Re: FYI unwinder unwinder limits

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Mon, 28 Oct 2013 11:19:24 +0100, Mark Wielaard wrote:
> I think with this the parts for libebl, backends and libdw/libwfl can go
> in.

OK.  With tests on RHEL-6, on i386 and with -O2 I have found some other
issues [attached].


> I'll look at the src and tests changes later. But those seem separate
> from the main part of this patch.

BTW there are also waiting the s390* and ppc* ports in the queue, not yet
posted, I have to rebase it a bit.


Thanks,
Jan

diff --git a/backends/i386_initreg.c b/backends/i386_initreg.c
index 7e5907e..9e819a4 100644
--- a/backends/i386_initreg.c
+++ b/backends/i386_initreg.c
@@ -40,9 +40,9 @@
 #include "libebl_CPU.h"
 
 bool
-i386_set_initial_registers_tid (pid_t tid,
-				ebl_tid_registers_t *setfunc,
-				void *arg)
+i386_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+				void *arg __attribute__ ((unused)))
 {
 #if !defined __i386__ && !defined __x86_64__
   return false;
diff --git a/backends/x86_64_initreg.c b/backends/x86_64_initreg.c
index 754b320..0c49364 100644
--- a/backends/x86_64_initreg.c
+++ b/backends/x86_64_initreg.c
@@ -40,9 +40,9 @@
 #include "libebl_CPU.h"
 
 bool
-x86_64_set_initial_registers_tid (pid_t tid,
-				  ebl_tid_registers_t *setfunc,
-				  void *arg)
+x86_64_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+				  void *arg __attribute__ ((unused)))
 {
 #ifndef __x86_64__
   return false;
diff --git a/libdwfl/frame_unwind.c b/libdwfl/frame_unwind.c
index 38137ba..1aed8cb 100644
--- a/libdwfl/frame_unwind.c
+++ b/libdwfl/frame_unwind.c
@@ -48,6 +48,7 @@
 #endif
 
 bool
+internal_function
 __libdwfl_frame_reg_get (Dwfl_Frame *state, unsigned regno, Dwarf_Addr *val)
 {
   Ebl *ebl = state->thread->process->ebl;
@@ -62,6 +63,7 @@ __libdwfl_frame_reg_get (Dwfl_Frame *state, unsigned regno, Dwarf_Addr *val)
 }
 
 bool
+internal_function
 __libdwfl_frame_reg_set (Dwfl_Frame *state, unsigned regno, Dwarf_Addr val)
 {
   Ebl *ebl = state->thread->process->ebl;
diff --git a/libdwfl/dwfl_frame.c b/libdwfl/dwfl_frame.c
index af584fb..b785e2c 100644
--- a/libdwfl/dwfl_frame.c
+++ b/libdwfl/dwfl_frame.c
@@ -154,6 +154,7 @@ dwfl_attach_state (Dwfl *dwfl, int machine, pid_t pid,
     }
   else
     {
+      ebl = NULL;
       for (Dwfl_Module *mod = dwfl->modulelist; mod != NULL; mod = mod->next)
 	{
 	  Dwfl_Error error = __libdwfl_module_getebl (mod);
@@ -326,13 +326,14 @@ dwfl_thread_getframes (Dwfl_Thread *thread,
   Dwfl_Error err = dwfl_errno ();
   if (process->callbacks->thread_detach)
     process->callbacks->thread_detach (thread, thread->callbacks_arg);
-  thread_free_all_states (thread);
   if (state == NULL || state->pc_state == DWFL_FRAME_STATE_ERROR)
     {
+      thread_free_all_states (thread);
       __libdwfl_seterrno (err);
       return -1;
     }
   assert (state->pc_state == DWFL_FRAME_STATE_PC_UNDEFINED);
+  thread_free_all_states (thread);
   return 0;
 }
 INTDEF(dwfl_thread_getframes)
diff --git a/tests/backtrace.c b/tests/backtrace.c
index 8dd7177..ba2fb0f 100644
--- a/tests/backtrace.c
+++ b/tests/backtrace.c
@@ -208,7 +208,8 @@ thread_callback (Dwfl_Thread *thread, void *thread_arg)
       return 1;
     case -1:
       error (0, 0, "dwfl_thread_getframes: %s", dwfl_errmsg (-1));
-      return 1;
+      /* All platforms do not have yet proper unwind termination.  */
+      break;
     default:
       abort ();
     }