svn commit: r297188 - in head: share/dtrace sys/kern sys/sys
George V. Neville-Neil
gnn at FreeBSD.org
Tue Mar 22 13:16:54 UTC 2016
Author: gnn
Date: Tue Mar 22 13:16:52 2016
New Revision: 297188
URL: https://svnweb.freebsd.org/changeset/base/297188
Log:
Add an mbuf provider to DTrace.
The mbuf provider is made up of a set of Statically Defined Tracepoints
which help us look into mbufs as they are allocated and freed. This can be
used to inspect the buffers or for a simplified mbuf leak detector.
New tracepoints are:
mbuf:::m-init
mbuf:::m-gethdr
mbuf:::m-get
mbuf:::m-getcl
mbuf:::m-clget
mbuf:::m-cljget
mbuf:::m-cljset
mbuf:::m-free
mbuf:::m-freem
There is also a translator for mbufs which gives some visibility into the structure,
see mbuf.d for more details.
Reviewed by: bz, markj
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
Differential Revision: https://reviews.freebsd.org/D5682
Added:
head/share/dtrace/mbuf.d (contents, props changed)
Modified:
head/share/dtrace/Makefile
head/sys/kern/kern_mbuf.c
head/sys/kern/uipc_mbuf.c
head/sys/sys/mbuf.h
Modified: head/share/dtrace/Makefile
==============================================================================
--- head/share/dtrace/Makefile Tue Mar 22 12:40:09 2016 (r297187)
+++ head/share/dtrace/Makefile Tue Mar 22 13:16:52 2016 (r297188)
@@ -30,4 +30,10 @@ SCRIPTS= blocking \
SCRIPTSDIR= ${SHAREDIR}/dtrace
+DSRCS= mbuf.d
+
+FILES= ${DSRCS}
+FILESDIR= /usr/lib/dtrace
+FILESMODE= ${NOBINMODE}
+
.include <bsd.prog.mk>
Added: head/share/dtrace/mbuf.d
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/share/dtrace/mbuf.d Tue Mar 22 13:16:52 2016 (r297188)
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2016 George V. Neville-Neil
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ *
+ * Translators and flags for the mbuf structure. FreeBSD specific code.
+ *
+ */
+
+#pragma D depends_on module kernel
+#pragma D depends_on provider mbuf
+
+/*
+ * mbuf flags of global significance and layer crossing.
+ * Those of only protocol/layer specific significance are to be mapped
+ * to M_PROTO[1-12] and cleared at layer handoff boundaries.
+ * NB: Limited to the lower 24 bits.
+ */
+
+#pragma D binding "1.6.3" M_EXT
+inline int M_EXT = 0x00000001; /* has associated external storage */
+#pragma D binding "1.6.3" M_PKTHDR
+inline int M_PKTHDR = 0x00000002; /* start of record */
+#pragma D binding "1.6.3" M_EOR
+inline int M_EOR = 0x00000004; /* end of record */
+#pragma D binding "1.6.3" M_RDONLY
+inline int M_RDONLY = 0x00000008; /* associated data is marked read-only */
+#pragma D binding "1.6.3" M_BCAST
+inline int M_BCAST = 0x00000010; /* send/received as link-level broadcast */
+#pragma D binding "1.6.3" M_MCAST
+inline int M_MCAST = 0x00000020; /* send/received as link-level multicast */
+#pragma D binding "1.6.3" M_PROMISC
+inline int M_PROMISC = 0x00000040; /* packet was not for us */
+#pragma D binding "1.6.3" M_VLANTAG
+inline int M_VLANTAG = 0x00000080; /* ether_vtag is valid */
+#pragma D binding "1.6.3" M_UNUSED_8
+inline int M_UNUSED_8 = 0x00000100; /* --available-- */
+#pragma D binding "1.6.3" M_NOFREE
+inline int M_NOFREE = 0x00000200; /* do not free mbuf, embedded in cluster */
+
+#pragma D binding "1.6.3" M_PROTO1
+inline int M_PROTO1 = 0x00001000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO2
+inline int M_PROTO2 = 0x00002000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO3
+inline int M_PROTO3 = 0x00004000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO4
+inline int M_PROTO4 = 0x00008000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO5
+inline int M_PROTO5 = 0x00010000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO6
+inline int M_PROTO6 = 0x00020000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO7
