Date: Mon, 17 Feb 2014 11:36:31 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r262025 - in stable/9: share/man/man9 sys/cddl/dev/sdt sys/sys Message-ID: <201402171136.s1HBaVmh014183@svn.freebsd.org>
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Author: avg Date: Mon Feb 17 11:36:30 2014 New Revision: 262025 URL: http://svnweb.freebsd.org/changeset/base/262025 Log: MFC r254468,r254469: Add a "translated type" argument to SDT_PROBE_ARGTYPE() Note: this breaks ABI compatibility with older modules with SDT probes. My opinion is that benefits outweigh downsides, because I am not aware of any thirdparty binary-only modules with SDT probes. Modified: stable/9/share/man/man9/SDT.9 stable/9/sys/cddl/dev/sdt/sdt.c stable/9/sys/sys/sdt.h Directory Properties: stable/9/share/man/man9/ (props changed) stable/9/sys/ (props changed) stable/9/sys/sys/ (props changed) Modified: stable/9/share/man/man9/SDT.9 ============================================================================== --- stable/9/share/man/man9/SDT.9 Mon Feb 17 11:28:27 2014 (r262024) +++ stable/9/share/man/man9/SDT.9 Mon Feb 17 11:36:30 2014 (r262025) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd July 3, 2013 +.Dd August 17, 2013 .Dt SDT 9 .Os .Sh NAME @@ -45,6 +45,19 @@ .Fn SDT_PROBE_DEFINE6 prov mod func name sname arg0 arg1 arg2 arg3 arg4 arg5 .Fn SDT_PROBE_DEFINE7 prov mod func name sname arg0 arg1 arg2 arg3 arg4 arg5 \ arg6 +.Fn SDT_PROBE_DEFINE0_XLATE prov mod func name sname +.Fn SDT_PROBE_DEFINE1_XLATE prov mod func name sname arg0 xarg0 +.Fn SDT_PROBE_DEFINE2_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 +.Fn SDT_PROBE_DEFINE3_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 \ + arg2 xarg2 +.Fn SDT_PROBE_DEFINE4_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 \ + arg2 xarg2 arg3 xarg3 +.Fn SDT_PROBE_DEFINE5_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 \ + arg2 xarg2 arg3 xarg3 arg4 xarg4 +.Fn SDT_PROBE_DEFINE6_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 \ + arg2 xarg2 arg3 xarg3 arg4 xarg4 arg5 xarg5 +.Fn SDT_PROBE_DEFINE7_XLATE prov mod func name sname arg0 xarg0 arg1 xarg1 \ + arg2 xarg2 arg3 xarg3 arg4 xarg4 arg5 xarg5 arg6 xarg6 .Fn SDT_PROBE0 prov mod func name .Fn SDT_PROBE1 prov mod func name arg0 .Fn SDT_PROBE2 prov mod func name arg0 arg1 @@ -151,6 +164,30 @@ It is strongly recommended that probe de argument types. .Pp The +.Fn SDT_PROBE_DEFINE*_XLATE +macros are used for probes whose argument types are to be dynamically translated +to the types specified by the corresponding +.Ar xarg +arguments. +This is mainly useful when porting probe definitions from other operating +systems. +As seen by +.Xr dtrace 1 , +the arguments of a probe defined using these macros will have types which match +the +.Ar xarg +types in the probe definition. +However, the arguments passed in at the trace point will have types matching the +native argument types in the probe definition, and thus the native type is +dynamically translated to the translated type. +So long as an appropriate translator is defined in +.Pa /usr/lib/dtrace , +scripts making use of the probe need not concern themselves with the underlying +type of a given +.Nm +probe argument. +.Pp +The .Fn SDT_PROBE* macros are used to create .Nm @@ -166,21 +203,20 @@ of type Destination Unreachable: .Bd -literal -offset indent SDT_PROVIDER_DECLARE(icmp); -SDT_PROBE_DEFINE2(icmp, , unreach, pkt_receive, pkt-receive, - "struct mbuf *", "struct icmp *"); +SDT_PROBE_DEFINE1(icmp, , unreach, pkt_receive, pkt-receive, + "struct icmp *"); .Ed -This particular probe would take two arguments: a pointer to the -.Xr mbuf 9 -containing the incoming packet, and a pointer to the ICMP header for the packet. +This particular probe would take a single argument: a pointer to the struct +containing the ICMP header for the packet. Note that the module name of this probe is not specified. .Pp Consider a DTrace probe which fires when the network stack receives an IP packet. Such a probe would be defined by multiple tracepoints: .Bd -literal -offset indent -SDT_PROBE_DEFINE2(ip, , , receive, receive, "struct mbuf *", - "struct ifnet *", "struct ip *", "struct ip6_hdr *"); +SDT_PROBE_DEFINE3(ip, , , receive, receive, "struct ifnet *", + "struct ip *", "struct ip6_hdr *"); int ip_input(struct mbuf *m) @@ -188,7 +224,7 @@ ip_input(struct mbuf *m) struct ip *ip; ... ip = mtod(m, struct ip *); - SDT_PROBE4(ip, , , receive, m, m->m_pkthdr.rcvif, ip, NULL); + SDT_PROBE3(ip, , , receive, m->m_pkthdr.rcvif, ip, NULL); ... } @@ -198,13 +234,46 @@ ip6_input(struct mbuf *m) struct ip6_hdr *ip6; ... ip6 = mtod(m, struct ip6_hdr *); - SDT_PROBE4(ip, , , receive, m, m->m_pkthdr.rcvif, NULL, ip6); + SDT_PROBE3(ip, , , receive, m->m_pkthdr.rcvif, NULL, ip6); ... } .Ed In particular, the probe should fire when the kernel receives either an IPv4 packet or an IPv6 packet. +.Pp +Consider the ICMP probe discussed above. +We note that its second argument is of type +.Ar struct icmp , +which is a type defined in the FreeBSD kernel to represent the ICMP header of +an ICMP packet, defined in RFC 792. +Linux has a corresponding type, +.Ar struct icmphdr , +for the same purpose, but its field names differ from FreeBSD's +.Ar struct icmp . +Similarly, illumos defines the +.Ar icmph_t +type, again with different field names. +Even with the +.Ql icmp:::pkt-receive +probes defined in all three operating systems, +one would still have to write OS-specific scripts to extract a given field out +of the ICMP header argument. +Dynamically-translated types solve this problem: one can define an +OS-independent +.Xr c 7 +struct to represent an ICMP header, say +.Ar struct icmp_hdr_dt , +and define translators from each of the three OS-specific types to +.Ar struct icmp_hdr_dt , +all in the +.Xr dtrace 1 +library path. +Then the FreeBSD probe above can be defined with: +.Bd -literal -offset indent +SDT_PROBE_DEFINE1_XLATE(ip, , , receive, receive, "struct icmp *", + "struct icmp_hdr_dt *"); +.Ed .Sh SEE ALSO .Xr dtrace 1 .Sh AUTHORS Modified: stable/9/sys/cddl/dev/sdt/sdt.c ============================================================================== --- stable/9/sys/cddl/dev/sdt/sdt.c Mon Feb 17 11:28:27 2014 (r262024) +++ stable/9/sys/cddl/dev/sdt/sdt.c Mon Feb 17 11:36:30 2014 (r262025) @@ -201,11 +201,15 @@ sdt_getargdesc(void *arg, dtrace_id_t id if (desc->dtargd_ndx < probe->n_args) { TAILQ_FOREACH(argtype, &probe->argtype_list, argtype_entry) { if (desc->dtargd_ndx == argtype->ndx) { - /* XXX */ desc->dtargd_mapping = desc->dtargd_ndx; strlcpy(desc->dtargd_native, argtype->type, sizeof(desc->dtargd_native)); - desc->dtargd_xlate[0] = '\0'; /* XXX */ + if (argtype->xtype != NULL) + strlcpy(desc->dtargd_xlate, + argtype->xtype, + sizeof(desc->dtargd_xlate)); + else + desc->dtargd_xlate[0] = '\0'; } } } else Modified: stable/9/sys/sys/sdt.h ============================================================================== --- stable/9/sys/sys/sdt.h Mon Feb 17 11:28:27 2014 (r262024) +++ stable/9/sys/sys/sdt.h Mon Feb 17 11:36:30 2014 (r262025) @@ -87,7 +87,7 @@ #define SDT_PROBE_DEFINE(prov, mod, func, name, sname) #define SDT_PROBE_DECLARE(prov, mod, func, name) #define SDT_PROBE(prov, mod, func, name, arg0, arg1, arg2, arg3, arg4) -#define SDT_PROBE_ARGTYPE(prov, mod, func, name, num, type) +#define SDT_PROBE_ARGTYPE(prov, mod, func, name, num, type, xtype) #define SDT_PROBE_DEFINE0(prov, mod, func, name, sname) #define SDT_PROBE_DEFINE1(prov, mod, func, name, sname, arg0) @@ -110,6 +110,22 @@ #define SDT_PROBE7(prov, mod, func, name, arg0, arg1, arg2, arg3, arg4, arg5, \ arg6) +#define SDT_PROBE_DEFINE0_XLATE(prov, mod, func, name, sname) +#define SDT_PROBE_DEFINE1_XLATE(prov, mod, func, name, sname, arg0, xarg0) +#define SDT_PROBE_DEFINE2_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1) +#define SDT_PROBE_DEFINE3_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2) +#define SDT_PROBE_DEFINE4_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3) +#define SDT_PROBE_DEFINE5_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4) +#define SDT_PROBE_DEFINE6_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4, arg5, xarg5) +#define SDT_PROBE_DEFINE7_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4, arg5, xarg5, arg6, \ + xarg6) + #else SET_DECLARE(sdt_providers_set, struct sdt_provider); @@ -143,9 +159,9 @@ SET_DECLARE(sdt_argtypes_set, struct sdt (uintptr_t) arg3, (uintptr_t) arg4); \ } while (0) -#define SDT_PROBE_ARGTYPE(prov, mod, func, name, num, type) \ +#define SDT_PROBE_ARGTYPE(prov, mod, func, name, num, type, xtype) \ static struct sdt_argtype