diff options
authorVineet Gupta <>2015-06-30 12:16:56 (GMT)
committerWaldemar Brodkorb <>2015-06-30 19:02:47 (GMT)
commit7d303841dbb6e668e5acdd9218ce82231a00a967 (patch)
parentf347524fade67b41fb8e46283a6f0ae4aa19e6b0 (diff)
NPTL/arc: notify kernel of the TP value
Native gdb makes a ptrace (GET_THREAD_AREA) which needs to return the TP. however when libc sets up TP reg (for main thread), it doesn't call arc_settls syscall so kernel doesn't know of TP register details (moreso because clone doesnt have SETTLS flag) Note that kernel doesn't know about r25 being TP etc. This commit got lost in merge of NPTL tools into arc-mainline-dev and showed up again as STAR 9000919529 (native gdb can't debug threaded apps) ------->8--------------- [ARCLinux]# gdb ./pth Reading symbols from ./pth...(no debugging symbols found)...done. (gdb) b main Breakpoint 1 at 0x106f2 (gdb) r Starting program: /pth [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/". thread_get_info_callback: cannot get thread info: generic error (gdb) q ------->8--------------- Debugged-by: Anton Kolesov <> Signed-off-by: Vineet Gupta <> Signed-off-by: Vineet Gupta <>
1 files changed, 5 insertions, 2 deletions
diff --git a/libpthread/nptl/sysdeps/arc/tls.h b/libpthread/nptl/sysdeps/arc/tls.h
index 63dd113..4af415a 100644
--- a/libpthread/nptl/sysdeps/arc/tls.h
+++ b/libpthread/nptl/sysdeps/arc/tls.h
@@ -104,8 +104,11 @@ typedef struct
operation can cause a failure 'errno' must not be touched. */
# define TLS_INIT_TP(tcbp, secondcall) \
({ \
- __builtin_set_thread_pointer(tcbp); \
- NULL; \
+ long result_var; \
+ __builtin_set_thread_pointer(tcbp); \
+ result_var = INTERNAL_SYSCALL (arc_settls, err, 1, (tcbp)); \
+ INTERNAL_SYSCALL_ERROR_P (result_var, err) \
+ ? "unknown error" : NULL; \
/* Return the address of the dtv for the current thread.