Upstream submission: Author: Florian Weimer Date: Mon Jun 28 10:24:33 2021 +0200 nptl: Export libthread_db-used symbols under GLIBC_PRIVATE This allows distributions to strip debugging information from libc.so.6 without impacting the debugging experience. The commit also enhances the checks in nptl/db-symbols.awk to cover both the _thread_db_* descriptor symbols and the actual symbols themselves. diff --git a/nptl/Versions b/nptl/Versions index e4fae73c0b9fae0c..060d8d5dec2be29c 100644 --- a/nptl/Versions +++ b/nptl/Versions @@ -403,10 +403,14 @@ libc { __nptl_deallocate_tsd; __nptl_death_event; __nptl_free_tcb; + __nptl_last_event; __nptl_nthreads; + __nptl_rtld_global; __nptl_setxid_sighandler; __nptl_stack_list_add; __nptl_stack_list_del; + __nptl_threads_events; + __nptl_version; __pthread_attr_copy; __pthread_attr_destroy; __pthread_attr_init; @@ -430,6 +434,60 @@ libc { __pthread_unwind; __sched_fifo_max_prio; __sched_fifo_min_prio; + _thread_db___nptl_last_event; + _thread_db___nptl_nthreads; + _thread_db___nptl_rtld_global; + _thread_db___pthread_keys; + _thread_db_const_thread_area; + _thread_db_dtv_dtv; + _thread_db_dtv_slotinfo_gen; + _thread_db_dtv_slotinfo_list_len; + _thread_db_dtv_slotinfo_list_next; + _thread_db_dtv_slotinfo_list_slotinfo; + _thread_db_dtv_slotinfo_map; + _thread_db_dtv_t_counter; + _thread_db_dtv_t_pointer_val; + _thread_db_link_map_l_tls_modid; + _thread_db_link_map_l_tls_offset; + _thread_db_list_t_next; + _thread_db_list_t_prev; + _thread_db_pthread_cancelhandling; + _thread_db_pthread_dtvp; + _thread_db_pthread_eventbuf; + _thread_db_pthread_eventbuf_eventmask; + _thread_db_pthread_eventbuf_eventmask_event_bits; + _thread_db_pthread_key_data_data; + _thread_db_pthread_key_data_level2_data; + _thread_db_pthread_key_data_seq; + _thread_db_pthread_key_struct_destr; + _thread_db_pthread_key_struct_seq; + _thread_db_pthread_list; + _thread_db_pthread_nextevent; + _thread_db_pthread_report_events; + _thread_db_pthread_schedparam_sched_priority; + _thread_db_pthread_schedpolicy; + _thread_db_pthread_specific; + _thread_db_pthread_start_routine; + _thread_db_pthread_tid; + _thread_db_register32; + _thread_db_register32_thread_area; + _thread_db_register64; + _thread_db_register64_thread_area; + _thread_db_rtld_global__dl_stack_used; + _thread_db_rtld_global__dl_stack_user; + _thread_db_rtld_global__dl_tls_dtv_slotinfo_list; + _thread_db_sizeof_dtv_slotinfo; + _thread_db_sizeof_dtv_slotinfo_list; + _thread_db_sizeof_list_t; + _thread_db_sizeof_pthread; + _thread_db_sizeof_pthread_key_data; + _thread_db_sizeof_pthread_key_data_level2; + _thread_db_sizeof_pthread_key_struct; + _thread_db_sizeof_td_eventbuf_t; + _thread_db_sizeof_td_thr_events_t; + _thread_db_td_eventbuf_t_eventdata; + _thread_db_td_eventbuf_t_eventnum; + _thread_db_td_thr_events_t_event_bits; } } diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c index 3f017f1e26c0d107..d1b6817a81b21ef1 100644 --- a/nptl/pthread_create.c +++ b/nptl/pthread_create.c @@ -43,21 +43,24 @@ /* Globally enabled events. */ -static td_thr_events_t __nptl_threads_events __attribute_used__; +td_thr_events_t __nptl_threads_events __attribute__ ((nocommon)); +libc_hidden_proto (__nptl_threads_events) +libc_hidden_data_def (__nptl_threads_events) /* Pointer to descriptor with the last event. */ -static struct pthread *__nptl_last_event __attribute_used__; +struct pthread *__nptl_last_event __attribute__ ((nocommon)); +libc_hidden_proto (__nptl_last_event) +libc_hidden_data_def (__nptl_last_event) #ifdef SHARED /* This variable is used to access _rtld_global from libthread_db. If GDB loads libpthread before ld.so, it is not possible to resolve _rtld_global directly during libpthread initialization. */ -static struct rtld_global *__nptl_rtld_global __attribute_used__ - = &_rtld_global; +struct rtld_global *__nptl_rtld_global = &_rtld_global; #endif /* Version of the library, used in libthread_db to detect mismatches. */ -static const char nptl_version[] __attribute_used__ = VERSION; +const char __nptl_version[] = VERSION; /* This performs the initialization necessary when going from single-threaded to multi-threaded mode for the first time. */ diff --git a/nptl_db/Makefile b/nptl_db/Makefile index 1f79c018a1f9fe19..c04aa6140acff337 100644 --- a/nptl_db/Makefile +++ b/nptl_db/Makefile @@ -55,7 +55,7 @@ include ../Rules $(objpfx)db-symbols.out: $(objpfx)db-symbols.v.i \ $(common-objpfx)libc.so - LC_ALL=C $(READELF) -W -s $(filter %.so,$^) | $(AWK) -f $< > $@; \ + LC_ALL=C $(READELF) -W -D -s $(filter %.so,$^) | $(AWK) -f $< > $@; \ $(evaluate-test) $(objpfx)db-symbols.v.i: db-symbols.awk diff --git a/nptl_db/db-symbols.awk b/nptl_db/db-symbols.awk index ef1d91b167998d3d..a9289b4686a02dd2 100644 --- a/nptl_db/db-symbols.awk +++ b/nptl_db/db-symbols.awk @@ -1,7 +1,8 @@ -# This script processes the output of 'readelf -W -s' on the libpthread.so +# This script processes the output of 'readelf -W -D -s' on the libc.so # we've just built. It checks for all the symbols used in td_symbol_list. BEGIN { +# This processes the _thread_db_* names. %define DB_MAIN_VARIABLE(name) /* Nothing. */ %define DB_MAIN_SYMBOL(name) /* Nothing. */ %define DB_MAIN_ARRAY_VARIABLE(name) /* Nothing. */ @@ -9,10 +10,19 @@ BEGIN { %define DB_LOOKUP_NAME_TH_UNIQUE(idx, name) th_unique[STRINGIFY (name)] = 1; %include "db-symbols.h" +# And this processes the symbol names themselves. +%define DB_STRUCT(...) /* Nothing. */ +%define DB_STRUCT_FIELD(...) /* Nothing. */ +%define DB_STRUCT_FLEXIBLE_ARRAY(...) /* Nothing. */ +%define DB_SYMBOL(name) required[STRINGIFY (name)] = 1; +%define DB_FUNCTION(name) required[STRINGIFY (name)] = 1; +%define DB_VARIABLE(name) required[STRINGIFY (name)] = 1; +%include "structs.def" + in_symtab = 0; } -/Symbol table '.symtab'/ { in_symtab=1; next } +/Symbol table for image/ { in_symtab=1; next } NF == 0 { in_symtab=0; next } !in_symtab { next } @@ -23,6 +33,7 @@ END { status = 0; for (s in required) { + s = s "@@GLIBC_PRIVATE" if (s in seen) print s, "ok"; else { status = 1; @@ -32,6 +43,7 @@ END { any = ""; for (s in th_unique) { + s = s "@@GLIBC_PRIVATE" if (s in seen) { any = s; break;