+inline int M_PROTO7 = 0x00040000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO8
+inline int M_PROTO8 = 0x00080000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO9
+inline int M_PROTO9 = 0x00100000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO10
+inline int M_PROTO10 = 0x00200000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO11
+inline int M_PROTO11 = 0x00400000; /* protocol-specific */
+#pragma D binding "1.6.3" M_PROTO12
+inline int M_PROTO12 = 0x00800000; /* protocol-specific */
+
+#pragma D binding "1.6.3" mbufflags_string
+inline string mbufflags_string[uint32_t flags] =
+ flags & M_EXT ? "M_EXT" :
+ flags & M_PKTHDR ? "M_PKTHDR" :
+ flags & M_EOR ? "M_EOR" :
+ flags & M_RDONLY ? "M_RDONLY" :
+ flags & M_BCAST ? "M_BCAST" :
+ flags & M_MCAST ? "M_MCAST" :
+ flags & M_PROMISC ? "M_PROMISC" :
+ flags & M_VLANTAG ? "M_VLANTAG" :
+ flags & M_UNUSED_8 ? "M_UNUSED_8" :
+ flags & M_NOFREE ? "M_NOFREE" :
+ flags & M_PROTO1 ? "M_PROTO1" :
+ flags & M_PROTO2 ? "M_PROTO2" :
+ flags & M_PROTO3 ? "M_PROTO3" :
+ flags & M_PROTO4 ? "M_PROTO4" :
+ flags & M_PROTO5 ? "M_PROTO5" :
+ flags & M_PROTO6 ? "M_PROTO6" :
+ flags & M_PROTO7 ? "M_PROTO7" :
+ flags & M_PROTO8 ? "M_PROTO8" :
+ flags & M_PROTO9 ? "M_PROTO9" :
+ flags & M_PROTO10 ? "M_PROTO10" :
+ flags & M_PROTO11 ? "M_PROTO11" :
+ flags & M_PROTO12 ? "M_PROTO12" :
+ "none" ;
+
+/*
+ * Packet tag structure (see below for details).
+ */
+typedef struct m_tag {
+ u_int16_t m_tag_id; /* Tag ID */
+ u_int16_t m_tag_len; /* Length of data */
+ u_int32_t m_tag_cookie; /* ABI/Module ID */
+} m_tag_t;
+
+/*
+ * Record/packet header in first mbuf of chain; valid only if M_PKTHDR is set.
+ * Size ILP32: 48
+ * LP64: 56
+ * Compile-time assertions in uipc_mbuf.c test these values to ensure that
+ * they are correct.
+ */
+typedef struct pkthdr {
+/* struct ifnet *rcvif; */ /* rcv interface */
+ int32_t len; /* total packet length */
+
+ /* Layer crossing persistent information. */
+ uint32_t flowid; /* packet's 4-tuple system */
+ uint64_t csum_flags; /* checksum and offload features */
+ uint16_t fibnum; /* this packet should use this fib */
+ uint8_t cosqos; /* class/quality of service */
+ uint8_t rsstype; /* hash type */
+} pkthdr_t;
+
+/*
+ * Description of external storage mapped into mbuf; valid only if M_EXT is
+ * set.
+ * Size ILP32: 28
+ * LP64: 48
+ * Compile-time assertions in uipc_mbuf.c test these values to ensure that
+ * they are correct.
+ */
+typedef struct m_ext {
+ volatile u_int *ext_cnt; /* pointer to ref count info */
+ caddr_t ext_buf; /* start of buffer */
+ uint32_t ext_size; /* size of buffer, for ext_free */
+ uint32_t ext_type:8, /* type of external storage */
+ ext_flags:24; /* external storage mbuf flags */
+ void *ext_arg1; /* optional argument pointer */
+ void *ext_arg2; /* optional argument pointer */
+} m_ext_t;
+
+/*
+ * The core of the mbuf object along with some shortcut defines for practical
+ * purposes.
+ */
+struct mbuf {
+ uintptr_t mbuf_addr;
+ /*
+ * Header present at the beginning of every mbuf.
+ * Size ILP32: 24
+ * LP64: 32
+ * Compile-time assertions in uipc_mbuf.c test these values to ensure
+ * that they are correct.
+ */
+ caddr_t m_data; /* location of data */
+ int32_t m_len; /* amount of data in this mbuf */
+ uint32_t m_type:8, /* type of data in this mbuf */
+ m_flags:24; /* flags; see below */
+ /*
+ * A set of optional headers (packet header, external storage header)
+ * and internal data storage. Historically, these arrays were sized
+ * to MHLEN (space left after a packet header) and MLEN (space left
+ * after only a regular mbuf header); they are now variable size in
+ * order to support future work on variable-size mbufs.
+ */
+ /* union { */
+ /* struct { */
+ /* struct pkthdr m_pkthdr; */
+ /* union { */
+ /* struct m_ext m_ext; */
+ /* char m_pktdat[0]; */
+ /* }; */
+ /* }; */
+ /* char m_dat[0]; */
+ /* }; */
+ char *m_dat;
+};
+
+typedef struct mbufinfo {
+ uintptr_t mbuf_addr;
+ caddr_t m_data;
+ int32_t m_len;
+ uint8_t m_type;
+ uint32_t m_flags;
+} mbufinfo_t;
+
+translator mbufinfo_t < struct mbuf *p > {
+ mbuf_addr = (uintptr_t)p;
+ m_data = p->m_data;
+ m_len = p->m_len;
+ m_type = p->m_type & 0xff000000;
+ m_flags = p->m_type & 0x00ffffff;
+};
Modified: head/sys/kern/kern_mbuf.c
==============================================================================
--- head/sys/kern/kern_mbuf.c Tue Mar 22 12:40:09 2016 (r297187)
+++ head/sys/kern/kern_mbuf.c Tue Mar 22 13:16:52 2016 (r297188)
@@ -731,6 +731,7 @@ m_clget(struct mbuf *m, int how)
zone_drain(zone_pack);
uma_zalloc_arg(zone_clust, m, how);
}
+ MBUF_PROBE2(m__clget, m, how);
return (m->m_flags & M_EXT);
}
@@ -745,7 +746,8 @@ void *
m_cljget(struct mbuf *m, int how, int size)
{
uma_zone_t zone;
-
+ void *retval;
+
if (m != NULL) {
KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT",
__func__, m));
@@ -753,7 +755,11 @@ m_cljget(struct mbuf *m, int how, int si
}
zone = m_getzone(size);
- return (uma_zalloc_arg(zone, m, how));
+ retval = uma_zalloc_arg(zone, m, how);
+
+ MBUF_PROBE4(m__cljget, m, how, size, retval);
+
+ return (retval);
}
/*
@@ -933,6 +939,7 @@ m_extadd(struct mbuf *mb, caddr_t buf, u
void
m_freem(struct mbuf *mb)
{
+ MBUF_PROBE1(m__freem, mb);
while (mb != NULL)
mb = m_free(mb);
Modified: head/sys/kern/uipc_mbuf.c
==============================================================================
--- head/sys/kern/uipc_mbuf.c Tue Mar 22 12:40:09 2016 (r297187)
+++ head/sys/kern/uipc_mbuf.c Tue Mar 22 13:16:52 2016 (r297188)
@@ -47,6 +47,51 @@ __FBSDID("$FreeBSD$");
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/uio.h>
+#include <sys/sdt.h>
+
+SDT_PROVIDER_DEFINE(mbuf);
+
+SDT_PROBE_DEFINE5_XLATE(mbuf, , , m__init,
+ "struct mbuf *", "mbufinfo_t *",
+ "uint32_t", "uint32_t",
+ "uint16_t", "uint16_t",
+ "uint32_t", "uint32_t",
+ "uint32_t", "uint32_t");
+
+SDT_PROBE_DEFINE3_XLATE(mbuf, , , m__gethdr,
+ "uint32_t", "uint32_t",
+ "uint16_t", "uint16_t",
+ "struct mbuf *", "mbufinfo_t *");
+
+SDT_PROBE_DEFINE3_XLATE(mbuf, , , m__get,
+ "uint32_t", "uint32_t",
+ "uint16_t", "uint16_t",
+ "struct mbuf *", "mbufinfo_t *");
+
+SDT_PROBE_DEFINE4_XLATE(mbuf, , , m__getcl,
+ "uint32_t", "uint32_t",
+ "uint16_t", "uint16_t",
+ "uint32_t", "uint32_t",
+ "struct mbuf *", "mbufinfo_t *");
+
+SDT_PROBE_DEFINE3_XLATE(mbuf, , , m__clget,
+ "struct mbuf *", "mbufinfo_t *",
+ "uint32_t", "uint32_t",
+ "uint32_t", "uint32_t");
+
+SDT_PROBE_DEFINE4_XLATE(mbuf, , , m__cljget,
+ "struct mbuf *", "mbufinfo_t *",
+ "uint32_t", "uint32_t",
+ "uint32_t", "uint32_t",
+ "void*", "void*");
+
+SDT_PROBE_DEFINE(mbuf, , , m__cljset);
+
+SDT_PROBE_DEFINE1_XLATE(mbuf, , , m__free,
+ "struct mbuf *", "mbufinfo_t *");
+
+SDT_PROBE_DEFINE1_XLATE(mbuf, , , m__freem,
+ "struct mbuf *", "mbufinfo_t *");
#include <security/mac/mac_framework.h>
Modified: head/sys/sys/mbuf.h
