Re: [patch v5] unwinder: The unwinder (x86* only)

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

On Fri, 11 Oct 2013 14:34:48 +0200, Mark Wielaard wrote:
> So I was thinking something like the attached (it compiles, might not
> actually work).

FYI this part I have applied from your patch, as discussed in the other mail.


Thanks,
Jan

diff --git a/backends/i386_initreg.c b/backends/i386_initreg.c
index 9d904a4..b776e01 100644
--- a/backends/i386_initreg.c
+++ b/backends/i386_initreg.c
@@ -40,8 +40,9 @@
 #include "libebl_CPU.h"
 
 bool
-i386_set_initial_registers_tid (struct Dwfl_Thread *thread, pid_t tid,
-				dwfl_thread_state_registers_t *setfunc)
+i386_set_initial_registers_tid (pid_t tid,
+				ebl_tid_registers_t *setfunc,
+				void *arg)
 {
 #if !defined __i386__ && !defined __x86_64__
   return false;
@@ -73,7 +74,7 @@ i386_set_initial_registers_tid (struct Dwfl_Thread *thread, pid_t tid,
 # else /* (__i386__ || __x86_64__) && (!__i386__ && !__x86_64__) */
 #  error
 # endif /* (__i386__ || __x86_64__) && (!__i386__ && !__x86_64__) */
-  return setfunc (thread, 0, 9, dwarf_regs);
+  return setfunc (0, 9, dwarf_regs, arg);
 #endif /* __i386__ || __x86_64__ */
   return true;
 }
diff --git a/backends/x86_64_initreg.c b/backends/x86_64_initreg.c
index 9f7c119..1cc9b9f 100644
--- a/backends/x86_64_initreg.c
+++ b/backends/x86_64_initreg.c
@@ -40,8 +40,9 @@
 #include "libebl_CPU.h"
 
 bool
-x86_64_set_initial_registers_tid (struct Dwfl_Thread *thread, pid_t tid,
-				  dwfl_thread_state_registers_t *setfunc)
+x86_64_set_initial_registers_tid (pid_t tid,
+				  ebl_tid_registers_t *setfunc,
+				  void *arg)
 {
 #ifndef __x86_64__
   return false;
@@ -67,6 +68,6 @@ x86_64_set_initial_registers_tid (struct Dwfl_Thread *thread, pid_t tid,
   dwarf_regs[14] = user_regs.r14;
   dwarf_regs[15] = user_regs.r15;
   dwarf_regs[16] = user_regs.rip;
-  return setfunc (thread, 0, 17, dwarf_regs);
+  return setfunc (0, 17, dwarf_regs, arg);
 #endif /* __x86_64__ */
 }
diff --git a/libdwfl/dwfl_frame_pid.c b/libdwfl/dwfl_frame_pid.c
index e91e82f..1998589 100644
--- a/libdwfl/dwfl_frame_pid.c
+++ b/libdwfl/dwfl_frame_pid.c
@@ -134,6 +134,16 @@ pid_next_thread (Dwfl *dwfl __attribute__ ((unused)),
 }
 
 static bool
+pid_thread_state_registers_cb (const int firstreg,
+			       unsigned nregs,
+			       const Dwarf_Word *regs,
+			       void *arg)
+{
+  Dwfl_Thread *thread = (Dwfl_Thread *) arg;
+  return INTUSE(dwfl_thread_state_registers) (thread, firstreg, nregs, regs);
+}
+
+static bool
 pid_set_initial_registers (Dwfl_Thread *thread, void *thread_arg)
 {
   struct pid_arg *pid_arg = thread_arg;
@@ -151,8 +161,8 @@ pid_set_initial_registers (Dwfl_Thread *thread, void *thread_arg)
   pid_arg->tids_attached[pid_arg->tids_attached_used++] = tid;
   Dwfl_Process *process = thread->process;
   Ebl *ebl = process->ebl;
-  return ebl_set_initial_registers_tid (ebl, thread, tid,
-					INTUSE(dwfl_thread_state_registers));
+  return ebl_set_initial_registers_tid (ebl, tid,
+					pid_thread_state_registers_cb, thread);
 }
 
 static void
diff --git a/libebl/ebl-hooks.h b/libebl/ebl-hooks.h
index 05ca18b..32ca37c 100644
--- a/libebl/ebl-hooks.h
+++ b/libebl/ebl-hooks.h
@@ -156,8 +156,9 @@ int EBLHOOK(disasm) (const uint8_t **startp, const uint8_t *end,
 int EBLHOOK(abi_cfi) (Ebl *ebl, Dwarf_CIE *abi_info);
 
 /* Fetch process data from live TID into THREAD->unwound.  */
-bool EBLHOOK(set_initial_registers_tid) (struct Dwfl_Thread *thread, pid_t tid,
-					dwfl_thread_state_registers_t *setfunc);
+bool EBLHOOK(set_initial_registers_tid) (pid_t tid,
+					 ebl_tid_registers_t *setfunc,
+					 void *arg);
 
 /* Destructor for ELF backend handle.  */
 void EBLHOOK(destr) (struct ebl *);
diff --git a/libebl/eblinitreg.c b/libebl/eblinitreg.c
index 4aa9d9b..8909c50 100644
--- a/libebl/eblinitreg.c
+++ b/libebl/eblinitreg.c
@@ -34,13 +34,14 @@
 #include <assert.h>
 
 bool
-ebl_set_initial_registers_tid (Ebl *ebl, struct Dwfl_Thread *thread, pid_t tid,
-			       dwfl_thread_state_registers_t *setfunc)
+ebl_set_initial_registers_tid (Ebl *ebl, pid_t tid,
+			       ebl_tid_registers_t *setfunc,
+			       void *arg)
 {
   /* Otherwise caller could not allocate THREAD frame of proper size.
      If set_initial_registers_tid is unsupported then FRAME_NREGS is zero.  */
   assert (ebl->set_initial_registers_tid != NULL);
-  return ebl->set_initial_registers_tid (thread, tid, setfunc);
+  return ebl->set_initial_registers_tid (tid, setfunc, arg);
 }
 
 size_t
diff --git a/libebl/libebl.h b/libebl/libebl.h
index e3185b4..7c04355 100644
--- a/libebl/libebl.h
+++ b/libebl/libebl.h
@@ -383,17 +383,18 @@ extern int ebl_auxv_info (Ebl *ebl, GElf_Xword a_type,
 			  const char **name, const char **format)
   __nonnull_attribute__ (1, 3, 4);
 
-/* Fetch process data from live TID into THREAD->unwound.  */
-struct Dwfl_Thread;
-typedef bool (dwfl_thread_state_registers_t) (struct Dwfl_Thread *thread,
-					      const int firstreg,
-					      unsigned nregs,
-					      const Dwarf_Word *regs)
-  __nonnull_attribute__ (1, 4);
-extern bool ebl_set_initial_registers_tid (Ebl *ebl, struct Dwfl_Thread *thread,
+/* Callback to fetch process data from live TID.  */
+typedef bool (ebl_tid_registers_t) (const int firstreg,
+				    unsigned nregs,
+				    const Dwarf_Word *regs,
+				    void *arg)
+  __nonnull_attribute__ (3);
+
+extern bool ebl_set_initial_registers_tid (Ebl *ebl,
 					   pid_t tid,
-					 dwfl_thread_state_registers_t *setfunc)
-  __nonnull_attribute__ (1);
+					   ebl_tid_registers_t *setfunc,
+					   void *arg)
+  __nonnull_attribute__ (1, 3);
 
 /* Number of registers to allocate
    for STATE of ebl_set_initial_registers_tid.  */