buildrun.cxx

   1 // build/run probes
   2 // Copyright (C) 2005-2016 Red Hat Inc.
   3 //
   4 // This file is part of systemtap, and is free software.  You can
   5 // redistribute it and/or modify it under the terms of the GNU General
   6 // Public License (GPL); either version 2, or (at your option) any
   7 // later version.
   8
   9 #include "config.h"
  10 #include "buildrun.h"
  11 #include "session.h"
  12 #include "util.h"
  13 #include "hash.h"
  14 #include "translate.h"
  15
  16 #include <cstdlib>
  17 #include <fstream>
  18 #include <sstream>
  19
  20 extern "C" {
  21 #include <signal.h>
  22 #include <sys/wait.h>
  23 #include <pwd.h>
  24 #include <grp.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <string.h>
  29 #include <errno.h>
  30 #include <sys/resource.h>
  31 }
  32
  33 // A bit of obfuscation for Gentoo's sake.
  34 // We *need* -Werror for stapconf to work correctly.
  35 // https://bugs.gentoo.org/show_bug.cgi?id=522908
  36 #define WERROR ("-W" "error")
  37
  38 using namespace std;
  39
  40 /* Adjust and run make_cmd to build a kernel module. */
  41 static int
  42 run_make_cmd(systemtap_session& s, vector<string>& make_cmd,
  43              bool null_out=false, bool null_err=false)
  44 {
  45   assert_no_interrupts();
  46
  47   // PR14168: we used to unsetenv values here; instead do it via
  48   // env(1) in make_any_make_cmd().
  49
  50   // Disable ccache to avoid saving files that will never be reused.
  51   // (ccache is useless to us, because our compiler commands always
  52   // include the randomized tmpdir path.)
  53   // It's not critical if this fails, so the return is ignored.
  54   (void) setenv("CCACHE_DISABLE", "1", 0);
  55
  56   if (s.verbose > 2)
  57     make_cmd.push_back("V=1");
  58   else if (s.verbose > 1)
  59     make_cmd.push_back("--no-print-directory");
  60   else
  61     {
  62       make_cmd.push_back("-s");
  63       make_cmd.push_back("--no-print-directory");
  64     }
  65
  66   // Exploit SMP parallelism, if available.
  67   long smp = sysconf(_SC_NPROCESSORS_ONLN);
  68   if (smp <= 0) smp = 1;
  69   // PR16276: but only if we're not running severely nproc-rlimited
  70   struct rlimit rlim;
  71   int rlimit_rc = getrlimit(RLIMIT_NPROC, &rlim);
  72   const unsigned int severely_limited = smp*30; // WAG at number of gcc+make etc. nested processes
  73   bool nproc_limited = (rlimit_rc == 0 && (rlim.rlim_max <= severely_limited ||
  74                                            rlim.rlim_cur <= severely_limited));
  75   if (smp >= 1 && !nproc_limited)
  76     make_cmd.push_back("-j" + lex_cast(smp+1));
  77
  78   if (strverscmp (s.kernel_base_release.c_str(), "2.6.29") < 0)
  79     {
  80       // Older kernels, before linux commit #fd54f502841c1, include
  81       // gratuitous "echo"s in their Makefile.  We need to suppress
  82       // that with this bluntness.
  83       null_out = true;
  84     }
  85
  86   int rc = stap_system (s.verbose, "kbuild", make_cmd, null_out, null_err);
  87   if (rc != 0)
  88     s.set_try_server ();
  89   return rc;
  90 }
  91
  92 static vector<string>
  93 make_any_make_cmd(systemtap_session& s, const string& dir, const string& target)
  94 {
  95   string newpath("PATH=/usr/bin:/bin");
  96   const char *oldpath = getenv("PATH");
  97   if (oldpath != NULL)
  98     {
  99       newpath += ':';
 100       newpath += oldpath;
 101     }
 102
 103   vector<string> make_cmd
 104     {
 105       // PR14168: sanitize environment variables for kbuild invocation
 106       "env", "-uARCH", "-uKBUILD_EXTMOD", "-uCROSS_COMPILE", "-uKBUILD_IMAGE",
 107       "-uKCONFIG_CONFIG", "-uINSTALL_PATH", newpath,
 108
 109       "make", "-C", s.kernel_build_tree,
 110       "M=" + dir, // need make-quoting?
 111       target,
 112
 113       // PR13847: suppress debuginfo creation by default
 114       "CONFIG_DEBUG_INFO=",
 115
 116       // RHBZ1321628: suppress stack validation; expected to be temporary
 117       "CONFIG_STACK_VALIDATION=",
 118     };
 119
 120   // Add architecture, except for old powerpc (RHBZ669082)
 121   if (s.architecture != "powerpc" ||
 122       (strverscmp (s.kernel_base_release.c_str(), "2.6.15") >= 0))
 123     make_cmd.push_back("ARCH=" + s.architecture); // need make-quoting?
 124
 125   // Add any custom kbuild flags
 126   make_cmd.insert(make_cmd.end(), s.kbuildflags.begin(), s.kbuildflags.end());
 127
 128   return make_cmd;
 129 }
 130
 131 static vector<string>
 132 make_make_cmd(systemtap_session& s, const string& dir)
 133 {
 134   return make_any_make_cmd(s, dir, "modules");
 135 }
 136
 137 static vector<string>
 138 make_make_objs_cmd(systemtap_session& s, const string& dir)
 139 {
 140   // Kbuild uses these rules to build external modules:
 141   //
 142   //   module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
 143   //   modules: $(module-dirs)
 144   //       @$(kecho) '  Building modules, stage 2.';
 145   //       $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 146   //
 147   // So if we're only interested in the stage 1 objects, we can
 148   // cheat and make only the $(module-dirs) part.
