Merge branch 'for-2.6.34-incoming' into for-2.6.35-incoming
[pandora-kernel.git] / fs / binfmt_elf.c
index fd5b2ea..535e763 100644 (file)
@@ -31,6 +31,7 @@
 #include <linux/random.h>
 #include <linux/elf.h>
 #include <linux/utsname.h>
+#include <linux/coredump.h>
 #include <asm/uaccess.h>
 #include <asm/param.h>
 #include <asm/page.h>
@@ -1085,36 +1086,6 @@ out:
  * Modelled on fs/exec.c:aout_core_dump()
  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
  */
-/*
- * These are the only things you should do on a core-file: use only these
- * functions to write out all the necessary info.
- */
-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, loff_t off)
-{
-       if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
-               if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
-                       return 0;
-       } else {
-               char *buf = (char *)get_zeroed_page(GFP_KERNEL);
-               if (!buf)
-                       return 0;
-               while (off > 0) {
-                       unsigned long n = off;
-                       if (n > PAGE_SIZE)
-                               n = PAGE_SIZE;
-                       if (!dump_write(file, buf, n))
-                               return 0;
-                       off -= n;
-               }
-               free_page((unsigned long)buf);
-       }
-       return 1;
-}
 
 /*
  * Decide what to dump of a segment, part, all or none.
@@ -1249,11 +1220,6 @@ static int writenote(struct memelfnote *men, struct file *file,
 }
 #undef DUMP_WRITE
 
-#define DUMP_WRITE(addr, nr)                           \
-       if ((size += (nr)) > cprm->limit ||             \
-           !dump_write(cprm->file, (addr), (nr)))      \
-               goto end_coredump;
-
 static void fill_elf_header(struct elfhdr *elf, int segs,
                            u16 machine, u32 flags, u8 osabi)
 {
@@ -1872,6 +1838,34 @@ static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
        return gate_vma;
 }
 
+static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
+                            elf_addr_t e_shoff, int segs)
+{
+       elf->e_shoff = e_shoff;
+       elf->e_shentsize = sizeof(*shdr4extnum);
+       elf->e_shnum = 1;
+       elf->e_shstrndx = SHN_UNDEF;
+
+       memset(shdr4extnum, 0, sizeof(*shdr4extnum));
+
+       shdr4extnum->sh_type = SHT_NULL;
+       shdr4extnum->sh_size = elf->e_shnum;
+       shdr4extnum->sh_link = elf->e_shstrndx;
+       shdr4extnum->sh_info = segs;
+}
+
+static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
+                                    unsigned long mm_flags)
+{
+       struct vm_area_struct *vma;
+       size_t size = 0;
+
+       for (vma = first_vma(current, gate_vma); vma != NULL;
+            vma = next_vma(vma, gate_vma))
+               size += vma_dump_size(vma, mm_flags);
+       return size;
+}
+
 /*
  * Actual dumper
  *
@@ -1888,8 +1882,11 @@ static int elf_core_dump(struct coredump_params *cprm)
        struct vm_area_struct *vma, *gate_vma;
        struct elfhdr *elf = NULL;
        loff_t offset = 0, dataoff, foffset;
-       unsigned long mm_flags;
        struct elf_note_info info;
+       struct elf_phdr *phdr4note = NULL;
+       struct elf_shdr *shdr4extnum = NULL;
+       Elf_Half e_phnum;
+       elf_addr_t e_shoff;
 
        /*
         * We no longer stop all VM operations.
@@ -1912,20 +1909,25 @@ static int elf_core_dump(struct coredump_params *cprm)
         * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
         */
        segs = current->mm->map_count;
-#ifdef ELF_CORE_EXTRA_PHDRS
-       segs += ELF_CORE_EXTRA_PHDRS;
-#endif
+       segs += elf_core_extra_phdrs();
 
        gate_vma = get_gate_vma(current);
        if (gate_vma != NULL)
                segs++;
 
