make dump_emit() use vfs_write() instead of banging at ->f_op->write directly
... and deal with short writes properly - the output might be to pipe, after
all; as it is, e.g. no-MMU case of elf_fdpic coredump can write a whole lot
more than a page worth of data at one call.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/coredump.c b/fs/coredump.c
index 319f973..2472ed9 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -696,13 +696,20 @@
int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
{
struct file *file = cprm->file;
- if (dump_interrupted() || !access_ok(VERIFY_READ, addr, nr))
- return 0;
+ loff_t pos = file->f_pos;
+ ssize_t n;
if (cprm->written + nr > cprm->limit)
return 0;
- if (file->f_op->write(file, addr, nr, &file->f_pos) != nr)
- return 0;
- cprm->written += nr;
+ while (nr) {
+ if (dump_interrupted())
+ return 0;
+ n = vfs_write(file, addr, nr, &pos);
+ if (n <= 0)
+ return 0;
+ file->f_pos = pos;
+ cprm->written += n;
+ nr -= n;
+ }
return 1;
}
EXPORT_SYMBOL(dump_emit);