make dump_emit() use vfs_write() instead of banging at ->f_op->write directly (2507a4fb) · Commits · 戴 / test

... 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>

fs/coredump.c

+12 −5

Original line number	Diff line number	Diff line
		@@ -696,13 +696,20 @@ EXPORT_SYMBOL(dump_write);
		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)
		while (nr) {
		if (dump_interrupted())
		return 0;
		n = vfs_write(file, addr, nr, &pos);
		if (n <= 0)
		return 0;
		cprm->written += nr;
		file->f_pos = pos;
		cprm->written += n;
		nr -= n;
		}
		return 1;
		}
		EXPORT_SYMBOL(dump_emit);

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