mips: Differentiate between 32 and 64 bit ELF header

Depending on the configuration either the 32 or 64 bit version of
elf_check_arch() is defined. parse_crash_elf{32|64}_headers() does
some basic verification of the ELF header via
vmcore_elf{32|64}_check_arch() which happen to map to elf_check_arch().
Since the implementation 32 and 64 bit version of elf_check_arch()
differ, we use the wrong type:

   In file included from include/linux/elf.h:4:0,
                    from fs/proc/vmcore.c:13:
   fs/proc/vmcore.c: In function 'parse_crash_elf64_headers':
>> arch/mips/include/asm/elf.h:228:23: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     struct elfhdr *__h = (hdr);     \
                          ^
   include/linux/crash_dump.h:41:37: note: in expansion of macro 'elf_check_arch'
    #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
                                        ^
   fs/proc/vmcore.c:1015:4: note: in expansion of macro 'vmcore_elf64_check_arch'
      !vmcore_elf64_check_arch(&ehdr) ||
       ^

Therefore, we rather define vmcore_elf{32|64}_check_arch() as a
basic machine check and use it also in binfm_elf?32.c as well.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Suggested-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: Maciej W. Rozycki <macro@imgtec.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12529/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 9 insertions, 4 deletions

diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index cefb7a596878..e090fc388e02 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -227,7 +227,7 @@ struct mips_elf_abiflags_v0 {
         int __res = 1;                                                  \
         struct elfhdr *__h = (hdr);                                     \
                                                                         \
-        if (__h->e_machine != EM_MIPS)                                  \
+        if (!mips_elf_check_machine(__h))                               \
                 __res = 0;                                              \
         if (__h->e_ident[EI_CLASS] != ELFCLASS32)                       \
                 __res = 0;                                              \
@@ -258,7 +258,7 @@ struct mips_elf_abiflags_v0 {
         int __res = 1;                                                  \
         struct elfhdr *__h = (hdr);                                     \
                                                                         \
-        if (__h->e_machine != EM_MIPS)                                  \
+        if (!mips_elf_check_machine(__h))                               \
                 __res = 0;                                              \
         if (__h->e_ident[EI_CLASS] != ELFCLASS64)                       \
                 __res = 0;                                              \
@@ -285,6 +285,11 @@ struct mips_elf_abiflags_v0 {
 
 #endif /* !defined(ELF_ARCH) */
 
+#define mips_elf_check_machine(x) ((x)->e_machine == EM_MIPS)
+
+#define vmcore_elf32_check_arch mips_elf_check_machine
+#define vmcore_elf64_check_arch mips_elf_check_machine
+
 struct mips_abi;
 
 extern struct mips_abi mips_abi;
diff --git a/arch/mips/kernel/binfmt_elfn32.c b/arch/mips/kernel/binfmt_elfn32.c
index 1188e00bb120..1b992c6e3d8e 100644
--- a/arch/mips/kernel/binfmt_elfn32.c
+++ b/arch/mips/kernel/binfmt_elfn32.c
@@ -35,7 +35,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
         int __res = 1;                                                  \
         struct elfhdr *__h = (hdr);                                     \
                                                                         \
-        if (__h->e_machine != EM_MIPS)                                  \
+        if (!mips_elf_check_machine(__h))                               \
                 __res = 0;                                              \
         if (__h->e_ident[EI_CLASS] != ELFCLASS32)                       \
                 __res = 0;                                              \
diff --git a/arch/mips/kernel/binfmt_elfo32.c b/arch/mips/kernel/binfmt_elfo32.c
index 928767858b86..abd3affe5fb3 100644
--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -47,7 +47,7 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
         int __res = 1;                                                  \
         struct elfhdr *__h = (hdr);                                     \
                                                                         \
-        if (__h->e_machine != EM_MIPS)                                  \
+        if (!mips_elf_check_machine(__h))                               \
                 __res = 0;                                              \
         if (__h->e_ident[EI_CLASS] != ELFCLASS32)                       \
                 __res = 0;                                              \