[RFC PATCH -tip 4/6] net: sctp: Remove debug SCTP probe module

[Masami Hiramatsu <mhiramat@kernel.org>]

Remove SCTP probe module since jprobe has been deprecated.
That function is now replaced by sctp/sctp_probe and
sctp/sctp_probe_path trace-events.
You can use it via ftrace or perftools.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 net/sctp/Kconfig  |   12 ---
 net/sctp/Makefile |    3 -
 net/sctp/probe.c  |  244 -----------------------------------------------------
 3 files changed, 259 deletions(-)
 delete mode 100644 net/sctp/probe.c

diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index d9c04dc1b3f3..c740b189d4ba 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -37,18 +37,6 @@ menuconfig IP_SCTP
 
 if IP_SCTP
 
-config NET_SCTPPROBE
-	tristate "SCTP: Association probing"
-        depends on PROC_FS && KPROBES
-        ---help---
-        This module allows for capturing the changes to SCTP association
-        state in response to incoming packets. It is used for debugging
-        SCTP congestion control algorithms. If you don't understand
-        what was just said, you don't need it: say N.
-
-        To compile this code as a module, choose M here: the
-        module will be called sctp_probe.
-
 config SCTP_DBG_OBJCNT
 	bool "SCTP: Debug object counts"
 	depends on PROC_FS
diff --git a/net/sctp/Makefile b/net/sctp/Makefile
index 8c434af3e68f..28961220b582 100644
--- a/net/sctp/Makefile
+++ b/net/sctp/Makefile
@@ -4,7 +4,6 @@
 #
 
 obj-$(CONFIG_IP_SCTP) += sctp.o
-obj-$(CONFIG_NET_SCTPPROBE) += sctp_probe.o
 obj-$(CONFIG_INET_SCTP_DIAG) += sctp_diag.o
 
 sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
@@ -15,8 +14,6 @@ sctp-y := sm_statetable.o sm_statefuns.o sm_sideeffect.o \
 	  output.o input.o debug.o stream.o auth.o \
 	  offload.o
 
