diff --git a/libexec/rtld-elf/rtld-libc/Makefile.inc b/libexec/rtld-elf/rtld-libc/Makefile.inc index dc3a1e47da3..90e9f97251a 100644 --- a/libexec/rtld-elf/rtld-libc/Makefile.inc +++ b/libexec/rtld-elf/rtld-libc/Makefile.inc @@ -45,8 +45,9 @@ _libc_string_objects= bcmp bcopy bzero memset memchr memcmp memcpy memmove \ strlen strncmp strncpy strrchr strsep strspn strstr strtok # Also use all the syscall .o files from libc_nossp_pic: _libc_other_objects= sigsetjmp lstat stat fstat fstatat fstatfs syscall \ - cerror geteuid getegid munmap mprotect sysarch __sysctl issetugid __getcwd \ - utrace thr_self thr_kill pread mmap lseek _exit _fstat _fstatat _fstatfs \ + cerror geteuid getegid sigfastblock munmap mprotect \ + sysarch __sysctl issetugid __getcwd utrace \ + thr_self thr_kill pread mmap lseek _exit _fstat _fstatat _fstatfs \ getdirentries _getdirentries _close _fcntl _open _openat _read \ _sigprocmask _write readlink _setjmp setjmp setjmperr diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c index 3e87e53a315..4d3b32381cb 100644 --- a/libexec/rtld-elf/rtld.c +++ b/libexec/rtld-elf/rtld.c @@ -286,6 +286,7 @@ Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ int tls_max_index = 1; /* Largest module index allocated */ static bool ld_library_path_rpath = false; +bool ld_fast_sigblock = false; /* * Globals for path names, and such @@ -444,6 +445,10 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) main_argc = argc; main_argv = argv; + if (aux_info[AT_BSDFLAGS] != NULL && + (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) + ld_fast_sigblock = true; + trust = !issetugid(); md_abi_variant_hook(aux_info); diff --git a/libexec/rtld-elf/rtld.h b/libexec/rtld-elf/rtld.h index c1996f04219..f21b1d79cf2 100644 --- a/libexec/rtld-elf/rtld.h +++ b/libexec/rtld-elf/rtld.h @@ -365,6 +365,7 @@ void free_aligned(void *ptr); extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; extern Elf_Sym sym_zero; /* For resolving undefined weak refs. */ extern bool ld_bind_not; +extern bool ld_fast_sigblock; void dump_relocations(Obj_Entry *); void dump_obj_relocations(Obj_Entry *); diff --git a/libexec/rtld-elf/rtld_lock.c b/libexec/rtld-elf/rtld_lock.c index 77f8f5d747d..c453584b96e 100644 --- a/libexec/rtld-elf/rtld_lock.c +++ b/libexec/rtld-elf/rtld_lock.c @@ -45,6 +45,7 @@ */ #include +#include #include #include #include @@ -68,6 +69,7 @@ typedef struct Struct_Lock { static sigset_t fullsigmask, oldsigmask; static int thread_flag, wnested; +static uint32_t fsigblock; static void * def_lock_create(void) @@ -117,6 +119,17 @@ def_rlock_acquire(void *lock) ; /* Spin */ } +static void +sig_fastunblock(void) +{ + uint32_t oldval; + + assert((fsigblock & ~SIGFASTBLOCK_FLAGS) >= SIGFASTBLOCK_INC); + oldval = atomic_fetchadd_32(&fsigblock, -SIGFASTBLOCK_INC); + if (oldval == (SIGFASTBLOCK_PEND | SIGFASTBLOCK_INC)) + __sys_sigfastblock(SIGFASTBLOCK_UNBLOCK, NULL); +} + static void def_wlock_acquire(void *lock) { @@ -124,14 +137,23 @@ def_wlock_acquire(void *lock) sigset_t tmp_oldsigmask; l = (Lock *)lock; - for (;;) { - sigprocmask(SIG_BLOCK, &fullsigmask, &tmp_oldsigmask); - if (atomic_cmpset_acq_int(&l->lock, 0, WAFLAG)) - break; - sigprocmask(SIG_SETMASK, &tmp_oldsigmask, NULL); + if (ld_fast_sigblock) { + for (;;) { + atomic_add_32(&fsigblock, SIGFASTBLOCK_INC); + if (atomic_cmpset_acq_int(&l->lock, 0, WAFLAG)) + break; + sig_fastunblock(); + } + } else { + for (;;) { + sigprocmask(SIG_BLOCK, &fullsigmask, &tmp_oldsigmask); + if (atomic_cmpset_acq_int(&l->lock, 0, WAFLAG)) + break; + sigprocmask(SIG_SETMASK, &tmp_oldsigmask, NULL); + } + if (atomic_fetchadd_int(&wnested, 1) == 0) + oldsigmask = tmp_oldsigmask; } - if (atomic_fetchadd_int(&wnested, 1) == 0) - oldsigmask = tmp_oldsigmask; } static void @@ -143,9 +165,10 @@ def_lock_release(void *lock) if ((l->lock & WAFLAG) == 0) atomic_add_rel_int(&l->lock, -RC_INCR); else { - assert(wnested > 0); atomic_add_rel_int(&l->lock, -WAFLAG); - if (atomic_fetchadd_int(&wnested, -1) == 1) + if (ld_fast_sigblock) + sig_fastunblock(); + else if (atomic_fetchadd_int(&wnested, -1) == 1) sigprocmask(SIG_SETMASK, &oldsigmask, NULL); } } @@ -279,38 +302,36 @@ lock_restart_for_upgrade(RtldLockState *lockstate) void lockdflt_init(void) { - int i; + int i; - deflockinfo.rtli_version = RTLI_VERSION; - deflockinfo.lock_create = def_lock_create; - deflockinfo.lock_destroy = def_lock_destroy; - deflockinfo.rlock_acquire = def_rlock_acquire; - deflockinfo.wlock_acquire = def_wlock_acquire; - deflockinfo.lock_release = def_lock_release; - deflockinfo.thread_set_flag = def_thread_set_flag; - deflockinfo.thread_clr_flag = def_thread_clr_flag; - deflockinfo.at_fork = NULL; + deflockinfo.rtli_version = RTLI_VERSION; + deflockinfo.lock_create = def_lock_create; + deflockinfo.lock_destroy = def_lock_destroy; + deflockinfo.rlock_acquire = def_rlock_acquire; + deflockinfo.wlock_acquire = def_wlock_acquire; + deflockinfo.lock_release = def_lock_release; + deflockinfo.thread_set_flag = def_thread_set_flag; + deflockinfo.thread_clr_flag = def_thread_clr_flag; + deflockinfo.at_fork = NULL; - for (i = 0; i < RTLD_LOCK_CNT; i++) { - rtld_locks[i].mask = (1 << i); - rtld_locks[i].handle = NULL; - } + for (i = 0; i < RTLD_LOCK_CNT; i++) { + rtld_locks[i].mask = (1 << i); + rtld_locks[i].handle = NULL; + } - memcpy(&lockinfo, &deflockinfo, sizeof(lockinfo)); - _rtld_thread_init(NULL); - /* - * Construct a mask to block all signals except traps which might - * conceivably be generated within the dynamic linker itself. - */ - sigfillset(&fullsigmask); - sigdelset(&fullsigmask, SIGILL); - sigdelset(&fullsigmask, SIGTRAP); - sigdelset(&fullsigmask, SIGABRT); - sigdelset(&fullsigmask, SIGEMT); - sigdelset(&fullsigmask, SIGFPE); - sigdelset(&fullsigmask, SIGBUS); - sigdelset(&fullsigmask, SIGSEGV); - sigdelset(&fullsigmask, SIGSYS); + memcpy(&lockinfo, &deflockinfo, sizeof(lockinfo)); + _rtld_thread_init(NULL); + if (ld_fast_sigblock) { + __sys_sigfastblock(SIGFASTBLOCK_SETPTR, &fsigblock); + } else { + /* + * Construct a mask to block all signals. Note that + * blocked traps mean that the process is terminated + * if trap occurs while we are in locked section, with + * the default settings for kern.forcesigexit. + */ + sigfillset(&fullsigmask); + } } /* @@ -331,7 +352,10 @@ _rtld_thread_init(struct RtldLockInfo *pli) if (pli == NULL) pli = &deflockinfo; - + else if (ld_fast_sigblock) { + fsigblock = 0; + __sys_sigfastblock(SIGFASTBLOCK_UNSETPTR, NULL); + } for (i = 0; i < RTLD_LOCK_CNT; i++) if ((locks[i] = pli->lock_create()) == NULL)