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1 
2 /*--------------------------------------------------------------------*/
3 /*--- The thread state.                     pub_core_threadstate.h ---*/
4 /*--------------------------------------------------------------------*/
5 
6 /*
7    This file is part of Valgrind, a dynamic binary instrumentation
8    framework.
9 
10    Copyright (C) 2000-2012 Julian Seward
11       jseward@acm.org
12 
13    This program is free software; you can redistribute it and/or
14    modify it under the terms of the GNU General Public License as
15    published by the Free Software Foundation; either version 2 of the
16    License, or (at your option) any later version.
17 
18    This program is distributed in the hope that it will be useful, but
19    WITHOUT ANY WARRANTY; without even the implied warranty of
20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21    General Public License for more details.
22 
23    You should have received a copy of the GNU General Public License
24    along with this program; if not, write to the Free Software
25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26    02111-1307, USA.
27 
28    The GNU General Public License is contained in the file COPYING.
29 */
30 
31 #ifndef __PUB_CORE_THREADSTATE_H
32 #define __PUB_CORE_THREADSTATE_H
33 
34 //--------------------------------------------------------------------
35 // PURPOSE: This module defines the ThreadState type and the
36 // VG_(threads)[] data structure which holds all the important thread
37 // state.  It also defines some simple operations on the data structure
38 // that don't require any external help.  (m_scheduler does the complex
39 // stuff).
40 //--------------------------------------------------------------------
41 
42 #include "pub_tool_threadstate.h"
43 
44 /*------------------------------------------------------------*/
45 /*--- Types                                                ---*/
46 /*------------------------------------------------------------*/
47 
48 /*
49    Thread state machine:
50 
51    Empty -> Init -> Runnable <=> WaitSys/Yielding
52      ^                 |
53      \---- Zombie -----/
54  */
55 typedef
56    enum ThreadStatus {
57       VgTs_Empty,      /* this slot is not in use */
58       VgTs_Init,       /* just allocated */
59       VgTs_Runnable,   /* ready to run */
60       VgTs_WaitSys,    /* waiting for a syscall to complete */
61       VgTs_Yielding,   /* temporarily yielding the CPU */
62       VgTs_Zombie,     /* transient state just before exiting */
63    }
64    ThreadStatus;
65 
66 /* Return codes from the scheduler. */
67 typedef
68    enum {
69       VgSrc_None,	 /* not exiting yet */
70       VgSrc_ExitThread,  /* just this thread is exiting */
71       VgSrc_ExitProcess, /* entire process is exiting */
72       VgSrc_FatalSig	 /* Killed by the default action of a fatal
73 			    signal */
74    }
75    VgSchedReturnCode;
76 
77 
78 #if defined(VGA_x86)
79    typedef VexGuestX86State   VexGuestArchState;
80 #elif defined(VGA_amd64)
81    typedef VexGuestAMD64State VexGuestArchState;
82 #elif defined(VGA_ppc32)
83    typedef VexGuestPPC32State VexGuestArchState;
84 #elif defined(VGA_ppc64)
85    typedef VexGuestPPC64State VexGuestArchState;
86 #elif defined(VGA_arm)
87    typedef VexGuestARMState   VexGuestArchState;
88 #elif defined(VGA_s390x)
89    typedef VexGuestS390XState VexGuestArchState;
90 #elif defined(VGA_mips32)
91    typedef VexGuestMIPS32State VexGuestArchState;
92 #else
93 #  error Unknown architecture
94 #endif
95 
96 /* Forward declarations */
97 struct SyscallStatus;
98 struct SyscallArgs;
99 
100 /* Architecture-specific thread state */
101 typedef
102    struct {
103       /* --- BEGIN vex-mandated guest state --- */
104 
105       /* Note that for code generation reasons, we require that the
106          guest state area, its two shadows, and the spill area, are
107          16-aligned and have 16-aligned sizes, and there are no holes
108          in between.  This is checked by do_pre_run_checks() in
109          scheduler.c. */
110 
111       /* Saved machine context. */
112       VexGuestArchState vex __attribute__((aligned(16)));
113 
114       /* Saved shadow context (2 copies). */
115       VexGuestArchState vex_shadow1 __attribute__((aligned(16)));
116       VexGuestArchState vex_shadow2 __attribute__((aligned(16)));
117 
118       /* Spill area. */
119       UChar vex_spill[LibVEX_N_SPILL_BYTES] __attribute__((aligned(16)));
120 
121       /* --- END vex-mandated guest state --- */
122    }
123    ThreadArchState;
124 
125 
126 /* OS-specific thread state.  IMPORTANT: if you add fields to this,
127    you _must_ add code to os_state_clear() to initialise those
128    fields. */
129 typedef
130    struct {
131       /* who we are */
132       Int lwpid;        // PID of kernel task  (Darwin: Mach thread)
133       Int threadgroup;  // thread group id
134 
135       ThreadId parent;  // parent tid (if any)
136 
137       /* runtime details */
138       Addr valgrind_stack_base;    // Valgrind's stack (VgStack*)
139       Addr valgrind_stack_init_SP; // starting value for SP
140 
141       /* exit details */
142       Word exitcode; // in the case of exitgroup, set by someone else
143       Int  fatalsig; // fatal signal
144 
145 #     if defined(VGO_darwin)
146       // Mach trap POST handler as chosen by PRE
147       void (*post_mach_trap_fn)(ThreadId tid,
148                                 struct SyscallArgs *, struct SyscallStatus *);
149 
150       // This thread's pthread
151       Addr pthread;
152 
153       // Argument passed when thread started
154       Addr func_arg;
155 
156       // Synchronization between child thread and parent thread's POST wrapper
157       semaphore_t child_go;
158       semaphore_t child_done;
159 
160       // Workqueue re-entry
161       // (setjmp in PRE(workq_ops), longjmp in wqthread_hijack)
162       // DDD: JRS fixme: this comment is no longer correct; wq_jmpbuf is
163       // never used, and there is no such setjmp or longjmp pair.
