| |
| /*--------------------------------------------------------------------*/ |
| /*--- Pthreads library modelling. vg_pthreadmodel.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, an extensible x86 protected-mode |
| emulator for monitoring program execution on x86-Unixes. |
| |
| Copyright (C) 2005 Jeremy Fitzhardinge |
| jeremy@goop.org |
| |
| This program is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| /* |
| This file wraps the client's use of libpthread functions and calls |
| on vg_threadmodel.c to model the state of the the client's threads. |
| The intent is to 1) look for problem's in the client's use of the |
| pthread API, and 2) tell tools which care about thread events (eg, |
| helgrind). |
| |
| This file is intended to be implementation-independent. It assumes |
| that the client is using the same pthread.h as the one we include |
| here, but makes minimal assumptions about the actual structures |
| defined and so on (ie, the exact nature of pthread_t). |
| |
| (For now we assume there's a 1:1 relationship between pthread_t's |
| and Valgrind-visible threads; N:M implementations will need further |
| work.) |
| |
| The model is based on the pthread standard rather than any |
| particular implementation, in order to encourage portable use of |
| libpthread. On the other hand, we will probably need to implement |
| particular implementation extensions if they're widely used. |
| |
| One tricky problem we need to solve is the mapping between |
| pthread_t identifiers and internal thread identifiers. |
| */ |
| |
| #include "core.h" |
| |
| #if 0 |
| |
| #define __USE_GNU |
| #define __USE_UNIX98 |
| #include <pthread.h> |
| |
| static const Bool debug = False; |
| |
| static Bool check_wrappings(void); |
| |
| #define ENTER(x) \ |
| do { \ |
| if (VG_(clo_trace_pthreads)) \ |
| VG_(message)(Vg_DebugMsg, ">>> %d entering %s", \ |
| VG_(get_running_tid)(), #x); \ |
| } while(0) |
| |
| static const Char *pp_retval(enum return_type rt, Word retval) |
| { |
| static Char buf[50]; |
| |
| switch(rt) { |
| case RT_RETURN: |
| VG_(sprintf)(buf, "return %d 0x%x", retval, retval); |
| return buf; |
| |
| case RT_LONGJMP: |
| return "LONGJMPed out"; |
| |
| case RT_EXIT: |
| return "thread exit"; |
| } |
| return "??"; |
| } |
| |
| #define LEAVE(x, rt, retval) \ |
| do { \ |
| if (VG_(clo_trace_pthreads)) \ |
| VG_(message)(Vg_DebugMsg, "<<< %d leaving %s -> %s", \ |
| VG_(get_running_tid)(), #x, pp_retval(rt, retval)); \ |
| } while(0) |
| |
| struct pthread_map |
| { |
| pthread_t id; |
| |
| ThreadId tid; |
| }; |
| |
| static Int pthread_cmp(const void *v1, const void *v2) |
| { |
| const pthread_t *a = (const pthread_t *)v1; |
| const pthread_t *b = (const pthread_t *)v2; |
| |
| return VG_(memcmp)(a, b, sizeof(*a)); |
| } |
| |
| static SkipList sk_pthread_map = VG_SKIPLIST_INIT(struct pthread_map, id, pthread_cmp, |
| NULL, VG_AR_CORE); |
| |
| /* Find a ThreadId for a particular pthread_t; block until it becomes available */ |
| static ThreadId get_pthread_mapping(pthread_t id) |
| { |
| /* Nasty little spin loop; revise if this turns out to be a |
| problem. This should only spin for as long as it takes for the |
| child thread to register the pthread_t. */ |
