From bb33381d0c97cdee25f2cdab540b6e2bd16fa03b Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 28 Jun 2013 19:49:40 +0200 Subject: net: sctp: rework debugging framework to use pr_debug and friends We should get rid of all own SCTP debug printk macros and use the ones that the kernel offers anyway instead. This makes the code more readable and conform to the kernel code, and offers all the features of dynamic debbuging that pr_debug() et al has, such as only turning on/off portions of debug messages at runtime through debugfs. The runtime cost of having CONFIG_DYNAMIC_DEBUG enabled, but none of the debug statements printing, is negligible [1]. If kernel debugging is completly turned off, then these statements will also compile into "empty" functions. While we're at it, we also need to change the Kconfig option as it /now/ only refers to the ifdef'ed code portions in outqueue.c that enable further debugging/tracing of SCTP transaction fields. Also, since SCTP_ASSERT code was enabled with this Kconfig option and has now been removed, we transform those code parts into WARNs resp. where appropriate BUG_ONs so that those bugs can be more easily detected as probably not many people have SCTP debugging permanently turned on. To turn on all SCTP debugging, the following steps are needed: # mount -t debugfs none /sys/kernel/debug # echo -n 'module sctp +p' > /sys/kernel/debug/dynamic_debug/control This can be done more fine-grained on a per file, per line basis and others as described in [2]. [1] https://www.kernel.org/doc/ols/2009/ols2009-pages-39-46.pdf [2] Documentation/dynamic-debug-howto.txt Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- net/sctp/Kconfig | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/sctp/Kconfig') diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig index cf4852814e0c..d80bf1aebaed 100644 --- a/net/sctp/Kconfig +++ b/net/sctp/Kconfig @@ -30,7 +30,8 @@ menuconfig IP_SCTP homing at either or both ends of an association." To compile this protocol support as a module, choose M here: the - module will be called sctp. + module will be called sctp. Debug messages are handeled by the + kernel's dynamic debugging framework. If in doubt, say N. @@ -48,13 +49,14 @@ config NET_SCTPPROBE To compile this code as a module, choose M here: the module will be called sctp_probe. -config SCTP_DBG_MSG - bool "SCTP: Debug messages" +config SCTP_DBG_TSNS + bool "SCTP: Debug transactions" help - If you say Y, this will enable verbose debugging messages. + If you say Y, this will enable transaction debugging, visible + from the kernel's dynamic debugging framework. If unsure, say N. However, if you are running into problems, use - this option to gather detailed trace information + this option to gather outqueue trace information. config SCTP_DBG_OBJCNT bool "SCTP: Debug object counts" -- cgit v1.2.3 From e02010adeeb21ef56d6b9b68c785ed1ecc832aee Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 1 Jul 2013 11:31:36 +0200 Subject: net: sctp: get rid of SCTP_DBG_TSNS entirely After having reworked the debugging framework, Neil and Vlad agreed to get rid of the leftover SCTP_DBG_TSNS code for a couple of reasons: We can use systemtap scripts to investigate these things, we now have pr_debug() helpers that make life easier, and if we really need anything else besides those tools, we will be forced to come up with something better than we have there. Therefore, get rid of this ifdef debugging code entirely for now. Signed-off-by: Daniel Borkmann CC: Vlad Yasevich CC: Neil Horman Acked-by: Neil Horman Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/Kconfig | 9 ----- net/sctp/outqueue.c | 105 ---------------------------------------------------- 2 files changed, 114 deletions(-) (limited to 