Commit a1b59e80 authored by Kawai, Hidehiro's avatar Kawai, Hidehiro Committed by Linus Torvalds
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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
......@@ -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;
......
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