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

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
......@@ -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
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment