From 82802f968bd3118af04eaeb3814c21d9813be527 Mon Sep 17 00:00:00 2001 From: Hidehiro Kawai Date: Mon, 27 Jul 2015 14:55:16 +0900 Subject: [PATCH] ipmi: Don't flush messages in sender() in run-to-completion mode When flushing queued messages in run-to-completion mode, smi_event_handler() is recursively called. flush_messages() smi_event_handler() handle_transaction_done() deliver_recv_msg() ipmi_smi_msg_received() smi_recv_tasklet() sender() flush_messages() smi_event_handler() ... The depth of the recursive call depends on the number of queued messages, so it can cause a stack overflow if many messages have been queued. To solve this problem, this patch removes flush_messages() from sender()@ipmi_si_intf.c. Instead, add flush_messages() to caller side of sender() if needed. Additionally, to implement this, add new handler flush_messages to struct ipmi_smi_handlers. Signed-off-by: Hidehiro Kawai Fixed up a comment and some spacing issues. Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 3 +++ drivers/char/ipmi/ipmi_si_intf.c | 10 +++++----- include/linux/ipmi_smi.h | 5 +++++ 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 5e31c339062e..6e191ff910e6 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -4295,6 +4295,9 @@ static void ipmi_panic_request_and_wait(ipmi_smi_t intf, 0, 1); /* Don't retry, and don't wait. */ if (rv) atomic_sub(2, &panic_done_count); + else if (intf->handlers->flush_messages) + intf->handlers->flush_messages(intf->send_info); + while (atomic_read(&panic_done_count) != 0) ipmi_poll(intf); } diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 5bd6d5b974cd..2f4cf6e78f72 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -924,8 +924,9 @@ static void check_start_timer_thread(struct smi_info *smi_info) } } -static void flush_messages(struct smi_info *smi_info) +static void flush_messages(void *send_info) { + struct smi_info *smi_info = send_info; enum si_sm_result result; /* @@ -949,12 +950,10 @@ static void sender(void *send_info, if (smi_info->run_to_completion) { /* - * If we are running to completion, start it and run - * transactions until everything is clear. + * If we are running to completion, start it. Upper + * layer will call flush_messages to clear it out. */ smi_info->waiting_msg = msg; - - flush_messages(smi_info); return; } @@ -1260,6 +1259,7 @@ static const struct ipmi_smi_handlers handlers = { .set_need_watch = set_need_watch, .set_maintenance_mode = set_maintenance_mode, .set_run_to_completion = set_run_to_completion, + .flush_messages = flush_messages, .poll = poll, }; diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h index 41de0cf34c49..f8cea14485dd 100644 --- a/include/linux/ipmi_smi.h +++ b/include/linux/ipmi_smi.h @@ -115,6 +115,11 @@ struct ipmi_smi_handlers { implement it. */ void (*set_need_watch)(void *send_info, bool enable); + /* + * Called when flushing all pending messages. + */ + void (*flush_messages)(void *send_info); + /* Called when the interface should go into "run to completion" mode. If this call sets the value to true, the interface should make sure that all messages are flushed -- GitLab