| |
| /* This is a replacement for the standard libpthread.so. It is loaded |
| as part of the client's image (if required) and directs pthread |
| calls through to Valgrind's request mechanism. |
| |
| A couple of caveats. |
| |
| 1. Since it's a binary-compatible replacement for an existing library, |
| we must take care to used exactly the same data layouts, etc, as |
| the standard pthread.so does. |
| |
| 2. Since this runs as part of the client, there are no specific |
| restrictions on what headers etc we can include, so long as |
| this libpthread.so does not end up having dependencies on .so's |
| which the real one doesn't. |
| |
| Later ... it appears we cannot call file-related stuff in libc here, |
| perhaps fair enough. Be careful what you call from here. Even exit() |
| doesn't work (gives infinite recursion and then stack overflow); hence |
| myexit(). Also fprintf doesn't seem safe. |
| */ |
| |
| #include "valgrind.h" /* For the request-passing mechanism */ |
| #include "vg_include.h" /* For the VG_USERREQ__* constants */ |
| |
| #include <pthread.h> |
| #include <unistd.h> |
| #include <string.h> |
| |
| /* --------------------------------------------------------------------- |
| Mini-configuration. |
| ------------------------------------------------------------------ */ |
| |
| /* Set to 1 to see IGNORED debugging messages. */ |
| static int show_IGNORED = 0; |
| |
| |
| /* --------------------------------------------------------------------- |
| Helpers. We have to be pretty self-sufficient. |
| ------------------------------------------------------------------ */ |
| |
| static |
| void myexit ( int arg ) |
| { |
| int __res; |
| __asm__ volatile ("movl %%ecx, %%ebx ; int $0x80" |
| : "=a" (__res) |
| : "0" (__NR_exit), |
| "c" (arg) ); |
| /* We don't bother to mention the fact that this asm trashes %ebx, |
| since it won't return. If you ever do let it return ... fix |
| this! */ |
| } |
| |
| |
| /* Give up without using printf etc, since they seem to give |
| segfaults. */ |
| static |
| void ensure_valgrind ( char* caller ) |
| { |
| char* str; |
| int is_valgrind = RUNNING_ON_VALGRIND; |
| if (!is_valgrind) { |
| str = "\nvalgrind-ed process: vg_libpthread.so: " |
| "pthread call when\n"; |
| write(2, str, strlen(str)); |
| str = "not running on valgrind; aborting! " |
| "This is probably a bug in\n"; |
| write(2, str, strlen(str)); |
| str = "valgrind. Please report it to me at: " |
| "jseward@acm.org. Thanks.\n"; |
| write(2, str, strlen(str)); |
| str = "unexpectedly called function is: "; |
| write(2, str, strlen(str)); |
| write(2, caller, strlen(caller)); |
| str = "\n\n"; |
| write(2, str, strlen(str)); |
| myexit(1); |
| } |
| } |
| |
| |
| static |
| void barf ( char* str ) |
| { |
| char buf[100]; |
| buf[0] = 0; |
| strcat(buf, "\nvg_libpthread.so: "); |
| strcat(buf, str); |
| strcat(buf, "\n\n"); |
| write(2, buf, strlen(buf)); |
| myexit(1); |
| } |
| |
| |
| static void ignored ( char* msg ) |
| { |
| char* ig = "vg_libpthread.so: IGNORED call to: "; |
| if (!show_IGNORED) return; |
| write(2, ig, strlen(ig)); |
| write(2, msg, strlen(msg)); |
| ig = "\n"; |
| write(2, ig, strlen(ig)); |
| } |
| |
| |
| /* --------------------------------------------------------------------- |
| Pass pthread_ calls to Valgrind's request mechanism. |
| ------------------------------------------------------------------ */ |
