i = binary->global_symbol_count; i > 0; --i) {
  67                         uint64_t lhs = binary->global_symbol_offsets[i - 1];
  68                         uint64_t rhs = binary->global_symbol_offsets[i];
  69                         if (lhs < rhs) {
  70                                 break;
  71                         }
  72                         binary->global_symbol_offsets[i] = lhs;
  73                         binary->global_symbol_offsets[i - 1] = rhs;
  74                 }
  75                 ++binary->global_symbol_count;
  76         }
  77 }
  78
  79 static void parse_relocs(Elf *elf, Elf_Data *relocs, Elf_Data *symbols,
  80                         unsigned symbol_sh_link,
  81                         struct radeon_shader_binary *binary)
  82 {
  83         unsigned i;
  84
  85         if (!relocs || !symbols || !binary->reloc_count) {
  86                 return;
  87         }
  88         binary->relocs = CALLOC(binary->reloc_count,
  89                         sizeof(struct radeon_shader_reloc));
  90         for (i = 0; i < binary->reloc_count; i++) {
  91                 GElf_Sym symbol;
  92                 GElf_Rel rel;
  93                 char *symbol_name;
  94                 struct radeon_shader_reloc *reloc = &binary->relocs[i];
  95
  96                 gelf_getrel(relocs, i, &rel);
  97                 gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &symbol);
  98                 symbol_name = elf_strptr(elf, symbol_sh_link, symbol.st_name);
  99
 100                 reloc->offset = rel.r_offset;
 101                 strncpy(reloc->name, symbol_name, sizeof(reloc->name)-1);
 102                 reloc->name[sizeof(reloc->name)-1] = 0;
 103         }
 104 }
 105
 106 void radeon_elf_read(const char *elf_data, unsigned elf_size,
 107                      struct radeon_shader_binary *binary)
 108 {
 109         char *elf_buffer;
 110         Elf *elf;
 111         Elf_Scn *section = NULL;
 112         Elf_Data *symbols = NULL, *relocs = NULL;
 113         size_t section_str_index;
 114         unsigned symbol_sh_link = 0;
 115
 116         /* One of the libelf implementations
 117          * (http://www.mr511.de/software/english.htm) requires calling
 118          * elf_version() before elf_memory().
 119          */
 120         elf_version(EV_CURRENT);
 121         elf_buffer = MALLOC(elf_size);
 122         memcpy(elf_buffer, elf_data, elf_size);
 123
 124         elf = elf_memory(elf_buffer, elf_size);
 125
 126         elf_getshdrstrndx(elf, &section_str_index);
 127
 128         while ((section = elf_nextscn(elf, section))) {
 129                 const char *name;
 130                 Elf_Data *section_data = NULL;
 131                 GElf_Shdr section_header;
 132                 if (gelf_getshdr(section, &section_header) != &section_header) {
 133                         fprintf(stderr, "Failed to read ELF section header\n");
 134                         return;
 135                 }
 136                 name = elf_strptr(elf, section_str_index, section_header.sh_name);
 137                 if (!strcmp(name, ".text")) {
 138                         section_data = elf_getdata(section, section_data);
 139                         binary->code_size = section_data->d_size;
 140                         binary->code = MALLOC(binary->code_size * sizeof(unsigned char));
 141                         memcpy(binary->code, section_data->d_buf, binary->code_size);
 142                 } else if (!strcmp(name, ".AMDGPU.config")) {
 143                         section_data = elf_getdata(section, section_data);
 144                         binary->config_size = section_data->d_size;
 145                         binary->config = MALLOC(binary->config_size * sizeof(unsigned char));
 146                         memcpy(binary->config, section_data->d_buf, binary->config_size);
 147                 } else if (!strcmp(name, ".AMDGPU.disasm")) {
 148                         /* Always read disassembly if it's available. */
 149                         section_data = elf_getdata(section, section_data);
 150                         binary->disasm_string = strndup(section_data->d_buf,
 151                                                         section_data->d_size);
 152                 } else if (!strncmp(name, ".rodata", 7)) {
 153                         section_data = elf_getdata(section, section_data);
 154                         binary->rodata_size = section_data->d_size;
 155                         binary->rodata = MALLOC(binary->rodata_size * sizeof(unsigned char));
 156                         memcpy(binary->rodata, section_data->d_buf, binary->rodata_size);
 157                 } else if (!strncmp(name, ".symtab", 7)) {
 158                         symbols = elf_getdata(section, section_data);
 159                         symbol_sh_link = section_header.sh_link;
 160                         parse_symbol_table(symbols, &section_header, binary);
 161                 } else if (!strcmp(name, ".rel.text")) {
 162                         relocs = elf_getdata(section, section_data);
 163                         binary->reloc_count = section_header.sh_size /
 164                                         section_header.sh_entsize;
 165                 }
 166         }
 167
 168         parse_relocs(elf, relocs, symbols, symbol_sh_link, binary);
 169
 170         if (elf){
 171                 elf_end(elf);
 172         }
 173         FREE(elf_buffer);
 174
 175         /* Cache the config size per symbol */
 176         if (binary->global_symbol_count) {
 177                 binary->config_size_per_symbol =
 178                         binary->config_size / binary->global_symbol_count;
 179         } else {
 180                 binary->global_symbol_count = 1;
 181                 binary->config_size_per_symbol = binary->config_size;
 182         }
 183 }
 184
 185 const unsigned char *radeon_shader_binary_config_start(
 186         const struct radeon_shader_binary *binary,
 187         uint64_t symbol_offset)
 188 {
 189         unsigned i;
 190         for (i = 0; i < binary->global_symbol_count; ++i) {
 191                 if (binary->global_symbol_offsets[i] == symbol_offset) {
 192                         unsigned offset = i * binary->config_size_per_symbol;
 193                         return binary->config + offset;
 194                 }
 195         }
 196         return binary->config;
 197 }