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authorSam Ravnborg <sam@ravnborg.org>2008-06-12 15:02:55 +0200
committerSam Ravnborg <sam@ravnborg.org>2008-06-12 16:41:48 +0200
commit4d7365d664e79710ac0e782a23443471ddf05bdd (patch)
treefb50ae07b59871082f43fb19b2ce112a546b64d8
parent631025b4d87d5a9d7e04a1ed652d247191e223d4 (diff)
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kbuild: ignore powerpc specific symbols in modpost
Kumar Gala <galak@kernel.crashing.org> wrote: We have a case in powerpc in which we want to link some library routines with all module objects. The routines are intended for handling out-of-line function call register save/restore so having them as EXPORT_SYMBOL() is counter productive (we do also need to link the same "library" code into the kernel). Without this patch a powerpc build would error out and fail to build modules with the added register save/restore module. There were two obvious solutions: 1) To link the .o file before the modpost stage 2) To ignore the symbols in modpost Option 1) was ruled out because we do not have any separate linking stage for single file modules. This patch implements option 2 - and do so only for powerpc. The symbols we ignore are all undefined symbols named: _restgpr_*, _savegpr_*, _rest32gpr_*, _save32gpr_* Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org>
-rw-r--r--scripts/mod/modpost.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 508c5895c68..a07f91aac92 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -467,6 +467,25 @@ static void parse_elf_finish(struct elf_info *info)
release_file(info->hdr, info->size);
}
+static int ignore_undef_symbol(struct elf_info *info, const char *symname)
+{
+ /* ignore __this_module, it will be resolved shortly */
+ if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ return 1;
+ /* ignore global offset table */
+ if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
+ return 1;
+ if (info->hdr->e_machine == EM_PPC)
+ /* Special register function linked on all modules during final link of .ko */
+ if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
+ strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
+ strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
+ strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
+ return 1;
+ /* Do not ignore this symbol */
+ return 0;
+}
+
#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
@@ -493,11 +512,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
ELF_ST_BIND(sym->st_info) != STB_WEAK)
break;
- /* ignore global offset table */
- if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
- break;
- /* ignore __this_module, it will be resolved shortly */
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ if (ignore_undef_symbol(info, symname))
break;
/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)