scripts: Add sortextable to sort the kernel's exception table.

[linux-block.git] / scripts / sortextable.h

diff --git a/scripts/sortextable.h b/scripts/sortextable.h
new file mode 100644 (file)
index 0000000..bb6aaf1
--- /dev/null
+++ b/scripts/sortextable.h
@@ -0,0 +1,168 @@
+/*
+ * sortextable.h
+ *
+ * Copyright 2011 Cavium, Inc.
+ *
+ * Some of this code was taken out of recordmcount.h written by:
+ *
+ * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
+ * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
+ *
+ *
+ * Licensed under the GNU General Public License, version 2 (GPLv2).
+ */
+
+#undef extable_ent_size
+#undef compare_extable
+#undef do_func
+#undef Elf_Addr
+#undef Elf_Ehdr
+#undef Elf_Shdr
+#undef Elf_Rel
+#undef Elf_Rela
+#undef Elf_Sym
+#undef ELF_R_SYM
+#undef Elf_r_sym
+#undef ELF_R_INFO
+#undef Elf_r_info
+#undef ELF_ST_BIND
+#undef ELF_ST_TYPE
+#undef fn_ELF_R_SYM
+#undef fn_ELF_R_INFO
+#undef uint_t
+#undef _w
+
+#ifdef SORTEXTABLE_64
+# define extable_ent_size      16
+# define compare_extable       compare_extable_64
+# define do_func               do64
+# define Elf_Addr              Elf64_Addr
+# define Elf_Ehdr              Elf64_Ehdr
+# define Elf_Shdr              Elf64_Shdr
+# define Elf_Rel               Elf64_Rel
+# define Elf_Rela              Elf64_Rela
+# define Elf_Sym               Elf64_Sym
+# define ELF_R_SYM             ELF64_R_SYM
+# define Elf_r_sym             Elf64_r_sym
+# define ELF_R_INFO            ELF64_R_INFO
+# define Elf_r_info            Elf64_r_info
+# define ELF_ST_BIND           ELF64_ST_BIND
+# define ELF_ST_TYPE           ELF64_ST_TYPE
+# define fn_ELF_R_SYM          fn_ELF64_R_SYM
+# define fn_ELF_R_INFO         fn_ELF64_R_INFO
+# define uint_t                        uint64_t
+# define _w                    w8
+#else
+# define extable_ent_size      8
+# define compare_extable       compare_extable_32
+# define do_func               do32
+# define Elf_Addr              Elf32_Addr
+# define Elf_Ehdr              Elf32_Ehdr
+# define Elf_Shdr              Elf32_Shdr
+# define Elf_Rel               Elf32_Rel
+# define Elf_Rela              Elf32_Rela
+# define Elf_Sym               Elf32_Sym
+# define ELF_R_SYM             ELF32_R_SYM
+# define Elf_r_sym             Elf32_r_sym
+# define ELF_R_INFO            ELF32_R_INFO
+# define Elf_r_info            Elf32_r_info
+# define ELF_ST_BIND           ELF32_ST_BIND
+# define ELF_ST_TYPE           ELF32_ST_TYPE
+# define fn_ELF_R_SYM          fn_ELF32_R_SYM
+# define fn_ELF_R_INFO         fn_ELF32_R_INFO
+# define uint_t                        uint32_t
+# define _w                    w
+#endif
+
+static int compare_extable(const void *a, const void *b)
+{
+       const uint_t *aa = a;
+       const uint_t *bb = b;
+
+       if (_w(*aa) < _w(*bb))
+               return -1;
+       if (_w(*aa) > _w(*bb))
+               return 1;
+       return 0;
+}
+
+static void
+do_func(Elf_Ehdr *const ehdr, char const *const fname)
+{
+       Elf_Shdr *shdr;
+       Elf_Shdr *shstrtab_sec;
+       Elf_Shdr *strtab_sec = NULL;
+       Elf_Shdr *symtab_sec = NULL;
+       Elf_Shdr *extab_sec = NULL;
+       Elf_Sym *sym;
+       Elf_Sym *sort_needed_sym;
+       Elf_Shdr *sort_needed_sec;
+       uint32_t *sort_done_location;
+       const char *secstrtab;
+       const char *strtab;
+       int i;
+       int idx;
+
+       shdr = (Elf_Shdr *)((void *)ehdr + _w(ehdr->e_shoff));
+       shstrtab_sec = shdr + w2(ehdr->e_shstrndx);
+       secstrtab = (const char *)ehdr + _w(shstrtab_sec->sh_offset);
+       for (i = 0; i < w2(ehdr->e_shnum); i++) {
+               idx = w(shdr[i].sh_name);
+               if (strcmp(secstrtab + idx, "__ex_table") == 0)
+                       extab_sec = shdr + i;
+               if (strcmp(secstrtab + idx, ".symtab") == 0)
+                       symtab_sec = shdr + i;
+               if (strcmp(secstrtab + idx, ".strtab") == 0)
+                       strtab_sec = shdr + i;
+       }
+       if (strtab_sec == NULL) {
+               fprintf(stderr, "no .strtab in  file: %s\n", fname);
+               fail_file();
+       }
+       if (symtab_sec == NULL) {
+               fprintf(stderr, "no .symtab in  file: %s\n", fname);
+               fail_file();
+       }
+       if (extab_sec == NULL) {
+               fprintf(stderr, "no __ex_table in  file: %s\n", fname);
+               fail_file();
+       }
+       strtab = (const char *)ehdr + _w(strtab_sec->sh_offset);
+
+       /* Sort the table in place */
+       qsort((void *)ehdr + _w(extab_sec->sh_offset),
+             (_w(extab_sec->sh_size) / extable_ent_size),
+             extable_ent_size, compare_extable);
+
+       /* find main_extable_sort_needed */
+       sort_needed_sym = NULL;
+       for (i = 0; i < _w(symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
+               sym = (void *)ehdr + _w(symtab_sec->sh_offset);
+               sym += i;
+               if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
+                       continue;
+               idx = w(sym->st_name);
+               if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
+                       sort_needed_sym = sym;
+                       break;
+               }
+       }
+       if (sort_needed_sym == NULL) {
+               fprintf(stderr,
+                       "no main_extable_sort_needed symbol in  file: %s\n",
+                       fname);
+               fail_file();
+       }
+       sort_needed_sec = &shdr[w2(sort_needed_sym->st_shndx)];
+       sort_done_location = (void *)ehdr +
+               _w(sort_needed_sec->sh_offset) +
+               _w(sort_needed_sym->st_value) -
+               _w(sort_needed_sec->sh_addr);
+
+       printf("sort done marker at %lx\n",
+               (unsigned long) (_w(sort_needed_sec->sh_offset) +
+                                _w(sort_needed_sym->st_value) -
+                                _w(sort_needed_sec->sh_addr)));
+       /* We sorted it, clear the flag. */
+       *sort_done_location = 0;
+}