| for(;;) { |
| struct pthread_map *m = VG_(SkipList_Find_Exact)(&sk_pthread_map, &id); |
| |
| if (m && m->tid != VG_INVALID_THREADID) |
| return m->tid; |
| |
| //VG_(printf)("find %x -> %p\n", id, m); |
| VG_(vg_yield)(); |
| } |
| } |
| |
| /* Create a mapping between a ThreadId and a pthread_t */ |
| static void pthread_id_mapping(ThreadId tid, Addr idp, UInt idsz) |
| { |
| pthread_t id = *(pthread_t *)idp; |
| struct pthread_map *m = VG_(SkipList_Find_Exact)(&sk_pthread_map, &id); |
| |
| if (debug) |
| VG_(printf)("Thread %d maps to %p\n", tid, id); |
| |
| if (m == NULL) { |
| m = VG_(SkipNode_Alloc)(&sk_pthread_map); |
| m->id = id; |
| m->tid = tid; |
| VG_(SkipList_Insert)(&sk_pthread_map, m); |
| } else { |
| if (m->tid != VG_INVALID_THREADID && m->tid != tid) |
| VG_(message)(Vg_UserMsg, "Thread %d is creating duplicate mapping for pthread identifier %x; previously mapped to %d\n", |
| tid, (UInt)id, m->tid); |
| m->tid = tid; |
| } |
| } |
| |
| static void check_thread_exists(ThreadId tid) |
| { |
| if (!VG_(tm_thread_exists)(tid)) { |
| if (debug) |
| VG_(printf)("creating thread %d\n", tid); |
| VG_(tm_thread_create)(VG_INVALID_THREADID, tid, False); |
| } |
| } |
| |
| static Addr startfunc_wrapper = 0; |
| |
| void VG_(pthread_startfunc_wrapper)(Addr wrapper) |
| { |
| startfunc_wrapper = wrapper; |
| } |
| |
| struct pthread_create_nonce { |
| Bool detached; |
| pthread_t *threadid; |
| }; |
| |
| static void *before_pthread_create(va_list va) |
| { |
| pthread_t *threadp = va_arg(va, pthread_t *); |
| const pthread_attr_t *attr = va_arg(va, const pthread_attr_t *); |
| void *(*start)(void *) = va_arg(va, void *(*)(void *)); |
| void *arg = va_arg(va, void *); |
| struct pthread_create_nonce *n; |
| struct vg_pthread_newthread_data *data; |
| ThreadState *tst; |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_create); |
| |
| /* Data is in the client heap and is freed by the client in the |
| startfunc_wrapper. */ |
| vg_assert(startfunc_wrapper != 0); |
| |
| tst = VG_(get_ThreadState)(VG_(get_running_tid)()); |
| |
| // XXX: why use TL_(malloc)() here? What characteristics does this |
| // allocation require? |
| // [Possible: When using a tool that replaces malloc(), we want to call |
| // the replacement version. Otherwise, we want to use VG_(cli_malloc)(). |
| // So we go via the default version of TL_(malloc)() in vg_default?] |
| tl_assert2(0, "read the comment in the code about this..."); |
| |
| // XXX: These three lines are going to have to change. They relied on |
| // TL_(malloc) being a weak symbol, and it just doesn't fit with the |
| // VG_(tdict) approach that we've switched to. The right way to do this |
| // will be to provide a function in the core that checks if |
| // VG_(tdict).malloc_malloc has been set; if so, it should |
| // call it, if not, it should call VG_(cli_malloc)(). |
| // VG_(tl_malloc_called_deliberately) = True; |
| // data = TL_(malloc)(sizeof(*data)); |
| // VG_(tl_malloc_called_deliberately) = False; |
| |
| VG_TRACK(pre_mem_write, Vg_CorePThread, tst->tid, "new thread data", |
| (Addr)data, sizeof(*data)); |
| data->startfunc = start; |
| data->arg = arg; |
| VG_TRACK(post_mem_write, (Addr)data, sizeof(*data)); |
