On Thu, 20 Apr 2006 01:19:00 +0100, Thiemo Seufer <ths@xxxxxxxxxxxx> wrote:
> > +#define ELF64_MIPS_R_TYPE(i) \
> > + (((_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1 \
> > + | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
> > + ).r_info_fields.r_type2 << 8) \
> > + | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
> > + ).r_info_fields.r_type3 << 16) \
> > + | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
> > + ).r_info_fields.r_ssym << 24))
>
> Why is it the right thing to combine the type info into a 32bit word?
Well, I just take ELF64_MIPS_R_TYPE() from glibc source.
> It will never get used as such for MIPS ELF64. I would have expected
> something like:
>
> #define ELF64_MIPS_R_INFO(sym,ssym,t3,t2,t1) \
> {( \
> _Elf64_Mips_R_Info info = { \
> .r_sym = sym, \
> .r_ssym = ssym, \
> .r_type3 = t3, \
> .r_type2 = t2, \
> .r_type1 = t1, \
> } \
> (Elf64_Xword)info; \
> )}
>
> without a corresponding ELF64_MIPS_R_TYPE, and then:
>
> if (hdr->e_ident[EI_CLASS] == ELFCLASS64
> && hdr->e_machine == EM_MIPS) {
> _Elf64_Mips_R_Info info = (_Elf64_Mips_R_Info)r.r_info;
> r.r_info = ELF64_MIPS_R_INFO(TO_NATIVE(info.r_sym),
> info.r_ssym, info.r_type3,
> info.r_type2, info.r_type1);
> }
Sorry, I can not see what you mean ... it just does byte-swap only
r_sym part, doesn't it? It is not enough because a position of r_sym
in MIPS ELF64 r_info is different from standard ELF64 r_info.
And I found my previous patch does unnecessary byte-swap on r_type.
This is a take 3. It also checks hdr->e_ident[EI_CLASS] instead of
KERNEL_ELFCLASS.
64bit mips has different r_info layout. This patch fixes modpost
segfault for 64bit little endian mips kernel.
Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index cd00e9f..8f5e814 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -710,7 +710,17 @@ static void check_sec_ref(struct module
Elf_Rela r;
const char *secname;
r.r_offset = TO_NATIVE(rela->r_offset);
- r.r_info = TO_NATIVE(rela->r_info);
+ if (hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
+ hdr->e_machine == EM_MIPS) {
+ unsigned int r_sym =
+ ELF64_MIPS_R_SYM(rela->r_info);
+ unsigned int r_type =
+ ELF64_MIPS_R_TYPE(rela->r_info);
+ r.r_info = ELF_R_INFO(TO_NATIVE(r_sym),
+ r_type);
+ } else {
+ r.r_info = TO_NATIVE(rela->r_info);
+ }
r.r_addend = TO_NATIVE(rela->r_addend);
sym = elf->symtab_start + ELF_R_SYM(r.r_info);
/* Skip special sections */
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index b14255c..7d1c04d 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -24,6 +24,7 @@
#define Elf_Rela Elf32_Rela
#define ELF_R_SYM ELF32_R_SYM
#define ELF_R_TYPE ELF32_R_TYPE
+#define ELF_R_INFO ELF32_R_INFO
#else
#define Elf_Ehdr Elf64_Ehdr
@@ -37,8 +38,43 @@
#define Elf_Rela Elf64_Rela
#define ELF_R_SYM ELF64_R_SYM
#define ELF_R_TYPE ELF64_R_TYPE
+#define ELF_R_INFO ELF64_R_INFO
#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;
+
+typedef struct
+{
+ Elf64_Addr r_offset; /* Address */
+ _Elf64_Mips_R_Info_union r_info; /* Relocation type and symbol index */
+ Elf64_Sxword r_addend; /* Addend */
+} Elf64_Mips_Rela;
+
+#define ELF64_MIPS_R_SYM(i) \
+ ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym)
+#define ELF64_MIPS_R_TYPE(i) \
+ (((_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1 \
+ | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
+ ).r_info_fields.r_type2 << 8) \
+ | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
+ ).r_info_fields.r_type3 << 16) \
+ | ((Elf32_Word)(__extension__ (_Elf64_Mips_R_Info_union)(i) \
+ ).r_info_fields.r_ssym << 24))
+
#if KERNEL_ELFDATA != HOST_ELFDATA
static inline void __endian(const void *src, void *dest, unsigned int size)
