Bug 161344
| Summary: | Failure to init TLS variables with func ptr inside shared lib | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Alex Dupre <ale> |
| Component: | threads | Assignee: | Konstantin Belousov <kib> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 8.2-STABLE | ||
| Hardware: | Any | ||
| OS: | Any | ||
Responsible Changed From-To: freebsd-threads->kib Grab. Author: kib Date: Sat Oct 8 12:39:47 2011 New Revision: 226155 URL: http://svn.freebsd.org/changeset/base/226155 Log: Setting up TLS block for the main thread must be done after the relocations are processed, since tls initialization section might be itself subject for relocations. Only set up of the block is postponed, the tls block offsets are allocated before relocation processing, since TLS-related relocations may need offsets ready. Reported by: ale PR: threads/161344 Reviewed by: kan MFC after: 1 week Modified: head/libexec/rtld-elf/rtld.c Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Sat Oct 8 12:33:10 2011 (r226154) +++ head/libexec/rtld-elf/rtld.c Sat Oct 8 12:39:47 2011 (r226155) @@ -495,8 +495,12 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_ exit (0); } - /* setup TLS for main thread */ - dbg("initializing initial thread local storage"); + /* + * Processing tls relocations requires having the tls offsets + * initialized. Prepare offsets before starting initial + * relocation processing. + */ + dbg("initializing initial thread local storage offsets"); STAILQ_FOREACH(entry, &list_main, link) { /* * Allocate all the initial objects out of the static TLS @@ -504,7 +508,6 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_ */ allocate_tls_offset(entry->obj); } - allocate_initial_tls(obj_list); if (relocate_objects(obj_main, ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, NULL) == -1) @@ -519,6 +522,14 @@ _rtld(Elf_Addr *sp, func_ptr_type *exit_ exit (0); } + /* + * Setup TLS for main thread. This must be done after the + * relocations are processed, since tls initialization section + * might be the subject for relocations. + */ + dbg("initializing initial thread local storage"); + allocate_initial_tls(obj_list); + dbg("initializing key program variables"); set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); set_program_var("environ", env); _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org" State Changed From-To: open->closed Committed to all supported branches already. |
Initialisation of Thread Local Storage variables to some values which are function address doesn't work inside a shared library. How-To-Repeat: t1.c: int f(int x) { return x; } struct s_t { int (*func)(int); }; struct s_t __thread x = { f }; Build it as: cc -shared -o t1.so -fPIC t1.c t2.c: struct s_t { int (*func)(int); }; extern struct s_t __thread x; int main(int argc, const char *argv[]) { return (*x.func)(argc); } Build it as: cc t2.c t1.so export LD_LIBRARY_PATH=. ./a.out Segmentation fault