diff options
| -rw-r--r-- | ldso/dynlink.c | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/ldso/dynlink.c b/ldso/dynlink.c index c2447bc9..ec921dfd 100644 --- a/ldso/dynlink.c +++ b/ldso/dynlink.c @@ -1453,9 +1453,31 @@ hidden void __dls2(unsigned char *base, size_t *sp) ldso.relocated = 0; - /* Call dynamic linker stage-3, __dls3, looking it up + /* Call dynamic linker stage-2b, __dls2b, looking it up * symbolically as a barrier against moving the address * load across the above relocation processing. */ + struct symdef dls2b_def = find_sym(&ldso, "__dls2b", 0); + if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp); + else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp); +} + +/* Stage 2b sets up a valid thread pointer, which requires relocations + * completed in stage 2, and on which stage 3 is permitted to depend. + * This is done as a separate stage, with symbolic lookup as a barrier, + * so that loads of the thread pointer and &errno can be pure/const and + * thereby hoistable. */ + +_Noreturn void __dls2b(size_t *sp) +{ + /* Setup early thread pointer in builtin_tls for ldso/libc itself to + * use during dynamic linking. If possible it will also serve as the + * thread pointer at runtime. */ + libc.tls_size = sizeof builtin_tls; + libc.tls_align = tls_align; + if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) { + a_crash(); + } + struct symdef dls3_def = find_sym(&ldso, "__dls3", 0); if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp); else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp); @@ -1490,15 +1512,6 @@ _Noreturn void __dls3(size_t *sp) libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]); - /* Setup early thread pointer in builtin_tls for ldso/libc itself to - * use during dynamic linking. If possible it will also serve as the - * thread pointer at runtime. */ - libc.tls_size = sizeof builtin_tls; - libc.tls_align = tls_align; - if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) { - a_crash(); - } - /* Only trust user/env if kernel says we're not suid/sgid */ if (!libc.secure) { env_path = getenv("LD_LIBRARY_PATH"); |