Building with a large config and -ffunction-sections results in a large
number of sections and sortextable needs to be able to handle that.
Implement support for > 64K sections as modpost does.
Cc: David Daney <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Signed-off-by: Jamie Iles <[email protected]>
---
scripts/sortextable.c | 24 ++++++++++++++++++++++++
scripts/sortextable.h | 26 +++++++++++++++++++++++---
2 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/scripts/sortextable.c b/scripts/sortextable.c
index f19ddc4..1bd0c60 100644
--- a/scripts/sortextable.c
+++ b/scripts/sortextable.c
@@ -156,6 +156,30 @@ static void (*w2)(uint16_t, uint16_t *);
typedef void (*table_sort_t)(char *, int);
+/*
+ * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
+ * the way to -256..-1, to avoid conflicting with real section
+ * indices.
+ */
+#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
+
+static inline int is_shndx_special(unsigned int i)
+{
+ return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
+}
+
+/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
+static inline unsigned int get_secindex(unsigned int shndx,
+ unsigned int sym_offs,
+ const Elf32_Word *symtab_shndx_start)
+{
+ if (is_shndx_special(shndx))
+ return SPECIAL(shndx);
+ if (shndx != SHN_XINDEX)
+ return shndx;
+ return r(&symtab_shndx_start[sym_offs]);
+}
+
/* 32 bit and 64 bit are very similar */
#include "sortextable.h"
#define SORTEXTABLE_64
diff --git a/scripts/sortextable.h b/scripts/sortextable.h
index e4fd45b..8206594 100644
--- a/scripts/sortextable.h
+++ b/scripts/sortextable.h
@@ -98,6 +98,8 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
Elf_Shdr *symtab_sec = NULL;
Elf_Shdr *extab_sec = NULL;
Elf_Sym *sym;
+ const Elf_Sym *symtab;
+ Elf32_Word *symtab_shndx_start = NULL;
Elf_Sym *sort_needed_sym;
Elf_Shdr *sort_needed_sec;
Elf_Rel *relocs = NULL;
@@ -109,11 +111,22 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
int extab_index = 0;
int i;
int idx;
+ unsigned int num_sections;
+ unsigned int secindex_strings;
shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
- shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
+
+ num_sections = r2(&ehdr->e_shnum);
+ if (num_sections == SHN_UNDEF)
+ num_sections = _r(&shdr[0].sh_size);
+
+ secindex_strings = r2(&ehdr->e_shstrndx);
+ if (secindex_strings == SHN_XINDEX)
+ secindex_strings = r(&shdr[0].sh_link);
+
+ shstrtab_sec = shdr + secindex_strings;
secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
- for (i = 0; i < r2(&ehdr->e_shnum); i++) {
+ for (i = 0; i < num_sections; i++) {
idx = r(&shdr[i].sh_name);
if (strcmp(secstrtab + idx, "__ex_table") == 0) {
extab_sec = shdr + i;
@@ -129,6 +142,9 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
symtab_sec = shdr + i;
if (strcmp(secstrtab + idx, ".strtab") == 0)
strtab_sec = shdr + i;
+ if (r(&shdr[i].sh_type) == SHT_SYMTAB_SHNDX)
+ symtab_shndx_start = (Elf32_Word *)(
+ (const char *)ehdr + _r(&shdr[i].sh_offset));
}
if (strtab_sec == NULL) {
fprintf(stderr, "no .strtab in file: %s\n", fname);
@@ -138,6 +154,8 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
fprintf(stderr, "no .symtab in file: %s\n", fname);
fail_file();
}
+ symtab = (const Elf_Sym *)((const char *)ehdr +
+ _r(&symtab_sec->sh_offset));
if (extab_sec == NULL) {
fprintf(stderr, "no __ex_table in file: %s\n", fname);
fail_file();
@@ -176,7 +194,9 @@ do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
fname);
fail_file();
}
- sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)];
+ sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
+ sort_needed_sym - symtab,
+ symtab_shndx_start)];
sort_done_location = (void *)ehdr +
_r(&sort_needed_sec->sh_offset) +
_r(&sort_needed_sym->st_value) -
--
1.7.10.4
On 11/05/2012 01:06 AM, Jamie Iles wrote:
> Building with a large config and -ffunction-sections results in a large
> number of sections and sortextable needs to be able to handle that.
> Implement support for > 64K sections as modpost does.
>
> Cc: David Daney <[email protected]>
> Cc: H. Peter Anvin <[email protected]>
> Signed-off-by: Jamie Iles <[email protected]>
> ---
> scripts/sortextable.c | 24 ++++++++++++++++++++++++
> scripts/sortextable.h | 26 +++++++++++++++++++++++---
> 2 files changed, 47 insertions(+), 3 deletions(-)
>
I don't plan on extensively testing this, but I have no objections.
David Daney