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Commit ee78b0a6 authored by Kawai, Hidehiro's avatar Kawai, Hidehiro Committed by Linus Torvalds
Browse files

coredump masking: ELF-FDPIC: enable core dump filtering 



This patch enables core dump filtering for ELF-FDPIC-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 e2e00906

fs/binfmt_elf_fdpic.c

+35 −17
Original line number Diff line number Diff line
@@ -1181,8 +1181,10 @@ 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)

{

	int dump_ok;



	/* Do not dump I/O mapped devices or special mappings */

	if (vma->vm_flags & (VM_IO | VM_RESERVED)) {

		kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
@@ -1197,27 +1199,35 @@ static int maydump(struct vm_area_struct *vma) 
		return 0;

	}



	/* Dump shared memory only if mapped from an anonymous file. */

	/* 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) {

			kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);

			return 1;

			dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);

			kdcore("%08lx: %08lx: %s (share)", vma->vm_start,

			       vma->vm_flags, dump_ok ? "yes" : "no");

			return dump_ok;

		}



		kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);

		return 0;

		dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);

		kdcore("%08lx: %08lx: %s (share)", vma->vm_start,

		       vma->vm_flags, dump_ok ? "yes" : "no");

		return dump_ok;

	}



#ifdef CONFIG_MMU

	/* 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) {

		kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);

		return 0;

		dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);

		kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,

		       vma->vm_flags, dump_ok ? "yes" : "no");

		return dump_ok;

	}

#endif



	kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);

	return 1;

	dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);

	kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,

	       dump_ok ? "yes" : "no");

	return dump_ok;

}



/* An ELF note in memory */
@@ -1457,14 +1467,14 @@ static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 
 */

#ifdef CONFIG_MMU

static int elf_fdpic_dump_segments(struct file *file, size_t *size,

				   unsigned long *limit)

			   unsigned long *limit, unsigned long mm_flags)

{

	struct vm_area_struct *vma;



	for (vma = current->mm->mmap; vma; vma = vma->vm_next) {

		unsigned long addr;



		if (!maydump(vma))

		if (!maydump(vma, mm_flags))

			continue;



		for (addr = vma->vm_start;
@@ -1512,14 +1522,14 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size, 
 */

#ifndef CONFIG_MMU

static int elf_fdpic_dump_segments(struct file *file, size_t *size,

				   unsigned long *limit)

			   unsigned long *limit, unsigned long mm_flags)

{

	struct vm_list_struct *vml;



	for (vml = current->mm->context.vmlist; vml; vml = vml->next) {

	struct vm_area_struct *vma = vml->vma;



		if (!maydump(vma))

		if (!maydump(vma, mm_flags))

			continue;



		if ((*size += PAGE_SIZE) > *limit)
@@ -1570,6 +1580,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 
	struct vm_list_struct *vml;

#endif

	elf_addr_t *auxv;

	unsigned long mm_flags;



	/*

	 * We no longer stop all VM operations.
@@ -1707,6 +1718,13 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 
	/* Page-align dumped data */

	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 (

#ifdef CONFIG_MMU
@@ -1728,7 +1746,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 
		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;
@@ -1762,7 +1780,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 


	DUMP_SEEK(dataoff);



	if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)

	if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)

		goto end_coredump;



#ifdef ELF_CORE_WRITE_EXTRA_DATA