File: tapset-debuginfod.cxx

package info (click to toggle)
systemtap 5.1-5
  • links: PTS, VCS
  • area: main
  • in suites: sid, trixie
  • size: 47,964 kB
  • sloc: cpp: 80,838; ansic: 54,757; xml: 49,725; exp: 43,665; sh: 11,527; python: 5,003; perl: 2,252; tcl: 1,312; makefile: 1,006; javascript: 149; lisp: 105; awk: 101; asm: 91; java: 70; sed: 16
file content (286 lines) | stat: -rw-r--r-- 10,821 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
// tapset for debuginfod searching
// Copyright (C) 2005-2023 Red Hat Inc.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.

#include "session.h"
#include "tapsets.h"
#include "translate.h"
#include "util.h"
#include "fnmatch.h"

#if defined(HAVE_LIBDEBUGINFOD) && defined(HAVE_JSON_C) && defined(METADATA_QUERY_ENABLED)

#include <elfutils/debuginfod.h>
#include <json-c/json.h>
#include <unistd.h>

using namespace std;
using namespace __gnu_cxx;

static const string TOK_DEBUGINFOD("debuginfod");
static const string TOK_ARCHIVE("archive");
static const string TOK_PROCESS("process");


struct metadata_result { string archive; string file; };

map<string,metadata_result>
get_buildids(bool has_archive, string archive, string process_path) {
  static unique_ptr <debuginfod_client, void (*)(debuginfod_client*)>
    client (debuginfod_begin(), &debuginfod_end);

  map<string,metadata_result> buildids;
  
  int metadata_fd;
  if((metadata_fd = debuginfod_find_metadata(client.get(), "glob", (char*)process_path.c_str(), NULL)) < 0)
    throw SEMANTIC_ERROR(_("can't retrieve buildids from debuginfod"));

  vector<pid_t> debuginfod_workers;
  json_object *metadata = json_object_from_fd(metadata_fd);
  json_object *metadata_array;
  close(metadata_fd);
  if(!metadata || !json_object_object_get_ex(metadata, "results", &metadata_array))
    throw SEMANTIC_ERROR(_("retrieved invalid buildids from debuginfod"));
  size_t n_bid = json_object_array_length(metadata_array);

  if(0 == n_bid)
    throw SEMANTIC_ERROR(_("can't retrieve buildids from debuginfod"));

  int d_out, d_err;
  json_object *file_metadata, *json_field;
  string buildid;
  for(size_t i = 0; i < n_bid; i++)
  {
    file_metadata = json_object_array_get_idx(metadata_array, i);

    // Reject missing buildid
    if(json_object_object_get_ex(file_metadata, "buildid", &json_field))
      buildid = json_object_get_string(json_field);
    else
      continue;

    // Reject sus buildids
    if(! is_build_id(buildid))
      continue;

    // Reject duplicate buildid - they are equivalent as far as we're concerned
    if (buildids.find(buildid) != buildids.end())
      continue;
    
    // Reject non-executables
    if (! (json_object_object_get_ex(file_metadata, "type", &json_field)
           && 0 == strcmp(json_object_get_string(json_field), "executable")))
      continue;

    // Extract archive name (if any - might be empty).
    string archive_fullname;
    if (json_object_object_get_ex(file_metadata, "archive", &json_field)) {
      archive_fullname = json_object_get_string(json_field);
    }
    string archive_basename = archive_fullname.substr(archive_fullname.find_last_of("/") + 1);

    // Reject mismatching archive, if user specified
    if (has_archive) {
      // documented as basename comparison, so no FNM_PATHNAME needed        
      if(0 != fnmatch(archive.c_str(), archive_basename.c_str(), 0))
        continue;
    }

    // Extract file name (mandatory)
    string filename;
    if (json_object_object_get_ex(file_metadata, "file", &json_field))
      filename = json_object_get_string(json_field);
    else
      continue;
    
    metadata_result af; af.archive = archive_basename; af.file = filename;
    buildids.insert(make_pair(buildid, af));

    debuginfod_workers.push_back(stap_spawn_piped(0, {"debuginfod-find", "executable", buildid}, NULL, &d_out, &d_err));
    // NB: we don't really have to preload the debuginfo - a probe point may not call for dwarf
    // NB: but if it does, we'd suffer latency by downloading one at a time, sequentially
    debuginfod_workers.push_back(stap_spawn_piped(0, {"debuginfod-find", "debuginfo" , buildid}, NULL, &d_out, &d_err));
  }
  json_object_put(metadata);

  // Make sure all the executables/debuginfo are found before continuing
  for(auto worker_pid = debuginfod_workers.begin(); worker_pid != debuginfod_workers.end(); ++worker_pid)
    if(*worker_pid > 0) stap_waitpid(0, *worker_pid);

  return buildids;
}


// ------------------------------------------------------------------------
// debuginfod_builder derived probes
// ------------------------------------------------------------------------
struct debuginfod_builder: public derived_probe_builder
{
public:
  void build(systemtap_session & sess, probe * base,
    probe_point * location,
    literal_map_t const & parameters,
    vector<derived_probe *> & finished_results);

  void build_with_suffix(systemtap_session & sess, probe * base,
    probe_point * location,
    literal_map_t const & parameters,
    std::vector<derived_probe *> & finished_results,
    std::vector<probe_point::component *> const & suffix);

  virtual string name() { return "debuginfod builder"; }
};


void
debuginfod_builder::build(systemtap_session & sess, probe * base,
  probe_point * location,
  literal_map_t const & parameters,
  vector<derived_probe *> & finished_results)
{
  interned_string archive;
  interned_string process_path;
  bool has_debuginfod = has_null_param (parameters, TOK_DEBUGINFOD);
  bool has_process    = get_param (parameters, TOK_PROCESS, process_path);
  bool has_archive    = get_param (parameters, TOK_ARCHIVE, archive);
  
  if(!has_debuginfod || !has_process)
    throw SEMANTIC_ERROR(_("the probe must be of the form debuginfod.[.archive(\"foobar\")]process(\"foo/bar\").**{...}"));