-sctp_probe-y := probe.o
-
 sctp-$(CONFIG_SCTP_DBG_OBJCNT) += objcnt.o
 sctp-$(CONFIG_PROC_FS) += proc.o
 sctp-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/net/sctp/probe.c b/net/sctp/probe.c
deleted file mode 100644
index 1280f85a598d..000000000000
--- a/net/sctp/probe.c
+++ /dev/null
@@ -1,244 +0,0 @@
-/*
- * sctp_probe - Observe the SCTP flow with kprobes.
- *
- * The idea for this came from Werner Almesberger's umlsim
- * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
- *
- * Modified for SCTP from Stephen Hemminger's code
- * Copyright (C) 2010, Wei Yongjun <yjwei@cn.fujitsu.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/kernel.h>
-#include <linux/kprobes.h>
-#include <linux/socket.h>
-#include <linux/sctp.h>
-#include <linux/proc_fs.h>
-#include <linux/vmalloc.h>
-#include <linux/module.h>
-#include <linux/kfifo.h>
-#include <linux/time.h>
-#include <net/net_namespace.h>
-
-#include <net/sctp/sctp.h>
-#include <net/sctp/sm.h>
-
-MODULE_SOFTDEP("pre: sctp");
-MODULE_AUTHOR("Wei Yongjun <yjwei@cn.fujitsu.com>");
-MODULE_DESCRIPTION("SCTP snooper");
-MODULE_LICENSE("GPL");
-
-static int port __read_mostly = 0;
-MODULE_PARM_DESC(port, "Port to match (0=all)");
-module_param(port, int, 0);
-
-static unsigned int fwmark __read_mostly = 0;
-MODULE_PARM_DESC(fwmark, "skb mark to match (0=no mark)");
-module_param(fwmark, uint, 0);
-
-static int bufsize __read_mostly = 64 * 1024;
-MODULE_PARM_DESC(bufsize, "Log buffer size (default 64k)");
-module_param(bufsize, int, 0);
-
-static int full __read_mostly = 1;
-MODULE_PARM_DESC(full, "Full log (1=every ack packet received,  0=only cwnd changes)");
-module_param(full, int, 0);
-
-static const char procname[] = "sctpprobe";
-
-static struct {
-	struct kfifo	  fifo;
-	spinlock_t	  lock;
-	wait_queue_head_t wait;
-	struct timespec64 tstart;
-} sctpw;
-
-static __printf(1, 2) void printl(const char *fmt, ...)
-{
-	va_list args;
-	int len;
-	char tbuf[256];
-
-	va_start(args, fmt);
-	len = vscnprintf(tbuf, sizeof(tbuf), fmt, args);
-	va_end(args);
-
-	kfifo_in_locked(&sctpw.fifo, tbuf, len, &sctpw.lock);
-	wake_up(&sctpw.wait);
-}
-
-static int sctpprobe_open(struct inode *inode, struct file *file)
-{
-	kfifo_reset(&sctpw.fifo);
-	ktime_get_ts64(&sctpw.tstart);
-
-	return 0;
-}
-
-static ssize_t sctpprobe_read(struct file *file, char __user *buf,
-			      size_t len, loff_t *ppos)
-{
-	int error = 0, cnt = 0;
-	unsigned char *tbuf;
-
-	if (!buf)
-		return -EINVAL;
-
-	if (len == 0)
-		return 0;
-
-	tbuf = vmalloc(len);
-	if (!tbuf)
-		return -ENOMEM;
-
-	error = wait_event_interruptible(sctpw.wait,
-					 kfifo_len(&sctpw.fifo) != 0);
-	if (error)
-		goto out_free;
-
-	cnt = kfifo_out_locked(&sctpw.fifo, tbuf, len, &sctpw.lock);
-	error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
-
-out_free:
-	vfree(tbuf);
-
-	return error ? error : cnt;
-}
-
-static const struct file_operations sctpprobe_fops = {
-	.owner	= THIS_MODULE,
-	.open	= sctpprobe_open,
-	.read	= sctpprobe_read,
-	.llseek = noop_llseek,
-};
-
-static enum sctp_disposition jsctp_sf_eat_sack(
-					struct net *net,
-					const struct sctp_endpoint *ep,
-					const struct sctp_association *asoc,
-					const union sctp_subtype type,
-					void *arg,
-					struct sctp_cmd_seq *commands)
-{
-	struct sctp_chunk *chunk = arg;
-	struct sk_buff *skb = chunk->skb;
-	struct sctp_transport *sp;
-	static __u32 lcwnd = 0;
-	struct timespec64 now;
-
-	sp = asoc->peer.primary_path;
-
-	if (((port == 0 && fwmark == 0) ||
-	     asoc->peer.port == port ||
-	     ep->base.bind_addr.port == port ||
-	     (fwmark > 0 && skb->mark == fwmark)) &&
-	    (full || sp->cwnd != lcwnd)) {
-		lcwnd = sp->cwnd;
-
-		ktime_get_ts64(&now);
-		now = timespec64_sub(now, sctpw.tstart);
-
-		printl("%lu.%06lu ", (unsigned long) now.tv_sec,
-		       (unsigned long) now.tv_nsec / NSEC_PER_USEC);
-
-		printl("%p %5d %5d %5d %8d %5d ", asoc,
-		       ep->base.bind_addr.port, asoc->peer.port,
-		       asoc->pathmtu, asoc->peer.rwnd, asoc->unack_data);
-
-		list_for_each_entry(sp, &asoc->peer.transport_addr_list,
-					transports) {
-			if (sp == asoc->peer.primary_path)
-				printl("*");
-
-			printl("%pISc %2u %8u %8u %8u %8u %8u ",
-			       &sp->ipaddr, sp->state, sp->cwnd, sp->ssthresh,
-			       sp->flight_size, sp->partial_bytes_acked,
-			       sp->pathmtu);
-		}
-		printl("\n");
-	}
-
-	jprobe_return();
-	return 0;
-}
-
-static struct jprobe sctp_recv_probe = {
-	.kp	= {
-		.symbol_name = "sctp_sf_eat_sack_6_2",
-	},
-	.entry	= jsctp_sf_eat_sack,
-};
-
-static __init int sctp_setup_jprobe(void)
-{
-	int ret = register_jprobe(&sctp_recv_probe);
-
-	if (ret) {
-		if (request_module("sctp"))
-			goto out;
-		ret = register_jprobe(&sctp_recv_probe);
-	}
-
-out:
-	return ret;
-}
-
-static __init int sctpprobe_init(void)
-{
-	int ret = -ENOMEM;
-
-	/* Warning: if the function signature of sctp_sf_eat_sack_6_2,
-	 * has been changed, you also have to change the signature of
-	 * jsctp_sf_eat_sack, otherwise you end up right here!
-	 */
-	BUILD_BUG_ON(__same_type(sctp_sf_eat_sack_6_2,
-				 jsctp_sf_eat_sack) == 0);
-
-	init_waitqueue_head(&sctpw.wait);
-	spin_lock_init(&sctpw.lock);
-	if (kfifo_alloc(&sctpw.fifo, bufsize, GFP_KERNEL))
-		return ret;
-
-	if (!proc_create(procname, S_IRUSR, init_net.proc_net,
-			 &sctpprobe_fops))
-		goto free_kfifo;
-
-	ret = sctp_setup_jprobe();
-	if (ret)
-		goto remove_proc;
-
-	pr_info("probe registered (port=%d/fwmark=%u) bufsize=%u\n",
-		port, fwmark, bufsize);
-	return 0;
-
-remove_proc:
-	remove_proc_entry(procname, init_net.proc_net);
-free_kfifo:
-	kfifo_free(&sctpw.fifo);
-	return ret;
-}
-
-static __exit void sctpprobe_exit(void)
-{
-	kfifo_free(&sctpw.fifo);
-	remove_proc_entry(procname, init_net.proc_net);
-	unregister_jprobe(&sctp_recv_probe);
-}
-
-module_init(sctpprobe_init);
-module_exit(sctpprobe_exit);