binfmt_flat: don't offset the data start

Ever since the initial commit of the binfmt_flat shared library
support back in the bitkeeper days we've offset the actual in-memory
.data start by one field per possible shared library, or 1 in case
shared library support isn't enabled.  I can't find anything in the
loader that actually makes use of it, nor was it present before
shared library support it.

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

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index ccd9843e979eb81485e414663d2aebefcab1203b..80d902fb46e394f834ba53bc1d265c03eff8e448 100644 (file)
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -573,7 +573,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                        goto err;
                }
 
-               len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+               len = data_len + extra;
                len = PAGE_ALIGN(len);
                realdatastart = vm_mmap(NULL, 0, len,
                        PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
@@ -587,9 +587,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                        vm_munmap(textpos, text_len);
                        goto err;
                }
-               datapos = ALIGN(realdatastart +
-                               MAX_SHARED_LIBS * sizeof(unsigned long),
-                               FLAT_DATA_ALIGN);
+               datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
 
                pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
                         data_len + bss_len + stack_len, datapos);
@@ -619,7 +617,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                memp_size = len;
        } else {
 
-               len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
+               len = text_len + data_len + extra;
                len = PAGE_ALIGN(len);
                textpos = vm_mmap(NULL, 0, len,
                        PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
@@ -634,9 +632,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                }
 
                realdatastart = textpos + ntohl(hdr->data_start);
-               datapos = ALIGN(realdatastart +
-                               MAX_SHARED_LIBS * sizeof(u32),
-                               FLAT_DATA_ALIGN);
+               datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
 
                reloc = (__be32 __user *)
                        (datapos + (ntohl(hdr->reloc_start) - text_len));
@@ -653,8 +649,9 @@ static int load_flat_file(struct linux_binprm *bprm,
                                         (text_len + full_data
                                                  - sizeof(struct flat_hdr)),
                                         0);
-                       memmove((void *) datapos, (void *) realdatastart,
-                                       full_data);
+                       if (datapos != realdatastart)
+                               memmove((void *)datapos, (void *)realdatastart,
+                                               full_data);
 #else
                        /*
                         * This is used on MMU systems mainly for testing.
@@ -710,8 +707,7 @@ static int load_flat_file(struct linux_binprm *bprm,
                if (IS_ERR_VALUE(result)) {
                        ret = result;
                        pr_err("Unable to read code+data+bss, errno %d\n", ret);
-                       vm_munmap(textpos, text_len + data_len + extra +
-                               MAX_SHARED_LIBS * sizeof(u32));
+                       vm_munmap(textpos, text_len + data_len + extra);
                        goto err;
                }
        }