sdt_##prov##_##mod##_##func##_##name##num[1] \ - = { { num, type, { NULL, NULL }, \ + = { { num, type, xtype, { NULL, NULL }, \ sdt_##prov##_##mod##_##func##_##name } \ }; \ DATA_SET(sdt_argtypes_set, sdt_##prov##_##mod##_##func##_##name##num); @@ -155,54 +171,113 @@ SET_DECLARE(sdt_argtypes_set, struct sdt #define SDT_PROBE_DEFINE1(prov, mod, func, name, sname, arg0) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0) + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL) #define SDT_PROBE_DEFINE2(prov, mod, func, name, sname, arg0, arg1) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1) + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL) #define SDT_PROBE_DEFINE3(prov, mod, func, name, sname, arg0, arg1, arg2)\ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2) + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, NULL) #define SDT_PROBE_DEFINE4(prov, mod, func, name, sname, arg0, arg1, arg2, arg3) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3) + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, NULL) #define SDT_PROBE_DEFINE5(prov, mod, func, name, sname, arg0, arg1, arg2, arg3, arg4) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4) + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, NULL) #define SDT_PROBE_DEFINE6(prov, mod, func, name, sname, arg0, arg1, arg2, arg3,\ arg4, arg5) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5); + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5, NULL) #define SDT_PROBE_DEFINE7(prov, mod, func, name, sname, arg0, arg1, arg2, arg3,\ arg4, arg5, arg6) \ SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5); \ - SDT_PROBE_ARGTYPE(prov, mod, func, name, 6, arg6); + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5, NULL); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 6, arg6, NULL) + +#define SDT_PROBE_DEFINE0_XLATE(prov, mod, func, name, sname) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname) + +#define SDT_PROBE_DEFINE1_XLATE(prov, mod, func, name, sname, arg0, xarg0) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0) + +#define SDT_PROBE_DEFINE2_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1) + +#define SDT_PROBE_DEFINE3_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, xarg2) + +#define SDT_PROBE_DEFINE4_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, xarg2); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, xarg3) + +#define SDT_PROBE_DEFINE5_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, xarg2); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, xarg3); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, xarg4) + +#define SDT_PROBE_DEFINE6_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4, arg5, xarg5) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, xarg2); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, xarg3); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, xarg4); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5, xarg5) + +#define SDT_PROBE_DEFINE7_XLATE(prov, mod, func, name, sname, arg0, xarg0, \ + arg1, xarg1, arg2, xarg2, arg3, xarg3, arg4, xarg4, arg5, xarg5, arg6, \ + xarg6) \ + SDT_PROBE_DEFINE(prov, mod, func, name, sname); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 0, arg0, xarg0); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 1, arg1, xarg1); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 2, arg2, xarg2); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 3, arg3, xarg3); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 4, arg4, xarg4); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 5, arg5, xarg5); \ + SDT_PROBE_ARGTYPE(prov, mod, func, name, 6, arg6, xarg6) #define SDT_PROBE0(prov, mod, func, name) \ SDT_PROBE(prov, mod, func, name, 0, 0, 0, 0, 0) @@ -257,12 +332,12 @@ struct sdt_provider; struct linker_file; struct sdt_argtype { - int ndx; /* Argument index. */ - const char *type; /* Argument type string. */ + int ndx; /* Argument index. */ + const char *type; /* Argument type string. */ + const char *xtype; /* Translated argument type. */ TAILQ_ENTRY(sdt_argtype) argtype_entry; /* Argument type list entry. */ - struct sdt_probe - *probe; /* Ptr to the probe structure. */ + struct sdt_probe *probe; /* Ptr to the probe structure. */ }; struct sdt_probe {
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