Merge branch 'modversions' (modversions fixes for powerpc from Ard)

Merge kcrctab entry fixes from Ard Biesheuvel:
 "This is a followup to [0] 'modversions: redefine kcrctab entries as
  relative CRC pointers', but since relative CRC pointers do not work in
  modules, and are actually only needed by powerpc with
  CONFIG_RELOCATABLE=y, I have made it a Kconfig selectable feature
  instead.

  First it introduces the MODULE_REL_CRCS Kconfig symbol, and adds the
  kbuild handling of it, i.e., modpost, genksyms and kallsyms.

  Then it switches all architectures to 32-bit CRC entries in kcrctab,
  where all architectures except powerpc with CONFIG_RELOCATABLE=y use
  absolute ELF symbol references as before"

[0] http://marc.info/?l=linux-arch&m=148493613415294&w=2

* emailed patches from Ard Biesheuvel:
  module: unify absolute krctab definitions for 32-bit and 64-bit
  modversions: treat symbol CRCs as 32 bit quantities
  kbuild: modversions: add infrastructure for emitting relative CRCs
This commit is contained in:
Linus Torvalds
2017-02-03 10:30:27 -08:00
12 changed files with 93 additions and 62 deletions

View File

@@ -43,12 +43,19 @@ extern struct module __this_module;
#ifdef CONFIG_MODVERSIONS
/* Mark the CRC weak since genksyms apparently decides not to
* generate a checksums for some symbols */
#if defined(CONFIG_MODULE_REL_CRCS)
#define __CRC_SYMBOL(sym, sec) \
extern __visible void *__crc_##sym __attribute__((weak)); \
static const unsigned long __kcrctab_##sym \
__used \
__attribute__((section("___kcrctab" sec "+" #sym), used)) \
= (unsigned long) &__crc_##sym;
asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
" .weak " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
" .long " VMLINUX_SYMBOL_STR(__crc_##sym) " - . \n" \
" .previous \n");
#else
#define __CRC_SYMBOL(sym, sec) \
asm(" .section \"___kcrctab" sec "+" #sym "\", \"a\" \n" \
" .weak " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
" .long " VMLINUX_SYMBOL_STR(__crc_##sym) " \n" \
" .previous \n");
#endif
#else
#define __CRC_SYMBOL(sym, sec)
#endif

View File

@@ -346,7 +346,7 @@ struct module {
/* Exported symbols */
const struct kernel_symbol *syms;
const unsigned long *crcs;
const s32 *crcs;
unsigned int num_syms;
/* Kernel parameters. */
@@ -359,18 +359,18 @@ struct module {
/* GPL-only exported symbols. */
unsigned int num_gpl_syms;
const struct kernel_symbol *gpl_syms;
const unsigned long *gpl_crcs;
const s32 *gpl_crcs;
#ifdef CONFIG_UNUSED_SYMBOLS
/* unused exported symbols. */
const struct kernel_symbol *unused_syms;
const unsigned long *unused_crcs;
const s32 *unused_crcs;
unsigned int num_unused_syms;
/* GPL-only, unused exported symbols. */
unsigned int num_unused_gpl_syms;
const struct kernel_symbol *unused_gpl_syms;
const unsigned long *unused_gpl_crcs;
const s32 *unused_gpl_crcs;
#endif
#ifdef CONFIG_MODULE_SIG
@@ -382,7 +382,7 @@ struct module {
/* symbols that will be GPL-only in the near future. */
const struct kernel_symbol *gpl_future_syms;
const unsigned long *gpl_future_crcs;
const s32 *gpl_future_crcs;
unsigned int num_gpl_future_syms;
/* Exception table */
@@ -523,7 +523,7 @@ struct module *find_module(const char *name);
struct symsearch {
const struct kernel_symbol *start, *stop;
const unsigned long *crcs;
const s32 *crcs;
enum {
NOT_GPL_ONLY,
GPL_ONLY,
@@ -539,7 +539,7 @@ struct symsearch {
*/
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
const s32 **crc,
bool gplok,
bool warn);