buildrun.cxx

   1 // build/run probes
   2 // Copyright (C) 2005-2013 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 }
  31
  32
  33 using namespace std;
  34
  35 /* Adjust and run make_cmd to build a kernel module. */
  36 static int
  37 run_make_cmd(systemtap_session& s, vector<string>& make_cmd,
  38              bool null_out=false, bool null_err=false)
  39 {
  40   assert_no_interrupts();
  41
  42   // PR14168: we used to unsetenv values here; instead do it via
  43   // env(1) in make_any_make_cmd().
  44
  45   // Disable ccache to avoid saving files that will never be reused.
  46   // (ccache is useless to us, because our compiler commands always
  47   // include the randomized tmpdir path.)
  48   // It's not critical if this fails, so the return is ignored.
  49   (void) setenv("CCACHE_DISABLE", "1", 0);
  50
  51   if (s.verbose > 2)
  52     make_cmd.push_back("V=1");
  53   else if (s.verbose > 1)
  54     make_cmd.push_back("--no-print-directory");
  55   else
  56     {
  57       make_cmd.push_back("-s");
  58       make_cmd.push_back("--no-print-directory");
  59     }
  60
  61   // Exploit SMP parallelism, if available.
  62   long smp = sysconf(_SC_NPROCESSORS_ONLN);
  63   if (smp >= 1)
  64     make_cmd.push_back("-j" + lex_cast(smp+1));
  65
  66   if (strverscmp (s.kernel_base_release.c_str(), "2.6.29") < 0)
  67     {
  68       // Older kernels, before linux commit #fd54f502841c1, include
  69       // gratuitous "echo"s in their Makefile.  We need to suppress
  70       // that with this bluntness.
  71       null_out = true;
  72     }
  73
  74   int rc = stap_system (s.verbose, "kbuild", make_cmd, null_out, null_err);
  75   if (rc != 0)
  76     s.set_try_server ();
  77   return rc;
  78 }
  79
  80 static vector<string>
  81 make_any_make_cmd(systemtap_session& s, const string& dir, const string& target)
  82 {
  83   vector<string> make_cmd;
  84
  85   // PR14168: sanitize environment variables for kbuild invocation
  86   make_cmd.push_back("env");
  87   make_cmd.push_back("-uARCH");
  88   make_cmd.push_back("-uKBUILD_EXTMOD");
  89   make_cmd.push_back("-uCROSS_COMPILE");
  90   make_cmd.push_back("-uKBUILD_IMAGE");
  91   make_cmd.push_back("-uKCONFIG_CONFIG");
  92   make_cmd.push_back("-uINSTALL_PATH");
  93   string newpath = string("PATH=/usr/bin:/bin:") + (getenv("PATH") ?: "");
  94   make_cmd.push_back(newpath.c_str());
  95
  96   make_cmd.push_back("make");
  97   make_cmd.push_back("-C");
  98   make_cmd.push_back(s.kernel_build_tree);
  99   make_cmd.push_back("M=" + dir); // need make-quoting?
 100   make_cmd.push_back(target);
 101
 102   // Add architecture, except for old powerpc (RHBZ669082)
 103   if (s.architecture != "powerpc" ||
 104       (strverscmp (s.kernel_base_release.c_str(), "2.6.15") >= 0))
 105     make_cmd.push_back("ARCH=" + s.architecture); // need make-quoting?
 106
 107   // PR13847: suppress debuginfo creation by default
 108   make_cmd.insert(make_cmd.end(), "CONFIG_DEBUG_INFO=");
 109
 110   // Add any custom kbuild flags
 111   make_cmd.insert(make_cmd.end(), s.kbuildflags.begin(), s.kbuildflags.end());
 112
 113   return make_cmd;
 114 }
 115
 116 static vector<string>
 117 make_make_cmd(systemtap_session& s, const string& dir)
 118 {
 119   return make_any_make_cmd(s, dir, "modules");
 120 }
 121
 122 static vector<string>
 123 make_make_objs_cmd(systemtap_session& s, const string& dir)
 124 {
 125   // Kbuild uses these rules to build external modules:
 126   //
 127   //   module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
 128   //   modules: $(module-dirs)
 129   //       @$(kecho) '  Building modules, stage 2.';
 130   //       $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 131   //
 132   // So if we're only interested in the stage 1 objects, we can
 133   // cheat and make only the $(module-dirs) part.