| |
| /* Substitute arguments |
| XXX hack: need an API to do this. */ |
| ((Word *)tst->arch.m_esp)[3] = startfunc_wrapper; |
| ((Word *)tst->arch.m_esp)[4] = (Word)data; |
| |
| if (debug) |
| VG_(printf)("starting thread at wrapper %p\n", startfunc_wrapper); |
| |
| n = VG_(arena_malloc)(VG_AR_CORE, sizeof(*n)); |
| n->detached = attr && !!attr->__detachstate; |
| n->threadid = threadp; |
| |
| return n; |
| } |
| |
| static void after_pthread_create(void *nonce, enum return_type rt, Word retval) |
| { |
| struct pthread_create_nonce *n = (struct pthread_create_nonce *)nonce; |
| ThreadId tid = VG_(get_running_tid)(); |
| |
| if (n == NULL) |
| return; |
| |
| if (rt == RT_RETURN && retval == 0) { |
| if (!VG_(tm_thread_exists)(tid)) |
| VG_(tm_thread_create)(tid, get_pthread_mapping(*n->threadid), |
| n->detached); |
| else { |
| if (n->detached) |
| VG_(tm_thread_detach)(tid); |
| /* XXX set creator tid as well? */ |
| } |
| } |
| |
| VG_(arena_free)(VG_AR_CORE, n); |
| |
| LEAVE(pthread_create, rt, retval); |
| } |
| |
| static void *before_pthread_join(va_list va) |
| { |
| pthread_t pt_joinee = va_arg(va, pthread_t); |
| ThreadId joinee; |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_join); |
| |
| joinee = get_pthread_mapping(pt_joinee); |
| |
| VG_(tm_thread_join)(VG_(get_running_tid)(), joinee); |
| |
| return NULL; |
| } |
| |
| static void after_pthread_join(void *v, enum return_type rt, Word retval) |
| { |
| /* nothing to be done? */ |
| if (!check_wrappings()) |
| return; |
| |
| LEAVE(pthread_join, rt, retval); |
| } |
| |
| struct pthread_detach_data { |
| pthread_t id; |
| }; |
| |
| static void *before_pthread_detach(va_list va) |
| { |
| pthread_t id = va_arg(va, pthread_t); |
| struct pthread_detach_data *data; |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_detach); |
| |
| data = VG_(arena_malloc)(VG_AR_CORE, sizeof(*data)); |
| data->id = id; |
| |
| return data; |
| } |
| |
| static void after_pthread_detach(void *nonce, enum return_type rt, Word retval) |
| { |
| struct pthread_detach_data *data = (struct pthread_detach_data *)nonce; |
| ThreadId tid; |
| |
| if (data == NULL) |
| return; |
| |
| tid = get_pthread_mapping(data->id); |
| |
| VG_(arena_free)(VG_AR_CORE, data); |
| |
| if (rt == RT_RETURN && retval == 0) |
| VG_(tm_thread_detach)(tid); |
| |
| LEAVE(pthread_detach, rt, retval); |
| } |
| |
| |
| |
| static void *before_pthread_self(va_list va) |
| { |
| /* If pthread_t is a structure, then this might be passed a pointer |
| to the return value. On Linux/glibc, it's a simple scalar, so it is |
| returned normally. */ |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_self); |
| |
| check_thread_exists(VG_(get_running_tid)()); |
| return NULL; |
| } |
| |
| static void after_pthread_self(void *nonce, enum return_type rt, Word retval) |
| { |
| pthread_t ret = (pthread_t)retval; |
| |
| if (!check_wrappings()) |
| return; |
| |
| pthread_id_mapping(VG_(get_running_tid)(), (Addr)&ret, sizeof(ret)); |
| |
| LEAVE(pthread_self, rt, retval); |
| } |
| |
| |
| /* If a mutex hasn't been initialized, check it against all the static |
| initializers to see if it appears to have been statically |
| initialized. */ |
| static void check_mutex_init(ThreadId tid, pthread_mutex_t *mx) |
| { |
| static const pthread_mutex_t initializers[] = { |
| PTHREAD_MUTEX_INITIALIZER, |
| PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, |
| PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, |
| PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP, |
| }; |
| Int i; |
| |
| if (VG_(tm_mutex_exists)((Addr)mx)) |
| return; |
| |
| VG_TRACK(pre_mem_read, Vg_CorePThread, tid, "pthread_mutex_t", (Addr)mx, sizeof(*mx)); |
| |
| for(i = 0; i < sizeof(initializers)/sizeof(*initializers); i++) |
| if (VG_(memcmp)(&initializers[i], mx, sizeof(*mx)) == 0) { |
| VG_(tm_mutex_init)(tid, (Addr)mx); |
| break; |
| } |
| } |
| |
| static void *before_pthread_mutex_init(va_list va) |
| { |
| pthread_mutex_t *mx = va_arg(va, pthread_mutex_t *); |
| const pthread_mutexattr_t *attr = va_arg(va, const pthread_mutexattr_t *); |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_mutex_init); |
| |
| /* XXX look for recursive mutex */ |
| /* XXX look for non-process scope */ |
| (void)attr; |
| |
| return mx; |
| } |
| |
| static void after_pthread_mutex_init(void *nonce, enum return_type rt, Word retval) |
| { |
| if (!check_wrappings()) |
| return; |
| |
| if (rt == RT_RETURN && retval == 0) |
| VG_(tm_mutex_init)(VG_(get_running_tid)(), (Addr)nonce); |
| |
| LEAVE(pthread_mutex_init, rt, retval); |
| } |
| |
| static void *before_pthread_mutex_destroy(va_list va) |
| { |
| pthread_mutex_t *mx = va_arg(va, pthread_mutex_t *); |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_mutex_destroy); |
| |
| VG_(tm_mutex_destroy)(VG_(get_running_tid)(), (Addr)mx); |
| |
| return NULL; |
| } |
| |
| static void after_pthread_mutex_destroy(void *nonce, enum return_type rt, Word retval) |
| { |
| if (!check_wrappings()) |
| return; |
| |
| LEAVE(pthread_mutex_destroy, rt, retval); |
| } |
| |
| static void *before_pthread_mutex_lock(va_list va) |
| { |
| pthread_mutex_t *mx = va_arg(va, pthread_mutex_t *); |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_mutex_lock); |
| |
| if (debug) |
| VG_(printf)("%d locking %p\n", VG_(get_running_tid)(), mx); |
| check_thread_exists(VG_(get_running_tid)()); |
| check_mutex_init(VG_(get_running_tid)(), mx); /* mutex might be statically initialized */ |
| VG_(tm_mutex_trylock)(VG_(get_running_tid)(), (Addr)mx); |
| |
| return mx; |
| } |
| |
| static void after_pthread_mutex_lock(void *nonce, enum return_type rt, Word retval) |
| { |
| if (!check_wrappings()) |
| return; |
| |
| if (rt == RT_RETURN && retval == 0) |
| VG_(tm_mutex_acquire)(VG_(get_running_tid)(), (Addr)nonce); |
| else { |
| if (debug) |
| VG_(printf)("after mutex_lock failed: rt=%d ret=%d\n", rt, retval); |
| VG_(tm_mutex_giveup)(VG_(get_running_tid)(), (Addr)nonce); |
| } |
| |
| LEAVE(pthread_mutex_lock, rt, retval); |
| } |
| |
| static void *before_pthread_mutex_trylock(va_list va) |
| { |
| pthread_mutex_t *mx = va_arg(va, pthread_mutex_t *); |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_mutex_trylock); |
| |
| if (debug) |
| VG_(printf)("%d trylocking %p\n", VG_(get_running_tid)(), mx); |
| check_thread_exists(VG_(get_running_tid)()); |
| check_mutex_init(VG_(get_running_tid)(), mx); /* mutex might be statically initialized */ |
