[PATCH 8/8] xen/hvc: replace BUG_ON() with negative return value
From: Juergen Gross <jgross@suse.com>
Date: 2021-05-13 10:06:05
Also in:
lkml, xen-devel
Subsystem:
hypervisor virtual console driver, the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
Xen frontends shouldn't BUG() in case of illegal data received from their backends. So replace the BUG_ON()s when reading illegal data from the ring page with negative return values. Signed-off-by: Juergen Gross <jgross@suse.com> --- drivers/tty/hvc/hvc_xen.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 92c9a476defc..30d7ffb1e04c 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c@@ -86,6 +86,11 @@ static int __write_console(struct xencons_info *xencons, cons = intf->out_cons; prod = intf->out_prod; mb(); /* update queue values before going on */ + + if (WARN_ONCE((prod - cons) > sizeof(intf->out), + "Illegal ring page indices")) + return -EINVAL; + BUG_ON((prod - cons) > sizeof(intf->out)); while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
@@ -114,7 +119,10 @@ static int domU_write_console(uint32_t vtermno, const char *data, int len) */ while (len) { int sent = __write_console(cons, data, len); - + + if (sent < 0) + return sent; + data += sent; len -= sent;
@@ -138,7 +146,10 @@ static int domU_read_console(uint32_t vtermno, char *buf, int len) cons = intf->in_cons; prod = intf->in_prod; mb(); /* get pointers before reading ring */ - BUG_ON((prod - cons) > sizeof(intf->in)); + + if (WARN_ONCE((prod - cons) > sizeof(intf->in), + "Illegal ring page indices")) + return -EINVAL; while (cons != prod && recv < len) buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
--
2.26.2