 134   return make_any_make_cmd(s, dir, "_module_" + dir);
 135 }
 136
 137 static void
 138 output_autoconf(systemtap_session& s, ofstream& o, const char *autoconf_c,
 139                 const char *deftrue, const char *deffalse)
 140 {
 141   o << "\t";
 142   if (s.verbose < 4)
 143     o << "@";
 144   o << "if $(CHECK_BUILD) $(SYSTEMTAP_RUNTIME)/linux/" << autoconf_c;
 145   if (s.verbose < 5)
 146     o << " > /dev/null 2>&1";
 147   o << "; then ";
 148   if (deftrue)
 149     o << "echo \"#define " << deftrue << " 1\"";
 150   if (deffalse)
 151     o << "; else echo \"#define " << deffalse << " 1\"";
 152   o << "; fi >> $@" << endl;
 153 }
 154
 155
 156 void output_exportconf(systemtap_session& s, ofstream& o, const char *symbol,
 157                      const char *deftrue)
 158 {
 159   o << "\t";
 160   if (s.verbose < 4)
 161     o << "@";
 162   if (s.kernel_exports.find(symbol) != s.kernel_exports.end())
 163     o << "echo \"#define " << deftrue << " 1\"";
 164   o << ">> $@" << endl;
 165 }
 166
 167
 168 void output_dual_exportconf(systemtap_session& s, ofstream& o,
 169                             const char *symbol1, const char *symbol2,
 170                             const char *deftrue)
 171 {
 172   o << "\t";
 173   if (s.verbose < 4)
 174     o << "@";
 175   if (s.kernel_exports.find(symbol1) != s.kernel_exports.end()
 176       && s.kernel_exports.find(symbol2) != s.kernel_exports.end())
 177     o << "echo \"#define " << deftrue << " 1\"";
 178   o << ">> $@" << endl;
 179 }
 180
 181
 182 void output_either_exportconf(systemtap_session& s, ofstream& o,
 183                               const char *symbol1, const char *symbol2,
 184                               const char *deftrue)
 185 {
 186   o << "\t";
 187   if (s.verbose < 4)
 188     o << "@";
 189   if (s.kernel_exports.find(symbol1) != s.kernel_exports.end()
 190       || s.kernel_exports.find(symbol2) != s.kernel_exports.end())
 191     o << "echo \"#define " << deftrue << " 1\"";
 192   o << ">> $@" << endl;
 193 }
 194
 195
 196 static int
 197 compile_dyninst (systemtap_session& s)
 198 {
 199   const string module = s.tmpdir + "/" + s.module_filename();
 200
 201   vector<string> cmd;
 202   cmd.push_back("gcc");
 203   cmd.push_back("--std=gnu99");
 204   cmd.push_back("-Wall");
 205   cmd.push_back("-Werror");
 206   cmd.push_back("-Wno-unused");
 207   cmd.push_back("-Wno-strict-aliasing");
 208   cmd.push_back("-O2");
 209   cmd.push_back("-I" + s.runtime_path);
 210   cmd.push_back("-D__DYNINST__");
 211   for (size_t i = 0; i < s.c_macros.size(); ++i)
 212     cmd.push_back("-D" + s.c_macros[i]);
 213   cmd.push_back(s.translated_source);
 214   cmd.push_back("-pthread");
 215   cmd.push_back("-lrt");
 216   cmd.push_back("-fPIC");
 217   cmd.push_back("-shared");
 218   cmd.push_back("-o");
 219   cmd.push_back(module);
 220   if (s.verbose > 3)
 221     {
 222       cmd.push_back("-ftime-report");
 223       cmd.push_back("-Q");
 224     }
 225
 226   int rc = stap_system (s.verbose, cmd);
 227   if (rc)
 228     s.set_try_server ();
 229   return rc;
 230 }
 231
 232
 233 int
 234 compile_pass (systemtap_session& s)
 235 {
 236   if (s.runtime_usermode_p())
 237     return compile_dyninst (s);
 238
 239   int rc = uprobes_pass (s);
 240   if (rc)
 241     {
 242       s.set_try_server ();
 243       return rc;
 244     }
 245
 246   // fill in a quick Makefile
 247   string makefile_nm = s.tmpdir + "/Makefile";
 248   ofstream o (makefile_nm.c_str());
 249
 250   // Create makefile
 251
 252   // Clever hacks copied from vmware modules
 253   string superverbose;
 254   if (s.verbose > 3)
 255     superverbose = "set -x;";
 256
 257   string redirecterrors = "> /dev/null 2>&1";
 258   if (s.verbose > 6)
 259     redirecterrors = "";
 260
 261   // Support O= (or KBUILD_OUTPUT) option
 262   o << "_KBUILD_CFLAGS := $(call flags,KBUILD_CFLAGS)" << endl;
 263
 264   o << "stap_check_gcc = $(shell " << superverbose << " if $(CC) $(1) -S -o /dev/null -xc /dev/null > /dev/null 2>&1; then echo \"$(1)\"; else echo \"$(2)\"; fi)" << endl;
 265   o << "CHECK_BUILD := $(CC) $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(LINUXINCLUDE) $(_KBUILD_CFLAGS) $(CFLAGS_KERNEL) $(EXTRA_CFLAGS) $(CFLAGS) -DKBUILD_BASENAME=\\\"" << s.module_name << "\\\"" << (s.omit_werror ? "" : " -Werror") << " -S -o /dev/null -xc " << endl;
 266   o << "stap_check_build = $(shell " << superverbose << " if $(CHECK_BUILD) $(1) " << redirecterrors << " ; then echo \"$(2)\"; else echo \"$(3)\"; fi)" << endl;
 267
 268   o << "SYSTEMTAP_RUNTIME = \"" << s.runtime_path << "\"" << endl;
 269
 270   // "autoconf" options go here
 271
 272   // RHBZ 543529: early rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 273   o << "CONFIG_MODULE_SIG := n" << endl;
 274
 275   string module_cflags = "EXTRA_CFLAGS";
 276   o << module_cflags << " :=" << endl;
 277
 278   // XXX: This gruesome hack is needed on some kernels built with separate O=directory,
 279   // where files like 2.6.27 x86's asm/mach-*/mach_mpspec.h are not found on the cpp path.
 280   // This could be a bug in arch/x86/Makefile that names
 281   //      mflags-y += -Iinclude/asm-x86/mach-default
 282   // but that path does not exist in an O= build tree.