| |
| int |
| pthread_create (pthread_t *__restrict __thread, |
| __const pthread_attr_t *__restrict __attr, |
| void *(*__start_routine) (void *), |
| void *__restrict __arg) |
| { |
| int res; |
| ensure_valgrind("pthread_create"); |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_CREATE, |
| __thread, __attr, __start_routine, __arg); |
| return res; |
| } |
| |
| |
| |
| int |
| pthread_join (pthread_t __th, void **__thread_return) |
| { |
| int res; |
| ensure_valgrind("pthread_join"); |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_JOIN, |
| __th, __thread_return, 0, 0); |
| return res; |
| } |
| |
| |
| /* What are these? Anybody know? I don't. */ |
| |
| void _pthread_cleanup_push_defer ( void ) |
| { |
| // char* str = "_pthread_cleanup_push_defer\n"; |
| // write(2, str, strlen(str)); |
| } |
| |
| void _pthread_cleanup_pop_restore ( void ) |
| { |
| // char* str = "_pthread_cleanup_pop_restore\n"; |
| // write(2, str, strlen(str)); |
| } |
| |
| |
| static int thread_specific_errno[VG_N_THREADS]; |
| |
| int* __errno_location ( void ) |
| { |
| int tid; |
| ensure_valgrind("__errno_location"); |
| VALGRIND_MAGIC_SEQUENCE(tid, 0 /* default */, |
| VG_USERREQ__PTHREAD_GET_THREADID, |
| 0, 0, 0, 0); |
| /* 'cos I'm paranoid ... */ |
| if (tid < 0 || tid >= VG_N_THREADS) |
| barf("__errno_location: invalid ThreadId"); |
| return & thread_specific_errno[tid]; |
| } |
| |
| |
| int pthread_mutexattr_init(pthread_mutexattr_t *attr) |
| { |
| ignored("pthread_mutexattr_init"); |
| return 0; |
| } |
| |
| int pthread_mutex_init(pthread_mutex_t *mutex, |
| const pthread_mutexattr_t *mutexattr) |
| { |
| int res; |
| // char* str = "pthread_mutex_init\n"; |
| // write(2, str, strlen(str)); |
| ensure_valgrind("pthread_mutex_init"); |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_MUTEX_INIT, |
| mutex, mutexattr, 0, 0); |
| return res; |
| } |
| |
| int pthread_mutexattr_destroy(pthread_mutexattr_t *attr) |
| { |
| ignored("pthread_mutexattr_destroy"); |
| return 0; |
| } |
| |
| int pthread_mutex_lock(pthread_mutex_t *mutex) |
| { |
| int res; |
| if (!(RUNNING_ON_VALGRIND)) { |
| char* str = "pthread_mutex_lock-NOT-INSIDE-VALGRIND\n"; |
| write(2, str, strlen(str)); |
| return 0; |
| } else { |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_MUTEX_LOCK, |
| mutex, 0, 0, 0); |
| return res; |
| } |
| } |
| |
| int pthread_mutex_unlock(pthread_mutex_t *mutex) |
| { |
| int res; |
| if (!(RUNNING_ON_VALGRIND)) { |
| char* str = "pthread_mutex_unlock-NOT-INSIDE-VALGRIND\n"; |
| write(2, str, strlen(str)); |
| return 0; |
| } else { |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_MUTEX_UNLOCK, |
| mutex, 0, 0, 0); |
| return res; |
| } |
| } |
| |
| pthread_t pthread_self(void) |
| { |
| int tid; |
| ensure_valgrind("pthread_self"); |
| VALGRIND_MAGIC_SEQUENCE(tid, 0 /* default */, |
| VG_USERREQ__PTHREAD_GET_THREADID, |
| 0, 0, 0, 0); |
| if (tid < 0 || tid >= VG_N_THREADS) |
| barf("pthread_self: invalid ThreadId"); |
| return tid; |
| } |
| |
| int pthread_mutex_destroy(pthread_mutex_t *mutex) |
| { |
| int res; |
| if (!(RUNNING_ON_VALGRIND)) { |
| char* str = "pthread_mutex_destroy-NOT-INSIDE-VALGRIND\n"; |
| write(2, str, strlen(str)); |
| return 0; |
| } else { |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_MUTEX_DESTROY, |
| mutex, 0, 0, 0); |
| } |
| return res; |
| } |
| |
| |