 149   return make_any_make_cmd(s, dir, "_module_" + dir);
 150 }
 151
 152 static void
 153 output_autoconf(systemtap_session& s, ofstream& o, const char *autoconf_c,
 154                 const char *deftrue, const char *deffalse)
 155 {
 156   o << "\t";
 157   if (s.verbose < 4)
 158     o << "@";
 159   o << "if $(CHECK_BUILD) $(SYSTEMTAP_RUNTIME)/linux/" << autoconf_c;
 160   if (s.verbose < 5)
 161     o << " > /dev/null 2>&1";
 162   o << "; then ";
 163   if (deftrue)
 164     o << "echo \"#define " << deftrue << " 1\"";
 165   if (deffalse)
 166     o << "; else echo \"#define " << deffalse << " 1\"";
 167   o << "; fi >> $@" << endl;
 168 }
 169
 170
 171 void output_exportconf(systemtap_session& s, ofstream& o, const char *symbol,
 172                      const char *deftrue)
 173 {
 174   o << "\t";
 175   if (s.verbose < 4)
 176     o << "@";
 177   if (s.kernel_exports.find(symbol) != s.kernel_exports.end())
 178     o << "echo \"#define " << deftrue << " 1\"";
 179   o << ">> $@" << endl;
 180 }
 181
 182
 183 void output_dual_exportconf(systemtap_session& s, ofstream& o,
 184                             const char *symbol1, const char *symbol2,
 185                             const char *deftrue)
 186 {
 187   o << "\t";
 188   if (s.verbose < 4)
 189     o << "@";
 190   if (s.kernel_exports.find(symbol1) != s.kernel_exports.end()
 191       && s.kernel_exports.find(symbol2) != s.kernel_exports.end())
 192     o << "echo \"#define " << deftrue << " 1\"";
 193   o << ">> $@" << endl;
 194 }
 195
 196
 197 void output_either_exportconf(systemtap_session& s, ofstream& o,
 198                               const char *symbol1, const char *symbol2,
 199                               const char *deftrue)
 200 {
 201   o << "\t";
 202   if (s.verbose < 4)
 203     o << "@";
 204   if (s.kernel_exports.find(symbol1) != s.kernel_exports.end()
 205       || s.kernel_exports.find(symbol2) != s.kernel_exports.end())
 206     o << "echo \"#define " << deftrue << " 1\"";
 207   o << ">> $@" << endl;
 208 }
 209
 210
 211 static int
 212 compile_dyninst (systemtap_session& s)
 213 {
 214   const string module = s.tmpdir + "/" + s.module_filename();
 215
 216   vector<string> cmd
 217     {
 218       "gcc", "--std=gnu99", s.translated_source, "-o", module,
 219       "-fvisibility=hidden", "-O2", "-I" + s.runtime_path, "-D__DYNINST__",
 220       "-Wall", WERROR, "-Wno-unused", "-Wno-strict-aliasing",
 221       "-pthread", "-lrt", "-fPIC", "-shared",
 222     };
 223
 224   // BZ855981/948279.  Since dyninst/runtime.h includes __sync_* calls,
 225   // the compiler may generate different code for it depending on -march.
 226   // For example, if the default is i386, we may get references to auxiliary
 227   // functions like __sync_add_and_fetch_4, which appear to be defined
 228   // nowhere.  We hack around this problem thusly:
 229   if (s.architecture == "i386")
 230     cmd.push_back("-march=i586");
 231
 232   for (size_t i = 0; i < s.c_macros.size(); ++i)
 233     cmd.push_back("-D" + s.c_macros[i]);
 234
 235   if (s.verbose > 3)
 236     cmd.insert(cmd.end(), { "-ftime-report", "-Q" });
 237
 238   // Add any custom kbuild flags
 239   cmd.insert(cmd.end(), s.kbuildflags.begin(), s.kbuildflags.end());
 240
 241   int rc = stap_system (s.verbose, cmd);
 242   if (rc)
 243     s.set_try_server ();
 244   return rc;
 245 }
 246
 247
 248 int
 249 compile_pass (systemtap_session& s)
 250 {
 251   if (s.runtime_usermode_p())
 252     return compile_dyninst (s);
 253
 254   int rc = uprobes_pass (s);
 255   if (rc)
 256     {
 257       s.set_try_server ();
 258       return rc;
 259     }
 260
 261   // fill in a quick Makefile
 262   string makefile_nm = s.tmpdir + "/Makefile";
 263   ofstream o (makefile_nm.c_str());
 264
 265   // Create makefile
 266
 267   // Clever hacks copied from vmware modules
 268   string superverbose;
 269   if (s.verbose > 3)
 270     superverbose = "set -x;";
 271
 272   string redirecterrors = "> /dev/null 2>&1";
 273   if (s.verbose > 6)
 274     redirecterrors = "";
 275
 276   // Support O= (or KBUILD_OUTPUT) option
 277   o << "_KBUILD_CFLAGS := $(call flags,KBUILD_CFLAGS)" << endl;
 278
 279   o << "stap_check_gcc = $(shell " << superverbose
 280     << " if $(CC) $(1) -S -o /dev/null -xc /dev/null > /dev/null 2>&1; then "
 281     << "echo \"$(1)\"; else echo \"$(2)\"; fi)" << endl;
 282   o << "CHECK_BUILD := $(CC) $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CPPFLAGS) "
 283     << "$(LINUXINCLUDE) $(_KBUILD_CFLAGS) $(CFLAGS_KERNEL) $(EXTRA_CFLAGS) "
 284     << "$(CFLAGS) -DKBUILD_BASENAME=\\\"" << s.module_name << "\\\" "
 285     << WERROR << " -S -o /dev/null -xc " << endl;
 286   o << "stap_check_build = $(shell " << superverbose << " if $(CHECK_BUILD) $(1) "
 287     << redirecterrors << " ; then echo \"$(2)\"; else echo \"$(3)\"; fi)" << endl;
 288
 289   o << "SYSTEMTAP_RUNTIME = \"" << s.runtime_path << "\"" << endl;
 290
 291   // "autoconf" options go here
 292
 293   // RHBZ 543529: early rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 294   o << "CONFIG_MODULE_SIG := n" << endl;
 295
 296   string module_cflags = "EXTRA_CFLAGS";
 297   o << module_cflags << " :=" << endl;
 298
 299   // XXX: This gruesome hack is needed on some kernels built with separate O=directory,
 300   // where files like 2.6.27 x86's asm/mach-*/mach_mpspec.h are not found on the cpp path.
 301   // This could be a bug in arch/x86/Makefile that names
 302   //      mflags-y += -Iinclude/asm-x86/mach-default
 303   // but that path does not exist in an O= build tree.
