From 466c1ea15f461edb8e3ffaf5d86d708876343bbf Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 3 Jun 2021 08:26:04 +0200 Subject: dlfcn: Rework static dlopen hooks Consolidate all hooks structures into a single one. There are no static dlopen ABI concerns because glibc 2.34 already comes with substantial ABI-incompatible changes in this area. (Static dlopen requires the exact same dynamic glibc version that was used for static linking.) The new approach uses a pointer to the hooks structure into _rtld_global_ro and initalizes it in __rtld_static_init. This avoids a back-and-forth with various callback functions. Reviewed-by: Adhemerval Zanella --- dlfcn/dladdr.c | 2 +- dlfcn/dladdr1.c | 2 +- dlfcn/dlclose.c | 2 +- dlfcn/dlerror.c | 32 +------------------------------- dlfcn/dlinfo.c | 2 +- dlfcn/dlmopen.c | 10 ++-------- dlfcn/dlopen.c | 10 ++-------- dlfcn/dlopenold.c | 2 +- dlfcn/dlsym.c | 2 +- dlfcn/dlvsym.c | 3 ++- 10 files changed, 13 insertions(+), 54 deletions(-) (limited to 'dlfcn') diff --git a/dlfcn/dladdr.c b/dlfcn/dladdr.c index 3ef1b7f0b6..1cc305f0c4 100644 --- a/dlfcn/dladdr.c +++ b/dlfcn/dladdr.c @@ -25,7 +25,7 @@ __dladdr (const void *address, Dl_info *info) { #ifdef SHARED if (!rtld_active ()) - return _dlfcn_hook->dladdr (address, info); + return GLRO (dl_dlfcn_hook)->dladdr (address, info); #endif return _dl_addr (address, info, NULL, NULL); } diff --git a/dlfcn/dladdr1.c b/dlfcn/dladdr1.c index 203d6398e4..78560dbac2 100644 --- a/dlfcn/dladdr1.c +++ b/dlfcn/dladdr1.c @@ -25,7 +25,7 @@ __dladdr1 (const void *address, Dl_info *info, void **extra, int flags) { #ifdef SHARED if (!rtld_active ()) - return _dlfcn_hook->dladdr1 (address, info, extra, flags); + return GLRO (dl_dlfcn_hook)->dladdr1 (address, info, extra, flags); #endif switch (flags) diff --git a/dlfcn/dlclose.c b/dlfcn/dlclose.c index 4d5d307ab1..6a013a81bb 100644 --- a/dlfcn/dlclose.c +++ b/dlfcn/dlclose.c @@ -25,7 +25,7 @@ __dlclose (void *handle) { #ifdef SHARED if (!rtld_active ()) - return _dlfcn_hook->dlclose (handle); + return GLRO (dl_dlfcn_hook)->dlclose (handle); #endif return _dlerror_run (GLRO (dl_close), handle) ? -1 : 0; diff --git a/dlfcn/dlerror.c b/dlfcn/dlerror.c index 3df8602f4d..d0194a7cef 100644 --- a/dlfcn/dlerror.c +++ b/dlfcn/dlerror.c @@ -33,7 +33,7 @@ __dlerror (void) { # ifdef SHARED if (!rtld_active ()) - return _dlfcn_hook->dlerror (); + return GLRO (dl_dlfcn_hook)->dlerror (); # endif struct dl_action_result *result = __libc_dlerror_result; @@ -197,33 +197,3 @@ _dlerror_run (void (*operate) (void *), void *args) } } libc_hidden_def (_dlerror_run) - -#ifdef SHARED -struct dlfcn_hook *_dlfcn_hook __attribute__((nocommon)); -libc_hidden_data_def (_dlfcn_hook) - -#else /* !SHARED */ - -static struct dlfcn_hook _dlfcn_hooks = - { - .dlopen = __dlopen, - .dlclose = __dlclose, - .dlsym = __dlsym, - .dlvsym = __dlvsym, - .dlerror = __dlerror, - .dladdr = __dladdr, - .dladdr1 = __dladdr1, - .dlinfo = __dlinfo, - .dlmopen = __dlmopen - }; - -void -__libc_register_dlfcn_hook (struct link_map *map) -{ - struct dlfcn_hook **hook; - - hook = (struct dlfcn_hook **) __libc_dlsym_private (map, "_dlfcn_hook"); - if (hook != NULL) - *hook = &_dlfcn_hooks; -} -#endif /* !SHARED */ diff --git a/dlfcn/dlinfo.c b/dlfcn/dlinfo.c index 15fcbc5dc1..c6f9a1da09 100644 --- a/dlfcn/dlinfo.c +++ b/dlfcn/dlinfo.c @@ -90,7 +90,7 @@ int ___dlinfo (void *handle, int request, void *arg) { if (!rtld_active ()) - return _dlfcn_hook->dlinfo (handle, request, arg); + return GLRO (dl_dlfcn_hook)->dlinfo (handle, request, arg); else return dlinfo_implementation (handle, request, arg); } diff --git a/dlfcn/dlmopen.c b/dlfcn/dlmopen.c index ae42814bbf..c171c8953d 100644 --- a/dlfcn/dlmopen.c +++ b/dlfcn/dlmopen.c @@ -81,7 +81,7 @@ void * ___dlmopen (Lmid_t nsid, const char *file, int mode) { if (!rtld_active ()) - return _dlfcn_hook->dlmopen (nsid, file, mode, RETURN_ADDRESS (0)); + return GLRO (dl_dlfcn_hook)->dlmopen (nsid, file, mode, RETURN_ADDRESS (0)); else return dlmopen_implementation (nsid, file, mode, RETURN_ADDRESS (0)); } @@ -101,13 +101,7 @@ __dlmopen (Lmid_t nsid, const char *file, int mode, void *dl_caller) void * ___dlmopen (Lmid_t nsid, const char *file, int mode) { - struct link_map *l = __dlmopen (nsid, file, mode, RETURN_ADDRESS (0)); - if (l != NULL) - { - __libc_register_dl_open_hook (l); - __libc_register_dlfcn_hook (l); - } - return l; + return __dlmopen (nsid, file, mode, RETURN_ADDRESS (0)); } weak_alias (___dlmopen, dlmopen) static_link_warning (dlmopen) diff --git a/dlfcn/dlopen.c b/dlfcn/dlopen.c index afdc113efb..e04b374b82 100644 --- a/dlfcn/dlopen.c +++ b/dlfcn/dlopen.c @@ -76,7 +76,7 @@ void * ___dlopen (const char *file, int mode) { if (!rtld_active ()) - return _dlfcn_hook->dlopen (file, mode, RETURN_ADDRESS (0)); + return GLRO (dl_dlfcn_hook)->dlopen (file, mode, RETURN_ADDRESS (0)); else return dlopen_implementation (file, mode, RETURN_ADDRESS (0)); } @@ -96,13 +96,7 @@ __dlopen (const char *file, int mode, void *dl_caller) void * ___dlopen (const char *file, int mode) { - struct link_map *l = __dlopen (file, mode, RETURN_ADDRESS (0)); - if (l != NULL) - { - __libc_register_dl_open_hook (l); - __libc_register_dlfcn_hook (l); - } - return l; + return __dlopen (file, mode, RETURN_ADDRESS (0)); } weak_alias (___dlopen, dlopen) static_link_warning (dlopen) diff --git a/dlfcn/dlopenold.c b/dlfcn/dlopenold.c index 0fe5f24cc5..9115501ac1 100644 --- a/dlfcn/dlopenold.c +++ b/dlfcn/dlopenold.c @@ -71,7 +71,7 @@ __dlopen_nocheck (const char *file, int mode) args.mode = mode; if (!rtld_active ()) - return _dlfcn_hook->dlopen (file, mode, RETURN_ADDRESS (0)); + return GLRO (dl_dlfcn_hook)->dlopen (file, mode, RETURN_ADDRESS (0)); return _dlerror_run (dlopen_doit, &args) ? NULL : args.new; } diff --git a/dlfcn/dlsym.c b/dlfcn/dlsym.c index 6b03b7b7ab..43044cf7bb 100644 --- a/dlfcn/dlsym.c +++ b/dlfcn/dlsym.c @@ -63,7 +63,7 @@ void * ___dlsym (void *handle, const char *name) { if (!rtld_active ()) - return _dlfcn_hook->dlsym (handle, name, RETURN_ADDRESS (0)); + return GLRO (dl_dlfcn_hook)->dlsym (handle, name, RETURN_ADDRESS (0)); else return dlsym_implementation (handle, name, RETURN_ADDRESS (0)); } diff --git a/dlfcn/dlvsym.c b/dlfcn/dlvsym.c index de6b340647..9b76f9afa5 100644 --- a/dlfcn/dlvsym.c +++ b/dlfcn/dlvsym.c @@ -66,7 +66,8 @@ void * ___dlvsym (void *handle, const char *name, const char *version) { if (!rtld_active ()) - return _dlfcn_hook->dlvsym (handle, name, version, RETURN_ADDRESS (0)); + return GLRO (dl_dlfcn_hook)->dlvsym (handle, name, version, + RETURN_ADDRESS (0)); else return dlvsym_implementation (handle, name, version, RETURN_ADDRESS (0)); } -- cgit 1.4.1