vserver 2.0 rc7

[linux-2.6.git] / fs / binfmt_elf.c

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index e80e8e2..3c89c56 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -37,6 +37,7 @@
 #include <linux/pagemap.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
+#include <linux/random.h>
 #include <linux/vs_memory.h>
 
 #include <asm/uaccess.h>
@@ -166,21 +167,14 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr * exec,
        if (k_platform) {
                size_t len = strlen(k_platform) + 1;
 
-#ifdef CONFIG_X86_HT
                /*
                 * In some cases (e.g. Hyper-Threading), we want to avoid L1
                 * evictions by the processes running on the same package. One
                 * thing we can do is to shuffle the initial stack for them.
-                *
-                * The conditionals here are unneeded, but kept in to make the
-                * code behaviour the same as pre change unless we have
-                * hyperthreaded processors. This should be cleaned up
-                * before 2.6
                 */
         
-               if (smp_num_siblings > 1)
-                       STACK_ALLOC(p, ((current->pid % 64) << 7));
-#endif
+               p = arch_align_stack(p);
+
                u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
                if (__copy_to_user(u_platform, k_platform, len))
                        return -EFAULT;
@@ -502,6 +496,19 @@ out:
 #define INTERPRETER_ELF 2
 
 
+static unsigned long randomize_stack_top(unsigned long stack_top)
+{
+       unsigned int random_variable = 0;
+
+       if (current->flags & PF_RANDOMIZE)
+               random_variable = get_random_int() % (8*1024*1024);
+#ifdef CONFIG_STACK_GROWSUP
+       return PAGE_ALIGN(stack_top + random_variable);
+#else
+       return PAGE_ALIGN(stack_top - random_variable);
+#endif
+}
+
 static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 {
        struct file *interpreter = NULL; /* to shut gcc up */
@@ -761,13 +768,16 @@ static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
        if (elf_read_implies_exec(loc->elf_ex, executable_stack))
                current->personality |= READ_IMPLIES_EXEC;
 
+       if ( !(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+               current->flags |= PF_RANDOMIZE;
        arch_pick_mmap_layout(current->mm);
 
        /* Do this so that we can load the interpreter, if need be.  We will
           change some of these later */
-       vx_rsspages_sub(current->mm, current->mm->rss);
+       set_mm_counter(current->mm, rss, 0);
        current->mm->free_area_cache = current->mm->mmap_base;
-       retval = setup_arg_pages(bprm, STACK_TOP, executable_stack);
+       retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
+                                executable_stack);
        if (retval < 0) {
                send_sig(SIGKILL, current, 0);
                goto out_free_dentry;
@@ -932,6 +942,14 @@ static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 
        set_binfmt(&elf_format);
 
+#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
+       retval = arch_setup_additional_pages(bprm, executable_stack);
+       if (retval < 0) {
+               send_sig(SIGKILL, current, 0);
+               goto out;
+       }
+#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
+
        compute_creds(bprm);
        current->flags &= ~PF_FORKNOEXEC;
        create_elf_tables(bprm, &loc->elf_ex, (interpreter_type == INTERPRETER_AOUT),
@@ -1108,7 +1126,7 @@ static int dump_write(struct file *file, const void *addr, int nr)
        return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
 }
 
-static int dump_seek(struct file *file, off_t off)
+static int dump_seek(struct file *file, loff_t off)
 {
        if (file->f_op->llseek) {
                if (file->f_op->llseek(file, off, 0) != off)
@@ -1127,10 +1145,14 @@ static int dump_seek(struct file *file, off_t off)
  */
 static int maydump(struct vm_area_struct *vma)
 {
-       /* Do not dump I/O mapped devices, shared memory, or special mappings */
-       if (vma->vm_flags & (VM_IO | VM_SHARED | VM_RESERVED))
+       /* Do not dump I/O mapped devices or special mappings */
+       if (vma->vm_flags & (VM_IO | VM_RESERVED))
                return 0;
 
+       /* Dump shared memory only if mapped from an anonymous file.  */
+       if (vma->vm_flags & VM_SHARED)
+               return vma->vm_file->f_dentry->d_inode->i_nlink == 0;
+
        /* If it hasn't been written to, don't write it out */
        if (!vma->anon_vma)
                return 0;
@@ -1590,7 +1612,7 @@ static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file)
                                        DUMP_SEEK (file->f_pos + PAGE_SIZE);
                                } else {
                                        void *kaddr;
-                                       flush_cache_page(vma, addr);
+                                       flush_cache_page(vma, addr, page_to_pfn(page));
                                        kaddr = kmap(page);
                                        if ((size += PAGE_SIZE) > limit ||
                                            !dump_write(file, kaddr,