| int pthread_setcanceltype(int type, int *oldtype) |
| { |
| ignored("pthread_setcanceltype"); |
| return 0; |
| } |
| |
| |
| int pthread_cancel(pthread_t thread) |
| { |
| int res; |
| ensure_valgrind("pthread_cancel"); |
| VALGRIND_MAGIC_SEQUENCE(res, 0 /* default */, |
| VG_USERREQ__PTHREAD_CANCEL, |
| thread, 0, 0, 0); |
| return res; |
| } |
| |
| |
| |
| int pthread_key_create(pthread_key_t *key, |
| void (*destr_function) (void *)) |
| { |
| ignored("pthread_key_create"); |
| return 0; |
| } |
| |
| int pthread_key_delete(pthread_key_t key) |
| { |
| ignored("pthread_key_delete"); |
| return 0; |
| } |
| |
| int pthread_setspecific(pthread_key_t key, const void *pointer) |
| { |
| ignored("pthread_setspecific"); |
| return 0; |
| } |
| |
| void * pthread_getspecific(pthread_key_t key) |
| { |
| ignored("pthread_setspecific"); |
| return NULL; |
| } |
| |
| /* --------------------------------------------------------------------- |
| These are here (I think) because they are deemed cancellation |
| points by POSIX. For the moment we'll simply pass the call along |
| to the corresponding thread-unaware (?) libc routine. |
| ------------------------------------------------------------------ */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <signal.h> |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| |
| extern |
| int __libc_sigaction |
| (int signum, |
| const struct sigaction *act, |
| struct sigaction *oldact); |
| int sigaction(int signum, |
| const struct sigaction *act, |
| struct sigaction *oldact) |
| { |
| // char* str = "sigaction\n"; |
| // write(2, str, strlen(str)); |
| return __libc_sigaction(signum, act, oldact); |
| } |
| |
| |
| extern |
| int __libc_connect(int sockfd, |
| const struct sockaddr *serv_addr, |
| socklen_t addrlen); |
| int connect(int sockfd, |
| const struct sockaddr *serv_addr, |
| socklen_t addrlen) |
| { |
| // char* str = "connect\n"; |
| // write(2, str, strlen(str)); |
| return __libc_connect(sockfd, serv_addr, addrlen); |
| } |
| |
| |
| extern |
| int __libc_fcntl(int fd, int cmd, long arg); |
| int fcntl(int fd, int cmd, long arg) |
| { |
| // char* str = "fcntl\n"; |
| // write(2, str, strlen(str)); |
| return __libc_fcntl(fd, cmd, arg); |
| } |
| |
| |
| extern |
| ssize_t __libc_write(int fd, const void *buf, size_t count); |
| ssize_t write(int fd, const void *buf, size_t count) |
| { |
| // char* str = "write\n"; |
| // write(2, str, strlen(str)); |
| return __libc_write(fd, buf, count); |
| } |
| |
| |
| extern |
| ssize_t __libc_read(int fd, void *buf, size_t count); |
| ssize_t read(int fd, void *buf, size_t count) |
| { |
| // char* str = "read\n"; |
| // write(2, str, strlen(str)); |
| return __libc_read(fd, buf, count); |
| } |
| |
| |
| extern |
| int __libc_open(const char *pathname, int flags); |
| int open(const char *pathname, int flags) |
| { |
| // char* str = "open\n"; |
| // write(2, str, strlen(str)); |
| return __libc_open(pathname, flags); |
| } |
| |
| |
| extern |
| int __libc_close(int fd); |
| int close(int fd) |
| { |
| // char* str = "open\n"; |
| // write(2, str, strlen(str)); |
| return __libc_close(fd); |
| } |
| |
| |
| extern |
| int __libc_accept(int s, struct sockaddr *addr, socklen_t *addrlen); |
| int accept(int s, struct sockaddr *addr, socklen_t *addrlen) |
| { |
| // char* str = "accept\n"; |
| // write(2, str, strlen(str)); |
| return __libc_accept(s, addr, addrlen); |