'net/sctp/Kconfig') diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig index d80bf1aebaed..71c1a598d9bc 100644 --- a/net/sctp/Kconfig +++ b/net/sctp/Kconfig @@ -49,15 +49,6 @@ config NET_SCTPPROBE To compile this code as a module, choose M here: the module will be called sctp_probe. -config SCTP_DBG_TSNS - bool "SCTP: Debug transactions" - help - If you say Y, this will enable transaction debugging, visible - from the kernel's dynamic debugging framework. - - If unsure, say N. However, if you are running into problems, use - this option to gather outqueue trace information. - config SCTP_DBG_OBJCNT bool "SCTP: Debug object counts" depends on PROC_FS diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 511b3b35d609..cb80a8e060b7 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1335,21 +1335,6 @@ static void sctp_check_transmitted(struct sctp_outq *q, int bytes_acked = 0; int migrate_bytes = 0; - /* These state variables are for coherent debug output. --xguo */ - -#ifdef CONFIG_SCTP_DBG_TSNS - __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */ - __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */ - __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */ - __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */ - - /* 0 : The last TSN was ACKed. - * 1 : The last TSN was NOT ACKed (i.e. KEPT). - * -1: We need to initialize. - */ - int dbg_prt_state = -1; -#endif /* CONFIG_SCTP_DBG_TSNS */ - sack_ctsn = ntohl(sack->cum_tsn_ack); INIT_LIST_HEAD(&tlist); @@ -1471,49 +1456,6 @@ static void sctp_check_transmitted(struct sctp_outq *q, */ list_add_tail(lchunk, &tlist); } - -#ifdef CONFIG_SCTP_DBG_TSNS - switch (dbg_prt_state) { - case 0: /* last TSN was ACKed */ - if (dbg_last_ack_tsn + 1 == tsn) { - /* This TSN belongs to the - * current ACK range. - */ - break; - } - - if (dbg_last_ack_tsn != dbg_ack_tsn) { - /* Display the end of the - * current range. - */ - pr_cont("-%08x", dbg_last_ack_tsn); - } - - /* Start a new range. */ - pr_cont(",%08x", tsn); - dbg_ack_tsn = tsn; - break; - - case 1: /* The last TSN was NOT ACKed. */ - if (dbg_last_kept_tsn != dbg_kept_tsn) { - /* Display the end of current range. */ - pr_cont("-%08x", dbg_last_kept_tsn); - } - - pr_cont("\n"); - /* FALL THROUGH... */ - default: - /* This is the first-ever TSN we examined. */ - /* Start a new range of ACK-ed TSNs. */ - pr_debug("ACKed: %08x", tsn); - - dbg_prt_state = 0; - dbg_ack_tsn = tsn; - } - - dbg_last_ack_tsn = tsn; -#endif /* CONFIG_SCTP_DBG_TSNS */ - } else { if (tchunk->tsn_gap_acked) { pr_debug("%s: receiver reneged on data TSN:0x%x\n", @@ -1537,56 +1479,9 @@ static void sctp_check_transmitted(struct sctp_outq *q, } list_add_tail(lchunk, &tlist); - -#ifdef CONFIG_SCTP_DBG_TSNS - /* See the above comments on ACK-ed TSNs. */ - switch (dbg_prt_state) { - case 1: - if (dbg_last_kept_tsn + 1 == tsn) - break; - - if (dbg_last_kept_tsn != dbg_kept_tsn) - pr_cont("-%08x", dbg_last_kept_tsn); - - pr_cont(",%08x", tsn); - dbg_kept_tsn = tsn; - break; - - case 0: - if (dbg_last_ack_tsn != dbg_ack_tsn) - pr_cont("-%08x", dbg_last_ack_tsn); - - pr_cont("\n"); - /* FALL THROUGH... */ - default: - pr_debug("KEPT: %08x", tsn); - - dbg_prt_state = 1; - dbg_kept_tsn = tsn; - } - - dbg_last_kept_tsn = tsn; -#endif /* CONFIG_SCTP_DBG_TSNS */ } } -#ifdef CONFIG_SCTP_DBG_TSNS - /* Finish off the last range, displaying its ending TSN. */ - switch (dbg_prt_state) { - case 0: - if (dbg_last_ack_tsn != dbg_ack_tsn) - pr_cont("-%08x\n", dbg_last_ack_tsn); - else - pr_cont("\n"); - break; - case 1: - if (dbg_last_kept_tsn != dbg_kept_tsn) - pr_cont("-%08x\n", dbg_last_kept_tsn); - else - pr_cont("\n"); - break; - } -#endif /* CONFIG_SCTP_DBG_TSNS */ if (transport) { if (bytes_acked) { struct sctp_association *asoc = transport->asoc; -- cgit v1.2.3