From 1daccf403b1bd86370eb94edca794dc106d02039 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Mon, 16 Nov 2020 19:33:30 +0100 Subject: nptl: Move stack list variables into _rtld_global Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT, formerly __wait_lookup_done) can be implemented directly in ld.so, eliminating the unprotected GL (dl_wait_lookup_done) function pointer. Reviewed-by: Adhemerval Zanella --- elf/Makefile | 6 ++++-- elf/dl-support.c | 9 +++++---- elf/dl-thread_gscope_wait.c | 2 ++ elf/rtld.c | 12 ++++++++++++ 4 files changed, 23 insertions(+), 6 deletions(-) create mode 100644 elf/dl-thread_gscope_wait.c (limited to 'elf') diff --git a/elf/Makefile b/elf/Makefile index f10cc59e7c..2015383eb2 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -34,7 +34,8 @@ dl-routines = $(addprefix dl-,load lookup object reloc deps \ version profile tls origin scope \ execstack open close trampoline \ exception sort-maps lookup-direct \ - call-libc-early-init write) + call-libc-early-init write \ + thread_gscope_wait) ifeq (yes,$(use-ldconfig)) dl-routines += dl-cache endif @@ -54,7 +55,8 @@ endif all-dl-routines = $(dl-routines) $(sysdep-dl-routines) # But they are absent from the shared libc, because that code is in ld.so. elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \ - dl-sysdep dl-exception dl-reloc-static-pie + dl-sysdep dl-exception dl-reloc-static-pie \ + thread_gscope_wait # ld.so uses those routines, plus some special stuff for being the program # interpreter and operating independent of libc. diff --git a/elf/dl-support.c b/elf/dl-support.c index afbc94df54..15e6d787c9 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -183,10 +183,11 @@ ElfW(Word) _dl_stack_flags = DEFAULT_STACK_PERMS; int (*_dl_make_stack_executable_hook) (void **) = _dl_make_stack_executable; -/* Function in libpthread to wait for termination of lookups. */ -void (*_dl_wait_lookup_done) (void); - -#if !THREAD_GSCOPE_IN_TCB +#if THREAD_GSCOPE_IN_TCB +list_t _dl_stack_used; +list_t _dl_stack_user; +int _dl_stack_cache_lock; +#else int _dl_thread_gscope_count; #endif struct dl_scope_free_list *_dl_scope_free_list; diff --git a/elf/dl-thread_gscope_wait.c b/elf/dl-thread_gscope_wait.c new file mode 100644 index 0000000000..28e1494730 --- /dev/null +++ b/elf/dl-thread_gscope_wait.c @@ -0,0 +1,2 @@ +/* By default, the dynamic linker does not use an out-of-line + __thread_gscope_wait function. */ diff --git a/elf/rtld.c b/elf/rtld.c index 5d117d0d2c..c4ffc8d4b7 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -48,6 +48,7 @@ #include #include #include +#include #include @@ -799,6 +800,9 @@ 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_called = true; return tcbp; @@ -1139,6 +1143,11 @@ 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; @@ -2383,6 +2392,9 @@ 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 } /* Make sure no new search directories have been added. */ -- cgit v1.2.3-70-g09d2