Commit 1607f09c authored by Mateusz Guzik's avatar Mateusz Guzik Committed by Al Viro
Browse files

coredump: fix dumping through pipes 



The offset in the core file used to be tracked with ->written field of
the coredump_params structure. The field was retired in favour of
file->f_pos.

However, ->f_pos is not maintained for pipes which leads to breakage.

Restore explicit tracking of the offset in coredump_params. Introduce
->pos field for this purpose since ->written was already reused.

Fixes: a0083939 ("get rid of coredump_params->written").

Reported-by: default avatarZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: default avatarMateusz Guzik <mguzik@redhat.com>
Reviewed-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a01e718f

arch/powerpc/platforms/cell/spufs/coredump.c

+1 −1
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static int spufs_arch_write_note(struct spu_context *ctx, int i, 
	if (rc < 0)

		goto out;



	skip = roundup(cprm->file->f_pos - total + sz, 4) - cprm->file->f_pos;

	skip = roundup(cprm->pos - total + sz, 4) - cprm->pos;

	if (!dump_skip(cprm, skip))

		goto Eio;

out:

fs/binfmt_elf.c

+1 −1
Original line number Diff line number Diff line
@@ -2275,7 +2275,7 @@ static int elf_core_dump(struct coredump_params *cprm) 
		goto end_coredump;



	/* Align to page */

	if (!dump_skip(cprm, dataoff - cprm->file->f_pos))

	if (!dump_skip(cprm, dataoff - cprm->pos))

		goto end_coredump;



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

fs/binfmt_elf_fdpic.c

+1 −1
Original line number Diff line number Diff line
@@ -1787,7 +1787,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) 
				goto end_coredump;

	}



	if (!dump_skip(cprm, dataoff - cprm->file->f_pos))

	if (!dump_skip(cprm, dataoff - cprm->pos))

		goto end_coredump;



	if (!elf_fdpic_dump_segments(cprm))

fs/coredump.c

+3 −1
Original line number Diff line number Diff line
@@ -794,6 +794,7 @@ int dump_emit(struct coredump_params *cprm, const void *addr, int nr) 
			return 0;

		file->f_pos = pos;

		cprm->written += n;

		cprm->pos += n;

		nr -= n;

	}

	return 1;
@@ -808,6 +809,7 @@ int dump_skip(struct coredump_params *cprm, size_t nr) 
		if (dump_interrupted() ||

		    file->f_op->llseek(file, nr, SEEK_CUR) < 0)

			return 0;

		cprm->pos += nr;

		return 1;

	} else {

		while (nr > PAGE_SIZE) {
@@ -822,7 +824,7 @@ EXPORT_SYMBOL(dump_skip); 


int dump_align(struct coredump_params *cprm, int align)

{

	unsigned mod = cprm->file->f_pos & (align - 1);

	unsigned mod = cprm->pos & (align - 1);

	if (align & (align - 1))

		return 0;

	return mod ? dump_skip(cprm, align - mod) : 1;

include/linux/binfmts.h

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ struct coredump_params { 
	unsigned long limit;

	unsigned long mm_flags;

	loff_t written;

	loff_t pos;

};



/*

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