return read_memory_integer (addr + LINUX_SIGCONTEXT_SP_OFFSET, 4);
}
+/* Signal trampolines don't have a meaningful frame. As in
+ "i386/tm-i386.h", the frame pointer value we use is actually the
+ frame pointer of the calling frame -- that is, the frame which was
+ in progress when the signal trampoline was entered. GDB mostly
+ treats this frame pointer value as a magic cookie. We detect the
+ case of a signal trampoline by looking at the SIGNAL_HANDLER_CALLER
+ field, which is set based on IN_SIGTRAMP.
+
+ When a signal trampoline is invoked from a frameless function, we
+ essentially have two frameless functions in a row. In this case,
+ we use the same magic cookie for three frames in a row. We detect
+ this case by seeing whether the next frame has
+ SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
+ current frame is actually frameless. In this case, we need to get
+ the PC by looking at the SP register value stored in the signal
+ context.
+
+ This should work in most cases except in horrible situations where
+ a signal occurs just as we enter a function but before the frame
+ has been set up. */
+
+#define FRAMELESS_SIGNAL(frame) \
+ ((frame)->next != NULL \
+ && (frame)->next->signal_handler_caller \
+ && frameless_look_for_prologue (frame))
+
+CORE_ADDR
+i386_linux_frame_chain (struct frame_info *frame)
+{
+ if (frame->signal_handler_caller || FRAMELESS_SIGNAL (frame))
+ return frame->frame;
+
+ if (! inside_entry_file (frame->pc))
+ return read_memory_unsigned_integer (frame->frame, 4);
+
+ return 0;
+}
+
/* Return the saved program counter for FRAME. */
CORE_ADDR
if (frame->signal_handler_caller)
return i386_linux_sigtramp_saved_pc (frame);
- /* See comment in "i386/tm-linux.h" for an explanation what this
- "FRAMELESS_SIGNAL" stuff is supposed to do.
-
- FIXME: kettenis/2001-03-26: That comment should eventually be
- moved to this file. */
if (FRAMELESS_SIGNAL (frame))
{
CORE_ADDR sp = i386_linux_sigtramp_saved_sp (frame->next);
if (frame->signal_handler_caller)
return i386_linux_sigtramp_saved_pc (frame);
- return read_memory_integer (read_register (SP_REGNUM), 4);
+ return read_memory_unsigned_integer (read_register (SP_REGNUM), 4);
}
-
\f
/* Calling functions in shared libraries. */