| } |
| |
| |
| extern |
| pid_t __libc_fork(void); |
| pid_t fork(void) |
| { |
| // char* str = "fork\n"; |
| // write(2, str, strlen(str)); |
| return __libc_fork(); |
| } |
| |
| |
| extern |
| pid_t __libc_waitpid(pid_t pid, int *status, int options); |
| pid_t waitpid(pid_t pid, int *status, int options) |
| { |
| // char* str = "waitpid\n"; |
| // write(2, str, strlen(str)); |
| return __libc_waitpid(pid, status, options); |
| } |
| |
| |
| extern |
| int __libc_nanosleep(const struct timespec *req, struct timespec *rem); |
| int nanosleep(const struct timespec *req, struct timespec *rem) |
| { |
| return __libc_nanosleep(req, rem); |
| } |
| |
| extern |
| int __libc_fsync(int fd); |
| int fsync(int fd) |
| { |
| return __libc_fsync(fd); |
| } |
| |
| extern |
| off_t __libc_lseek(int fildes, off_t offset, int whence); |
| off_t lseek(int fildes, off_t offset, int whence) |
| { |
| return __libc_lseek(fildes, offset, whence); |
| } |
| |
| /*--------------------------------------------------*/ |
| |
| /* I've no idea what these are, but they get called quite a lot. |
| Anybody know? */ |
| |
| #undef _IO_flockfile |
| void _IO_flockfile ( _IO_FILE * file ) |
| { |
| // char* str = "_IO_flockfile\n"; |
| // write(2, str, strlen(str)); |
| // barf("_IO_flockfile"); |
| } |
| |
| #undef _IO_funlockfile |
| void _IO_funlockfile ( _IO_FILE * file ) |
| { |
| // char* str = "_IO_funlockfile\n"; |
| // write(2, str, strlen(str)); |
| //barf("_IO_funlockfile"); |
| } |
| |
| /*--------------------------------------------------*/ |
| |
| #include "vg_kerneliface.h" |
| |
| static |
| __inline__ |
| int is_kerror ( int res ) |
| { |
| if (res >= -4095 && res <= -1) |
| return 1; |
| else |
| return 0; |
| } |
| |
| |
| static |
| int my_do_syscall1 ( int syscallno, int arg1 ) |
| { |
| int __res; |
| __asm__ volatile ("pushl %%ebx; movl %%edx,%%ebx ; int $0x80 ; popl %%ebx" |
| : "=a" (__res) |
| : "0" (syscallno), |
| "d" (arg1) ); |
| return __res; |
| } |
| |
| static |
| int my_do_syscall2 ( int syscallno, |
| int arg1, int arg2 ) |
| { |
| int __res; |
| __asm__ volatile ("pushl %%ebx; movl %%edx,%%ebx ; int $0x80 ; popl %%ebx" |
| : "=a" (__res) |
| : "0" (syscallno), |
| "d" (arg1), |
| "c" (arg2) ); |
| return __res; |
| } |
| |
| static |
| int do_syscall_select( int n, |
| vki_fd_set* readfds, |
| vki_fd_set* writefds, |
| vki_fd_set* exceptfds, |
| struct vki_timeval * timeout ) |
| { |
| int res; |
| int args[5]; |
| args[0] = n; |
| args[1] = (int)readfds; |
| args[2] = (int)writefds; |
| args[3] = (int)exceptfds; |
| args[4] = (int)timeout; |
| res = my_do_syscall1(__NR_select, (int)(&(args[0])) ); |
| if (is_kerror(res)) { |
| * (__errno_location()) = -res; |
| return -1; |
| } else { |
| return res; |
| } |
| } |
| |
| |
| /* This is a wrapper round select(), which makes it thread-safe, |
| meaning that only this thread will block, rather than the entire |
| process. This wrapper in turn depends on nanosleep() not to block |
| the entire process, but I think (hope? suspect?) that POSIX |
| pthreads guarantees that to be the case. |
| |
| Basic idea is: modify the timeout parameter to select so that it |
| returns immediately. Poll like this until select returns non-zero, |
| indicating something interesting happened, or until our time is up. |
| Space out the polls with nanosleeps of say 20 milliseconds, which |
| is required to be nonblocking; this allows other threads to run. |
| */ |
| #include <assert.h> |
| |
| |
| int select ( int n, |
| fd_set *rfds, |
| fd_set *wfds, |
| fd_set *xfds, |
| struct timeval *timeout ) |
| { |
| int res; |
| fd_set rfds_copy; |
| fd_set wfds_copy; |
| fd_set xfds_copy; |
| struct vki_timeval t_now; |
| struct vki_timeval t_end; |
| struct vki_timeval zero_timeout; |
| struct vki_timespec nanosleep_interval; |
| |
| ensure_valgrind("select"); |
| |
| /* We assume that the kernel and libc data layouts are identical |
| for the following types. These asserts provide a crude |
| check. */ |
| if (sizeof(fd_set) != sizeof(vki_fd_set) |
| || sizeof(struct timeval) != sizeof(struct vki_timeval)) |
| barf("valgrind's hacky non-blocking select(): data sizes error"); |
| |
| /* If a zero timeout specified, this call is harmless. */ |
| if (timeout && timeout->tv_sec == 0 && timeout->tv_usec == 0) |
| return do_syscall_select( n, (vki_fd_set*)rfds, |
| (vki_fd_set*)wfds, |
| (vki_fd_set*)xfds, |
| (struct vki_timeval*)timeout); |
| |
| /* If a timeout was specified, set t_end to be the end wallclock |
| time. */ |
| if (timeout) { |
| res = my_do_syscall2(__NR_gettimeofday, (int)&t_now, (int)NULL); |
| assert(res == 0); |
| t_end = t_now; |
| t_end.tv_usec += timeout->tv_usec; |
| t_end.tv_sec += timeout->tv_sec; |
| if (t_end.tv_usec >= 1000000) { |
| t_end.tv_usec -= 1000000; |
| t_end.tv_sec += 1; |
| } |
| /* Stay sane ... */ |
| assert (t_end.tv_sec > t_now.tv_sec |
| || (t_end.tv_sec == t_now.tv_sec |
| && t_end.tv_usec >= t_now.tv_usec)); |
| } |
| |
| /* fprintf(stderr, "MY_SELECT: before loop\n"); */ |
| |
| /* Either timeout == NULL, meaning wait indefinitely, or timeout != |
| NULL, in which case t_end holds the end time. */ |
| while (1) { |
| if (timeout) { |
| res = my_do_syscall2(__NR_gettimeofday, (int)&t_now, (int)NULL); |
| assert(res == 0); |
| if (t_now.tv_sec > t_end.tv_sec |
| || (t_now.tv_sec == t_end.tv_sec |
| && t_now.tv_usec > t_end.tv_usec)) { |
| /* timeout; nothing interesting happened. */ |
| if (rfds) FD_ZERO(rfds); |
| if (wfds) FD_ZERO(wfds); |
| if (xfds) FD_ZERO(xfds); |
| return 0; |
| } |
| } |
| |
| /* These could be trashed each time round the loop, so restore |
| them each time. */ |
| if (rfds) rfds_copy = *rfds; |
| if (wfds) wfds_copy = *wfds; |
| if (xfds) xfds_copy = *xfds; |
| |
| zero_timeout.tv_sec = zero_timeout.tv_usec = 0; |
| |
| res = do_syscall_select( n, |
| rfds ? (vki_fd_set*)(&rfds_copy) : NULL, |
| wfds ? (vki_fd_set*)(&wfds_copy) : NULL, |
| xfds ? (vki_fd_set*)(&xfds_copy) : NULL, |
| & zero_timeout ); |
| if (res < 0) { |
| /* some kind of error (including EINTR); errno is set, so just |
| return. The sets are unspecified in this case. */ |
| return res; |
| } |
| if (res > 0) { |
| /* one or more fds is ready. Copy out resulting sets and |
| return. */ |
| if (rfds) *rfds = rfds_copy; |
| if (wfds) *wfds = wfds_copy; |
| if (xfds) *xfds = xfds_copy; |
| return res; |
| } |
| /* fprintf(stderr, "MY_SELECT: nanosleep\n"); */ |
| /* nanosleep and go round again */ |
| nanosleep_interval.tv_sec = 0; |
| nanosleep_interval.tv_nsec = 20 * 1000 * 1000; /* 20 milliseconds */ |
| /* It's critical here that valgrind's nanosleep implementation |
| is nonblocking. */ |
| (void)my_do_syscall2(__NR_nanosleep, |
| (int)(&nanosleep_interval), (int)NULL); |
| } |
| } |