coredump: refactor page range dumping into common helper

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

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 13d053982dd73c323efc935489370393011204a8..cf956edf05eff409380e9eaa4311c4685aee5ce8 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
+#include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/errno.h>
@@ -421,6 +422,26 @@ static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
        return 0;
 }
 
+static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
+{
+       unsigned long alignment = 0;
+       int i;
+
+       for (i = 0; i < nr; i++) {
+               if (cmds[i].p_type == PT_LOAD) {
+                       unsigned long p_align = cmds[i].p_align;
+
+                       /* skip non-power of two alignments as invalid */
+                       if (!is_power_of_2(p_align))
+                               continue;
+                       alignment = max(alignment, p_align);
+               }
+       }
+
+       /* ensure we align to at least one page */
+       return ELF_PAGEALIGN(alignment);
+}
+
 /**
  * load_elf_phdrs() - load ELF program headers
  * @elf_ex:   ELF header of the binary whose program headers should be loaded
@@ -1008,6 +1029,7 @@ out_free_interp:
                int elf_prot, elf_flags;
                unsigned long k, vaddr;
                unsigned long total_size = 0;
+               unsigned long alignment;
 
                if (elf_ppnt->p_type != PT_LOAD)
                        continue;
@@ -1086,6 +1108,9 @@ out_free_interp:
                                load_bias = ELF_ET_DYN_BASE;
                                if (current->flags & PF_RANDOMIZE)
                                        load_bias += arch_mmap_rnd();
+                               alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
+                               if (alignment)
+                                       load_bias &= ~(alignment - 1);
                                elf_flags |= MAP_FIXED;
                        } else
                                load_bias = 0;
@@ -2419,26 +2444,8 @@ static int elf_core_dump(struct coredump_params *cprm)
 
        for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
                        vma = next_vma(vma, gate_vma)) {
-               unsigned long addr;
-               unsigned long end;
-
-               end = vma->vm_start + vma_filesz[i++];
-
-               for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
-                       struct page *page;
-                       int stop;
-
-                       page = get_dump_page(addr);
-                       if (page) {
-                               void *kaddr = kmap(page);
-                               stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
-                               kunmap(page);
-                               put_page(page);
-                       } else
-                               stop = !dump_skip(cprm, PAGE_SIZE);
-                       if (stop)
-                               goto end_coredump;
-               }
+               if (!dump_user_range(cprm, vma->vm_start, vma_filesz[i++]))
+                       goto end_coredump;
        }
        dump_truncate(cprm);