linux-mips
[Top] [All Lists]

Re: [PATCH] fix modpost segfault for 64bit mipsel kernel

To: ths@networkno.de
Subject: Re: [PATCH] fix modpost segfault for 64bit mipsel kernel
From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Date: Fri, 21 Apr 2006 02:05:14 +0900 (JST)
Cc: linux-mips@linux-mips.org, ralf@linux-mips.org, sam@ravnborg.org
In-reply-to: <20060420162319.GD10665@networkno.de>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20060420001900.GC30806@networkno.de> <20060421.010237.25910405.anemo@mba.ocn.ne.jp> <20060420162319.GD10665@networkno.de>
Sender: linux-mips-bounce@linux-mips.org
On Thu, 20 Apr 2006 17:23:19 +0100, Thiemo Seufer <ths@networkno.de> wrote:
> > Well, I just take ELF64_MIPS_R_TYPE() from glibc source.
> 
> It is not more useful in glibc. :-)  Any use of the TYPE data will have
> to take the MIPS64 specifics in account, and thus split it up again
> into single characters.

OK, then I drop TYPE data and simplify the patch.  Take 4.


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 cd00e9f..fcd4306 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -709,10 +709,17 @@ 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 (hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
+                           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));
+                       }
                        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_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)


<Prev in Thread] Current Thread [Next in Thread>