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

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
......@@ -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:
......
......@@ -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;
......
......@@ -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))
......
......@@ -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;
......
......@@ -65,6 +65,7 @@ struct coredump_params {
unsigned long limit;
unsigned long mm_flags;
loff_t written;
loff_t pos;
};
/*
......
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