Adding upstream version 1:10.0.2+ds.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

scripts/qemugdb/coroutine.py

@@ -0,0 +1,196 @@
+#
+# GDB debugging support
+#
+# Copyright 2012 Red Hat, Inc. and/or its affiliates
+#
+# Authors:
+#  Avi Kivity <avi@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2
+# or later.  See the COPYING file in the top-level directory.
+
+import gdb
+
+VOID_PTR = gdb.lookup_type('void').pointer()
+
+def pthread_self():
+    '''Fetch the base address of TLS.'''
+    return gdb.parse_and_eval("$fs_base")
+
+def get_glibc_pointer_guard():
+    '''Fetch glibc pointer guard value'''
+    fs_base = pthread_self()
+    return gdb.parse_and_eval('*(uint64_t*)((uint64_t)%s + 0x30)' % fs_base)
+
+def glibc_ptr_demangle(val, pointer_guard):
+    '''Undo effect of glibc's PTR_MANGLE()'''
+    return gdb.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val, val, pointer_guard))
+
+def get_jmpbuf_regs(jmpbuf):
+    JB_RBX  = 0
+    JB_RBP  = 1
+    JB_R12  = 2
+    JB_R13  = 3
+    JB_R14  = 4
+    JB_R15  = 5
+    JB_RSP  = 6
+    JB_PC   = 7
+
+    pointer_guard = get_glibc_pointer_guard()
+    return {'rbx': jmpbuf[JB_RBX],
+        'rbp': glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard),
+        'rsp': glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard),
+        'r12': jmpbuf[JB_R12],
+        'r13': jmpbuf[JB_R13],
+        'r14': jmpbuf[JB_R14],
+        'r15': jmpbuf[JB_R15],
+        'rip': glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard) }
+
+def symbol_lookup(addr):
+    # Example: "__clone3 + 44 in section .text of /lib64/libc.so.6"
+    result = gdb.execute(f"info symbol {hex(addr)}", to_string=True).strip()
+    try:
+        if "+" in result:
+            (func, result) = result.split(" + ")
+            (offset, result) = result.split(" in ")
+        else:
+            offset = "0"
+            (func, result) = result.split(" in ")
+        func_str = f"{func}<+{offset}> ()"
+    except:
+        return f"??? ({result})"
+
+    # Example: Line 321 of "../util/coroutine-ucontext.c" starts at address
+    # 0x55cf3894d993 <qemu_coroutine_switch+99> and ends at 0x55cf3894d9ab
+    # <qemu_coroutine_switch+123>.
+    result = gdb.execute(f"info line *{hex(addr)}", to_string=True).strip()
+    if not result.startswith("Line "):
+        return func_str
+    result = result[5:]
+
+    try:
+        result = result.split(" starts ")[0]
+        (line, path) = result.split(" of ")
+        path = path.replace("\"", "")
+    except:
+        return func_str
+
+    return f"{func_str} at {path}:{line}"
+
+def dump_backtrace(regs):
+    '''
+    Backtrace dump with raw registers, mimic GDB command 'bt'.
+    '''
+    # Here only rbp and rip that matter..
+    rbp = regs['rbp']
+    rip = regs['rip']
+    i = 0
+
+    while rbp:
+        # For all return addresses on stack, we want to look up symbol/line
+        # on the CALL command, because the return address is the next
+        # instruction instead of the CALL.  Here -1 would work for any
+        # sized CALL instruction.
+        print(f"#{i}  {hex(rip)} in {symbol_lookup(rip if i == 0 else rip-1)}")
+        rip = gdb.parse_and_eval(f"*(uint64_t *)(uint64_t)({hex(rbp)} + 8)")
+        rbp = gdb.parse_and_eval(f"*(uint64_t *)(uint64_t)({hex(rbp)})")
+        i += 1
+
+def dump_backtrace_live(regs):
+    '''
+    Backtrace dump with gdb's 'bt' command, only usable in a live session.
+    '''
+    old = dict()
+
+    # remember current stack frame and select the topmost
+    # so that register modifications don't wreck it
+    selected_frame = gdb.selected_frame()
+    gdb.newest_frame().select()
+
+    for i in regs:
+        old[i] = gdb.parse_and_eval('(uint64_t)$%s' % i)
+
+    for i in regs:
+        gdb.execute('set $%s = %s' % (i, regs[i]))
+
+    gdb.execute('bt')
+
+    for i in regs:
+        gdb.execute('set $%s = %s' % (i, old[i]))
+
+    selected_frame.select()
+
+def bt_jmpbuf(jmpbuf):
+    '''Backtrace a jmpbuf'''
+    regs = get_jmpbuf_regs(jmpbuf)
+    try:
+        # This reuses gdb's "bt" command, which can be slightly prettier
+        # but only works with live sessions.
+        dump_backtrace_live(regs)
+    except:
+        # If above doesn't work, fallback to poor man's unwind
+        dump_backtrace(regs)
+
+def co_cast(co):
+    return co.cast(gdb.lookup_type('CoroutineUContext').pointer())
+
+def coroutine_to_jmpbuf(co):
+    coroutine_pointer = co_cast(co)
+    return coroutine_pointer['env']['__jmpbuf']
+
+
+class CoroutineCommand(gdb.Command):
+    '''Display coroutine backtrace'''
+    def __init__(self):
+        gdb.Command.__init__(self, 'qemu coroutine', gdb.COMMAND_DATA,
+                             gdb.COMPLETE_NONE)
+
+    def invoke(self, arg, from_tty):
+        argv = gdb.string_to_argv(arg)
+        if len(argv) != 1:
+            gdb.write('usage: qemu coroutine <coroutine-pointer>\n')
+            return
+
+        bt_jmpbuf(coroutine_to_jmpbuf(gdb.parse_and_eval(argv[0])))
+
+class CoroutineBt(gdb.Command):
+    '''Display backtrace including coroutine switches'''
+    def __init__(self):
+        gdb.Command.__init__(self, 'qemu bt', gdb.COMMAND_STACK,
+                             gdb.COMPLETE_NONE)
+
+    def invoke(self, arg, from_tty):
+
+        gdb.execute("bt")
+
+        try:
+            # This only works with a live session
+            co_ptr = gdb.parse_and_eval("qemu_coroutine_self()")
+        except:
+            # Fallback to use hard-coded ucontext vars if it's coredump
+            co_ptr = gdb.parse_and_eval("co_tls_current")
+
+        if co_ptr == False:
+            return
+
+        while True:
+            co = co_cast(co_ptr)
+            co_ptr = co["base"]["caller"]
+            if co_ptr == 0:
+                break
+            gdb.write("Coroutine at " + str(co_ptr) + ":\n")
+            bt_jmpbuf(coroutine_to_jmpbuf(co_ptr))
+
+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)