binfmt_flat: use fixed size type for the on-disk format

So far binfmt_flat has only been supported on 32-bit platforms, so the
variable size of the fields didn't matter.  But the upcoming RISC-V
nommu port supports 64-bit CPUs, and we now have a conflict between
the elf2flt creation tool that always uses 32-bit fields and the kernel
that uses (unsigned) long field.  Switch to the userspace view as the
rest of the binfmt_flat format is completely architecture neutral,
and binfmt_flat isn't the right binary format for huge executables to
start with.

While we're at it also ensure these fields are using __be types as
they big endian and are byte swapped when loaded.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

diff --git a/include/linux/flat.h b/include/linux/flat.h
index 19c586b74b99e94e36c17d6f2844cd5d0a1a0ef7..d586bb6e64a70f7b94587df4f35fcc7aad34a433 100644 (file)
--- a/include/linux/flat.h
+++ b/include/linux/flat.h
@@ -24,26 +24,26 @@
  */
 
 struct flat_hdr {
-       char magic[4];
-       unsigned long rev;          /* version (as above) */
-       unsigned long entry;        /* Offset of first executable instruction
-                                      with text segment from beginning of file */
-       unsigned long data_start;   /* Offset of data segment from beginning of
-                                      file */
-       unsigned long data_end;     /* Offset of end of data segment
-                                      from beginning of file */
-       unsigned long bss_end;      /* Offset of end of bss segment from beginning
-                                      of file */
+       char    magic[4];
+       __be32  rev;          /* version (as above) */
+       __be32  entry;        /* Offset of first executable instruction
+                                with text segment from beginning of file */
+       __be32  data_start;   /* Offset of data segment from beginning of
+                                file */
+       __be32  data_end;     /* Offset of end of data segment from beginning
+                                of file */
+       __be32  bss_end;      /* Offset of end of bss segment from beginning
+                                of file */
 
        /* (It is assumed that data_end through bss_end forms the bss segment.) */
 
-       unsigned long stack_size;   /* Size of stack, in bytes */
-       unsigned long reloc_start;  /* Offset of relocation records from
-                                      beginning of file */
-       unsigned long reloc_count;  /* Number of relocation records */
-       unsigned long flags;
-       unsigned long build_date;   /* When the program/library was built */
-       unsigned long filler[5];    /* Reservered, set to zero */
+       __be32  stack_size;   /* Size of stack, in bytes */
+       __be32  reloc_start;  /* Offset of relocation records from beginning of
+                                file */
+       __be32  reloc_count;  /* Number of relocation records */
+       __be32  flags;
+       __be32  build_date;   /* When the program/library was built */
+       __u32   filler[5];    /* Reservered, set to zero */
 };
 
 #define FLAT_FLAG_RAM    0x0001 /* load program entirely into RAM */
@@ -67,15 +67,15 @@ struct flat_hdr {
 #define OLD_FLAT_RELOC_TYPE_BSS                2
 
 typedef union {
-       unsigned long   value;
+       u32             value;
        struct {
 #if defined(__LITTLE_ENDIAN_BITFIELD) || \
     (defined(mc68000) && !defined(CONFIG_COLDFIRE))
-               signed long offset : 30;
-               unsigned long type : 2;
+               s32     offset : 30;
+               u32     type : 2;
 # elif defined(__BIG_ENDIAN_BITFIELD)
-               unsigned long type : 2;
-               signed long offset : 30;
+               u32     type : 2;
+               s32     offset : 30;
 # else
 #      error "Unknown bitfield order for flat files."
 # endif