2.4.13-ac8

 fs

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla/fs/binfmt_elf.c linux.ac/fs/binfmt_elf.c
--- linux.vanilla/fs/binfmt_elf.c   Thu Oct 25 16:26:38 2001
+++ linux.ac/fs/binfmt_elf.c   Fri Nov  2 14:31:33 2001
@@ -32,7 +32,7 @@
 #include <linux/highuid.h>
 #include <linux/smp_lock.h>
 #include <linux/compiler.h>
-#include <linux/limits.h>
+#include <linux/highmem.h>
 
 #include <asm/uaccess.h>
 #include <asm/param.h>
@@ -609,9 +609,14 @@
    /* Do this so that we can load the interpreter, if need be.  We will
       change some of these later */
    current->mm->rss = 0;
-   setup_arg_pages(bprm); /* XXX: check error */
+   retval = setup_arg_pages(bprm);
+   if (retval < 0) {
+      /* Someone check-me: is this error path enough? */
+      send_sig(SIGKILL, current, 0);
+      return retval;
+   }
+   
    current->mm->start_stack = bprm->p;
-
    /* Now we do a little grungy work by mmaping the ELF image into
       the correct location in memory.  At this point, we assume that
       the image should be loaded at fixed address, not at a variable
@@ -1032,6 +1037,25 @@
    elf_fpregset_t fpu;      /* NT_PRFPREG */
    struct elf_prpsinfo psinfo;   /* NT_PRPSINFO */
 
+   /* first copy the parameters from user space */
+   memset(&psinfo, 0, sizeof(psinfo));
+   {
+      int i, len;
+
+      len = current->mm->arg_end - current->mm->arg_start;
+      if (len >= ELF_PRARGSZ)
+         len = ELF_PRARGSZ-1;
+      copy_from_user(&psinfo.pr_psargs,
+               (const char *)current->mm->arg_start, len);
+      for(i = 0; i < len; i++)
+         if (psinfo.pr_psargs[i] == 0)
+            psinfo.pr_psargs[i] = ' ';
+      psinfo.pr_psargs[len] = 0;
+
+   }
+
+   /* now stop all vm operations */
+   down_write(¤t->mm->mmap_sem);
    segs = current->mm->map_count;
 
 #ifdef DEBUG
@@ -1073,7 +1097,6 @@
     * Set up the notes in similar form to SVR4 core dumps made
     * with info from their /proc.
     */
-   memset(&psinfo, 0, sizeof(psinfo));
    memset(&prstatus, 0, sizeof(prstatus));
 
    notes[0].name = "CORE";
@@ -1129,23 +1152,6 @@
    psinfo.pr_flag = current->flags;
    psinfo.pr_uid = NEW_TO_OLD_UID(current->uid);
    psinfo.pr_gid = NEW_TO_OLD_GID(current->gid);
-   {
-      int i, len;
-
-      set_fs(fs);
-
-      len = current->mm->arg_end - current->mm->arg_start;
-      if (len >= ELF_PRARGSZ)
-         len = ELF_PRARGSZ-1;
-      copy_from_user(&psinfo.pr_psargs,
-               (const char *)current->mm->arg_start, len);
-      for(i = 0; i < len; i++)
-         if (psinfo.pr_psargs[i] == 0)
-            psinfo.pr_psargs[i] = ' ';
-      psinfo.pr_psargs[len] = 0;
-
-      set_fs(KERNEL_DS);
-   }
    strncpy(psinfo.pr_fname, current->comm, sizeof(psinfo.pr_fname));
 
    notes[2].name = "CORE";
@@ -1217,8 +1223,6 @@
       if (!writenote(¬es[i], file))
          goto end_coredump;
 
-   set_fs(fs);
-
    DUMP_SEEK(dataoff);
 
    for(vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
@@ -1232,22 +1236,24 @@
       for (addr = vma->vm_start;
            addr < vma->vm_end;
            addr += PAGE_SIZE) {
-         pgd_t *pgd;
-         pmd_t *pmd;
-         pte_t *pte;
-
-         pgd = pgd_offset(vma->vm_mm, addr);
-         if (pgd_none(*pgd))
-            goto nextpage_coredump;
-         pmd = pmd_offset(pgd, addr);
-         if (pmd_none(*pmd))
-            goto nextpage_coredump;
-         pte = pte_offset(pmd, addr);
-         if (pte_none(*pte)) {
-nextpage_coredump:
+         struct page* page;
+         struct vm_area_struct *vma;
+
+         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
+                  &page, &vma) <= 0) {
             DUMP_SEEK (file->f_pos + PAGE_SIZE);
          } else {
-            DUMP_WRITE((void*)addr, PAGE_SIZE);
+            if (page == ZERO_PAGE(addr)) {
+               DUMP_SEEK (file->f_pos + PAGE_SIZE);
+            } else {
+               void *kaddr;
+               flush_cache_page(vma, addr);
+               kaddr = kmap(page);
+               DUMP_WRITE(kaddr, PAGE_SIZE);
+               flush_page_to_ram(page);
+               kunmap(page);
+            }
+            put_page(page);
          }
       }
    }
@@ -1260,6 +1266,7 @@
 
  end_coredump:
    set_fs(fs);
+   up_write(¤t->mm->mmap_sem);
    return has_dumped;
 }
 #endif      /* USE_ELF_CORE_DUMP */