 283   o << module_cflags << " += -Iinclude2/asm/mach-default" << endl;
 284   if (s.kernel_source_tree != "")
 285     o << module_cflags << " += -I" + s.kernel_source_tree << endl;
 286
 287   // NB: don't try
 288   // o << module_cflags << " += -Iusr/include" << endl;
 289   // since such headers are cleansed of _KERNEL_ pieces that we need
 290
 291   o << "STAPCONF_HEADER := " << s.tmpdir << "/" << s.stapconf_name << endl;
 292   o << "$(STAPCONF_HEADER):" << endl;
 293   o << "\t@echo -n > $@" << endl;
 294   output_autoconf(s, o, "autoconf-hrtimer-rel.c", "STAPCONF_HRTIMER_REL", NULL);
 295   output_autoconf(s, o, "autoconf-generated-compile.c", "STAPCONF_GENERATED_COMPILE", NULL);
 296   output_autoconf(s, o, "autoconf-hrtimer-getset-expires.c", "STAPCONF_HRTIMER_GETSET_EXPIRES", NULL);
 297   output_autoconf(s, o, "autoconf-inode-private.c", "STAPCONF_INODE_PRIVATE", NULL);
 298   output_autoconf(s, o, "autoconf-constant-tsc.c", "STAPCONF_CONSTANT_TSC", NULL);
 299   output_autoconf(s, o, "autoconf-ktime-get-real.c", "STAPCONF_KTIME_GET_REAL", NULL);
 300   output_autoconf(s, o, "autoconf-x86-uniregs.c", "STAPCONF_X86_UNIREGS", NULL);
 301   output_autoconf(s, o, "autoconf-nameidata.c", "STAPCONF_NAMEIDATA_CLEANUP", NULL);
 302   output_dual_exportconf(s, o, "unregister_kprobes", "unregister_kretprobes", "STAPCONF_UNREGISTER_KPROBES");
 303   output_autoconf(s, o, "autoconf-kprobe-symbol-name.c", "STAPCONF_KPROBE_SYMBOL_NAME", NULL);
 304   output_autoconf(s, o, "autoconf-real-parent.c", "STAPCONF_REAL_PARENT", NULL);
 305   output_autoconf(s, o, "autoconf-uaccess.c", "STAPCONF_LINUX_UACCESS_H", NULL);
 306   output_autoconf(s, o, "autoconf-oneachcpu-retry.c", "STAPCONF_ONEACHCPU_RETRY", NULL);
 307   output_autoconf(s, o, "autoconf-dpath-path.c", "STAPCONF_DPATH_PATH", NULL);
 308   output_exportconf(s, o, "synchronize_sched", "STAPCONF_SYNCHRONIZE_SCHED");
 309   output_autoconf(s, o, "autoconf-task-uid.c", "STAPCONF_TASK_UID", NULL);
 310   output_dual_exportconf(s, o, "alloc_vm_area", "free_vm_area", "STAPCONF_VM_AREA");
 311   output_autoconf(s, o, "autoconf-procfs-owner.c", "STAPCONF_PROCFS_OWNER", NULL);
 312   output_autoconf(s, o, "autoconf-alloc-percpu-align.c", "STAPCONF_ALLOC_PERCPU_ALIGN", NULL);
 313   output_autoconf(s, o, "autoconf-x86-gs.c", "STAPCONF_X86_GS", NULL);
 314   output_autoconf(s, o, "autoconf-grsecurity.c", "STAPCONF_GRSECURITY", NULL);
 315   output_autoconf(s, o, "autoconf-trace-printk.c", "STAPCONF_TRACE_PRINTK", NULL);
 316   output_autoconf(s, o, "autoconf-regset.c", "STAPCONF_REGSET", NULL);
 317   output_autoconf(s, o, "autoconf-utrace-regset.c", "STAPCONF_UTRACE_REGSET", NULL);
 318   output_autoconf(s, o, "autoconf-uprobe-get-pc.c", "STAPCONF_UPROBE_GET_PC", NULL);
 319   output_autoconf(s, o, "autoconf-hlist-4args.c", "STAPCONF_HLIST_4ARGS", NULL);
 320   output_exportconf(s, o, "tsc_khz", "STAPCONF_TSC_KHZ");
 321   output_exportconf(s, o, "cpu_khz", "STAPCONF_CPU_KHZ");
 322   output_exportconf(s, o, "__module_text_address", "STAPCONF_MODULE_TEXT_ADDRESS");
 323   output_exportconf(s, o, "add_timer_on", "STAPCONF_ADD_TIMER_ON");
 324
 325   output_dual_exportconf(s, o, "probe_kernel_read", "probe_kernel_write", "STAPCONF_PROBE_KERNEL");
 326   output_autoconf(s, o, "autoconf-hw_breakpoint_context.c",
 327                   "STAPCONF_HW_BREAKPOINT_CONTEXT", NULL);
 328   output_autoconf(s, o, "autoconf-save-stack-trace.c",
 329                   "STAPCONF_KERNEL_STACKTRACE", NULL);
 330   output_autoconf(s, o, "autoconf-save-stack-trace-no-bp.c",
 331                   "STAPCONF_KERNEL_STACKTRACE_NO_BP", NULL);
 332   output_autoconf(s, o, "autoconf-asm-syscall.c",
 333                   "STAPCONF_ASM_SYSCALL_H", NULL);
 334   output_autoconf(s, o, "autoconf-ring_buffer-flags.c", "STAPCONF_RING_BUFFER_FLAGS", NULL);