 304   o << module_cflags << " += -Iinclude2/asm/mach-default" << endl;
 305   o << module_cflags << " += -I" + s.kernel_build_tree << endl;
 306   if (s.kernel_source_tree != "")
 307     o << module_cflags << " += -I" + s.kernel_source_tree << endl;
 308   for (unsigned i = 0; i < s.kernel_extra_cflags.size(); i++)
 309     o << module_cflags << " += " + s.kernel_extra_cflags[i] << endl;
 310
 311   // NB: don't try
 312   // o << module_cflags << " += -Iusr/include" << endl;
 313   // since such headers are cleansed of _KERNEL_ pieces that we need
 314
 315   o << "STAPCONF_HEADER := " << s.tmpdir << "/" << s.stapconf_name << endl;
 316   o << "$(STAPCONF_HEADER):" << endl;
 317   o << "\t@> $@" << endl;
 318   output_autoconf(s, o, "autoconf-hrtimer-rel.c", "STAPCONF_HRTIMER_REL", NULL);
 319   output_exportconf(s, o, "hrtimer_get_res", "STAPCONF_HRTIMER_GET_RES");
 320   output_autoconf(s, o, "autoconf-generated-compile.c", "STAPCONF_GENERATED_COMPILE", NULL);
 321   output_autoconf(s, o, "autoconf-hrtimer-getset-expires.c", "STAPCONF_HRTIMER_GETSET_EXPIRES", NULL);
 322   output_autoconf(s, o, "autoconf-inode-private.c", "STAPCONF_INODE_PRIVATE", NULL);
 323   output_autoconf(s, o, "autoconf-constant-tsc.c", "STAPCONF_CONSTANT_TSC", NULL);
 324   output_autoconf(s, o, "autoconf-ktime-get-real.c", "STAPCONF_KTIME_GET_REAL", NULL);
 325   output_autoconf(s, o, "autoconf-x86-uniregs.c", "STAPCONF_X86_UNIREGS", NULL);
 326   output_autoconf(s, o, "autoconf-nameidata.c", "STAPCONF_NAMEIDATA_CLEANUP", NULL);
 327   output_dual_exportconf(s, o, "unregister_kprobes", "unregister_kretprobes", "STAPCONF_UNREGISTER_KPROBES");
 328   output_autoconf(s, o, "autoconf-kprobe-symbol-name.c", "STAPCONF_KPROBE_SYMBOL_NAME", NULL);
 329   output_autoconf(s, o, "autoconf-real-parent.c", "STAPCONF_REAL_PARENT", NULL);
 330   output_autoconf(s, o, "autoconf-uaccess.c", "STAPCONF_LINUX_UACCESS_H", NULL);
 331   output_autoconf(s, o, "autoconf-oneachcpu-retry.c", "STAPCONF_ONEACHCPU_RETRY", NULL);
 332   output_autoconf(s, o, "autoconf-dpath-path.c", "STAPCONF_DPATH_PATH", NULL);
 333   output_exportconf(s, o, "synchronize_kernel", "STAPCONF_SYNCHRONIZE_KERNEL");
 334   output_exportconf(s, o, "synchronize_rcu", "STAPCONF_SYNCHRONIZE_RCU");
 335   output_exportconf(s, o, "synchronize_sched", "STAPCONF_SYNCHRONIZE_SCHED");
 336   output_autoconf(s, o, "autoconf-task-uid.c", "STAPCONF_TASK_UID", NULL);
 337   output_autoconf(s, o, "autoconf-from_kuid_munged.c", "STAPCONF_FROM_KUID_MUNGED", NULL);
 338   output_exportconf(s, o, "get_mm_exe_file", "STAPCONF_GET_MM_EXE_FILE");
 339   output_dual_exportconf(s, o, "alloc_vm_area", "free_vm_area", "STAPCONF_VM_AREA");
 340   output_autoconf(s, o, "autoconf-procfs-owner.c", "STAPCONF_PROCFS_OWNER", NULL);
 341   output_autoconf(s, o, "autoconf-alloc-percpu-align.c", "STAPCONF_ALLOC_PERCPU_ALIGN", NULL);
 342   output_autoconf(s, o, "autoconf-x86-fs.c", "STAPCONF_X86_FS", NULL);
 343   output_autoconf(s, o, "autoconf-x86-xfs.c", "STAPCONF_X86_XFS", NULL);
 344   output_autoconf(s, o, "autoconf-x86-gs.c", "STAPCONF_X86_GS", NULL);
 345   output_autoconf(s, o, "autoconf-grsecurity.c", "STAPCONF_GRSECURITY", NULL);
 346   output_autoconf(s, o, "autoconf-trace-printk.c", "STAPCONF_TRACE_PRINTK", NULL);
 347   output_autoconf(s, o, "autoconf-regset.c", "STAPCONF_REGSET", NULL);
 348   output_autoconf(s, o, "autoconf-utrace-regset.c", "STAPCONF_UTRACE_REGSET", NULL);
 349   output_autoconf(s, o, "autoconf-uprobe-get-pc.c", "STAPCONF_UPROBE_GET_PC", NULL);
 350   output_autoconf(s, o, "autoconf-hlist-4args.c", "STAPCONF_HLIST_4ARGS", NULL);
 351   output_exportconf(s, o, "tsc_khz", "STAPCONF_TSC_KHZ");
 352   output_exportconf(s, o, "cpu_khz", "STAPCONF_CPU_KHZ");
 353   output_exportconf(s, o, "__module_text_address", "STAPCONF_MODULE_TEXT_ADDRESS");
 354   output_exportconf(s, o, "add_timer_on", "STAPCONF_ADD_TIMER_ON");
 355
 356   output_dual_exportconf(s, o, "probe_kernel_read", "probe_kernel_write", "STAPCONF_PROBE_KERNEL");
 357   output_autoconf(s, o, "autoconf-hw_breakpoint_context.c",
 358                   "STAPCONF_HW_BREAKPOINT_CONTEXT", NULL);
 359   output_autoconf(s, o, "autoconf-save-stack-trace.c",
 360                   "STAPCONF_KERNEL_STACKTRACE", NULL);
 361   output_autoconf(s, o, "autoconf-save-stack-trace-no-bp.c",
 362                   "STAPCONF_KERNEL_STACKTRACE_NO_BP", NULL);
 363   output_autoconf(s, o, "autoconf-asm-syscall.c",
 364                   "STAPCONF_ASM_SYSCALL_H", NULL);
 365   output_autoconf(s, o, "autoconf-ring_buffer-flags.c", "STAPCONF_RING_BUFFER_FLAGS", NULL);
 366   output_autoconf(s, o, "autoconf-ring_buffer_lost_events.c", "STAPCONF_RING_BUFFER_LOST_EVENTS", NULL);
 367   output_autoconf(s, o, "autoconf-ring_buffer_read_prepare.c", "STAPCONF_RING_BUFFER_READ_PREPARE", NULL);
 368   output_autoconf(s, o, "autoconf-kallsyms-on-each-symbol.c", "STAPCONF_KALLSYMS_ON_EACH_SYMBOL", NULL);
 369   output_autoconf(s, o, "autoconf-walk-stack.c", "STAPCONF_WALK_STACK", NULL);
 370   output_autoconf(s, o, "autoconf-stacktrace_ops-warning.c",
 371                   "STAPCONF_STACKTRACE_OPS_WARNING", NULL);
 372   output_autoconf(s, o, "autoconf-mm-context-vdso.c", "STAPCONF_MM_CONTEXT_VDSO", NULL);
