diff options
| -rw-r--r-- | buildrun.cxx | 75 | ||||
| -rw-r--r-- | buildrun.h | 1 | ||||
| -rw-r--r-- | session.h | 2 | ||||
| -rw-r--r-- | stapprobes.5.in | 36 | ||||
| -rw-r--r-- | tapsets.cxx | 768 |
5 files changed, 861 insertions, 21 deletions
diff --git a/buildrun.cxx b/buildrun.cxx index 973343cd..2685949d 100644 --- a/buildrun.cxx +++ b/buildrun.cxx @@ -24,6 +24,7 @@ extern "C" { #include <unistd.h> #include <string.h> #include <errno.h> +#include <glob.h> } @@ -336,4 +337,78 @@ run_pass (systemtap_session& s) return rc; } + +// Build a tiny kernel module to query tracepoints +int +make_tracequery(systemtap_session& s, string& name) +{ + // create a subdirectory for the module + string dir(s.tmpdir + "/tracequery"); + if (create_dir(dir.c_str()) != 0) + { + if (! s.suppress_warnings) + cerr << "Warning: failed to create directory for querying tracepoints." << endl; + return 1; + } + + name = dir + "/tracequery.ko"; + + // create a simple Makefile + string makefile(dir + "/Makefile"); + ofstream omf(makefile.c_str()); + omf << "EXTRA_CFLAGS := -g" << endl; // force debuginfo generation + omf << "obj-m := tracequery.o" << endl; + omf.close(); + + // create our source file + string source(dir + "/tracequery.c"); + ofstream osrc(source.c_str()); + osrc << "#include <linux/module.h>" << endl; + osrc << "#ifdef CONFIG_TRACEPOINTS" << endl; + osrc << "#include <linux/tracepoint.h>" << endl; + + // override DECLARE_TRACE to synthesize probe functions for us + osrc << "#undef DECLARE_TRACE" << endl; + osrc << "#define DECLARE_TRACE(name, proto, args) \\" << endl; + osrc << " void stapprobe_##name(proto) {}" << endl; + + // older tracepoints used DEFINE_TRACE, so redirect that too + osrc << "#undef DEFINE_TRACE" << endl; + osrc << "#define DEFINE_TRACE(name, proto, args) \\" << endl; + osrc << " DECLARE_TRACE(name, TPPROTO(proto), TPARGS(args))" << endl; + + // dynamically pull in all tracepoint headers from include/trace/ + glob_t trace_glob; + string glob_str(s.kernel_build_tree + "/include/trace/*.h"); + glob(glob_str.c_str(), 0, NULL, &trace_glob); + for (unsigned i = 0; i < trace_glob.gl_pathc; ++i) + { + string header(basename(trace_glob.gl_pathv[i])); + + // filter out a few known "internal-only" headers + if (header == "trace_events.h") + continue; + if (header.find("_event_types.h") != string::npos) + continue; + + osrc << "#include <trace/" << header << ">" << endl; + } + globfree(&trace_glob); + + // finish up the module source + osrc << "#endif /* CONFIG_TRACEPOINTS */" << endl; + osrc << "int init_module(void) { return 0; }" << endl; + osrc << "void cleanup_module(void) {}" << endl; + osrc << "MODULE_DESCRIPTION(\"tracepoint query\");" << endl; + osrc << "MODULE_LICENSE(\"GPL\");" << endl; + osrc.close(); + + // make the module + string make_cmd = "make -C '" + s.kernel_build_tree + "'" + + " M='" + dir + "' modules"; + if (s.verbose < 4) + make_cmd += " >/dev/null 2>&1"; + return run_make_cmd(s, make_cmd); +} + /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */ @@ -14,6 +14,7 @@ int compile_pass (systemtap_session& s); int run_pass (systemtap_session& s); +int make_tracequery(systemtap_session& s, std::string& name); #endif // BUILDRUN_H @@ -37,6 +37,7 @@ struct task_finder_derived_probe_group; struct timer_derived_probe_group; struct profile_derived_probe_group; struct mark_derived_probe_group; +struct tracepoint_derived_probe_group; struct hrtimer_derived_probe_group; struct perfmon_derived_probe_group; struct procfs_derived_probe_group; @@ -162,6 +163,7 @@ struct systemtap_session timer_derived_probe_group* timer_derived_probes; profile_derived_probe_group* profile_derived_probes; mark_derived_probe_group* mark_derived_probes; + tracepoint_derived_probe_group* tracepoint_derived_probes; hrtimer_derived_probe_group* hrtimer_derived_probes; perfmon_derived_probe_group* perfmon_derived_probes; procfs_derived_probe_group* procfs_derived_probes; diff --git a/stapprobes.5.in b/stapprobes.5.in index 