Fix tracing Thumb mode on ARM

- Drop what amounts to global variable thumb_mode from struct process
- Thumb mode is encoded to address.  That means that the code in
  callstack_push_symfunc and insert_breakpoint has to assume that
  what comes from get_return_address is mangled, and needs to go
  through creating the breakpoint and then looking at its address.
  That's awkward, and we should come up with a better API.

1 files changed, 5 insertions, 3 deletions

diff --git a/handle_event.c b/handle_event.c
index ea73785..3101847 100644
--- a/handle_event.c
+++ b/handle_event.c
@@ -737,9 +737,11 @@ callstack_push_symfunc(struct process *proc, struct library_symbol *sym)
 	elem->is_syscall = 0;
 	elem->c_un.libfunc = sym;
 
-	elem->return_addr = proc->return_addr;
-	if (elem->return_addr)
-		insert_breakpoint(proc, elem->return_addr, NULL);
+	arch_addr_t return_addr = get_return_addr(proc, proc->stack_pointer);
+	struct breakpoint *rbp = NULL;
+	if (return_addr != 0)
+		rbp = insert_breakpoint(proc, return_addr, NULL);
+	elem->return_addr = rbp != NULL ? rbp->addr : 0;
 
 	if (opt_T || options.summary) {
 		struct timezone tz;