| VG_(tm_mutex_trylock)(VG_(get_running_tid)(), (Addr)mx); |
| |
| return mx; |
| } |
| |
| static void after_pthread_mutex_trylock(void *nonce, enum return_type rt, Word retval) |
| { |
| if (nonce == NULL) |
| return; |
| |
| if (rt == RT_RETURN && retval == 0) |
| VG_(tm_mutex_acquire)(VG_(get_running_tid)(), (Addr)nonce); |
| else { |
| if (debug) |
| VG_(printf)("after mutex_trylock failed: rt=%d ret=%d\n", rt, retval); |
| VG_(tm_mutex_giveup)(VG_(get_running_tid)(), (Addr)nonce); |
| } |
| |
| LEAVE(pthread_mutex_trylock, rt, retval); |
| } |
| |
| static void *before_pthread_mutex_unlock(va_list va) |
| { |
| pthread_mutex_t *mx = va_arg(va, pthread_mutex_t *); |
| |
| if (!check_wrappings()) |
| return NULL; |
| |
| ENTER(pthread_mutex_unlock); |
| |
| VG_(tm_mutex_tryunlock)(VG_(get_running_tid)(), (Addr)mx); |
| |
| return mx; |
| } |
| |
| static void after_pthread_mutex_unlock(void *nonce, enum return_type rt, Word retval) |
| { |
| if (nonce == NULL) |
| return; |
| |
| if (rt == RT_RETURN && retval == 0) |
| VG_(tm_mutex_unlock)(VG_(get_running_tid)(), (Addr)nonce); /* complete unlock */ |
| else |
| VG_(tm_mutex_acquire)(VG_(get_running_tid)(), (Addr)nonce); /* re-acquire */ |
| |
| LEAVE(pthread_mutex_unlock, rt, retval); |
| } |
| |
| |
| static struct pt_wraps { |
| const Char *name; |
| FuncWrapper wrapper; |
| const CodeRedirect *redir; |
| } wraps[] = { |
| #define WRAP(func, extra) { #func extra, { before_##func, after_##func } } |
| WRAP(pthread_create, "@@GLIBC_2.1"), /* XXX TODO: 2.0 ABI (?) */ |
| WRAP(pthread_join, ""), |
| WRAP(pthread_detach, ""), |
| |
| WRAP(pthread_self, ""), |
| |
| WRAP(pthread_mutex_init, ""), |
| WRAP(pthread_mutex_destroy, ""), |
| WRAP(pthread_mutex_lock, ""), |
| WRAP(pthread_mutex_trylock, ""), |
| WRAP(pthread_mutex_unlock, ""), |
| #undef WRAP |
| }; |
| |
| /* Check to see if all the wrappers are resolved */ |
| static Bool check_wrappings() |
| { |
| Int i; |
| static Bool ok = True; |
| static Bool checked = False; |
| |
| if (checked) |
| return ok; |
| |
| for(i = 0; i < sizeof(wraps)/sizeof(*wraps); i++) { |
| if (!VG_(is_resolved)(wraps[i].redir)) { |
| VG_(message)(Vg_DebugMsg, "Pthread wrapper for \"%s\" is not resolved", |
| wraps[i].name); |
| ok = False; |
| } |
| } |
| |
| if (startfunc_wrapper == 0) { |
| VG_(message)(Vg_DebugMsg, "Pthread wrapper for thread start function is not resolved"); |
| ok = False; |
| } |
| |
| if (!ok) |
| VG_(message)(Vg_DebugMsg, "Missing intercepts; model disabled"); |
| |
| checked = True; |
| return ok; |
| } |
| |
| /* |
| Set up all the wrappers for interesting functions. |
| */ |
| void VG_(pthread_init)() |
| { |
| Int i; |
| |
| for(i = 0; i < sizeof(wraps)/sizeof(*wraps); i++) { |
| //VG_(printf)("adding pthread wrapper for %s\n", wraps[i].name); |
| wraps[i].redir = VG_(add_wrapper)("soname:libpthread.so.0", |
| wraps[i].name, &wraps[i].wrapper); |
| } |
| VG_(tm_init)(); |
| VG_(tm_thread_create)(VG_INVALID_THREADID, VG_(master_tid), True); |
| } |
| |
| #else /* !0 */ |
| /* Stubs for now */ |
| //:: void VG_(pthread_init)() |
| //:: { |
| //:: } |
| //:: |
| //:: void VG_(pthread_startfunc_wrapper)(Addr wrapper) |
| //:: { |
| //:: } |
| #endif /* 0 */ |