 335   output_autoconf(s, o, "autoconf-ring_buffer_lost_events.c", "STAPCONF_RING_BUFFER_LOST_EVENTS", NULL);
 336   output_autoconf(s, o, "autoconf-ring_buffer_read_prepare.c", "STAPCONF_RING_BUFFER_READ_PREPARE", NULL);
 337   output_autoconf(s, o, "autoconf-kallsyms-on-each-symbol.c", "STAPCONF_KALLSYMS_ON_EACH_SYMBOL", NULL);
 338   output_autoconf(s, o, "autoconf-walk-stack.c", "STAPCONF_WALK_STACK", NULL);
 339   output_autoconf(s, o, "autoconf-stacktrace_ops-warning.c",
 340                   "STAPCONF_STACKTRACE_OPS_WARNING", NULL);
 341   output_autoconf(s, o, "autoconf-mm-context-vdso.c", "STAPCONF_MM_CONTEXT_VDSO", NULL);
 342   output_autoconf(s, o, "autoconf-mm-context-vdso-base.c", "STAPCONF_MM_CONTEXT_VDSO_BASE", NULL);
 343   output_autoconf(s, o, "autoconf-blk-types.c", "STAPCONF_BLK_TYPES", NULL);
 344   output_autoconf(s, o, "autoconf-perf-structpid.c", "STAPCONF_PERF_STRUCTPID", NULL);
 345   output_autoconf(s, o, "perf_event_counter_context.c",
 346                   "STAPCONF_PERF_COUNTER_CONTEXT", NULL);
 347   output_autoconf(s, o, "perf_probe_handler_nmi.c",
 348                   "STAPCONF_PERF_HANDLER_NMI", NULL);
 349   output_exportconf(s, o, "path_lookup", "STAPCONF_PATH_LOOKUP");
 350   output_exportconf(s, o, "kern_path_parent", "STAPCONF_KERN_PATH_PARENT");
 351   output_exportconf(s, o, "vfs_path_lookup", "STAPCONF_VFS_PATH_LOOKUP");
 352   output_autoconf(s, o, "autoconf-module-sect-attrs.c", "STAPCONF_MODULE_SECT_ATTRS", NULL);
 353
 354   output_autoconf(s, o, "autoconf-utrace-via-tracepoints.c", "STAPCONF_UTRACE_VIA_TRACEPOINTS", NULL);
 355   output_autoconf(s, o, "autoconf-task_work-struct.c", "STAPCONF_TASK_WORK_STRUCT", NULL);
 356   output_autoconf(s, o, "autoconf-vm-area-pte.c", "STAPCONF_VM_AREA_PTE", NULL);
 357   output_autoconf(s, o, "autoconf-relay-umode_t.c", "STAPCONF_RELAY_UMODE_T", NULL);
 358   output_autoconf(s, o, "autoconf-fs_supers-hlist.c", "STAPCONF_FS_SUPERS_HLIST", NULL);
 359
 360   // used by tapset/timestamp_monotonic.stp
 361   output_exportconf(s, o, "cpu_clock", "STAPCONF_CPU_CLOCK");
 362   output_exportconf(s, o, "local_clock", "STAPCONF_LOCAL_CLOCK");
 363
 364   // used by runtime/uprobe-inode.c
 365   output_either_exportconf(s, o, "uprobe_register", "register_uprobe",
 366                            "STAPCONF_UPROBE_REGISTER_EXPORTED");
 367   output_either_exportconf(s, o, "uprobe_unregister", "unregister_uprobe",
 368                            "STAPCONF_UPROBE_UNREGISTER_EXPORTED");
 369   output_autoconf(s, o, "autoconf-old-inode-uprobes.c", "STAPCONF_OLD_INODE_UPROBES", NULL);
 370   output_autoconf(s, o, "autoconf-inode-uprobes-noaddr.c", "STAPCONF_INODE_UPROBES_NOADDR", NULL);
 371   output_autoconf(s, o, "autoconf-inode-uretprobes.c", "STAPCONF_INODE_URETPROBES", NULL);
 372
 373   // used by tapsets.cxx inode uprobe generated code
 374   output_exportconf(s, o, "uprobe_get_swbp_addr", "STAPCONF_UPROBE_GET_SWBP_ADDR_EXPORTED");
 375
 376   // used by runtime/loc2c-runtime.h
 377   output_exportconf(s, o, "task_user_regset_view", "STAPCONF_TASK_USER_REGSET_VIEW_EXPORTED");
 378
 379   // used by runtime/stp_utrace.c
 380   output_exportconf(s, o, "task_work_add", "STAPCONF_TASK_WORK_ADD_EXPORTED");
 381   output_exportconf(s, o, "signal_wake_up_state", "STAPCONF_SIGNAL_WAKE_UP_STATE_EXPORTED");
 382   output_exportconf(s, o, "signal_wake_up", "STAPCONF_SIGNAL_WAKE_UP_EXPORTED");
 383   output_exportconf(s, o, "__lock_task_sighand", "STAPCONF___LOCK_TASK_SIGHAND_EXPORTED");
 384
 385   output_autoconf(s, o, "autoconf-pagefault_disable.c", "STAPCONF_PAGEFAULT_DISABLE", NULL);
 386   output_exportconf(s, o, "kallsyms_lookup_name", "STAPCONF_KALLSYMS");
 387
 388   o << module_cflags << " += -include $(STAPCONF_HEADER)" << endl;
 389
 390   for (unsigned i=0; i<s.c_macros.size(); i++)
 391     o << "EXTRA_CFLAGS += -D " << lex_cast_qstring(s.c_macros[i]) << endl; // XXX right quoting?