  // The matching buildids from the archives/debuginfod
  map<string,metadata_result> buildids = get_buildids(has_archive, archive, process_path);

  for(auto it = buildids.begin(); it != buildids.end(); ++it) {
    interned_string buildid = it->first;
    interned_string m_archive = it->second.archive;
    interned_string m_file = it->second.file;

    probe *subbase = base;
    probe_point *subbase_pp = location;

    if (sess.verbose > 3) {
      clog << "from: ";
      subbase->printsig(clog);
    }
    
    // If the probe archive/process names were globs, interject an intermediate
    // probe into the chain that resolves the globs.
    if (process_path.find_first_of("*?[{") != string::npos ||
        (has_archive && archive.find_first_of("*?[{") != string::npos)) // was some globbing performed?
      {
        subbase_pp = new probe_point(*location);
        if (has_archive) {
          assert (subbase_pp->components[1]->functor == TOK_ARCHIVE);
          subbase_pp->components[1] = new probe_point::component(TOK_ARCHIVE,
                                                                 new literal_string(m_archive),
                                                                 false);
          assert (subbase_pp->components[2]->functor == TOK_PROCESS);
          subbase_pp->components[2] = new probe_point::component(TOK_PROCESS,
                                                                 new literal_string(m_file),
                                                                 false);
        } else {
          assert (subbase_pp->components[1]->functor == TOK_PROCESS);
          subbase_pp->components[1] = new probe_point::component(TOK_PROCESS,
                                                                 new literal_string(m_file),
                                                                 false);          
        }
        // subbase_pp->well_formed = true; // XXX: true, unless the FUNCTION etc. stuff has *
        subbase = new probe(base, subbase_pp);

        if (sess.verbose > 3) {
          clog << " through: ";
          subbase->printsig(clog);
        }
      }

    // OK time for the new process("buildid").foo probe
    probe_point *derived_pp = new probe_point(*subbase_pp);
    derived_pp->components.erase(derived_pp->components.begin()); // Remove the 'debuginfod'
    if (has_archive)
      derived_pp->components.erase(derived_pp->components.begin()); // Remove the 'archive' too
    assert (derived_pp->components[0]->functor == TOK_PROCESS);
    // NB: since probe_points are shallow-copied, we must not modify a
    // preexisting component, but create new
    derived_pp->components[0] = new probe_point::component(TOK_PROCESS,
                                                           new literal_string(buildid),
                                                           false);
    derived_pp->optional = true; // even if not from a glob, to accept wrong-arch buildids
    // derived_pp->well_formed = true; // XXX: true, unless the FUNCTION etc. stuff has *
    probe *derived_p = new probe(subbase, derived_pp);
    
    if (sess.verbose > 3) {
      clog << " to: ";
      derived_p->printsig(clog);
      clog << endl;
    }

    if (sess.verbose > 2)
      clog << _F("resolved debuginfod archive %s file %s -> buildid %s archive %s file %s",
                 has_archive ? archive.to_string().c_str() : "?",
                 process_path.to_string().c_str(),
                 buildid.to_string().c_str(),
                 m_archive.to_string().c_str(),
                 m_file.to_string().c_str())
           << endl;
    
    vector<derived_probe *> results;
    derive_probes(sess, derived_p, results, false, true);
    finished_results.insert(finished_results.end(), results.begin(), results.end());
  }
}

void
debuginfod_builder::build_with_suffix(systemtap_session & sess, probe * base,
    probe_point * location,
    literal_map_t const &,
    std::vector<derived_probe *> & finished_results,
    std::vector<probe_point::component *> const & suffix){

    /* Extract the parameters for the head of the probe
     * The probes are of the form debuginfod[.archive(**)].process("foo/bar").**. 
     * So the length should always be TWO (2) or THREE (3), 
     * when a archive parameter is provided.
     */
    unsigned num_param = location->components.size() - suffix.size();
    assert(num_param == 2 || num_param == 3);

    literal_map_t param_map;
    for (unsigned i=0; i<num_param; i++)
      param_map[location->components[i]->functor] = location->components[i]->arg;

    build(sess, base, location, param_map, finished_results);
    return;
}


void
register_tapset_debuginfod(systemtap_session& s)
{
    match_node* root = s.pattern_root;
    derived_probe_builder *builder = new debuginfod_builder();

    // All suffixes will get caught and processed by build_with_suffix
    
    //debuginfod.process()
    root->bind(TOK_DEBUGINFOD)->bind_str(TOK_PROCESS)->bind(builder);

    //debuginfod.archive().process()
    root->bind(TOK_DEBUGINFOD)->bind_str(TOK_ARCHIVE)->bind_str(TOK_PROCESS)->bind(builder);

}

#else /* no DEBUGINFOD and/or no JSON */

void
register_tapset_debuginfod(systemtap_session& s)
{
  (void) s;
}

#endif

/* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */