Commit b1c32fcf authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

vc_screen: extract vcs_read_buf_header 



The attribute header handling is terrible in vcs_read_buf. Separate it
to a new function and simply do memmove (of up to 4 bytes) to the start
of the con_buf -- if user seeked.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085706.12163-15-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6a6b76cc

drivers/tty/vt/vc_screen.c

+18 −13
Original line number Diff line number Diff line
@@ -297,6 +297,22 @@ static void vcs_read_buf_noattr(const struct vc_data *vc, char *con_buf, 
	}

}



static unsigned int vcs_read_buf_header(const struct vc_data *vc, char *con_buf,

		unsigned int pos, unsigned int count)

{

	count = min(HEADER_SIZE - pos, count);



	/* clamp header values if they don't fit */

	con_buf[0] = min(vc->vc_rows, 0xFFu);

	con_buf[1] = min(vc->vc_cols, 0xFFu);

	getconsxy(vc, con_buf + 2);



	if (pos)

		memmove(con_buf, con_buf + pos, count);



	return count;

}



static unsigned int vcs_read_buf(const struct vc_data *vc, char *con_buf,

		unsigned int pos, unsigned int count, bool viewed,

		unsigned int *skip)
@@ -306,22 +322,11 @@ static unsigned int vcs_read_buf(const struct vc_data *vc, char *con_buf, 
	unsigned int filled = count;



	if (pos < HEADER_SIZE) {

		/* clamp header values if they don't fit */

		con_buf[0] = min(vc->vc_rows, 0xFFu);

		con_buf[1] = min(vc->vc_cols, 0xFFu);

		getconsxy(vc, con_buf + 2);



		*skip += pos;

		count += pos;

		if (count > CON_BUF_SIZE) {

			count = CON_BUF_SIZE;

			filled = count - pos;

		}

		count -= vcs_read_buf_header(vc, con_buf, pos, count);



		/* Advance state pointers and move on. */

		count -= min(HEADER_SIZE, count);

		pos = HEADER_SIZE;

		con_buf += HEADER_SIZE;



		/* If count >= 0, then pos is even... */

	} else if (pos & 1) {

		/*

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