 392
 393   if (s.verbose > 3)
 394     o << "EXTRA_CFLAGS += -ftime-report -Q" << endl;
 395
 396   // XXX: unfortunately, -save-temps can't work since linux kbuild cwd
 397   // is not writable.
 398   //
 399   // if (s.keep_tmpdir)
 400   // o << "CFLAGS += -fverbose-asm -save-temps" << endl;
 401
 402   // Kernels can be compiled with CONFIG_CC_OPTIMIZE_FOR_SIZE to select
 403   // -Os, otherwise -O2 is the default.
 404   o << "EXTRA_CFLAGS += -freorder-blocks" << endl; // improve on -Os
 405
 406   // We used to allow the user to override default optimization when so
 407   // requested by adding a -O[0123s] so they could determine the
 408   // time/space/speed tradeoffs themselves, but we cannot guantantee that
 409   // the (un)optimized code actually compiles and/or generates functional
 410   // code, so we had to remove it.
 411   // o << "EXTRA_CFLAGS += " << s.gcc_flags << endl; // Add -O[0123s]
 412
 413   // o << "CFLAGS += -fno-unit-at-a-time" << endl;
 414
 415   // 256 bytes should be enough for anybody
 416   // XXX this doesn't validate varargs, per gcc bug #41633
 417   o << "EXTRA_CFLAGS += $(call cc-option,-Wframe-larger-than=256)" << endl;
 418
 419   // Assumes linux 2.6 kbuild
 420   o << "EXTRA_CFLAGS += -Wno-unused" << (s.omit_werror ? "" : " -Werror") << endl;
 421   #if CHECK_POINTER_ARITH_PR5947
 422   o << "EXTRA_CFLAGS += -Wpointer-arith" << endl;
 423   #endif
 424   o << "EXTRA_CFLAGS += -I\"" << s.runtime_path << "\"" << endl;
 425   // XXX: this may help ppc toc overflow
 426   // o << "CFLAGS := $(subst -Os,-O2,$(CFLAGS)) -fminimal-toc" << endl;
 427   o << "obj-m := " << s.module_name << ".o" << endl;
 428
 429   // print out all the auxiliary source (->object) file names
 430   o << s.module_name << "-y := ";
 431   for (unsigned i=0; i<s.auxiliary_outputs.size(); i++)
 432     {
 433       string srcname = s.auxiliary_outputs[i]->filename;
 434       assert (srcname != "" && srcname.rfind('/') != string::npos);
 435       string objname = srcname.substr(srcname.rfind('/')+1); // basename
 436       assert (objname != "" && objname[objname.size()-1] == 'c');
 437       objname[objname.size()-1] = 'o'; // now objname
 438       o << " " + objname;
 439     }
 440   // and once again, for the translated_source file.  It can't simply
 441   // be named MODULENAME.c, since kbuild doesn't allow a foo.ko file
 442   // consisting of multiple .o's to have foo.o/foo.c as a source.
 443   // (It uses ld -r -o foo.o EACH.o EACH.o).
 444   {
 445     string srcname = s.translated_source;
 446     assert (srcname != "" && srcname.rfind('/') != string::npos);
 447     string objname = srcname.substr(srcname.rfind('/')+1); // basename
 448     assert (objname != "" && objname[objname.size()-1] == 'c');
 449     objname[objname.size()-1] = 'o'; // now objname
 450     o << " " + objname;
 451   }
 452   o << endl;
 453
 454   // add all stapconf dependencies
 455   o << s.translated_source << ": $(STAPCONF_HEADER)" << endl;
 456   for (unsigned i=0; i<s.auxiliary_outputs.size(); i++)
 457     o << s.auxiliary_outputs[i]->filename << ": $(STAPCONF_HEADER)" << endl;
 458
 459
 460   o.close ();
 461
 462   // Generate module directory pathname and make sure it exists.
 463   string module_dir = s.kernel_build_tree;
 464   string module_dir_makefile = module_dir + "/Makefile";
 465   struct stat st;
 466   rc = stat(module_dir_makefile.c_str(), &st);
 467   if (rc != 0)
 468     {
 469         clog << _F("Checking \" %s \" failed with error: %s\nEnsure kernel development headers & makefiles are installed.",
 470                    module_dir_makefile.c_str(), strerror(errno)) << endl;
 471         s.set_try_server ();
 472         return rc;
 473     }
 474
 475   // Run make
 476   vector<string> make_cmd = make_make_cmd(s, s.tmpdir);
 477   rc = run_make_cmd(s, make_cmd);
 478   if (rc)
 479     s.set_try_server ();
 480   return rc;
 481 }
 482
 483 /*
 484  * If uprobes was built as part of the kernel build (either built-in
 485  * or as a module), the uprobes exports should show up.  This is to be
 486  * as distinct from the stap-built uprobes.ko from the runtime.
 487  */
 488 static bool
 489 kernel_built_uprobes (systemtap_session& s)
 490 {
 491   if (s.runtime_usermode_p())
 492     return true; // sort of, via dyninst
 493
 494   // see also tapsets.cxx:kernel_supports_inode_uprobes()
 495   return ((s.kernel_config["CONFIG_ARCH_SUPPORTS_UPROBES"] == "y" && s.kernel_config["CONFIG_UPROBES"] == "y") ||
 496           (s.kernel_exports.find("unregister_uprobe") != s.kernel_exports.end()));
 497 }
 498
 499 static int
 500 make_uprobes (systemtap_session& s)
 501 {
 502   if (s.verbose > 1)
 503     clog << _("Pass 4, preamble: (re)building SystemTap's version of uprobes.")
