Re: [git patches] kbuild fixes for -rc

[Atsushi Nemoto <anemo@mba.ocn.ne.jp>]

On Mon, 8 May 2006 22:01:53 +0200, Sam Ravnborg <sam@ravnborg.org> wrote:
> Please revert this bogus commit:
> > > commit c8d8b837ebe4b4f11e1b0c4a2bdc358c697692ed
> 
> I was discussed on mips list but apparently the fix was bogus.
> I will not have time to look into it so mips can carry this local
> fix until we get a proper fix in mainline.

Here is a updated fix to avoid breakage on 32-bit build.


64bit mips has different r_info layout.  This patch fixes modpost
segfault for 64bit little endian mips kernel.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6d04504..692a83b 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -709,10 +709,20 @@ static void check_sec_ref(struct module 
 		for (rela = start; rela < stop; rela++) {
 			Elf_Rela r;
 			const char *secname;
+			unsigned int r_sym;
 			r.r_offset = TO_NATIVE(rela->r_offset);
-			r.r_info   = TO_NATIVE(rela->r_info);
+#if KERNEL_ELFCLASS == ELFCLASS64
+			if (hdr->e_machine == EM_MIPS) {
+				r_sym = ELF64_MIPS_R_SYM(rela->r_info);
+				r_sym = TO_NATIVE(r_sym);
+			} else {
+				r_sym = ELF_R_SYM(TO_NATIVE(rela->r_info));
+			}
+#else
+			r_sym = ELF_R_SYM(TO_NATIVE(rela->r_info));
+#endif
 			r.r_addend = TO_NATIVE(rela->r_addend);
-			sym = elf->symtab_start + ELF_R_SYM(r.r_info);
+			sym = elf->symtab_start + r_sym;
 			/* Skip special sections */
 			if (sym->st_shndx >= SHN_LORESERVE)
 				continue;
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index b14255c..89b96c6 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -39,6 +39,25 @@ #define ELF_R_SYM   ELF64_R_SYM
 #define ELF_R_TYPE  ELF64_R_TYPE
 #endif
 
+/* The 64-bit MIPS ELF ABI uses an unusual reloc format. */
+typedef struct
+{
+  Elf32_Word    r_sym;		/* Symbol index */
+  unsigned char r_ssym;		/* Special symbol for 2nd relocation */
+  unsigned char r_type3;	/* 3rd relocation type */
+  unsigned char r_type2;	/* 2nd relocation type */
+  unsigned char r_type1;	/* 1st relocation type */
+} _Elf64_Mips_R_Info;
+
+typedef union
+{
+  Elf64_Xword	r_info_number;
+  _Elf64_Mips_R_Info r_info_fields;
+} _Elf64_Mips_R_Info_union;
+
+#define ELF64_MIPS_R_SYM(i) \
+  ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
+
 #if KERNEL_ELFDATA != HOST_ELFDATA
 
 static inline void __endian(const void *src, void *dest, unsigned int size)
-
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