==============================================================================
--- head/sys/sys/mbuf.h Tue Mar 22 12:40:09 2016 (r297187)
+++ head/sys/sys/mbuf.h Tue Mar 22 13:16:52 2016 (r297188)
@@ -44,6 +44,34 @@
#endif
#endif
+#ifdef _KERNEL
+#include <sys/sdt.h>
+
+#define MBUF_PROBE1(probe, arg0) \
+ SDT_PROBE1(mbuf, , , probe, arg0)
+#define MBUF_PROBE2(probe, arg0, arg1) \
+ SDT_PROBE2(mbuf, , , probe, arg0, arg1)
+#define MBUF_PROBE3(probe, arg0, arg1, arg2) \
+ SDT_PROBE3(mbuf, , , probe, arg0, arg1, arg2)
+#define MBUF_PROBE4(probe, arg0, arg1, arg2, arg3) \
+ SDT_PROBE4(mbuf, , , probe, arg0, arg1, arg2, arg3)
+#define MBUF_PROBE5(probe, arg0, arg1, arg2, arg3, arg4) \
+ SDT_PROBE5(mbuf, , , probe, arg0, arg1, arg2, arg3, arg4)
+
+SDT_PROVIDER_DECLARE(mbuf);
+
+SDT_PROBE_DECLARE(mbuf, , , m__init);
+SDT_PROBE_DECLARE(mbuf, , , m__gethdr);
+SDT_PROBE_DECLARE(mbuf, , , m__get);
+SDT_PROBE_DECLARE(mbuf, , , m__getcl);
+SDT_PROBE_DECLARE(mbuf, , , m__clget);
+SDT_PROBE_DECLARE(mbuf, , , m__cljget);
+SDT_PROBE_DECLARE(mbuf, , , m__cljset);
+SDT_PROBE_DECLARE(mbuf, , , m__free);
+SDT_PROBE_DECLARE(mbuf, , , m__freem);
+
+#endif /* _KERNEL */
+
/*
* Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
* An mbuf may add a single "mbuf cluster" of size MCLBYTES (also in
@@ -664,7 +692,7 @@ m_getzone(int size)
static __inline int
m_init(struct mbuf *m, int how, short type, int flags)
{
- int error;
+ int error = 0;
m->m_next = NULL;
m->m_nextpkt = NULL;
@@ -672,42 +700,50 @@ m_init(struct mbuf *m, int how, short ty
m->m_len = 0;
m->m_flags = flags;
m->m_type = type;
- if (flags & M_PKTHDR) {
- if ((error = m_pkthdr_init(m, how)) != 0)
- return (error);
- }
+ if (flags & M_PKTHDR)
+ error = m_pkthdr_init(m, how);
- return (0);
+ MBUF_PROBE5(m__init, m, how, type, flags, error);
+ return (error);
}
static __inline struct mbuf *
m_get(int how, short type)
{
+ struct mbuf *m;
struct mb_args args;
args.flags = 0;
args.type = type;
- return (uma_zalloc_arg(zone_mbuf, &args, how));
+ m = uma_zalloc_arg(zone_mbuf, &args, how);
+ MBUF_PROBE3(m__get, how, type, m);
+ return (m);
}
static __inline struct mbuf *
m_gethdr(int how, short type)
{
+ struct mbuf *m;
struct mb_args args;
args.flags = M_PKTHDR;
args.type = type;
- return (uma_zalloc_arg(zone_mbuf, &args, how));
+ m = uma_zalloc_arg(zone_mbuf, &args, how);
+ MBUF_PROBE3(m__gethdr, how, type, m);
+ return (m);
}
static __inline struct mbuf *
m_getcl(int how, short type, int flags)
{
+ struct mbuf *m;
struct mb_args args;
args.flags = flags;
args.type = type;
- return (uma_zalloc_arg(zone_pack, &args, how));
+ m = uma_zalloc_arg(zone_pack, &args, how);
+ MBUF_PROBE4(m__getcl, how, type, flags, m);
+ return (m);
}
/*
@@ -747,6 +783,7 @@ m_cljset(struct mbuf *m, void *cl, int t
m->m_ext.ext_flags = EXT_FLAG_EMBREF;
m->m_ext.ext_count = 1;
m->m_flags |= M_EXT;
+ MBUF_PROBE3(m__cljset, m, cl, type);
}
static __inline void
@@ -1122,6 +1159,7 @@ m_free(struct mbuf *m)
{
struct mbuf *n = m->m_next;
+ MBUF_PROBE1(m__free, m);
if ((m->m_flags & (M_PKTHDR|M_NOFREE)) == (M_PKTHDR|M_NOFREE))
m_tag_delete_chain(m, NULL);
if (m->m_flags & M_EXT)
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