binfmt_flat: make support for old format binaries optional

No need to carry the extra code around, given that systems using flat
binaries are generally very resource constrained.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 286b425b30b93b1b4801dea35034c1d8931a8ab7..62dc4f577ba1330e0f373719b33692b97a5aad15 100644 (file)
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -106,6 +106,13 @@ config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 config BINFMT_FLAT_OLD_ALWAYS_RAM
        bool
 
+config BINFMT_FLAT_OLD
+       bool "Enable support for very old legacy flat binaries"
+       depends on BINFMT_FLAT
+       help
+         Support decade old uClinux FLAT format binaries.  Unless you know
+         you have some of those say N here.
+
 config BINFMT_ZFLAT
        bool "Enable ZFLAT support"
        depends on BINFMT_FLAT

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 404a0bedc85b5e068ee40890d2938f518e6018c5..1e88f4e62e657d2efa29ec02aeef3b995a79907b 100644 (file)
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -374,6 +374,7 @@ failed:
 
 /****************************************************************************/
 
+#ifdef CONFIG_BINFMT_FLAT_OLD
 static void old_reloc(unsigned long rl)
 {
        static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
@@ -411,6 +412,7 @@ static void old_reloc(unsigned long rl)
 
        pr_debug("Relocation became %lx\n", val);
 }
+#endif /* CONFIG_BINFMT_FLAT_OLD */
 
 /****************************************************************************/
 
@@ -461,6 +463,7 @@ static int load_flat_file(struct linux_binprm *bprm,
        if (flags & FLAT_FLAG_KTRACE)
                pr_info("Loading file: %s\n", bprm->filename);
 
+#ifdef CONFIG_BINFMT_FLAT_OLD
        if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
                pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
                       rev, FLAT_VERSION, OLD_FLAT_VERSION);
@@ -476,6 +479,23 @@ static int load_flat_file(struct linux_binprm *bprm,
                goto err;
        }
 
+       /*
+        * fix up the flags for the older format,  there were all kinds
+        * of endian hacks,  this only works for the simple cases
+        */
+       if (rev == OLD_FLAT_VERSION &&
+          (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
+               flags = FLAT_FLAG_RAM;
+
+#else /* CONFIG_BINFMT_FLAT_OLD */
+       if (rev != FLAT_VERSION) {
+               pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
+                      rev, FLAT_VERSION);
+               ret = -ENOEXEC;
+               goto err;
+       }
+#endif /* !CONFIG_BINFMT_FLAT_OLD */
+
        /*
         * Make sure the header params are sane.
         * 28 bits (256 MB) is way more than reasonable in this case.
@@ -487,14 +507,6 @@ static int load_flat_file(struct linux_binprm *bprm,
                goto err;
        }
 
-       /*
-        * fix up the flags for the older format,  there were all kinds
-        * of endian hacks,  this only works for the simple cases
-        */
-       if (rev == OLD_FLAT_VERSION &&
-          (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
-               flags = FLAT_FLAG_RAM;
-
 #ifndef CONFIG_BINFMT_ZFLAT
        if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
                pr_err("Support for ZFLAT executables is not enabled.\n");
@@ -833,6 +845,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                                        goto err;
                        }
                }
+#ifdef CONFIG_BINFMT_FLAT_OLD
        } else {
                for (i = 0; i < relocs; i++) {
                        __be32 relval;
@@ -840,6 +853,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                                return -EFAULT;
                        old_reloc(ntohl(relval));
                }
+#endif /* CONFIG_BINFMT_FLAT_OLD */
        }
 
        flush_icache_range(start_code, end_code);