+       /* for notes section */
+       segs++;
+
+       /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
+        * this, kernel supports extended numbering. Have a look at
+        * include/linux/elf.h for further information. */
+       e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
+
        /*
         * Collect all the non-memory information about the process for the
         * notes.  This also sets up the file header.
         */
-       if (!fill_note_info(elf, segs + 1, /* including notes section */
-                           &info, cprm->signr, cprm->regs))
+       if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
                goto cleanup;
 
        has_dumped = 1;
@@ -1934,31 +1936,47 @@ static int elf_core_dump(struct coredump_params *cprm)
        fs = get_fs();
        set_fs(KERNEL_DS);
 
-       DUMP_WRITE(elf, sizeof(*elf));
        offset += sizeof(*elf);                         /* Elf header */
-       offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
+       offset += segs * sizeof(struct elf_phdr);       /* Program headers */
        foffset = offset;
 
        /* Write notes phdr entry */
        {
-               struct elf_phdr phdr;
                size_t sz = get_note_info_size(&info);
 
                sz += elf_coredump_extra_notes_size();
 
-               fill_elf_note_phdr(&phdr, sz, offset);
+               phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
+               if (!phdr4note)
+                       goto end_coredump;
+
+               fill_elf_note_phdr(phdr4note, sz, offset);
                offset += sz;
-               DUMP_WRITE(&phdr, sizeof(phdr));
        }
 
        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
 
-       /*
-        * We must use the same mm->flags while dumping core to avoid
-        * inconsistency between the program headers and bodies, otherwise an
-        * unusable core file can be generated.
-        */
-       mm_flags = current->mm->flags;
+       offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
+       offset += elf_core_extra_data_size();
+       e_shoff = offset;
+
+       if (e_phnum == PN_XNUM) {
+               shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
+               if (!shdr4extnum)
+                       goto end_coredump;
+               fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
+       }
+
+       offset = dataoff;
+
+       size += sizeof(*elf);
+       if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
+               goto end_coredump;
+
+       size += sizeof(*phdr4note);
+       if (size > cprm->limit
+           || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
+               goto end_coredump;
 
        /* Write program headers for segments dump */
        for (vma = first_vma(current, gate_vma); vma != NULL;
@@ -1969,7 +1987,7 @@ static int elf_core_dump(struct coredump_params *cprm)
                phdr.p_offset = offset;
                phdr.p_vaddr = vma->vm_start;
                phdr.p_paddr = 0;
-               phdr.p_filesz = vma_dump_size(vma, mm_flags);
+               phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
                phdr.p_memsz = vma->vm_end - vma->vm_start;
                offset += phdr.p_filesz;
                phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
@@ -1979,12 +1997,14 @@ static int elf_core_dump(struct coredump_params *cprm)
                        phdr.p_flags |= PF_X;
                phdr.p_align = ELF_EXEC_PAGESIZE;
 
-               DUMP_WRITE(&phdr, sizeof(phdr));
+               size += sizeof(phdr);
+               if (size > cprm->limit
+                   || !dump_write(cprm->file, &phdr, sizeof(phdr)))
+                       goto end_coredump;
        }
 
-#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
-       ELF_CORE_WRITE_EXTRA_PHDRS;
-#endif
+       if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
+               goto end_coredump;
 
        /* write out the notes section */
        if (!write_note_info(&info, cprm->file, &foffset))
@@ -2002,7 +2022,7 @@ static int elf_core_dump(struct coredump_params *cprm)
                unsigned long addr;
                unsigned long end;
 
-               end = vma->vm_start + vma_dump_size(vma, mm_flags);
+               end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
 
                for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
                        struct page *page;
@@ -2023,15 +2043,24 @@ static int elf_core_dump(struct coredump_params *cprm)
                }
        }
 
-#ifdef ELF_CORE_WRITE_EXTRA_DATA
-       ELF_CORE_WRITE_EXTRA_DATA;
-#endif
+       if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
+               goto end_coredump;
+
+       if (e_phnum == PN_XNUM) {
+               size += sizeof(*shdr4extnum);
+               if (size > cprm->limit
+                   || !dump_write(cprm->file, shdr4extnum,
+                                  sizeof(*shdr4extnum)))
+                       goto end_coredump;
+       }
 
 end_coredump:
        set_fs(fs);
 
 cleanup:
        free_note_info(&info);
+       kfree(shdr4extnum);
+       kfree(phdr4note);
        kfree(elf);
 out:
        return has_dumped;