of_node_put is needed before discarding a value received from of_find_node_by_name, eg in error handling code or when the device node is no longer used. The semantic match that catches the bug is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r exists@ local idexpression struct device_node *n; position p1, p2; statement S1,S2; expression E,E1; expression *ptr != NULL; @@ ( if (!(n@p1 = of_find_node_by_name(...))) S1 | n@p1 = of_find_node_by_name(...) ) <... when != of_node_put(n) when != if (...) { <+... of_node_put(n) ...+> } when != true !n || ... when != n = E when != E = n if (!n || ...) S2 ...> ( return \(0\|<+...n...+>\|ptr\); | return@p2 ...; | n = E1 | E1 = n ) @script:python@ p1 << r.p1; p2 << r.p2; @@ print "* file: %s of_find_node_by_name %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // </smpl> Signed-off-by: Nicolas Palix <npalix@xxxxxxx> Signed-off-by: Julia Lawall <julia@xxxxxxx> --- drivers/char/hvc_iseries.c | 4 +++- drivers/char/hvc_vio.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c index b74a2f8..449727b 100644 --- a/drivers/char/hvc_iseries.c +++ b/drivers/char/hvc_iseries.c @@ -575,8 +575,10 @@ static int __init hvc_find_vtys(void) * of console adapters. */ if ((num_found >= MAX_NR_HVC_CONSOLES) || - (num_found >= VTTY_PORTS)) + (num_found >= VTTY_PORTS)) { + of_node_put(vty); break; + } vtermno = of_get_property(vty, "reg", NULL); if (!vtermno) diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c index 019e0b5..bd62dc8 100644 --- a/drivers/char/hvc_vio.c +++ b/drivers/char/hvc_vio.c @@ -153,8 +153,10 @@ static int hvc_find_vtys(void) /* We have statically defined space for only a certain number * of console adapters. */ - if (num_found >= MAX_NR_HVC_CONSOLES) + if (num_found >= MAX_NR_HVC_CONSOLES) { + of_node_put(vty); break; + } vtermno = of_get_property(vty, "reg", NULL); if (!vtermno) -- Nicolas Palix -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