164       // I guess we could leave wq_jmpbuf_valid in place though, since
165       // it does allow for an assertion in ML_(wqthread_continue_NORETURN).
166       Bool wq_jmpbuf_valid;
167       //jmp_buf wq_jmpbuf;
168 
169       // Values saved from transient Mach RPC messages
170       Addr remote_port;  // destination for original message
171       Int msgh_id;       // outgoing message id
172       union {
173          struct {
174             Addr port;
175          } mach_port;
176          struct {
177             Int right;
178          } mach_port_allocate;
179          struct {
180             Addr port;
181             Int right;
182             Int delta;
183          } mach_port_mod_refs;
184          struct {
185             Addr task;
186             Addr name;
187             Int disposition;
188          } mach_port_insert_right;
189          struct {
190             Addr size;
191             int flags;
192          } vm_allocate;
193          struct {
194             Addr address;
195             Addr size;
196          } vm_deallocate;
197          struct {
198             Addr src;
199             Addr dst;
200             Addr size;
201          } vm_copy;
202          struct {
203             Addr address;
204             Addr size;
205             int set_maximum;
206             UWord new_protection;
207          } vm_protect;
208          struct {
209             Addr addr;
210             SizeT size;
211          } vm_read;
212          struct {
213             ULong addr;
214             ULong size;
215          } mach_vm_read;
216          struct {
217             Addr addr;
218             SizeT size;
219             Addr data;
220          } vm_read_overwrite;
221          struct {
222             Addr size;
223             int copy;
224             UWord protection;
225          } vm_map;
226          struct {
227             Addr size;
228          } vm_remap;
229          struct {
230             ULong size;
231             int flags;
232          } mach_vm_allocate;
233          struct {
234             ULong address;
235             ULong size;
236          } mach_vm_deallocate;
237          struct {
238             ULong address;
239             ULong size;
240             int set_maximum;
241             unsigned int new_protection;
242          } mach_vm_protect;
243          struct {
244             ULong size;
245             int copy;
246             UWord protection;
247          } mach_vm_map;
248          struct {
249             Addr thread;
250             UWord flavor;
251          } thread_get_state;
252          struct {
253             Addr address;
254          } io_connect_unmap_memory;
255          struct {
256             int which_port;
257          } task_get_special_port;
258          struct {
259             char *service_name;
260          } bootstrap_look_up;
261          struct {
262             vki_size_t size;
263          } WindowServer_29828;
264          struct {
265             Int access_rights;
266          } WindowServer_29831;
267          struct {
268             char *path;
269          } io_registry_entry_from_path;
270       } mach_args;
271 #     endif
272 
273    }
274    ThreadOSstate;
275 
276 
277 /* Overall thread state */
278 typedef struct {
279    /* ThreadId == 0 (and hence vg_threads[0]) is NEVER USED.
