fs/binfmt_elf.c: coredump: allow process with empty address space to coredump (1fbede6e) · Commits · 戴 / test

Unmapping whole address space at once with munmap(0, (1ULL<<47) - 4096) or equivalent will create empty coredump. It is silly way to exit, however registers content may still be useful. The right to coredump is fundamental right of a process! Link: http://lkml.kernel.org/r/20191222150137.GA1277@avx2 Signed-off-by:

Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -1595,6 +1595,10 @@ static int fill_files_note(struct memelfnote *note)
		if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
		return -EINVAL;
		size = round_up(size, PAGE_SIZE);
		/*
		* "size" can be 0 here legitimately.
		* Let it ENOMEM and omit NT_FILE section which will be empty anyway.
		*/
		data = kvmalloc(size, GFP_KERNEL);
		if (ZERO_OR_NULL_PTR(data))
		return -ENOMEM;
		@@ -2257,9 +2261,13 @@ static int elf_core_dump(struct coredump_params *cprm)

		dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);

		/*
		* Zero vma process will get ZERO_SIZE_PTR here.
		* Let coredump continue for register state at least.
		*/
		vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
		GFP_KERNEL);
		if (ZERO_OR_NULL_PTR(vma_filesz))
		if (!vma_filesz)
		goto end_coredump;

		for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;

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