0854be53..0daeb973 100644 --- a/stapprobes.5.in +++ b/stapprobes.5.in @@ -548,6 +548,42 @@ The marker format string associated with a marker is available in And also the marker name string is avalable in .BR $name . +.SS TRACEPOINTS + +This family of probe points hooks up to static probing tracepoints +inserted into the kernel or modules. As with markers, these +tracepoints are special macro calls inserted by kernel developers to +make probing faster and more reliable than with DWARF-based probes, +and DWARF debugging information is not required to probe tracepoints. +Tracepoints have an extra advantage of more strongly-typed parameters +than markers. + +Tracepoint probes begin with +.BR kernel . +The next part names the tracepoint itself: +.BR trace("name") . +The tracepoint name string, which may contain the usual wildcard +characters, is matched against the names defined by the kernel +developers in the tracepoint header files. + +The handler associated with a tracepoint-based probe may read the +optional parameters specified at the macro call site. These are +named according to the declaration by the tracepoint author. For +example, the tracepoint probe +.BR kernel.trace("sched_switch") +provides the parameters +.BR $rq ", " $prev ", and " $next . +If the parameter is a complex type, as in a struct pointer, then a +script can access fields with the same syntax as DWARF $target +variables. Also, tracepoint parameters cannot be modified, but in +guru-mode a script may modify fields of parameters. + +The name of the tracepoint is available in +.BR $$name , +and a string of name=value pairs for all parameters of the tracepoint +is available in +.BR $$vars . + .SS PERFORMANCE MONITORING HARDWARE The perfmon family of probe points is used to access the performance diff --git a/tapsets.cxx b/tapsets.cxx index 1c098425..defaf385 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -15,6 +15,7 @@ #include "translate.h" #include "session.h" #include "util.h" +#include "buildrun.h" #include "dwarf_wrappers.h" #include "auto_free.h" @@ -465,6 +466,7 @@ static string TOK_STATEMENT("statement"); static string TOK_ABSOLUTE("absolute"); static string TOK_PROCESS("process"); static string TOK_MARK("mark"); +static string TOK_TRACE("trace"); static string TOK_LABEL("label"); // Can we handle this query with just symbol-table info? @@ -958,6 +960,9 @@ struct dwflpp void setup_user(string module_name, bool debuginfo_needed = true) { + if (! sess.module_cache) + sess.module_cache = new module_cache (); + static const char *debuginfo_path_arr = "+:.debug:/usr/lib/debug:build"; static const char *debuginfo_env_arr = getenv("SYSTEMTAP_DEBUGINFO_PATH"); // NB: kernel_build_tree doesn't enter into this, as it's for @@ -1190,8 +1195,9 @@ struct dwflpp return DWARF_CB_OK; } - int iterate_over_functions (int (* callback)(Dwarf_Die * func, void * arg), - void * data); + int iterate_over_functions (int (* callback)(Dwarf_Die * func, base_query * q), + base_query * q, const string& function, + bool has_statement_num=false); int iterate_over_globals (int (* callback)(Dwarf_Die *, void *), void * data); @@ -2934,13 +2940,13 @@ dwflpp::iterate_over_globals (int (* callback)(Dwarf_Die *, void *), } int -dwflpp::iterate_over_functions (int (* callback)(Dwarf_Die * func, void * arg), - void * data) +dwflpp::iterate_over_functions (int (* callback)(Dwarf_Die * func, base_query * q), + base_query * q, const string& function, + bool has_statement_num) { int rc = DWARF_CB_OK; assert (module); assert (cu); - dwarf_query * q = static_cast<dwarf_query *>(data); string key = module_name + ":" + cu_name; cu_function_cache_t *v = cu_function_cache[key]; @@ -2953,13 +2959,13 @@ dwflpp::iterate_over_functions (int (* callback)(Dwarf_Die * func, void * arg), clog << "function cache " << key << " size " << v->size() << endl; } - string subkey = q->function; + string subkey = function; if (v->find(subkey) != v->end()) { Dwarf_Die die = v->find(subkey)->second; if (q->sess.verbose > 4) clog << "function cache " << key << " hit " << subkey << endl; - return (*callback)(& die, data); + return (*callback)(& die, q); } else if (name_has_wildcard (subkey)) { @@ -2973,17 +2979,17 @@ dwflpp::iterate_over_functions (int (* callback)(Dwarf_Die * func, void * arg), if (q->sess.verbose > 4) clog << "function cache " << key << " match " << func_name << " vs " << subkey << endl; - rc = (*callback)(& die, data); + rc = (*callback)(& die, q); if (rc != DWARF_CB_OK) break; } } } - else if (q->has_statement_num) // searching all for kernel.statement + else if (has_statement_num) // searching all for kernel.statement { for (cu_function_cache_t::iterator it = v->begin(); it != v->end(); it++) { Dwarf_Die die = it->second; - rc = (*callback)(& die, data); + rc = (*callback)(& die, q); if (rc != DWARF_CB_OK) break; } } @@ -3873,9 +3879,9 @@ query_dwarf_inline_instance (Dwarf_Die * die, void * arg) } static int -query_dwarf_func (Dwarf_Die * func, void * arg) +query_dwarf_func (Dwarf_Die * func, base_query * bq) { - dwarf_query * q = static_cast<dwarf_query *>(arg); + dwarf_query * q = static_cast<dwarf_query *>(bq); try { @@ -3889,7 +3895,7 @@ query_dwarf_func (Dwarf_Die * func, void * arg) if (q->sess.verbose>3) clog << "checking instances of inline " << q->dw.function_name << "\n"; - q->dw.iterate_over_inline_instances (query_dwarf_inline_instance, arg); + q->dw.iterate_over_inline_instances (query_dwarf_inline_instance, q); if (q->dw.function_name_final_match (q->function)) return DWARF_CB_ABORT; @@ -4023,7 +4029,9 @@ query_cu (Dwarf_Die * cudie, void * arg) // Pick up [entrypc, name, DIE] tuples for all the functions // matching the query, and fill in the prologue endings of them // all in a single pass. - int rc = q->dw.iterate_over_functions (query_dwarf_func, q); + int rc = q->dw.iterate_over_functions (query_dwarf_func, q, + q->function, + q->has_statement_num); if (rc != DWARF_CB_OK) q->query_done = true; @@ -4993,9 +5001,6 @@ void dwarf_cast_expanding_visitor::visit_cast_op (cast_op* e) if (e->module.empty()) e->module = "kernel"; // "*" may also be reasonable to search all kernel modules - if (! s.module_cache) - s.module_cache = new module_cache (); - string code; exp_type type = pe_long; try @@ -5655,10 +5660,6 @@ dwarf_builder::build(systemtap_session & sess, dwflpp* dw = 0; - if (! sess.module_cache) - sess.module_cache = new module_cache (); - - string module_name; if (has_null_param (parameters, TOK_KERNEL) || get_param (parameters, TOK_MODULE, module_name)) @@ -9202,6 +9203,726 @@ mark_builder::build(systemtap_session & sess, // ------------------------------------------------------------------------ +// statically inserted kernel-tracepoint derived probes +// ------------------------------------------------------------------------ + +struct tracepoint_arg +{ + string name, c_type; + bool used, isptr; + Dwarf_Die type_die; + tracepoint_arg(): used(false), isptr(false) {} +}; + +struct tracepoint_derived_probe: public derived_probe +{ + tracepoint_derived_probe (systemtap_session& s, + dwflpp& dw, Dwarf_Die& func_die, + const string& tracepoint_name, + probe* base_probe, probe_point* location); + + systemtap_session& sess; + string tracepoint_name, header; + vector <struct tracepoint_arg> args; + + void build_args(dwflpp& dw, Dwarf_Die& func_die); + void join_group (systemtap_session& s); + void emit_probe_context_vars (translator_output* o); +}; + + +struct tracepoint_derived_probe_group: public generic_dpg<tracepoint_derived_probe> +{ + void emit_module_decls (systemtap_session& s); + void emit_module_init (systemtap_session& s); + void emit_module_exit (systemtap_session& s); +}; + + +struct tracepoint_var_expanding_visitor: public var_expanding_visitor +{ + tracepoint_var_expanding_visitor(dwflpp& dw, const string& probe_name, + vector <struct tracepoint_arg>& args): + dw (dw), probe_name (probe_name), args (args) {} + dwflpp& dw; + const string& probe_name; + vector <struct tracepoint_arg>& args; + + void visit_target_symbol (target_symbol* e); + void visit_target_symbol_arg (target_symbol* e); + void visit_target_symbol_context (target_symbol* e); +}; + + +void +tracepoint_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e) +{ + string argname = e->base_name.substr(1); + + // search for a tracepoint parameter matching this name + tracepoint_arg *arg = NULL; + for (unsigned i = 0; i < args.size(); ++i) + if (args[i].name == argname) + { + arg = &args[i]; + arg->used = true; + break; + } + + if (arg == NULL) + { + stringstream alternatives; + for (unsigned i = 0; i < args.size(); ++i) + alternatives << " $" << args[i].name; + alternatives << " $$name $$vars"; + + // We hope that this value ends up not being referenced after all, so it + // can be optimized out quietly. + semantic_error* saveme = + new semantic_error("unable to find tracepoint variable '" + e->base_name + + "' (alternatives:" + alternatives.str () + ")", e->tok); + // NB: we can have multiple errors, since a target variable + // may be expanded in several different contexts: + // trace ("*") { $foo->bar } + saveme->chain = e->saved_conversion_error; + e->saved_conversion_error = saveme; + provide (e); + return; + } + + // make sure we're not dereferencing base types + if (!e->components.empty() && !arg->isptr) + switch (e->components[0].first) + { + case target_symbol::comp_literal_array_index: + throw semantic_error("tracepoint variable '" + e->base_name + + "' may not be used as array", e->tok); + case target_symbol::comp_struct_member: + throw semantic_error("tracepoint variable '" + e->base_name + + "' may not be used as a structure", e->tok); + default: + throw semantic_error("invalid use of tracepoint variable '" + + e->base_name + "'", e->tok); + } + + // we can only write to dereferenced fields, and only if guru mode is on + bool lvalue = is_active_lvalue(e); + if (lvalue && (!dw.sess.guru_mode || e->components.empty())) + throw semantic_error("write to tracepoint variable '" + e->base_name + + "' not permitted", e->tok); + + if (e->components.empty()) + { + // Synthesize a simple function to grab the parameter + functiondecl *fdecl = new functiondecl; + fdecl->tok = e->tok; + embeddedcode *ec = new embeddedcode; + ec->tok = e->tok; + + string fname = (string("_tracepoint_tvar_get") + + "_" + e->base_name.substr(1) + + "_" + lex_cast<string>(tick++)); + + fdecl->name = fname; + fdecl->body = ec; + fdecl->type = pe_long; + + ec->code = (string("THIS->__retvalue = CONTEXT->locals[0].") + + probe_name + string(".__tracepoint_arg_") + + arg->name + string (";/* pure */")); + + dw.sess.functions[fdecl->name] = fdecl; + + // Synthesize a functioncall. + functioncall* n = new functioncall; + n->tok = e->tok; + n->function = fname; + n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session + + provide (n); + } + else + { + // Synthesize a function to dereference the dwarf fields, + // with a pointer parameter that is the base tracepoint variable + functiondecl *fdecl = new functiondecl; + fdecl->tok = e->tok; + embeddedcode *ec = new embeddedcode; + ec->tok = e->tok; + + string fname = (string(lvalue ? "_tracepoint_tvar_set" : "_tracepoint_tvar_get") + + "_" + e->base_name.substr(1) + + "_" + lex_cast<string>(tick++)); + + fdecl->name = fname; + fdecl->body = ec; + + try + { + ec->code = dw.literal_stmt_for_pointer (&arg->type_die, e->components, + lvalue, fdecl->type); + } + catch (const semantic_error& er) + { + // We suppress this error message, and pass the unresolved + // variable to the next pass. We hope that this value ends + // up not being referenced after all, so it can be optimized out + // quietly. + semantic_error* saveme = new semantic_error (er); // copy it + saveme->tok1 = e->tok; // XXX: token not passed to dw code generation routines + // NB: we can have multiple errors, since a target variable + // may be expanded in several different contexts: + // trace ("*") { $foo->bar } + saveme->chain = e->saved_conversion_error; + e->saved_conversion_error = saveme; + provide (e); + return; + } + + // Give the fdecl an argument for the raw tracepoint value + vardecl *v1 = new vardecl; + v1->type = pe_long; + v1->name = "pointer"; + v1->tok = e->tok; + fdecl->formal_args.push_back(v1); + + if (lvalue) + { + // Modify the fdecl so it carries a pe_long formal + // argument called "value". + + // FIXME: For the time being we only support setting target + // variables which have base types; these are 'pe_long' in + // stap's type vocabulary. Strings and pointers might be + // reasonable, some day, but not today. + + vardecl *v2 = new vardecl; + v2->type = pe_long; + v2->name = "value"; + v2->tok = e->tok; + fdecl->formal_args.push_back(v2); + } + else + ec->code += "/* pure */"; + + dw.sess.functions[fdecl->name] = fdecl; + + // Synthesize a functioncall. + functioncall* n = new functioncall; + n->tok = e->tok; + n->function = fname; + n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session + + // make the original a bare target symbol for the tracepoint value, + // which will be passed into the dwarf dereferencing code + e->components.clear(); + n->args.push_back(require(e)); + + if (lvalue) + { + // Provide the functioncall to our parent, so that it can be + // used to substitute for the assignment node immediately above + // us. + assert(!target_symbol_setter_functioncalls.empty()); + *(target_symbol_setter_functioncalls.top()) = n; + } + + provide (n); + } +} + + +void +tracepoint_var_expanding_visitor::visit_target_symbol_context (target_symbol* e) +{ + if (is_active_lvalue (e)) + throw semantic_error("write to tracepoint '" + e->base_name + "' not permitted", e->tok); + + if (!e->components.empty()) + switch (e->components[0].first) + { + case target_symbol::comp_literal_array_index: + throw semantic_error("tracepoint '" + e->base_name + "' may not be used as array", + e->tok); + case target_symbol::comp_struct_member: + throw semantic_error("tracepoint '" + e->base_name + "' may not be used as a structure", + e->tok); + default: + throw semantic_error("invalid tracepoint '" + e->base_name + "' use", e->tok); + } + + if (e->base_name == "$$name") + { + // Synthesize a functioncall. + functioncall* n = new functioncall; + n->tok = e->tok; + n->function = "_mark_name_get"; + n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session + provide (n); + } + else if (e->base_name == "$$vars") + { + target_symbol *tsym = new target_symbol; + print_format* pf = new print_format; + + // Convert $$vars to sprintf of a list of vars which we recursively evaluate + // NB: we synthesize a new token here rather than reusing + // e->tok, because print_format::print likes to use + // its tok->content. + token* pf_tok = new token(*e->tok); + pf_tok->content = "sprintf"; + + pf->tok = pf_tok; + pf->print_to_stream = false; + pf->print_with_format = true; + pf->print_with_delim = false; + pf->print_with_newline = false; + pf->print_char = false; + + for (unsigned i = 0; i < args.size(); ++i) + { + if (i > 0) + pf->raw_components += " "; + pf->raw_components += args[i].name; + tsym->tok = e->tok; + tsym->base_name = "$" + args[i].name; + + // every variable should always be accessible! + tsym->saved_conversion_error = 0; + expression *texp = require (tsym); // NB: throws nothing ... + assert (!tsym->saved_conversion_error); // ... but this is how we know it happened. + + pf->raw_components += "=%#x"; + pf->args.push_back(texp); + } + + pf->components = print_format::string_to_components(pf->raw_components); + provide (pf); + } + else + assert(0); // shouldn't get here +} + +void +tracepoint_var_expanding_visitor::visit_target_symbol (target_symbol* e) +{ + assert(e->base_name.size() > 0 && e->base_name[0] == '$'); + + if (e->base_name == "$$name" || e->base_name == "$$vars") + visit_target_symbol_context (e); + else + visit_target_symbol_arg (e); +} + + + +tracepoint_derived_probe::tracepoint_derived_probe (systemtap_session& s, + dwflpp& dw, Dwarf_Die& func_die, + const string& tracepoint_name, + probe* base, probe_point* loc): + derived_probe (base, new probe_point(*loc) /* .components soon rewritten */), + sess (s), tracepoint_name (tracepoint_name) +{ + // create synthetic probe point name; preserve condition + vector<probe_point::component*> comps; + comps.push_back (new probe_point::component (TOK_KERNEL)); + comps.push_back (new probe_point::component (TOK_TRACE, new literal_string (tracepoint_name))); + this->sole_location()->components = comps; + + // fill out the available arguments in this tracepoint + build_args(dw, func_die); + + // determine which header defined this tracepoint + string decl_file = dwarf_decl_file(&func_die); + size_t header_pos = decl_file.rfind("trace/"); + if (header_pos == string::npos) + throw semantic_error ("cannot parse header location for tracepoint '" + + tracepoint_name + "' in '" + + decl_file + "'"); + header = decl_file.substr(header_pos); + + // tracepoints from FOO_event_types.h should really be included from FOO.h + // XXX can dwarf tell us the include hierarchy? it would be better to + // ... walk up to see which one was directly included by tracequery.c + header_pos = header.find("_event_types"); + if (header_pos != string::npos) + header.erase(header_pos, 12); + + // Now expand the local variables in the probe body + tracepoint_var_expanding_visitor v (dw, name, args); + this->body = v.require (this->body); + + if (sess.verbose > 2) + clog << "tracepoint-based " << name << " tracepoint='" << tracepoint_name + << "'" << endl; +} + + +static bool +dwarf_type_name(Dwarf_Die& type_die, string& c_type) +{ + // if this die has a direct name, then we're done + const char *diename = dwarf_diename_integrate(&type_die); + if (diename != NULL) + { + switch (dwarf_tag(&type_die)) + { + case DW_TAG_structure_type: + c_type.append("struct "); + break; + case DW_TAG_union_type: + c_type.append("union "); + break; + } + c_type.append(diename); + return true; + } + + // otherwise, this die is a type modifier. + + // recurse into the referent type + Dwarf_Attribute subtype_attr; + Dwarf_Die subtype_die; + if (!dwarf_attr_integrate(&type_die, DW_AT_type, &subtype_attr) + || !dwarf_formref_die(&subtype_attr, &subtype_die) + || !dwarf_type_name(subtype_die, c_type)) + return false; + + const char *suffix = NULL; + switch (dwarf_tag(&type_die)) + { + case DW_TAG_pointer_type: + suffix = "*"; + break; + case DW_TAG_array_type: + suffix = "[]"; + break; + case DW_TAG_const_type: + suffix = " const"; + break; + case DW_TAG_volatile_type: + suffix = " volatile"; + break; + default: + return false; + } + c_type.append(suffix); + return true; +} + + +static bool +resolve_tracepoint_arg_type(Dwarf_Die& type_die, bool& isptr) +{ + Dwarf_Attribute type_attr; + switch (dwarf_tag(&type_die)) + { + case DW_TAG_typedef: + case DW_TAG_const_type: + case DW_TAG_volatile_type: + // iterate on the referent type + return (dwarf_attr_integrate(&type_die, DW_AT_type, &type_attr) + && dwarf_formref_die(&type_attr, &type_die) + && resolve_tracepoint_arg_type(type_die, isptr)); + case DW_TAG_base_type: + // base types will simply be treated as script longs + isptr = false; + return true; + case DW_TAG_pointer_type: + // pointers can be either script longs, + // or dereferenced with their referent type + isptr = true; + return (dwarf_attr_integrate(&type_die, DW_AT_type, &type_attr) + && dwarf_formref_die(&type_attr, &type_die)); + default: + // should we consider other types too? + return false; + } +} + + +void +tracepoint_derived_probe::build_args(dwflpp& dw, Dwarf_Die& func_die) +{ + Dwarf_Die arg; + if (dwarf_child(&func_die, &arg) == 0) + do + if (dwarf_tag(&arg) == DW_TAG_formal_parameter) + { + // build a tracepoint_arg for this parameter + tracepoint_arg tparg; + tparg.name = dwarf_diename_integrate(&arg); + + // read the type of this parameter + Dwarf_Attribute type_attr; + if (!dwarf_attr_integrate (&arg, DW_AT_type, &type_attr) + || !dwarf_formref_die (&type_attr, &tparg.type_die) + || !dwarf_type_name(tparg.type_die, tparg.c_type) + || !resolve_tracepoint_arg_type(tparg.type_die, tparg.isptr)) + throw semantic_error ("cannot get type of tracepoint '" + + tracepoint_name + "' parameter '" + + tparg.name + "'"); + + args.push_back(tparg); + if (sess.verbose > 4) + clog << "found parameter for tracepoint '" << tracepoint_name + << "': type:'" << tparg.c_type + << "' name:'" << tparg.name << "'" << endl; + } + while (dwarf_siblingof(&arg, &arg) == 0); +} + + +void +tracepoint_derived_probe::join_group (systemtap_session& s) +{ + if (! s.tracepoint_derived_probes) + s.tracepoint_derived_probes = new tracepoint_derived_probe_group (); + s.tracepoint_derived_probes->enroll (this); +} + + +void +tracepoint_derived_probe::emit_probe_context_vars (translator_output* o) +{ + for (unsigned i = 0; i < args.size(); i++) + if (args[i].used) + o->newline() << "int64_t __tracepoint_arg_" << args[i].name << ";"; +} + + +void +tracepoint_derived_probe_group::emit_module_decls (systemtap_session& s) +{ + if (probes.empty()) + return; + + s.op->newline() << "/* ---- tracepointer probes ---- */"; + + for (unsigned i = 0; i < probes.size(); ++i) + { + tracepoint_derived_probe *p = probes[i]; + s.op->newline(); + s.op->newline() << "#include <" << p->header << ">"; + s.op->newline() << "static void enter_tracepoint_probe_" << i << "("; + for (unsigned j = 0; j < p->args.size(); ++j) + { + if (j > 0) + s.op->line() << ", "; + s.op->line() << p->args[j].c_type << " __tracepoint_arg_" << p->args[j].name; + } + s.op->line() << ") {"; + s.op->indent(1); + common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING"); + s.op->newline() << "c->probe_point = " + << lex_cast_qstring (*p->sole_location()) << ";"; + s.op->newline() << "c->marker_name = " + << lex_cast_qstring (p->tracepoint_name) << ";"; + for (unsigned j = 0; j < p->args.size(); ++j) + if (p->args[j].used) + { + s.op->newline() << "c->locals[0]." << p->name << ".__tracepoint_arg_" + << p->args[j].name << " = (int64_t)"; + if (p->args[j].isptr) + s.op->line() << "(intptr_t)"; + s.op->line() << "__tracepoint_arg_" << p->args[j].name << ";"; + } + s.op->newline() << p->name << " (c);"; + common_probe_entryfn_epilogue (s.op); + s.op->newline(-1) << "}"; + s.op->newline(); + } +} + + +void +tracepoint_derived_probe_group::emit_module_init (systemtap_session &s) +{ + if (probes.size () == 0) + return; + + s.op->newline() << "/* init tracepoint probes */"; + + // We can't use a simple runtime loop because the probe registration + // functions are distinct inlines. Instead, this will generate nesting as + // deep as the number of probe points. Gotos are also possible, but the end + // result is the same. + + for (unsigned i = 0; i < probes.size(); ++i) + { + s.op->newline() << "if (!rc) {"; + s.op->newline(1) << "probe_point = " + << lex_cast_qstring (*probes[i]->sole_location()) << ";"; + s.op->newline() << "rc = register_trace_" << probes[i]->tracepoint_name + << "(enter_tracepoint_probe_" << i << ");"; + } + + for (unsigned i = probes.size() - 1; i < probes.size(); --i) + { + s.op->newline() << "if (rc)"; + s.op->newline(1) << "unregister_trace_" << probes[i]->tracepoint_name + << "(enter_tracepoint_probe_" << i << ");"; + s.op->newline(-2) << "}"; + } + s.op->newline() << "if (rc)"; + s.op->newline(1) << "tracepoint_synchronize_unregister();"; + s.op->indent(-1); +} + + +void +tracepoint_derived_probe_group::emit_module_exit (systemtap_session& s) +{ + if (probes.empty()) + return; + + s.op->newline() << "/* deregister tracepointer probes */"; + for (unsigned i = 0; i < probes.size(); ++i) + s.op->newline() << "unregister_trace_" << probes[i]->tracepoint_name + << "(enter_tracepoint_probe_" << i << ");"; + s.op->newline() << "tracepoint_synchronize_unregister();"; +} + + +struct tracepoint_query : public base_query +{ + tracepoint_query(dwflpp & dw, const string & tracepoint, + probe * base_probe, probe_point * base_loc, + vector<derived_probe *> & results): + base_query(dw, "*"), tracepoint(tracepoint), + base_probe(base_probe), base_loc(base_loc), + results(results) {} + + const string& tracepoint; + + probe * base_probe; + probe_point * base_loc; + vector<derived_probe *> & results; + + void handle_query_module(); + int handle_query_cu(Dwarf_Die * cudie); + int handle_query_func(Dwarf_Die * func); + + static int tracepoint_query_cu (Dwarf_Die * cudie, void * arg); + static int tracepoint_query_func (Dwarf_Die * func, base_query * query); +}; + + +void +tracepoint_query::handle_query_module() +{ + // look for the tracepoints in each CU + dw.iterate_over_cus(tracepoint_query_cu, this); +} + + +int +tracepoint_query::handle_query_cu(Dwarf_Die * cudie) +{ + dw.focus_on_cu (cudie); + + // look at each function to see if it's a tracepoint + string function = "stapprobe_" + tracepoint; + return dw.iterate_over_functions (tracepoint_query_func, this, function); +} + + +int +tracepoint_query::handle_query_func(Dwarf_Die * func) +{ + dw.focus_on_function (func); + + assert(dw.function_name.compare(0, 10, "stapprobe_") == 0); + string tracepoint_instance = dw.function_name.substr(10); + derived_probe *dp = new tracepoint_derived_probe (dw.sess, dw, *func, + tracepoint_instance, + base_probe, base_loc); + results.push_back (dp); + return DWARF_CB_OK; +} + + +int +tracepoint_query::tracepoint_query_cu (Dwarf_Die * cudie, void * arg) +{ + tracepoint_query * q = static_cast<tracepoint_query *>(arg); + if (pending_interrupts) return DWARF_CB_ABORT; + return q->handle_query_cu(cudie); +} + + +int +tracepoint_query::tracepoint_query_func (Dwarf_Die * func, base_query * query) +{ + tracepoint_query * q = static_cast<tracepoint_query *>(query); + if (pending_interrupts) return DWARF_CB_ABORT; + return q->handle_query_func(func); +} + + +struct tracepoint_builder: public derived_probe_builder +{ +private: + dwflpp *dw; + bool init_dw(systemtap_session& s); + +public: + tracepoint_builder(): dw(0) {} + ~tracepoint_builder() { delete dw; } + + void build_no_more (systemtap_session& s) + { + if (dw && s.verbose > 3) + clog << "tracepoint_builder releasing dwflpp" << endl; + delete dw; + dw = NULL; + } + + void build(systemtap_session& s, + probe *base, probe_point *location, + literal_map_t const& parameters, + vector<derived_probe*>& finished_results); +}; + + +bool +tracepoint_builder::init_dw(systemtap_session& s) +{ + if (dw != NULL) + return true; + + string tracequery_ko; + int rc = make_tracequery(s, tracequery_ko); + if (rc != 0) + return false; + + // TODO cache tracequery.ko + + dw = new dwflpp(s); + dw->setup_user(tracequery_ko); + return true; +} + + +void +tracepoint_builder::build(systemtap_session& s, + probe *base, probe_point *location, + literal_map_t const& parameters, + vector<derived_probe*>& finished_results) +{ + if (!init_dw(s)) + return; + + string tracepoint; + assert(get_param (parameters, TOK_TRACE, tracepoint)); + + tracepoint_query q(*dw, tracepoint, base, location, finished_results); + dw->query_modules(&q); +} + + + +// ------------------------------------------------------------------------ // hrtimer derived probes // ------------------------------------------------------------------------ // This is a new timer interface that provides more flexibility in specifying @@ -10003,6 +10724,10 @@ register_standard_tapsets(systemtap_session & s) s.pattern_root->bind(TOK_KERNEL)->bind_str(TOK_MARK)->bind_str(TOK_FORMAT) ->bind(new mark_builder()); + // kernel tracepoint probes + s.pattern_root->bind(TOK_KERNEL)->bind_str(TOK_TRACE) + ->bind(new tracepoint_builder()); + // procfs parts s.pattern_root->bind(TOK_PROCFS)->bind(TOK_READ)->bind(new procfs_builder()); s.pattern_root->bind_str(TOK_PROCFS)->bind(TOK_READ) @@ -10031,6 +10756,7 @@ all_session_groups(systemtap_session& s) DOONE(timer); DOONE(profile); DOONE(mark); + DOONE(tracepoint); DOONE(hrtimer); DOONE(perfmon); DOONE(procfs); |