From 90d7e7e5bd3b0683a27c658388b6515ce950c78e Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 21 Apr 2021 19:49:51 +0200 Subject: [PATCH] elf: Introduce __tls_init_tp for second-phase TCB initialization TLS_INIT_TP is processor-specific, so it is not a good place to put thread library initialization code (it would have to be repeated for all CPUs). Introduce __tls_init_tp as a separate function, to be called immediately after TLS_INIT_TP. Move the existing stack list setup code for NPTL to this function. Reviewed-by: Adhemerval Zanella --- csu/libc-tls.c | 8 +------- elf/Makefile | 2 +- elf/dl-tls_init_tp.c | 24 ++++++++++++++++++++++++ elf/rtld.c | 14 ++------------ sysdeps/generic/ldsodefs.h | 5 +++++ sysdeps/nptl/dl-tls_init_tp.c | 30 ++++++++++++++++++++++++++++++ 6 files changed, 63 insertions(+), 20 deletions(-) create mode 100644 elf/dl-tls_init_tp.c create mode 100644 sysdeps/nptl/dl-tls_init_tp.c diff --git a/csu/libc-tls.c b/csu/libc-tls.c index f3a6a6a..22f8e48 100644 --- a/csu/libc-tls.c +++ b/csu/libc-tls.c @@ -24,7 +24,6 @@ #include #include #include -#include #ifdef SHARED #error makefile bug, this file is for static only @@ -193,12 +192,7 @@ __libc_setup_tls (void) #endif if (__builtin_expect (lossage != NULL, 0)) _startup_fatal (lossage); - -#if THREAD_GSCOPE_IN_TCB - INIT_LIST_HEAD (&_dl_stack_used); - INIT_LIST_HEAD (&_dl_stack_user); - list_add (&THREAD_SELF->list, &_dl_stack_user); -#endif + __tls_init_tp (); /* Update the executable's link map with enough information to make the TLS routines happy. */ diff --git a/elf/Makefile b/elf/Makefile index b51c158..f09988f 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -35,7 +35,7 @@ dl-routines = $(addprefix dl-,load lookup object reloc deps \ execstack open close trampoline \ exception sort-maps lookup-direct \ call-libc-early-init write \ - thread_gscope_wait) + thread_gscope_wait tls_init_tp) ifeq (yes,$(use-ldconfig)) dl-routines += dl-cache endif diff --git a/elf/dl-tls_init_tp.c b/elf/dl-tls_init_tp.c new file mode 100644 index 0000000..728cd84 --- /dev/null +++ b/elf/dl-tls_init_tp.c @@ -0,0 +1,24 @@ +/* Completion of TCB initialization after TLS_INIT_TP. Generic version. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +void +__tls_init_tp (void) +{ +} diff --git a/elf/rtld.c b/elf/rtld.c index c2ca4b7..3487901 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -48,7 +48,6 @@ #include #include #include -#include #include #include @@ -807,9 +806,7 @@ cannot allocate TLS data structures for initial thread\n"); const char *lossage = TLS_INIT_TP (tcbp); if (__glibc_unlikely (lossage != NULL)) _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); -#if THREAD_GSCOPE_IN_TCB - list_add (&THREAD_SELF->list, &GL (dl_stack_user)); -#endif + __tls_init_tp (); tls_init_tp_called = true; return tcbp; @@ -1150,11 +1147,6 @@ dl_main (const ElfW(Phdr) *phdr, GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive; #endif -#if THREAD_GSCOPE_IN_TCB - INIT_LIST_HEAD (&GL (dl_stack_used)); - INIT_LIST_HEAD (&GL (dl_stack_user)); -#endif - /* The explicit initialization here is cheaper than processing the reloc in the _rtld_local definition's initializer. */ GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable; @@ -2454,9 +2446,7 @@ dl_main (const ElfW(Phdr) *phdr, if (__glibc_unlikely (lossage != NULL)) _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); -#if THREAD_GSCOPE_IN_TCB - list_add (&THREAD_SELF->list, &GL (dl_stack_user)); -#endif + __tls_init_tp (); } /* Make sure no new search directories have been added. */ diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index dfc117a..67c6686 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -1163,6 +1163,11 @@ extern void _dl_determine_tlsoffset (void) attribute_hidden; number of audit modules are loaded. */ void _dl_tls_static_surplus_init (size_t naudit) attribute_hidden; +/* This function is called after processor-specific initialization of + the TCB and thread pointer via TLS_INIT_TP, to complete very early + initialization of the thread library. */ +void __tls_init_tp (void) attribute_hidden; + #ifndef SHARED /* Set up the TCB for statically linked applications. This is called early during startup because we always use TLS (for errno and the diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c new file mode 100644 index 0000000..8983808 --- /dev/null +++ b/sysdeps/nptl/dl-tls_init_tp.c @@ -0,0 +1,30 @@ +/* Completion of TCB initialization after TLS_INIT_TP. NPTL version. + Copyright (C) 2020-2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include + +void +__tls_init_tp (void) +{ + /* Set up thread stack list management. */ + INIT_LIST_HEAD (&GL (dl_stack_used)); + INIT_LIST_HEAD (&GL (dl_stack_user)); + list_add (&THREAD_SELF->list, &GL (dl_stack_user)); +} -- 2.7.4