From cba932a5a9e91cffd7f4172d7e91f9b2efb1f84b Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 12 Nov 2019 12:41:34 +0100 Subject: slotinfo in struct dtv_slotinfo_list should be flexible array [BZ #25097] GCC 10 will warn about subscribing inner length zero arrays. Use a GCC extension in csu/libc-tls.c to allocate space for the static_slotinfo variable. Adjust nptl_db so that the type description machinery does not attempt to determine the size of the flexible array member slotinfo. Change-Id: I51be146a7857186a4ede0bb40b332509487bdde8 --- csu/libc-tls.c | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-) (limited to 'csu') diff --git a/csu/libc-tls.c b/csu/libc-tls.c index 33d8b61e16..f9e5437d43 100644 --- a/csu/libc-tls.c +++ b/csu/libc-tls.c @@ -23,7 +23,7 @@ #include #include #include - +#include #ifdef SHARED #error makefile bug, this file is for static only @@ -32,17 +32,11 @@ dtv_t _dl_static_dtv[2 + TLS_SLOTINFO_SURPLUS]; -static struct -{ - struct dtv_slotinfo_list si; - /* The dtv_slotinfo_list data structure does not include the actual - information since it is defined as an array of size zero. We define - here the necessary entries. Note that it is not important whether - there is padding or not since we will always access the information - through the 'si' element. */ - struct dtv_slotinfo info[2 + TLS_SLOTINFO_SURPLUS]; -} static_slotinfo; - +static struct dtv_slotinfo_list static_slotinfo = + { + /* Allocate an array of 2 + TLS_SLOTINFO_SURPLUS elements. */ + .slotinfo = { [array_length (_dl_static_dtv) - 1] = { 0 } }, + }; /* Highest dtv index currently needed. */ size_t _dl_tls_max_dtv_idx; @@ -72,16 +66,16 @@ TLS_INIT_HELPER static void init_slotinfo (void) { - /* Create the slotinfo list. */ - static_slotinfo.si.len = (((char *) (&static_slotinfo + 1) - - (char *) &static_slotinfo.si.slotinfo[0]) - / sizeof static_slotinfo.si.slotinfo[0]); - // static_slotinfo.si.next = NULL; already zero + /* Create the slotinfo list. Note that the type of static_slotinfo + has effectively a zero-length array, so we cannot use the size of + static_slotinfo to determine the array length. */ + static_slotinfo.len = array_length (_dl_static_dtv); + /* static_slotinfo.next = NULL; -- Already zero. */ /* The slotinfo list. Will be extended by the code doing dynamic linking. */ GL(dl_tls_max_dtv_idx) = 1; - GL(dl_tls_dtv_slotinfo_list) = &static_slotinfo.si; + GL(dl_tls_dtv_slotinfo_list) = &static_slotinfo; } static void @@ -205,8 +199,8 @@ __libc_setup_tls (void) main_map->l_tls_modid = 1; init_slotinfo (); - // static_slotinfo.si.slotinfo[1].gen = 0; already zero - static_slotinfo.si.slotinfo[1].map = main_map; + /* static_slotinfo.slotinfo[1].gen = 0; -- Already zero. */ + static_slotinfo.slotinfo[1].map = main_map; memsz = roundup (memsz, align ?: 1); -- cgit 1.4.1