Hi Arnaldo
| Well, I'd rather prefer a WARN_ON type, probably rate limiting the
| printks, so that we can receive reports that something is fishy but
| don't panic the machine.
I have implemented such a macro and have changed the patch to use it.
If it is acceptable, I would like to propose it for general use.
Just as I was checking the patch again, Ian's answer arrived -- now I
understand why dump_stack() is used and WARN_ON preferred; the macros
support this use.
Also implemented the enum bit fields suggestion by Eddie. It compiles
fine on gcc 4.0.4; however, I am not sure about portability.
And I don't have your tool either :-(
The following is the revised patch with three macros added, I liked the
DCCP_BUG_ON():
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -18,6 +18,15 @@
#include <net/tcp.h>
#include "ackvec.h"
+#define DCCP_CRIT(fmt, args...) LIMIT_NETDEBUG(KERN_CRIT fmt "at %s:%d/%s()\n",\
+ __FILE__, __LINE__, __FUNCTION__, ##args)
+
+#define DCCP_BUG() do { DCCP_CRIT("DCCP BUG"); dump_stack(); } while (0)
+
+#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \
+ DCCP_BUG(); \
+ } while (0)
+
#ifdef MODULE
#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \
printk(fmt, ##args); \
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -73,6 +73,14 @@ struct ccid3_options_received {
u32 ccid3or_receive_rate;
};
+/* TFRC sender states */
+enum ccid3_hc_tx_states {
+ TFRC_SSTATE_NO_SENT = 1,
+ TFRC_SSTATE_NO_FBACK,
+ TFRC_SSTATE_FBACK,
+ TFRC_SSTATE_TERM,
+};
+
/** struct ccid3_hc_tx_sock - CCID3 sender half connection sock
*
* @ccid3hctx_state - Sender state
@@ -103,7 +111,7 @@ struct ccid3_hc_tx_sock {
#define ccid3hctx_t_rto ccid3hctx_tfrc.tfrctx_rto
#define ccid3hctx_t_ipi ccid3hctx_tfrc.tfrctx_ipi
u16 ccid3hctx_s;
- u8 ccid3hctx_state;
+ enum ccid3_hc_tx_states ccid3hctx_state:8;
u8 ccid3hctx_last_win_count;
u8 ccid3hctx_idle;
struct timeval ccid3hctx_t_last_win_count;
@@ -115,6 +123,13 @@ struct ccid3_hc_tx_sock {
struct ccid3_options_received ccid3hctx_options_received;
};
+/* TFRC receiver states */
+enum ccid3_hc_rx_states {
+ TFRC_RSTATE_NO_DATA = 1,
+ TFRC_RSTATE_DATA,
+ TFRC_RSTATE_TERM = 127,
+};
+
struct ccid3_hc_rx_sock {
struct tfrc_rx_info ccid3hcrx_tfrc;
#define ccid3hcrx_x_recv ccid3hcrx_tfrc.tfrcrx_x_recv
@@ -122,8 +137,8 @@ struct ccid3_hc_rx_sock {
#define ccid3hcrx_p ccid3hcrx_tfrc.tfrcrx_p
u64 ccid3hcrx_seqno_nonloss:48,
ccid3hcrx_ccval_nonloss:4,
- ccid3hcrx_state:8,
ccid3hcrx_ccval_last_counter:4;
+ enum ccid3_hc_rx_states ccid3hcrx_state:8;
u32 ccid3hcrx_bytes_recv;
struct timeval ccid3hcrx_tstamp_last_feedback;
struct timeval ccid3hcrx_tstamp_last_ack;
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -73,14 +73,6 @@ static struct dccp_tx_hist *ccid3_tx_his
static struct dccp_rx_hist *ccid3_rx_hist;
static struct dccp_li_hist *ccid3_li_hist;
-/* TFRC sender states */
-enum ccid3_hc_tx_states {
- TFRC_SSTATE_NO_SENT = 1,
- TFRC_SSTATE_NO_FBACK,
- TFRC_SSTATE_FBACK,
- TFRC_SSTATE_TERM,
-};
-
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
{
@@ -248,11 +240,8 @@ static void ccid3_hc_tx_no_feedback_time
2 * usecs_div(hctx->ccid3hctx_s,
hctx->ccid3hctx_x));
