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Diffstat (limited to 'src/daemon/ltdl-bind-now.c')
-rw-r--r-- | src/daemon/ltdl-bind-now.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/daemon/ltdl-bind-now.c b/src/daemon/ltdl-bind-now.c new file mode 100644 index 0000000..3492571 --- /dev/null +++ b/src/daemon/ltdl-bind-now.c @@ -0,0 +1,159 @@ +/*** + This file is part of PulseAudio. + + Copyright 2004-2008 Lennart Poettering + Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB + + PulseAudio is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of the License, + or (at your option) any later version. + + PulseAudio 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 Lesser General Public License + along with PulseAudio; if not, see <http://www.gnu.org/licenses/>. +***/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#ifdef HAVE_DLFCN_H +#include <dlfcn.h> +#endif + +#ifdef HAVE_SYS_DL_H +#include <sys/dl.h> +#endif + +#include <string.h> + +#include <ltdl.h> + +#include <pulsecore/i18n.h> +#include <pulsecore/macro.h> +#include <pulsecore/log.h> + +#include "ltdl-bind-now.h" + +#ifdef RTLD_NOW +#define PA_BIND_NOW RTLD_NOW +#elif defined(DL_NOW) +#define PA_BIND_NOW DL_NOW +#else +#undef PA_BIND_NOW +#endif + +#ifdef OS_IS_WIN32 +#undef PA_BIND_NOW +#endif + +#ifdef PA_BIND_NOW + +/* + To avoid lazy relocations during runtime in our RT threads we add + our own shared object loader with uses RTLD_NOW if it is + available. The standard ltdl loader prefers RTLD_LAZY. + + Please note that this loader doesn't have any influence on + relocations on any libraries that are already loaded into our + process, i.e. because the pulseaudio binary links directly to + them. To disable lazy relocations for those libraries it is possible + to set $LT_BIND_NOW before starting the pulseaudio binary. +*/ + +static lt_module bind_now_open(lt_user_data d, const char *fname, lt_dladvise advise) { + lt_module m; + + pa_assert(fname); + + if (!(m = dlopen(fname, PA_BIND_NOW))) { + pa_log(_("Failed to open module %s: %s"), fname, dlerror()); + lt_dlseterror(LT_ERROR_CANNOT_OPEN); + return NULL; + } + + return m; +} + +static int bind_now_close(lt_user_data d, lt_module m) { + + pa_assert(m); + + if (dlclose(m) != 0) { + lt_dlseterror(LT_ERROR_CANNOT_CLOSE); + return 1; + } + + return 0; +} + +static lt_ptr bind_now_find_sym(lt_user_data d, lt_module m, const char *symbol) { + lt_ptr ptr; + + pa_assert(m); + pa_assert(symbol); + + if (!(ptr = dlsym(m, symbol))) { + lt_dlseterror(LT_ERROR_SYMBOL_NOT_FOUND); + return NULL; + } + + return ptr; +} + +static lt_dlvtable *bindnow_loader = NULL; +#endif + +void pa_ltdl_init(void) { + +#ifdef PA_BIND_NOW + const lt_dlvtable *dlopen_loader; +#endif + + pa_assert_se(lt_dlinit() == 0); + +#ifdef PA_BIND_NOW + /* Already initialised */ + if (bindnow_loader) + return; + + if (!(dlopen_loader = lt_dlloader_find((char*) "lt_dlopen"))) { + pa_log_warn(_("Failed to find original lt_dlopen loader.")); + return; + } + + if (!(bindnow_loader = malloc(sizeof(lt_dlvtable)))) { + pa_log_error(_("Failed to allocate new dl loader.")); + return; + } + + memcpy(bindnow_loader, dlopen_loader, sizeof(*bindnow_loader)); + bindnow_loader->name = "bind-now-loader"; + bindnow_loader->module_open = bind_now_open; + bindnow_loader->module_close = bind_now_close; + bindnow_loader->find_sym = bind_now_find_sym; + bindnow_loader->priority = LT_DLLOADER_PREPEND; + + /* Add our BIND_NOW loader as the default module loader. */ + if (lt_dlloader_add(bindnow_loader) != 0) { + pa_log_warn(_("Failed to add bind-now-loader.")); + free(bindnow_loader); + bindnow_loader = NULL; + } +#endif +} + +void pa_ltdl_done(void) { + pa_assert_se(lt_dlexit() == 0); + +#ifdef PA_BIND_NOW + /* lt_dlexit() will free our loader vtable, hence reset our + * pointer to it here */ + bindnow_loader = NULL; +#endif +} |