Waldemar,
On Mon, Jul 20, 2015 at 4:33 PM, Junling Zheng <zhengjunling(a)huawei.com> wrote:
When debugging a program on ARMv7 with
thread-local storage declared using
"__thread", attempting to print a thread-local variable will result in the
following message:
Cannot find thread-local storage for Thread <snip> (LWP <snip>), executable
file /tmp/tls: capability not available
This can be traced back to uclibc libpthread/nptl_db/td_thr_tls_get_addr.c
which gdb uses to look up the address of the TLS. The function returns
TD_NOCAPAB due to a mismatch in size between the DTV pointer and the size
recorded in the db description. The problem lies in libpthread/nptl_db/db_info.c
which initializes the db with the sizeof the union dtv. Instead it should
be the sizeof a pointer to union dtv.
Fixed the initial size for dtvp to sizeof a pointer, instead of sizeof
the union.
Refer to:
http://sourceware.org/ml/libc-alpha/2006-10/msg00088.html
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=416b630981788c1f08e7…
Signed-off-by: Junling Zheng <zhengjunling(a)huawei.com>
---
libpthread/nptl_db/db_info.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libpthread/nptl_db/db_info.c b/libpthread/nptl_db/db_info.c
index a57a053..159a027 100644
--- a/libpthread/nptl_db/db_info.c
+++ b/libpthread/nptl_db/db_info.c
@@ -60,7 +60,7 @@ extern bool __nptl_initial_report_events;
i.e. at the very end of the area covered by TLS_PRE_TCB_SIZE. */
DESC (_thread_db_pthread_dtvp,
TLS_PRE_TCB_SIZE + offsetof (tcbhead_t, dtv)
- - (TLS_TCB_SIZE == 0 ? sizeof (tcbhead_t) : 0), union dtv)
+ - (TLS_TCB_SIZE == 0 ? sizeof (tcbhead_t) : 0), union dtv *)
#endif
Please apply this patch to the uClibc-ng as well, it fixes inspection of
TLS variables in gdb for many architectures.
Thanks for remembering me. Applied and pushed now!
best regards
Waldemar