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- goto out;
+ case TFRC_SSTATE_NO_SENT:
+ DCCP_BUG(); /* can't wait for feedback without having sent */
}
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
@@ -273,7 +262,7 @@ static int ccid3_hc_tx_send_packet(struc
long delay;
int rc = -ENOTCONN;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
/* Check if pure ACK or Terminating*/
/*
@@ -326,12 +315,8 @@ static int ccid3_hc_tx_send_packet(struc
/* divide by -1000 is to convert to ms and get sign right */
rc = delay > 0 ? delay : 0;
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- rc = -EINVAL;
- break;
+ case TFRC_SSTATE_TERM:
+ DCCP_BUG();
}
/* Can we send? if so add options and add to packet history */
@@ -353,7 +338,7 @@ static void ccid3_hc_tx_packet_sent(stru
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
struct timeval now;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
dccp_timestamp(sk, &now);
@@ -420,11 +405,8 @@ static void ccid3_hc_tx_packet_sent(stru
hctx->ccid3hctx_t_ipi);
}
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- break;
+ case TFRC_SSTATE_TERM:
+ DCCP_BUG();
}
}
@@ -441,7 +423,7 @@ static void ccid3_hc_tx_packet_recv(stru
u32 x_recv;
u32 r_sample;
- BUG_ON(hctx == NULL || hctx->ccid3hctx_state == TFRC_SSTATE_TERM);
+ BUG_ON(hctx == NULL);
/* we are only interested in ACKs */
if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
@@ -457,6 +439,7 @@ static void ccid3_hc_tx_packet_recv(stru
switch (hctx->ccid3hctx_state) {
case TFRC_SSTATE_NO_SENT:
/* FIXME: what to do here? */
+ DCCP_CRIT("action not implemented for state NO_SENT");
return;
case TFRC_SSTATE_NO_FBACK:
case TFRC_SSTATE_FBACK:
@@ -565,11 +548,8 @@ static void ccid3_hc_tx_packet_recv(stru
/* set idle flag */
hctx->ccid3hctx_idle = 1;
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
- dump_stack();
- break;
+ case TFRC_SSTATE_TERM:
+ DCCP_BUG();
}
}
@@ -686,13 +666,6 @@ static void ccid3_hc_tx_exit(struct sock
* RX Half Connection methods
*/
-/* TFRC receiver states */
-enum ccid3_hc_rx_states {
- TFRC_RSTATE_NO_DATA = 1,
- TFRC_RSTATE_DATA,
- TFRC_RSTATE_TERM = 127,
-};
-
#ifdef CONFIG_IP_DCCP_CCID3_DEBUG
static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
{
@@ -741,11 +714,8 @@ static void ccid3_hc_rx_send_feedback(st
delta);
}
break;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
- return;
+ case TFRC_RSTATE_TERM:
+ DCCP_BUG();
}
packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
@@ -1004,9 +974,7 @@ static void ccid3_hc_rx_packet_recv(stru
u32 p_prev, rtt_prev, r_sample, t_elapsed;
int loss;
- BUG_ON(hcrx == NULL ||
- !(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
- hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
+ BUG_ON(hcrx == NULL);
opt_recv = &dccp_sk(sk)->dccps_options_received;
@@ -1085,11 +1053,8 @@ static void ccid3_hc_rx_packet_recv(stru
ccid3_hc_rx_send_feedback(sk);
}
return;
- default:
- printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
- __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
- dump_stack();
- return;
+ case TFRC_RSTATE_TERM:
+ DCCP_BUG();
}
/* Dealing with packet loss */
-
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