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Commit a1b59e80 authored by Kawai, Hidehiro's avatar Kawai, Hidehiro Committed by Linus Torvalds
Browse files

coredump masking: ELF: enable core dump filtering 



This patch enables core dump filtering for ELF-formatted core file.

Signed-off-by: default avatarHidehiro 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3cb4a0bb

fs/binfmt_elf.c

+21 −9
Original line number Diff line number Diff line
@@ -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;