[uclibc-ng-devel] [PATCH] Fix TLS allocation and loading in !SHARED case

Yann Sionneau ysionneau at kalray.eu
Thu Apr 11 12:21:57 CEST 2019


For ARCH where shared lib are not supported:
- SHARED is not set (!SHARED is true)
- __ARCH_HAS_NO_LDSO__ is set

so code inside #if !defined __ARCH_HAS_NO_LDSO__ && !defined SHARED
is compiled-out.

But without a call do _dl_aux_init(), _dl_phdr stays NULL and
__libc_setup_tls won't be able to allocate memory for the in-executable TLS
and also won't be able to load the initimage from ELF TLS segment.

This results in segfault when doing things like "errno = 0" like
in tst-cancel15.c for instance in uClibc-ng testsuite.

Signed-off-by: Yann Sionneau <ysionneau at kalray.eu>
---
 libc/misc/internals/__uClibc_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c
index 849bca8..affa0ce 100644
--- a/libc/misc/internals/__uClibc_main.c
+++ b/libc/misc/internals/__uClibc_main.c
@@ -370,7 +370,7 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc,
 		    char **argv, void (*app_init)(void), void (*app_fini)(void),
 		    void (*rtld_fini)(void), void *stack_end attribute_unused)
 {
-#if !defined __ARCH_HAS_NO_LDSO__ && !defined SHARED
+#ifndef SHARED
     unsigned long *aux_dat;
     ElfW(auxv_t) auxvt[AT_EGID + 1];
 #endif
@@ -396,7 +396,7 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc,
 	__environ = &argv[argc];
     }
 
-#if !defined __ARCH_HAS_NO_LDSO__ && !defined SHARED
+#ifndef SHARED
     /* Pull stuff from the ELF header when possible */
     memset(auxvt, 0x00, sizeof(auxvt));
     aux_dat = (unsigned long*)__environ;
-- 
1.8.3.1



More information about the devel mailing list