 373   output_autoconf(s, o, "autoconf-mm-context-vdso-base.c", "STAPCONF_MM_CONTEXT_VDSO_BASE", NULL);
 374   output_autoconf(s, o, "autoconf-blk-types.c", "STAPCONF_BLK_TYPES", NULL);
 375   output_autoconf(s, o, "autoconf-perf-structpid.c", "STAPCONF_PERF_STRUCTPID", NULL);
 376   output_autoconf(s, o, "perf_event_counter_context.c",
 377                   "STAPCONF_PERF_COUNTER_CONTEXT", NULL);
 378   output_autoconf(s, o, "perf_probe_handler_nmi.c",
 379                   "STAPCONF_PERF_HANDLER_NMI", NULL);
 380   output_exportconf(s, o, "path_lookup", "STAPCONF_PATH_LOOKUP");
 381   output_exportconf(s, o, "kern_path_parent", "STAPCONF_KERN_PATH_PARENT");
 382   output_exportconf(s, o, "vfs_path_lookup", "STAPCONF_VFS_PATH_LOOKUP");
 383   output_exportconf(s, o, "kern_path", "STAPCONF_KERN_PATH");
 384   output_exportconf(s, o, "proc_create_data", "STAPCONF_PROC_CREATE_DATA");
 385   output_exportconf(s, o, "PDE_DATA", "STAPCONF_PDE_DATA");
 386   output_autoconf(s, o, "autoconf-module-sect-attrs.c", "STAPCONF_MODULE_SECT_ATTRS", NULL);
 387
 388   output_autoconf(s, o, "autoconf-utrace-via-tracepoints.c", "STAPCONF_UTRACE_VIA_TRACEPOINTS", NULL);
 389   output_autoconf(s, o, "autoconf-task_work-struct.c", "STAPCONF_TASK_WORK_STRUCT", NULL);
 390   output_autoconf(s, o, "autoconf-vm-area-pte.c", "STAPCONF_VM_AREA_PTE", NULL);
 391   output_autoconf(s, o, "autoconf-relay-umode_t.c", "STAPCONF_RELAY_UMODE_T", NULL);
 392   output_autoconf(s, o, "autoconf-fs_supers-hlist.c", "STAPCONF_FS_SUPERS_HLIST", NULL);
 393   output_autoconf(s, o, "autoconf-compat_sigaction.c", "STAPCONF_COMPAT_SIGACTION", NULL);
 394   output_autoconf(s, o, "autoconf-netfilter.c", "STAPCONF_NETFILTER_V313", NULL);
 395   output_autoconf(s, o, "autoconf-netfilter-313b.c", "STAPCONF_NETFILTER_V313B", NULL);
 396   output_autoconf(s, o, "autoconf-netfilter-4_1.c", "STAPCONF_NETFILTER_V41", NULL);
 397   output_autoconf(s, o, "autoconf-netfilter-4_4.c", "STAPCONF_NETFILTER_V44", NULL);
 398   output_autoconf(s, o, "autoconf-smpcall-5args.c", "STAPCONF_SMPCALL_5ARGS", NULL);
 399   output_autoconf(s, o, "autoconf-smpcall-4args.c", "STAPCONF_SMPCALL_4ARGS", NULL);
 400
 401   // used by tapset/timestamp_monotonic.stp
 402   output_exportconf(s, o, "cpu_clock", "STAPCONF_CPU_CLOCK");
 403   output_exportconf(s, o, "local_clock", "STAPCONF_LOCAL_CLOCK");
 404
 405   // used by runtime/uprobe-inode.c
 406   output_either_exportconf(s, o, "uprobe_register", "register_uprobe",
 407                            "STAPCONF_UPROBE_REGISTER_EXPORTED");
 408   output_either_exportconf(s, o, "uprobe_unregister", "unregister_uprobe",
 409                            "STAPCONF_UPROBE_UNREGISTER_EXPORTED");
 410   output_autoconf(s, o, "autoconf-old-inode-uprobes.c", "STAPCONF_OLD_INODE_UPROBES", NULL);
 411   output_autoconf(s, o, "autoconf-inode-uretprobes.c", "STAPCONF_INODE_URETPROBES", NULL);
 412
 413   // used by tapsets.cxx inode uprobe generated code
 414   output_exportconf(s, o, "uprobe_get_swbp_addr", "STAPCONF_UPROBE_GET_SWBP_ADDR_EXPORTED");
 415
 416   // used by runtime/loc2c-runtime.h
 417   output_exportconf(s, o, "task_user_regset_view", "STAPCONF_TASK_USER_REGSET_VIEW_EXPORTED");
 418
 419   // used by runtime/stp_utrace.c
 420   output_exportconf(s, o, "task_work_add", "STAPCONF_TASK_WORK_ADD_EXPORTED");
 421   output_exportconf(s, o, "wake_up_state", "STAPCONF_WAKE_UP_STATE_EXPORTED");
 422   output_exportconf(s, o, "try_to_wake_up", "STAPCONF_TRY_TO_WAKE_UP_EXPORTED");
 423   output_exportconf(s, o, "signal_wake_up_state", "STAPCONF_SIGNAL_WAKE_UP_STATE_EXPORTED");
 424   output_exportconf(s, o, "signal_wake_up", "STAPCONF_SIGNAL_WAKE_UP_EXPORTED");
 425   output_exportconf(s, o, "__lock_task_sighand", "STAPCONF___LOCK_TASK_SIGHAND_EXPORTED");
 426
 427   output_autoconf(s, o, "autoconf-pagefault_disable.c", "STAPCONF_PAGEFAULT_DISABLE", NULL);
 428   output_exportconf(s, o, "kallsyms_lookup_name", "STAPCONF_KALLSYMS");
 429   output_autoconf(s, o, "autoconf-uidgid.c", "STAPCONF_LINUX_UIDGID_H", NULL);
 430   output_exportconf(s, o, "sigset_from_compat", "STAPCONF_SIGSET_FROM_COMPAT_EXPORTED");
 431   output_exportconf(s, o, "vzalloc", "STAPCONF_VZALLOC");
 432   output_exportconf(s, o, "vzalloc_node", "STAPCONF_VZALLOC_NODE");
 433   output_exportconf(s, o, "vmalloc_node", "STAPCONF_VMALLOC_NODE");
 434
 435   // RHBZ1233912 - s390 temporary workaround for non-atomic udelay()
 436   output_exportconf(s, o, "udelay_simple", "STAPCONF_UDELAY_SIMPLE");
 437
 438   output_autoconf(s, o, "autoconf-tracepoint-strings.c", "STAPCONF_TRACEPOINT_STRINGS", NULL);
 439   output_autoconf(s, o, "autoconf-timerfd.c", "STAPCONF_TIMERFD_H", NULL);
 440
 441   output_autoconf(s, o, "autoconf-module_layout.c",
 442                   "STAPCONF_MODULE_LAYOUT", NULL);
 443   output_autoconf(s, o, "autoconf-mod_kallsyms.c",
 444                   "STAPCONF_MOD_KALLSYMS", NULL);
 445   output_exportconf(s, o, "get_user_pages_remote", "STAPCONF_GET_USER_PAGES_REMOTE");
 446
 447   o << module_cflags << " += -include $(STAPCONF_HEADER)" << endl;
 448
 449   for (unsigned i=0; i<s.c_macros.size(); i++)
 450     o << "EXTRA_CFLAGS += -D " << lex_cast_qstring(s.c_macros[i]) << endl; // XXX right quoting?