 504          << endl;
 505
 506   // create a subdirectory for the uprobes module
 507   string dir(s.tmpdir + "/uprobes");
 508   if (create_dir(dir.c_str()) != 0)
 509     {
 510       s.print_warning("failed to create directory for build uprobes.");
 511       s.set_try_server ();
 512       return 1;
 513     }
 514
 515   // create a simple Makefile
 516   string makefile(dir + "/Makefile");
 517   ofstream omf(makefile.c_str());
 518   omf << "obj-m := uprobes.o" << endl;
 519   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 520   omf << "CONFIG_MODULE_SIG := n" << endl;
 521   omf.close();
 522
 523   // create a simple #include-chained source file
 524   string runtimesourcefile(s.runtime_path + "/linux/uprobes/uprobes.c");
 525   string sourcefile(dir + "/uprobes.c");
 526   ofstream osrc(sourcefile.c_str());
 527   osrc << "#include \"" << runtimesourcefile << "\"" << endl;
 528
 529   // pass --modinfo k=v to uprobes build too
 530   for (unsigned i = 0; i < s.modinfos.size(); i++)
 531     {
 532       const string& mi = s.modinfos[i];
 533       size_t loc = mi.find('=');
 534       string tag = mi.substr (0, loc);
 535       string value = mi.substr (loc+1);
 536       osrc << "MODULE_INFO(" << tag << "," << lex_cast_qstring(value) << ");" << endl;
 537     }
 538
 539   osrc.close();
 540
 541   // make the module
 542   vector<string> make_cmd = make_make_cmd(s, dir);
 543   int rc = run_make_cmd(s, make_cmd);
 544   if (!rc && !copy_file(dir + "/Module.symvers",
 545                         s.tmpdir + "/Module.symvers"))
 546     rc = -1;
 547
 548   if (s.verbose > 1)
 549     clog << _("uprobes rebuild exit code: ") << rc << endl;
 550   if (rc)
 551     s.set_try_server ();
 552   else
 553     s.uprobes_path = dir + "/uprobes.ko";
 554   return rc;
 555 }
 556
 557 static bool
 558 get_cached_uprobes(systemtap_session& s)
 559 {
 560   s.uprobes_hash = s.use_cache ? find_uprobes_hash(s) : "";
 561   if (!s.uprobes_hash.empty())
 562     {
 563       // NB: We always put uprobes.ko in its own directory, especially so
 564       // stap-serverd can more easily locate it.
 565       string dir(s.tmpdir + "/uprobes");
 566       if (create_dir(dir.c_str()) != 0)
 567         return false;
 568
 569       string cacheko = s.uprobes_hash + ".ko";
 570       string tmpko = dir + "/uprobes.ko";
 571
 572       // The symvers file still needs to go in the script module's directory.
 573       string cachesyms = s.uprobes_hash + ".symvers";
 574       string tmpsyms = s.tmpdir + "/Module.symvers";
 575
 576       if (get_file_size(cacheko) > 0 && copy_file(cacheko, tmpko) &&
 577           get_file_size(cachesyms) > 0 && copy_file(cachesyms, tmpsyms))
 578         {
 579           s.uprobes_path = tmpko;
 580           return true;
 581         }
 582     }
 583   return false;
 584 }
 585
 586 static void
 587 set_cached_uprobes(systemtap_session& s)
 588 {
 589   if (s.use_cache && !s.uprobes_hash.empty())
 590     {
 591       string cacheko = s.uprobes_hash + ".ko";
 592       string tmpko = s.tmpdir + "/uprobes/uprobes.ko";
 593       copy_file(tmpko, cacheko);
 594
 595       string cachesyms = s.uprobes_hash + ".symvers";
 596       string tmpsyms = s.tmpdir + "/uprobes/Module.symvers";
 597       copy_file(tmpsyms, cachesyms);
 598     }
 599 }
 600
 601 int
 602 uprobes_pass (systemtap_session& s)
 603 {
 604   if (!s.need_uprobes || kernel_built_uprobes(s))
 605     return 0;
 606
 607   if (s.kernel_config["CONFIG_UTRACE"] != string("y"))
 608     {
 609       clog << _("user-space process-tracking facilities not available [man error::process-tracking]") << endl;
 610       s.set_try_server ();
 611       return 1;
 612     }
 613
 614   /*
 615    * We need to use the version of uprobes that comes with SystemTap.  Try to
 616    * get it from the cache first.  If not found, build it and try to save it to
 617    * the cache for future reuse.
