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authorKawai, Hidehiro <hidehiro.kawai.ez@hitachi.com>2007-07-19 01:48:29 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-19 10:04:47 -0700
commita1b59e802f846b6b0e057507386068fcc6dff442 (patch)
tree1ad51ffa807774986595e56b6fac3525b6a285ac /fs/binfmt_elf.c
parent3cb4a0bb1e773e3c41800b33a3f7dab32bd06c64 (diff)
downloadconfigs-a1b59e802f846b6b0e057507386068fcc6dff442.tar.gz
coredump masking: ELF: enable core dump filtering
This patch enables core dump filtering for ELF-formatted core file. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c30
1 files changed, 21 insertions, 9 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 295cbaa0e58..ba24cb2ff6c 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1262,7 +1262,7 @@ static int dump_seek(struct file *file, loff_t off)
*
* I think we should skip something. But I am not sure how. H.J.
*/
-static int maydump(struct vm_area_struct *vma)
+static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
{
/* The vma can be set up to tell us the answer directly. */
if (vma->vm_flags & VM_ALWAYSDUMP)
@@ -1272,15 +1272,19 @@ static int maydump(struct vm_area_struct *vma)
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_path.dentry->d_inode->i_nlink == 0;
+ /* By default, dump shared memory if mapped from an anonymous file. */
+ if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0)
+ return test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
+ else
+ return test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
+ }
- /* If it hasn't been written to, don't write it out */
+ /* By default, if it hasn't been written to, don't write it out. */
if (!vma->anon_vma)
- return 0;
+ return test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
- return 1;
+ return test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
}
/* An ELF note in memory */
@@ -1572,6 +1576,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
#endif
int thread_status_size = 0;
elf_addr_t *auxv;
+ unsigned long mm_flags;
#ifdef ELF_CORE_WRITE_EXTRA_NOTES
int extra_notes_size;
#endif
@@ -1715,6 +1720,13 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
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;
+
/* Write program headers for segments dump */
for (vma = first_vma(current, gate_vma); vma != NULL;
vma = next_vma(vma, gate_vma)) {
@@ -1727,7 +1739,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
phdr.p_offset = offset;
phdr.p_vaddr = vma->vm_start;
phdr.p_paddr = 0;
- phdr.p_filesz = maydump(vma) ? sz : 0;
+ phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
phdr.p_memsz = sz;
offset += phdr.p_filesz;
phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
@@ -1771,7 +1783,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
vma = next_vma(vma, gate_vma)) {
unsigned long addr;
- if (!maydump(vma))
+ if (!maydump(vma, mm_flags))
continue;
for (addr = vma->vm_start;