 451
 452   if (s.verbose > 3)
 453     o << "EXTRA_CFLAGS += -ftime-report -Q" << endl;
 454
 455   // XXX: unfortunately, -save-temps can't work since linux kbuild cwd
 456   // is not writable.
 457   //
 458   // if (s.keep_tmpdir)
 459   // o << "CFLAGS += -fverbose-asm -save-temps" << endl;
 460
 461   // Kernels can be compiled with CONFIG_CC_OPTIMIZE_FOR_SIZE to select
 462   // -Os, otherwise -O2 is the default.
 463   o << "EXTRA_CFLAGS += -freorder-blocks" << endl; // improve on -Os
 464
 465   // Generate eh_frame for self-backtracing
 466   o << "EXTRA_CFLAGS += -fasynchronous-unwind-tables" << endl;
 467
 468   // We used to allow the user to override default optimization when so
 469   // requested by adding a -O[0123s] so they could determine the
 470   // time/space/speed tradeoffs themselves, but we cannot guantantee that
 471   // the (un)optimized code actually compiles and/or generates functional
 472   // code, so we had to remove it.
 473   // o << "EXTRA_CFLAGS += " << s.gcc_flags << endl; // Add -O[0123s]
 474
 475   // o << "CFLAGS += -fno-unit-at-a-time" << endl;
 476
 477   // 256^W512 bytes should be enough for anybody
 478   // XXX this doesn't validate varargs, per gcc bug #41633
 479   o << "EXTRA_CFLAGS += $(call cc-option,-Wframe-larger-than=512)" << endl;
 480
 481   // gcc 5.0.0-0.13.fc23 ipa-icf seems to consume gigacpu on stap-generated code
 482   o << "EXTRA_CFLAGS += $(call cc-option,-fno-ipa-icf)" << endl;
 483
 484   // Assumes linux 2.6 kbuild
 485   o << "EXTRA_CFLAGS += -Wno-unused " << WERROR << endl;
 486   #if CHECK_POINTER_ARITH_PR5947
 487   o << "EXTRA_CFLAGS += -Wpointer-arith" << endl;
 488   #endif
 489   o << "EXTRA_CFLAGS += -I\"" << s.runtime_path << "\"" << endl;
 490   // XXX: this may help ppc toc overflow
 491   // o << "CFLAGS := $(subst -Os,-O2,$(CFLAGS)) -fminimal-toc" << endl;
 492   o << "obj-m := " << s.module_name << ".o" << endl;
 493
 494   // print out all the auxiliary source (->object) file names
 495   o << s.module_name << "-y := ";
 496   for (unsigned i=0; i<s.auxiliary_outputs.size(); i++)
 497     {
 498       if (s.auxiliary_outputs[i]->trailer_p) continue;
 499       string srcname = s.auxiliary_outputs[i]->filename;
 500       assert (srcname != "" && srcname.rfind('/') != string::npos);
 501       string objname = srcname.substr(srcname.rfind('/')+1); // basename
 502       assert (objname != "" && objname[objname.size()-1] == 'c');
 503       objname[objname.size()-1] = 'o'; // now objname
 504       o << " " + objname;
 505     }
 506   // and once again, for the translated_source file.  It can't simply
 507   // be named MODULENAME.c, since kbuild doesn't allow a foo.ko file
 508   // consisting of multiple .o's to have foo.o/foo.c as a source.
 509   // (It uses ld -r -o foo.o EACH.o EACH.o).
 510   {
 511     string srcname = s.translated_source;
 512     assert (srcname != "" && srcname.rfind('/') != string::npos);
 513     string objname = srcname.substr(srcname.rfind('/')+1); // basename
 514     assert (objname != "" && objname[objname.size()-1] == 'c');
 515     objname[objname.size()-1] = 'o'; // now objname
 516     o << " " + objname;
 517   }
 518   // and once again, for the trailer type auxiliary outputs.
 519   for (unsigned i=0; i<s.auxiliary_outputs.size(); i++)
 520     {
 521       if (! s.auxiliary_outputs[i]->trailer_p) continue;
 522       string srcname = s.auxiliary_outputs[i]->filename;
 523       assert (srcname != "" && srcname.rfind('/') != string::npos);
 524       string objname = srcname.substr(srcname.rfind('/')+1); // basename
 525       assert (objname != "" && objname[objname.size()-1] == 'c');
 526       objname[objname.size()-1] = 'o'; // now objname
 527       o << " " + objname;
 528     }
 529   o << endl;
 530
 531   // add all stapconf dependencies
 532   o << s.translated_source << ": $(STAPCONF_HEADER)" << endl;
 533   for (unsigned i=0; i<s.auxiliary_outputs.size(); i++)
 534     o << s.auxiliary_outputs[i]->filename << ": $(STAPCONF_HEADER)" << endl;
 535
 536
 537   o.close ();
 538
 539   // Generate module directory pathname and make sure it exists.