 618    */
 619   int rc = 0;
 620   if (!get_cached_uprobes(s))
 621     {
 622       rc = make_uprobes(s);
 623       if (!rc)
 624         set_cached_uprobes(s);
 625     }
 626   if (rc)
 627     s.set_try_server ();
 628   return rc;
 629 }
 630
 631 static
 632 vector<string>
 633 make_dyninst_run_command (systemtap_session& s, const string& remotedir,
 634                           const string& version)
 635 {
 636   vector<string> cmd;
 637   cmd.push_back(getenv("SYSTEMTAP_STAPDYN") ?: BINDIR "/stapdyn");
 638
 639   // use slightly less verbosity
 640   for (unsigned i=1; i<s.verbose; i++)
 641     cmd.push_back("-v");
 642   if (s.suppress_warnings)
 643     cmd.push_back("-w");
 644
 645   if (!s.cmd.empty())
 646     {
 647       cmd.push_back("-c");
 648       cmd.push_back(s.cmd);
 649     }
 650
 651   if (s.target_pid)
 652     {
 653       cmd.push_back("-x");
 654       cmd.push_back(lex_cast(s.target_pid));
 655     }
 656
 657   cmd.push_back((remotedir.empty() ? s.tmpdir : remotedir)
 658                 + "/" + s.module_filename());
 659
 660   return cmd;
 661 }
 662
 663 vector<string>
 664 make_run_command (systemtap_session& s, const string& remotedir,
 665                   const string& version)
 666 {
 667   if (s.runtime_usermode_p())
 668     return make_dyninst_run_command(s, remotedir, version);
 669
 670   // for now, just spawn staprun
 671   vector<string> staprun_cmd;
 672   staprun_cmd.push_back(getenv("SYSTEMTAP_STAPRUN") ?: BINDIR "/staprun");
 673
 674   // use slightly less verbosity
 675   for (unsigned i=1; i<s.verbose; i++)
 676     staprun_cmd.push_back("-v");
 677   if (s.suppress_warnings)
 678     staprun_cmd.push_back("-w");
 679
 680   if (!s.output_file.empty())
 681     {
 682       staprun_cmd.push_back("-o");
 683       staprun_cmd.push_back(s.output_file);
 684     }
 685
 686   if (!s.cmd.empty())
 687     {
 688       staprun_cmd.push_back("-c");
 689       staprun_cmd.push_back(s.cmd);
 690     }
 691
 692   if (s.target_pid)
 693     {
 694       staprun_cmd.push_back("-t");
 695       staprun_cmd.push_back(lex_cast(s.target_pid));
 696     }
 697
 698   if (s.buffer_size)
 699     {
 700       staprun_cmd.push_back("-b");
 701       staprun_cmd.push_back(lex_cast(s.buffer_size));
 702     }
 703
 704   if (s.need_uprobes && !kernel_built_uprobes(s))
 705     {
 706       string opt_u = "-u";
 707       if (!s.uprobes_path.empty() &&
 708           strverscmp("1.4", version.c_str()) <= 0)
 709         {
 710           if (remotedir.empty())
 711             opt_u.append(s.uprobes_path);
 712           else
 713             opt_u.append(remotedir + "/" + basename(s.uprobes_path.c_str()));
 714         }
 715       staprun_cmd.push_back(opt_u);
 716     }
 717
 718   if (s.load_only)
 719     staprun_cmd.push_back(s.output_file.empty() ? "-L" : "-D");
 720
 721   if(!s.modname_given && (strverscmp("1.6", version.c_str()) <= 0))
 722     staprun_cmd.push_back("-R");
 723
 724   if (!s.size_option.empty())
 725     {
 726       staprun_cmd.push_back("-S");
 727       staprun_cmd.push_back(s.size_option);
 728     }
 729
 730   staprun_cmd.push_back((remotedir.empty() ? s.tmpdir : remotedir)
 731                         + "/" + s.module_filename());
 732
 733   // add module arguments
 734   staprun_cmd.insert(staprun_cmd.end(),
 735                      s.globalopts.begin(), s.globalopts.end());
 736
 737   return staprun_cmd;
 738 }
 739
 740
 741 // Build tiny kernel modules to query tracepoints.
 742 // Given a (header-file -> test-contents) map, compile them ASAP, and return
 743 // a (header-file -> obj-filename) map.
 744
 745 map<string,string>
 746 make_tracequeries(systemtap_session& s, const map<string,string>& contents)
 747 {
 748   static unsigned tick = 0;
 749   string basename("tracequery_kmod_" + lex_cast(++tick));
 750   map<string,string> objs;
 751
 752   // create a subdirectory for the module
 753   string dir(s.tmpdir + "/" + basename);
 754   if (create_dir(dir.c_str()) != 0)
 755     {
 756       s.print_warning("failed to create directory for querying tracepoints.");
 757       s.set_try_server ();
 758       return objs;
 759     }
 760
 761   // create a simple Makefile
 762   string makefile(dir + "/Makefile");
 763   ofstream omf(makefile.c_str());
 764   // force debuginfo generation, and relax implicit functions
 765   omf << "EXTRA_CFLAGS := -g -Wno-implicit-function-declaration" << (s.omit_werror ? "" : " -Werror") << endl;
 766   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 767   omf << "CONFIG_MODULE_SIG := n" << endl;
 768
 769   if (s.kernel_source_tree != "")
 770     omf << "EXTRA_CFLAGS += -I" + s.kernel_source_tree << endl;
 771
 772   omf << "obj-m := " << endl;
 773   // write out each header-specific source file into a separate file
 774   for (map<string,string>::const_iterator it = contents.begin(); it != contents.end(); it++)
 775     {
 776       string sbasename = basename + "_" + lex_cast(++tick); // suffixed
 777
 778       // write out source code
 779       string srcname = dir + "/" + sbasename + ".c";
 780       string src = it->second;
 781       ofstream osrc(srcname.c_str());
 782       osrc << src;
 783       osrc.close();
 784
 785       if (s.verbose > 2)
 786         clog << _F("Processing tracepoint header %s with query %s",
 787                    it->first.c_str(), srcname.c_str())
 788              << endl;
 789
 790       // arrange to build it
 791       omf << "obj-m += " + sbasename + ".o" << endl; // NB: without <dir> prefix
 792       objs[it->first] = dir + "/" + sbasename + ".o";
 793     }
 794   omf.close();
 795
 796   // make the module
 797   vector<string> make_cmd = make_make_objs_cmd(s, dir);
 798   make_cmd.push_back ("-i"); // ignore errors, give rc 0 even in case of tracepoint header nits
 799   bool quiet = (s.verbose < 4);
 800   int rc = run_make_cmd(s, make_cmd, quiet, quiet);
 801   if (rc)
 802     s.set_try_server ();
 803
 804   // Sometimes we fail a tracequery due to PR9993 / PR11649 type
 805   // kernel trace header problems.  In this case, due to PR12729, we
 806   // used to get a lovely "Warning: make exited with status: 2" but no
 807   // other useful diagnostic.  -vvvv would let a user see what's up,
 808   // but the user can't fix the problem even with that.
