From 75ce4503950621b11fcc7f1fd1187dbcf3cde312 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 7 Jun 2015 20:55:23 +0000 Subject: [PATCH] fix regression in pre-v7 arm on kernels with kuser helper removed the arm atomics/TLS runtime selection code is called from __set_thread_area and depends on having libc.auxv and __hwcap available. commit 71f099cb7db821c51d8f39dfac622c61e54d794c moved the first call to __set_thread_area to the top of dynamic linking stage 3, before this data is made available, causing the runtime detection code to always see __hwcap as zero and thereby select the atomics/TLS implementations based on kuser helper. upcoming work on superh will use similar runtime detection. ideally this early-init code should be cleanly refactored and shared between the dynamic linker and static-linked startup. --- src/ldso/dynlink.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c index 42b056d2..71252d03 100644 --- a/src/ldso/dynlink.c +++ b/src/ldso/dynlink.c @@ -1192,6 +1192,17 @@ _Noreturn void __dls3(size_t *sp) char **argv_orig = argv; char **envp = argv+argc+1; + /* Find aux vector just past environ[] and use it to initialize + * global data that may be needed before we can make syscalls. */ + __environ = envp; + for (i=argc+1; argv[i]; i++); + libc.auxv = auxv = (void *)(argv+i+1); + decode_vec(auxv, aux, AUX_CNT); + __hwcap = aux[AT_HWCAP]; + libc.page_size = aux[AT_PAGESZ]; + 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. */ @@ -1200,25 +1211,11 @@ _Noreturn void __dls3(size_t *sp) a_crash(); } - /* Find aux vector just past environ[] */ - for (i=argc+1; argv[i]; i++) - if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16)) - env_path = argv[i]+16; - else if (!memcmp(argv[i], "LD_PRELOAD=", 11)) - env_preload = argv[i]+11; - auxv = (void *)(argv+i+1); - - decode_vec(auxv, aux, AUX_CNT); - /* Only trust user/env if kernel says we're not suid/sgid */ - if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID] - || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) { - env_path = 0; - env_preload = 0; - libc.secure = 1; + if (!libc.secure) { + env_path = getenv("LD_LIBRARY_PATH"); + env_preload = getenv("LD_PRELOAD"); } - libc.page_size = aux[AT_PAGESZ]; - libc.auxv = auxv; /* If the main program was already loaded by the kernel, * AT_PHDR will point to some location other than the dynamic -- 2.25.1