 540   string module_dir = s.kernel_build_tree;
 541   string module_dir_makefile = module_dir + "/Makefile";
 542   struct stat st;
 543   rc = stat(module_dir_makefile.c_str(), &st);
 544   if (rc != 0)
 545     {
 546         clog << _F("Checking \" %s \" failed with error: %s\nEnsure kernel development headers & makefiles are installed.",
 547                    module_dir_makefile.c_str(), strerror(errno)) << endl;
 548         s.set_try_server ();
 549         return rc;
 550     }
 551
 552   // Run make
 553   vector<string> make_cmd = make_make_cmd(s, s.tmpdir);
 554   rc = run_make_cmd(s, make_cmd);
 555   if (rc)
 556     s.set_try_server ();
 557   return rc;
 558 }
 559
 560 /*
 561  * If uprobes was built as part of the kernel build (either built-in
 562  * or as a module), the uprobes exports should show up.  This is to be
 563  * as distinct from the stap-built uprobes.ko from the runtime.
 564  */
 565 static bool
 566 kernel_built_uprobes (systemtap_session& s)
 567 {
 568   if (s.runtime_usermode_p())
 569     return true; // sort of, via dyninst
 570
 571   // see also tapsets.cxx:kernel_supports_inode_uprobes()
 572   return ((s.kernel_config["CONFIG_ARCH_SUPPORTS_UPROBES"] == "y" && s.kernel_config["CONFIG_UPROBES"] == "y") ||
 573           (s.kernel_exports.find("unregister_uprobe") != s.kernel_exports.end()));
 574 }
 575
 576 static int
 577 make_uprobes (systemtap_session& s)
 578 {
 579   if (s.verbose > 1)
 580     clog << _("Pass 4, preamble: (re)building SystemTap's version of uprobes.")
 581          << endl;
 582
 583   // create a subdirectory for the uprobes module
 584   string dir(s.tmpdir + "/uprobes");
 585   if (create_dir(dir.c_str()) != 0)
 586     {
 587       s.print_warning("failed to create directory for build uprobes.");
 588       s.set_try_server ();
 589       return 1;
 590     }
 591
 592   // create a simple Makefile
 593   string makefile(dir + "/Makefile");
 594   ofstream omf(makefile.c_str());
 595   omf << "obj-m := uprobes.o" << endl;
 596   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 597   omf << "CONFIG_MODULE_SIG := n" << endl;
 598   omf.close();
 599
 600   // create a simple #include-chained source file
 601   string runtimesourcefile(s.runtime_path + "/linux/uprobes/uprobes.c");
 602   string sourcefile(dir + "/uprobes.c");
 603   ofstream osrc(sourcefile.c_str());
 604   osrc << "#include \"" << runtimesourcefile << "\"" << endl;
 605
 606   // pass --modinfo k=v to uprobes build too
 607   for (unsigned i = 0; i < s.modinfos.size(); i++)
 608     {
 609       const string& mi = s.modinfos[i];
 610       size_t loc = mi.find('=');
 611       string tag = mi.substr (0, loc);
 612       string value = mi.substr (loc+1);
 613       osrc << "MODULE_INFO(" << tag << "," << lex_cast_qstring(value) << ");" << endl;
 614     }
 615
 616   osrc.close();
 617
 618   // make the module
 619   vector<string> make_cmd = make_make_cmd(s, dir);
 620   int rc = run_make_cmd(s, make_cmd);
 621   if (!rc && !copy_file(dir + "/Module.symvers",
 622                         s.tmpdir + "/Module.symvers"))
 623     rc = -1;
 624
 625   if (s.verbose > 1)
 626     clog << _("uprobes rebuild exit code: ") << rc << endl;
 627   if (rc)
 628     s.set_try_server ();
 629   else
 630     s.uprobes_path = dir + "/uprobes.ko";
 631   return rc;
 632 }
 633
 634 static bool
 635 get_cached_uprobes(systemtap_session& s)
 636 {
 637   s.uprobes_hash = s.use_cache ? find_uprobes_hash(s) : "";
 638   if (!s.uprobes_hash.empty())
 639     {
 640       // NB: We always put uprobes.ko in its own directory, especially so
 641       // stap-serverd can more easily locate it.
 642       string dir(s.tmpdir + "/uprobes");
 643       if (create_dir(dir.c_str()) != 0)
 644         return false;
 645
 646       string cacheko = s.uprobes_hash + ".ko";
 647       string tmpko = dir + "/uprobes.ko";
 648
 649       // The symvers file still needs to go in the script module's directory.
 650       string cachesyms = s.uprobes_hash + ".symvers";
 651       string tmpsyms = s.tmpdir + "/Module.symvers";
 652
 653       if (get_file_size(cacheko) > 0 && copy_file(cacheko, tmpko) &&
 654           get_file_size(cachesyms) > 0 && copy_file(cachesyms, tmpsyms))
 655         {
 656           s.uprobes_path = tmpko;
 657           return true;
 658         }
 659     }
 660   return false;
 661 }
 662
 663 static void
 664 set_cached_uprobes(systemtap_session& s)
 665 {
 666   if (s.use_cache && !s.uprobes_hash.empty())
 667     {
 668       string cacheko = s.uprobes_hash + ".ko";
 669       string tmpko = s.tmpdir + "/uprobes/uprobes.ko";
 670       copy_file(tmpko, cacheko);
 671
 672       string cachesyms = s.uprobes_hash + ".symvers";
 673       string tmpsyms = s.tmpdir + "/uprobes/Module.symvers";
 674       copy_file(tmpsyms, cachesyms);
 675     }
 676 }
 677
 678 int
 679 uprobes_pass (systemtap_session& s)
 680 {
 681   if (!s.need_uprobes || kernel_built_uprobes(s))
 682     return 0;
 683
 684   if (s.kernel_config["CONFIG_UTRACE"] != string("y"))
 685     {
 686       clog << _("user-space process-tracking facilities not available [man error::process-tracking]") << endl;
 687       s.set_try_server ();
 688       return 1;
 689     }
 690
 691   /*
 692    * We need to use the version of uprobes that comes with SystemTap.  Try to
 693    * get it from the cache first.  If not found, build it and try to save it to
 694    * the cache for future reuse.