280       The thread identity is simply the index in vg_threads[].
281       ThreadId == 1 is the root thread and has the special property
282       that we don't try and allocate or deallocate its stack.  For
283       convenience of generating error message, we also put the
284       ThreadId in this tid field, but be aware that it should
285       ALWAYS == the index in vg_threads[]. */
286    ThreadId tid;
287 
288    /* Current scheduling status. */
289    ThreadStatus status;
290 
291    /* This is set if the thread is in the process of exiting for any
292       reason.  The precise details of the exit are in the OS-specific
293       state. */
294    VgSchedReturnCode exitreason;
295 
296    /* Architecture-specific thread state. */
297    ThreadArchState arch;
298 
299    /* This thread's blocked-signals mask.  Semantics is that for a
300       signal to be delivered to this thread, the signal must not be
301       blocked by this signal mask.  If more than one thread accepts a
302       signal, then it will be delivered to one at random.  If all
303       threads block the signal, it will remain pending until either a
304       thread unblocks it or someone uses sigwaitsig/sigtimedwait. */
305    vki_sigset_t sig_mask;
306 
307    /* tmp_sig_mask is usually the same as sig_mask, and is kept in
308       sync whenever sig_mask is changed.  The only time they have
309       different values is during the execution of a sigsuspend, where
310       tmp_sig_mask is the temporary mask which sigsuspend installs.
311       It is only consulted to compute the signal mask applied to a
312       signal handler. */
313    vki_sigset_t tmp_sig_mask;
314 
315    /* A little signal queue for signals we can't get the kernel to
316       queue for us.  This is only allocated as needed, since it should
317       be rare. */
318    struct SigQueue *sig_queue;
319 
320    /* Client stacks.  When a thread slot is freed, we don't deallocate its
321       stack; we just leave it lying around for the next use of the
322       slot.  If the next use of the slot requires a larger stack,
323       only then is the old one deallocated and a new one
324       allocated.
325 
326       For the main thread (threadid == 1), this mechanism doesn't
327       apply.  We don't know the size of the stack since we didn't
328       allocate it, and furthermore we never reallocate it. */
329 
330    /* The allocated size of this thread's stack */
331    SizeT client_stack_szB;
332 
333    /* Address of the highest legitimate word in this stack.  This is
334       used for error messages only -- not critical for execution
335       correctness.  Is is set for all stacks, specifically including
336       ThreadId == 1 (the main thread). */
337    Addr client_stack_highest_word;
338 
339    /* Alternate signal stack */
340    vki_stack_t altstack;
341 
342    /* OS-specific thread state */
343    ThreadOSstate os_state;
344 
345    /* Error disablement level.  A counter which allows selectively
346       disabling error reporting in threads.  When zero, reporting is
347       enabled.  When nonzero, it is disabled.  This is controlled by
348       the client request 'VG_USERREQ__CHANGE_ERR_DISABLEMENT'.  New
349       threads are always created with this as zero (errors
350       enabled). */
351    UInt err_disablement_level;
352 
353    /* Per-thread jmp_buf to resume scheduler after a signal */
354    Bool               sched_jmpbuf_valid;
355    VG_MINIMAL_JMP_BUF(sched_jmpbuf);
356 }
357 ThreadState;
358 
359 
360 /*------------------------------------------------------------*/
361 /*--- The thread table.                                    ---*/
362 /*------------------------------------------------------------*/
363 
364 /* A statically allocated array of threads.  NOTE: [0] is
365    never used, to simplify the simulation of initialisers for
366    LinuxThreads. */
367 extern ThreadState VG_(threads)[VG_N_THREADS];
368 
369 // The running thread.  m_scheduler should be the only other module
370 // to write to this.
371 extern ThreadId VG_(running_tid);
372 
373 
374 /*------------------------------------------------------------*/
375 /*--- Basic operations on the thread table.                ---*/
376 /*------------------------------------------------------------*/
377 
378 /* Initialize the m_threadstate module. */
379 void VG_(init_Threads)(void);
380 
381 // Convert a ThreadStatus to a string.
382 const HChar* VG_(name_of_ThreadStatus) ( ThreadStatus status );
383 
384 /* Get the ThreadState for a particular thread */
385 extern ThreadState *VG_(get_ThreadState) ( ThreadId tid );
386 
387 /* Check that tid is in range and denotes a non-Empty thread. */
388 extern Bool VG_(is_valid_tid) ( ThreadId tid );
389 
390 /* Returns true if a thread is currently running (ie, has the CPU lock) */
391 extern Bool VG_(is_running_thread)(ThreadId tid);
392 
393 /* Returns true if the thread is in the process of exiting */
394 extern Bool VG_(is_exiting)(ThreadId tid);
395 
396 /* Return the number of non-dead Threads */
397 extern Int VG_(count_living_threads)(void);
398 
399 /* Return the number of threads in VgTs_Runnable state */
400 extern Int VG_(count_runnable_threads)(void);
401 
402 /* Given an LWP id (ie, real kernel thread id), find the corresponding
403    ThreadId */
404 extern ThreadId VG_(lwpid_to_vgtid)(Int lwpid);
405 
406 #endif   // __PUB_CORE_THREADSTATE_H
407 
408 /*--------------------------------------------------------------------*/
409 /*--- end                                                          ---*/
410 /*--------------------------------------------------------------------*/
411