qemu-gdb: add $qemu_coroutine_sp and $qemu_coroutine_pc

These can be useful to manually get a stack trace of a coroutine inside
a core dump.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

scripts/qemu-gdb.py

@@ -38,6 +38,9 @@ def __init__(self):
 coroutine.CoroutineCommand()
 mtree.MtreeCommand()
 
+coroutine.CoroutineSPFunction()
+coroutine.CoroutinePCFunction()
+
 # Default to silently passing through SIGUSR1, because QEMU sends it
 # to itself a lot.
 gdb.execute('handle SIGUSR1 pass noprint nostop')

scripts/qemugdb/coroutine.py

@@ -15,6 +15,8 @@
 
 import gdb
 
+VOID_PTR = gdb.lookup_type('void').pointer()
+
 def get_fs_base():
     '''Fetch %fs base value using arch_prctl(ARCH_GET_FS).  This is
        pthread_self().'''
@@ -101,3 +103,17 @@ def invoke(self, arg, from_tty):
             return
 
         bt_jmpbuf(coroutine_to_jmpbuf(gdb.parse_and_eval(argv[0])))
+
+class CoroutineSPFunction(gdb.Function):
+    def __init__(self):
+        gdb.Function.__init__(self, 'qemu_coroutine_sp')
+
+    def invoke(self, addr):
+        return get_jmpbuf_regs(coroutine_to_jmpbuf(addr))['rsp'].cast(VOID_PTR)
+
+class CoroutinePCFunction(gdb.Function):
+    def __init__(self):
+        gdb.Function.__init__(self, 'qemu_coroutine_pc')
+
+    def invoke(self, addr):
+        return get_jmpbuf_regs(coroutine_to_jmpbuf(addr))['rip'].cast(VOID_PTR)