 695    */
 696   int rc = 0;
 697   if (!get_cached_uprobes(s))
 698     {
 699       rc = make_uprobes(s);
 700       if (!rc)
 701         set_cached_uprobes(s);
 702     }
 703   if (rc)
 704     s.set_try_server ();
 705   return rc;
 706 }
 707
 708 static
 709 vector<string>
 710 make_dyninst_run_command (systemtap_session& s, const string& remotedir,
 711                           const string&)
 712 {
 713   vector<string> cmd { getenv("SYSTEMTAP_STAPDYN") ?: BINDIR "/stapdyn" };
 714
 715   // use slightly less verbosity
 716   if (s.verbose > 0)
 717     cmd.insert(cmd.end(), s.verbose - 1, "-v");
 718
 719   if (s.suppress_warnings)
 720     cmd.push_back("-w");
 721
 722   if (!s.cmd.empty())
 723     cmd.insert(cmd.end(), { "-c", s.cmd });
 724
 725   if (s.target_pid)
 726     cmd.insert(cmd.end(), { "-x", lex_cast(s.target_pid) });
 727
 728   if (!s.output_file.empty())
 729     cmd.insert(cmd.end(), { "-o", s.output_file });
 730
 731   if (s.color_mode != s.color_auto)
 732     {
 733       auto mode = s.color_mode == s.color_always ? "always" : "never";
 734       cmd.insert(cmd.end(), { "-C", mode });
 735     }
 736
 737   cmd.push_back((remotedir.empty() ? s.tmpdir : remotedir)
 738                 + "/" + s.module_filename());
 739
 740   // add module arguments
 741   cmd.insert(cmd.end(), s.globalopts.begin(), s.globalopts.end());
 742
 743   return cmd;
 744 }
 745
 746 vector<string>
 747 make_run_command (systemtap_session& s, const string& remotedir,
 748                   const string& version)
 749 {
 750   if (s.runtime_usermode_p())
 751     return make_dyninst_run_command(s, remotedir, version);
 752
 753   // for now, just spawn staprun
 754   vector<string> cmd { getenv("SYSTEMTAP_STAPRUN") ?: BINDIR "/staprun" };
 755
 756   // use slightly less verbosity
 757   if (s.verbose > 0)
 758     cmd.insert(cmd.end(), s.verbose - 1, "-v");
 759
 760   if (s.suppress_warnings)
 761     cmd.push_back("-w");
 762
 763   if (!s.output_file.empty())
 764     cmd.insert(cmd.end(), { "-o", s.output_file });
 765
 766   if (!s.cmd.empty())
 767     cmd.insert(cmd.end(), { "-c", s.cmd });
 768
 769   if (s.target_pid)
 770     cmd.insert(cmd.end(), { "-t", lex_cast(s.target_pid) });
 771
 772   if (s.target_namespaces_pid)
 773     cmd.insert(cmd.end(), { "-N", lex_cast(s.target_namespaces_pid) });
 774
 775   if (s.buffer_size)
 776     cmd.insert(cmd.end(), { "-b", lex_cast(s.buffer_size) });
 777
 778   if (s.need_uprobes && !kernel_built_uprobes(s))
 779     {
 780       string opt_u = "-u";
 781       if (!s.uprobes_path.empty() &&
 782           strverscmp("1.4", version.c_str()) <= 0)
 783         {
 784           if (remotedir.empty())
 785             opt_u.append(s.uprobes_path);
 786           else
 787             opt_u.append(remotedir + "/" + basename(s.uprobes_path.c_str()));
 788         }
 789       cmd.push_back(opt_u);
 790     }
 791
 792   if (s.load_only)
 793     cmd.push_back(s.output_file.empty() ? "-L" : "-D");
 794
 795   // Note that if this system requires signed modules, we can't rename
 796   // it after it has been signed.
 797   if (!s.modname_given && (strverscmp("1.6", version.c_str()) <= 0)
 798       && s.mok_fingerprints.empty())
 799     cmd.push_back("-R");
 800
 801   if (!s.size_option.empty())
 802     cmd.insert(cmd.end(), { "-S", s.size_option });
 803
 804   if (s.color_mode != s.color_auto)
 805     {
 806       auto mode = s.color_mode == s.color_always ? "always" : "never";
 807       cmd.insert(cmd.end(), { "-C", mode });
 808     }
 809
 810   if (s.monitor)
 811     cmd.insert(cmd.end(), { "-M", lex_cast(s.monitor_interval) });
 812
 813   cmd.push_back((remotedir.empty() ? s.tmpdir : remotedir)
 814                         + "/" + s.module_filename());
 815
 816   // add module arguments
 817   cmd.insert(cmd.end(), s.globalopts.begin(), s.globalopts.end());
 818
 819   return cmd;
 820 }
 821
 822
 823 // Build tiny kernel modules to query tracepoints.
 824 // Given a (header-file -> test-contents) map, compile them ASAP, and return
 825 // a (header-file -> obj-filename) map.
 826
 827 map<string,string>
 828 make_tracequeries(systemtap_session& s, const map<string,string>& contents)
 829 {
 830   static unsigned tick = 0;
 831   string basename("tracequery_kmod_" + lex_cast(++tick));
 832   map<string,string> objs;
 833
 834   // create a subdirectory for the module
 835   string dir(s.tmpdir + "/" + basename);
 836   if (create_dir(dir.c_str()) != 0)
 837     {
 838       s.print_warning("failed to create directory for querying tracepoints.");
 839       s.set_try_server ();
 840       return objs;
 841     }
 842
 843   // create a simple Makefile
 844   string makefile(dir + "/Makefile");
 845   ofstream omf(makefile.c_str());
 846   // force debuginfo generation, and relax implicit functions
 847   omf << "EXTRA_CFLAGS := -g -Wno-implicit-function-declaration " << WERROR << endl;
 848   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 849   omf << "CONFIG_MODULE_SIG := n" << endl;
 850
 851   // PR18389: disable GCC's Identical Code Folding, since the stubs may look identical
 852   omf << "EXTRA_CFLAGS += $(call cc-option,-fno-ipa-icf)" << endl;
 853
 854   omf << "EXTRA_CFLAGS += -I" + s.kernel_build_tree << endl;
 855   if (s.kernel_source_tree != "")
 856     omf << "EXTRA_CFLAGS += -I" + s.kernel_source_tree << endl;
 857   for (unsigned i = 0; i < s.kernel_extra_cflags.size(); i++)
 858     omf << "EXTRA_CFLAGS += " + s.kernel_extra_cflags[i] << endl;
 859
 860   omf << "obj-m := " << endl;
 861   // write out each header-specific source file into a separate file
 862   for (map<string,string>::const_iterator it = contents.begin(); it != contents.end(); it++)
 863     {
 864       string sbasename = basename + "_" + lex_cast(++tick); // suffixed
 865
 866       // write out source code
 867       string srcname = dir + "/" + sbasename + ".c";
 868       string src = it->second;
 869       ofstream osrc(srcname.c_str());
 870       osrc << src;
 871       osrc.close();
 872
 873       if (s.verbose > 2)
 874         clog << _F("Processing tracepoint header %s with query %s",
 875                    it->first.c_str(), srcname.c_str())
 876              << endl;
 877
 878       // arrange to build it
 879       omf << "obj-m += " + sbasename + ".o" << endl; // NB: without <dir> prefix
 880       objs[it->first] = dir + "/" + sbasename + ".o";
 881     }
 882   omf.close();
 883
 884   // make the module
 885   vector<string> make_cmd = make_make_objs_cmd(s, dir);
 886   make_cmd.push_back ("-i"); // ignore errors, give rc 0 even in case of tracepoint header nits
 887   bool quiet = (s.verbose < 4);
 888   int rc = run_make_cmd(s, make_cmd, quiet, quiet);
 889   if (rc)
 890     s.set_try_server ();
 891
 892   // Sometimes we fail a tracequery due to PR9993 / PR11649 type
 893   // kernel trace header problems.  In this case, due to PR12729, we
 894   // used to get a lovely "Warning: make exited with status: 2" but no
 895   // other useful diagnostic.  -vvvv would let a user see what's up,
 896   // but the user can't fix the problem even with that.
 897
 898   return objs;
 899 }
 900
 901
 902 // Build a tiny kernel module to query type information
 903 static int
 904 make_typequery_kmod(systemtap_session& s, const vector<string>& headers, string& name)
 905 {
 906   static unsigned tick = 0;
 907   string basename("typequery_kmod_" + lex_cast(++tick));
 908
 909   // create a subdirectory for the module
 910   string dir(s.tmpdir + "/" + basename);
 911   if (create_dir(dir.c_str()) != 0)
 912     {
 913       s.print_warning("failed to create directory for querying types.");
 914       s.set_try_server ();
 915       return 1;
 916     }
 917
 918   name = dir + "/" + basename + ".ko";
 919
 920   // create a simple Makefile
 921   string makefile(dir + "/Makefile");
 922   ofstream omf(makefile.c_str());
 923   omf << "EXTRA_CFLAGS := -g -fno-eliminate-unused-debug-types" << endl;
 924
 925   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 926   omf << "CONFIG_MODULE_SIG := n" << endl;
 927
 928   // NB: We use -include instead of #include because that gives us more power.
 929   // Using #include searches relative to the source's path, which in this case
 930   // is /tmp/..., so that's not helpful.  Using -include will search relative
 931   // to the cwd, which will be the kernel build root.  This means if you have a
 932   // full kernel build tree, it's possible to get at types that aren't in the
 933   // normal include path, e.g.:
 934   //    @cast(foo, "bsd_acct_struct", "kernel<kernel/acct.c>")->...
 935   omf << "CFLAGS_" << basename << ".o :=";
 936   for (size_t i = 0; i < headers.size(); ++i)
 937     omf << " -include " << lex_cast_qstring(headers[i]); // XXX right quoting?
 938   omf << endl;
 939
 940   omf << "obj-m := " + basename + ".o" << endl;
 941   omf.close();
 942
 943   // create our empty source file
 944   string source(dir + "/" + basename + ".c");
 945   ofstream osrc(source.c_str());
 946   osrc.close();
 947
 948   // make the module
 949   vector<string> make_cmd = make_make_cmd(s, dir);
 950   bool quiet = (s.verbose < 4);
 951   int rc = run_make_cmd(s, make_cmd, quiet, quiet);
 952   if (rc)
 953     s.set_try_server ();
 954   return rc;
 955 }
 956
 957
 958 // Build a tiny user module to query type information
 959 static int
 960 make_typequery_umod(systemtap_session& s, const vector<string>& headers, string& name)
 961 {
 962   static unsigned tick = 0;
 963
 964   name = s.tmpdir + "/typequery_umod_" + lex_cast(++tick) + ".so";
 965
 966   // make the module
 967   //
 968   // NB: As with kmod, using -include makes relative paths more useful.  The
 969   // cwd in this case will be the cwd of stap itself though, which may be
 970   // trickier to deal with.  It might be better to "cd `dirname $script`"
 971   // first...
 972   vector<string> cmd
 973     {
 974       "gcc", "-shared", "-g", "-fno-eliminate-unused-debug-types",
 975       "-xc", "/dev/null", "-o", name,
 976     };
 977   for (size_t i = 0; i < headers.size(); ++i)
 978     cmd.insert(cmd.end(), { "-include", headers[i] });
 979
 980   bool quiet = (s.verbose < 4);
 981   int rc = stap_system (s.verbose, cmd, quiet, quiet);
 982   if (rc)
 983     s.set_try_server ();
 984   return rc;
 985 }
 986
 987
 988 int
 989 make_typequery(systemtap_session& s, string& module)
 990 {
 991   int rc;
 992   string new_module;
 993   vector<string> headers;
 994   bool kernel = startswith(module, "kernel");
 995
 996   for (size_t end, i = kernel ? 6 : 0; i < module.size(); i = end + 1)
 997     {
 998       if (module[i] != '<')
 999         return -1;
1000       end = module.find('>', ++i);
1001       if (end == string::npos)
1002         return -1;
1003       string header = module.substr(i, end - i);
1004       vector<string> matches;
1005       if (regexp_match(header, "^[a-zA-Z0-9/_.+-]+$", matches))
1006         s.print_warning("skipping malformed @cast header \""+ header + "\"");
1007       else
1008         headers.push_back(header);
1009     }
1010   if (headers.empty())
1011     return -1;
1012
1013   if (kernel)
1014       rc = make_typequery_kmod(s, headers, new_module);
1015   else
1016       rc = make_typequery_umod(s, headers, new_module);
1017
1018   if (!rc)
1019     module = new_module;
1020
1021   return rc;
1022 }
1023
1024 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */