From: Alexandre Bounine <alexandre.bounine@xxxxxxx> Subject: rapidio/rio_cm: avoid GFP_KERNEL in atomic context As reported by Alexey Khoroshilov (https://lkml.org/lkml/2016/9/9/737): riocm_send_close() is called from rio_cm_shutdown() under spin_lock_bh(idr_lock), but riocm_send_close() uses a GFP_KERNEL allocation. Fix by taking riocm_send_close() outside of spinlock protected code. [akpm@xxxxxxxxxxxxxxxxxxxx: remove unneeded `if (!list_empty())'] Link: http://lkml.kernel.org/r/20160915175402.10122-1-alexandre.bounine@xxxxxxx Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx> Reported-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/rapidio/rio_cm.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff -puN drivers/rapidio/rio_cm.c~rapidio-rio_cm-avoid-gfp_kernel-in-atomic-context drivers/rapidio/rio_cm.c --- a/drivers/rapidio/rio_cm.c~rapidio-rio_cm-avoid-gfp_kernel-in-atomic-context +++ a/drivers/rapidio/rio_cm.c @@ -2247,17 +2247,30 @@ static int rio_cm_shutdown(struct notifi { struct rio_channel *ch; unsigned int i; + LIST_HEAD(list); riocm_debug(EXIT, "."); + /* + * If there are any channels left in connected state send + * close notification to the connection partner. + * First build a list of channels that require a closing + * notification because function riocm_send_close() should + * be called outside of spinlock protected code. + */ spin_lock_bh(&idr_lock); idr_for_each_entry(&ch_idr, ch, i) { - riocm_debug(EXIT, "close ch %d", ch->id); - if (ch->state == RIO_CM_CONNECTED) - riocm_send_close(ch); + if (ch->state == RIO_CM_CONNECTED) { + riocm_debug(EXIT, "close ch %d", ch->id); + idr_remove(&ch_idr, ch->id); + list_add(&ch->ch_node, &list); + } } spin_unlock_bh(&idr_lock); + list_for_each_entry(ch, &list, ch_node) + riocm_send_close(ch); + return NOTIFY_DONE; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
