scripts/sortextable: Handle relative entries, and other cleanups
x86 is now using relative rather than absolute addresses in its
exception table, so we add a sorter for these. If there are
relocations on the __ex_table section, they are redundant and probably
incorrect after the sort, so they are zeroed out leaving them valid
and consistent.
Also use the unaligned safe accessors from tools/{be,le}_byteshift.h
Signed-off-by: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1335291795-26693-2-git-send-email-ddaney.cavm@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/scripts/sortextable.h b/scripts/sortextable.h
index bb6aaf1..e4fd45b 100644
--- a/scripts/sortextable.h
+++ b/scripts/sortextable.h
@@ -1,7 +1,7 @@
/*
* sortextable.h
*
- * Copyright 2011 Cavium, Inc.
+ * Copyright 2011 - 2012 Cavium, Inc.
*
* Some of this code was taken out of recordmcount.h written by:
*
@@ -30,6 +30,7 @@
#undef fn_ELF_R_SYM
#undef fn_ELF_R_INFO
#undef uint_t
+#undef _r
#undef _w
#ifdef SORTEXTABLE_64
@@ -51,6 +52,7 @@
# define fn_ELF_R_SYM fn_ELF64_R_SYM
# define fn_ELF_R_INFO fn_ELF64_R_INFO
# define uint_t uint64_t
+# define _r r8
# define _w w8
#else
# define extable_ent_size 8
@@ -71,23 +73,24 @@
# define fn_ELF_R_SYM fn_ELF32_R_SYM
# define fn_ELF_R_INFO fn_ELF32_R_INFO
# define uint_t uint32_t
+# define _r r
# define _w w
#endif
static int compare_extable(const void *a, const void *b)
{
- const uint_t *aa = a;
- const uint_t *bb = b;
+ Elf_Addr av = _r(a);
+ Elf_Addr bv = _r(b);
- if (_w(*aa) < _w(*bb))
+ if (av < bv)
return -1;
- if (_w(*aa) > _w(*bb))
+ if (av > bv)
return 1;
return 0;
}
static void
-do_func(Elf_Ehdr *const ehdr, char const *const fname)
+do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
{
Elf_Shdr *shdr;
Elf_Shdr *shstrtab_sec;
@@ -97,19 +100,31 @@
Elf_Sym *sym;
Elf_Sym *sort_needed_sym;
Elf_Shdr *sort_needed_sec;
+ Elf_Rel *relocs = NULL;
+ int relocs_size;
uint32_t *sort_done_location;
const char *secstrtab;
const char *strtab;
+ char *extab_image;
+ int extab_index = 0;
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)
+ shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
+ shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
+ secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
+ for (i = 0; i < r2(&ehdr->e_shnum); i++) {
+ idx = r(&shdr[i].sh_name);
+ if (strcmp(secstrtab + idx, "__ex_table") == 0) {
extab_sec = shdr + i;
+ extab_index = i;
+ }
+ if ((r(&shdr[i].sh_type) == SHT_REL ||
+ r(&shdr[i].sh_type) == SHT_RELA) &&
+ r(&shdr[i].sh_info) == extab_index) {
+ relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
+ relocs_size = _r(&shdr[i].sh_size);
+ }
if (strcmp(secstrtab + idx, ".symtab") == 0)
symtab_sec = shdr + i;
if (strcmp(secstrtab + idx, ".strtab") == 0)
@@ -127,21 +142,29 @@
fprintf(stderr, "no __ex_table in file: %s\n", fname);
fail_file();
}
- strtab = (const char *)ehdr + _w(strtab_sec->sh_offset);
+ strtab = (const char *)ehdr + _r(&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);
+ extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
+
+ if (custom_sort) {
+ custom_sort(extab_image, _r(&extab_sec->sh_size));
+ } else {
+ int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
+ qsort(extab_image, num_entries,
+ extable_ent_size, compare_extable);
+ }
+ /* If there were relocations, we no longer need them. */
+ if (relocs)
+ memset(relocs, 0, relocs_size);
/* 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);
+ for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
+ sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
sym += i;
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
continue;
- idx = w(sym->st_name);
+ idx = r(&sym->st_name);
if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
sort_needed_sym = sym;
break;
@@ -153,16 +176,16 @@
fname);
fail_file();
}
- sort_needed_sec = &shdr[w2(sort_needed_sym->st_shndx)];
+ sort_needed_sec = &shdr[r2(&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);
+ _r(&sort_needed_sec->sh_offset) +
+ _r(&sort_needed_sym->st_value) -
+ _r(&sort_needed_sec->sh_addr);
+#if 1
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)));
+ (unsigned long)((char *)sort_done_location - (char *)ehdr));
+#endif
/* We sorted it, clear the flag. */
- *sort_done_location = 0;
+ w(0, sort_done_location);
}