 809
 810   return objs;
 811 }
 812
 813
 814 // Build a tiny kernel module to query type information
 815 static int
 816 make_typequery_kmod(systemtap_session& s, const vector<string>& headers, string& name)
 817 {
 818   static unsigned tick = 0;
 819   string basename("typequery_kmod_" + lex_cast(++tick));
 820
 821   // create a subdirectory for the module
 822   string dir(s.tmpdir + "/" + basename);
 823   if (create_dir(dir.c_str()) != 0)
 824     {
 825       s.print_warning("failed to create directory for querying types.");
 826       s.set_try_server ();
 827       return 1;
 828     }
 829
 830   name = dir + "/" + basename + ".ko";
 831
 832   // create a simple Makefile
 833   string makefile(dir + "/Makefile");
 834   ofstream omf(makefile.c_str());
 835   omf << "EXTRA_CFLAGS := -g -fno-eliminate-unused-debug-types" << endl;
 836
 837   // RHBZ 655231: later rhel6 kernels' module-signing kbuild logic breaks out-of-tree modules
 838   omf << "CONFIG_MODULE_SIG := n" << endl;
 839
 840   // NB: We use -include instead of #include because that gives us more power.
 841   // Using #include searches relative to the source's path, which in this case
 842   // is /tmp/..., so that's not helpful.  Using -include will search relative
 843   // to the cwd, which will be the kernel build root.  This means if you have a
 844   // full kernel build tree, it's possible to get at types that aren't in the
 845   // normal include path, e.g.:
 846   //    @cast(foo, "bsd_acct_struct", "kernel<kernel/acct.c>")->...
 847   omf << "CFLAGS_" << basename << ".o :=";
 848   for (size_t i = 0; i < headers.size(); ++i)
 849     omf << " -include " << lex_cast_qstring(headers[i]); // XXX right quoting?
 850   omf << endl;
 851
 852   omf << "obj-m := " + basename + ".o" << endl;
 853   omf.close();
 854
 855   // create our empty source file
 856   string source(dir + "/" + basename + ".c");
 857   ofstream osrc(source.c_str());
 858   osrc.close();
 859
 860   // make the module
 861   vector<string> make_cmd = make_make_cmd(s, dir);
 862   bool quiet = (s.verbose < 4);
 863   int rc = run_make_cmd(s, make_cmd, quiet, quiet);
 864   if (rc)
 865     s.set_try_server ();
 866   return rc;
 867 }
 868
 869
 870 // Build a tiny user module to query type information
 871 static int
 872 make_typequery_umod(systemtap_session& s, const vector<string>& headers, string& name)
 873 {
 874   static unsigned tick = 0;
 875
 876   name = s.tmpdir + "/typequery_umod_" + lex_cast(++tick) + ".so";
 877
 878   // make the module
 879   //
 880   // NB: As with kmod, using -include makes relative paths more useful.  The
 881   // cwd in this case will be the cwd of stap itself though, which may be
 882   // trickier to deal with.  It might be better to "cd `dirname $script`"
 883   // first...
 884   vector<string> cmd;
 885   cmd.push_back("gcc");
 886   cmd.push_back("-shared");
 887   cmd.push_back("-g");
 888   cmd.push_back("-fno-eliminate-unused-debug-types");
 889   cmd.push_back("-xc");
 890   cmd.push_back("/dev/null");
 891   cmd.push_back("-o");
 892   cmd.push_back(name);
 893   for (size_t i = 0; i < headers.size(); ++i)
 894     {
 895       cmd.push_back("-include");
 896       cmd.push_back(headers[i]);
 897     }
 898   bool quiet = (s.verbose < 4);
 899   int rc = stap_system (s.verbose, cmd, quiet, quiet);
 900   if (rc)
 901     s.set_try_server ();
 902   return rc;
 903 }
 904
 905
 906 int
 907 make_typequery(systemtap_session& s, string& module)
 908 {
 909   int rc;
 910   string new_module;
 911   vector<string> headers;
 912   bool kernel = startswith(module, "kernel");
 913
 914   for (size_t end, i = kernel ? 6 : 0; i < module.size(); i = end + 1)
 915     {
 916       if (module[i] != '<')
 917         return -1;
 918       end = module.find('>', ++i);
 919       if (end == string::npos)
 920         return -1;
 921       string header = module.substr(i, end - i);
 922       vector<string> matches;
 923       if (regexp_match(header, "^[a-zA-Z0-9/_.+-]+$", matches))
 924         s.print_warning("skipping malformed @cast header \""+ header + "\"");
 925       else
 926         headers.push_back(header);
 927     }
 928   if (headers.empty())
 929     return -1;
 930
 931   if (kernel)
 932       rc = make_typequery_kmod(s, headers, new_module);
 933   else
 934       rc = make_typequery_umod(s, headers, new_module);
 935
 936   if (!rc)
 937     module = new_module;
 938
 939   return rc;
 940 }
 941
 942 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */