def __call__(self, pending_frame):
fp = pending_frame.read_register(self.regs['fp'])
sp = pending_frame.read_register(self.regs['sp'])
ip = pending_frame.read_register(self.regs['ip'])
if not frame.is_jitted(fp, ip):
return None
# GDB wants a FrameId to be a pair of (stack pointer, starting PC) for
# a given function frame. Unfortunately, we can't restore the stack
# pointer correctly in the TC, and we don't know our starting IP.
#
# Instead, we just use the stack pointer value for our most
# recent call into native code, along with the current PC. It
# turns out that this is almost good enough. The problem is
# that we can end up with two frames with the same sp and pc
# in the same vm nesting (especially if we have interp ret
# helpers as the return address), and if two frame ids are the
# same, gdb bails out with an error.
#
# GDB expects stack pointers to be monotonically nondecreasing
# as we unwind, so we can't use fp instead of sp, but FrameIds
# are allowed to have a "special" field thats used to
# differentiate otherwise identical ones; so use fp there
# instead.
unwind_info = pending_frame.create_unwind_info(FrameId(sp, ip, fp))
# Restore the saved frame pointer and instruction pointer.
fp = fp.cast(T('uintptr_t').pointer())
unwind_info.add_saved_register(self.regs['fp'], fp[0])
unwind_info.add_saved_register(self.regs['ip'], fp[1])
if frame.is_jitted(fp[0], fp[1]):
# Our parent frame is jitted. Again, we are unable to track %rsp
# properly in the TC, so just preserve its value (just as we do in
# the TC's custom .eh_frame section).
unwind_info.add_saved_register(self.regs['sp'], sp)
else:
# Our parent frame is not jitted, so we're in g_ustubs.enterTCHelper,
# which has a special restore sequence
i = 0
for r in self.regs['cross_jit_save']:
i -= 1
unwind_info.add_saved_register(r, fp[i])
unwind_info.add_saved_register(self.regs['sp'], fp + 2)
return unwind_info
def try_unwinder_init():
"""Try to register the custom unwinder if it hasn't been already, and
return whether the unwinder has been successfully registered."""
global _did_init
if _did_init:
return True
# If we can't successfully call is_jitted(), then gdb startup hasn't
# proceeded to a point where it's safe to set up our unwinder yet, so just
# bail out.
try:
frame.is_jitted(0, 0)
except:
return False
register_unwinder(None, HHVMUnwinder())
_did_init = True
return True
def try_unwinder_init():
"""Try to register the custom unwinder if it hasn't been already, and
return whether the unwinder has been successfully registered."""
global _did_init
if _did_init:
return True
# If we can't successfully call is_jitted(), then gdb startup hasn't
# proceeded to a point where it's safe to set up our unwinder yet, so just
# bail out.
try:
frame.is_jitted(0, 0)
except:
return False
register_unwinder(None, HHVMUnwinder())
_did_init = True
return True
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 2:
print('Usage: walkfp [fp] [rip]')
return
fp_type = T('uintptr_t').pointer()
try:
arch = gdb.newest_frame().architecture().name()
except:
arch = 'i386:x86-64'
frame_reg = '$x29' if arch == 'aarch64' else '$rbp'
pc_reg = '$pc' if arch == 'aarch64' else '$rip'
fp = (argv[0] if len(argv) >= 1 else
gdb.parse_and_eval(frame_reg)).cast(fp_type)
rip = (argv[1] if len(argv) == 2 else gdb.parse_and_eval(pc_reg)).cast(
T('uintptr_t'))
i = 0
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
try:
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
print(
frame.stringify(
frame.create_php(idx=i,
ar=fp.cast(ar_type),
rip=rip)))
else:
print(
frame.stringify(
frame.create_native(idx=i,
fp=fp,
rip=rip,
name=_function_for(rip))))
except:
print(
frame.stringify(frame.create_native(idx=i, fp=fp,
rip=rip)))
i += 1
def __call__(self, pending_frame):
fp = pending_frame.read_register('rbp')
sp = pending_frame.read_register('rsp')
ip = pending_frame.read_register('rip')
if not frame.is_jitted(fp, ip):
return None
# GDB wants a FrameId to be a pair of (stack pointer, starting PC) for
# a given function frame. Unfortunately, we can't restore the stack
# pointer correctly in the TC, and we don't know our starting IP.
#
# Instead, we just use the stack pointer value for our most recent call
# into native code, along with the current PC. It turns out that this
# is good enough.
#
# GDB expects stack pointers to be monotonically nondecreasing as we
# unwind, so we can't use, e.g., the frame pointer as part of the ID.
unwind_info = pending_frame.create_unwind_info(FrameId(sp, ip))
# Restore the saved frame pointer and instruction pointer.
fp = fp.cast(T('uintptr_t').pointer())
unwind_info.add_saved_register('rbp', fp[0])
unwind_info.add_saved_register('rip', fp[1])
if frame.is_jitted(fp[0], fp[1]):
# Our parent frame is jitted. Again, we are unable to track %rsp
# properly in the TC, so just preserve its value (just as we do in
# the TC's custom .eh_frame section).
unwind_info.add_saved_register('rsp', sp)
else:
# Our parent frame is not jitted, so we're in enterTCHelper, and we
# can restore our parent's %rsp as usual.
unwind_info.add_saved_register('rsp', fp + 16)
return unwind_info
def __call__(self, pending_frame):
fp = pending_frame.read_register('rbp')
sp = pending_frame.read_register('rsp')
ip = pending_frame.read_register('rip')
if not frame.is_jitted(fp, ip):
return None
# GDB wants a FrameId to be a pair of (stack pointer, starting PC) for
# a given function frame. Unfortunately, we can't restore the stack
# pointer correctly in the TC, and we don't know our starting IP.
#
# Instead, we just use the stack pointer value for our most recent call
# into native code, along with the current PC. It turns out that this
# is good enough.
#
# GDB expects stack pointers to be monotonically nondecreasing as we
# unwind, so we can't use, e.g., the frame pointer as part of the ID.
unwind_info = pending_frame.create_unwind_info(FrameId(sp, ip))
# Restore the saved frame pointer and instruction pointer.
fp = fp.cast(T('uintptr_t').pointer())
unwind_info.add_saved_register('rbp', fp[0])
unwind_info.add_saved_register('rip', fp[1])
if frame.is_jitted(fp[0], fp[1]):
# Our parent frame is jitted. Again, we are unable to track %rsp
# properly in the TC, so just preserve its value (just as we do in
# the TC's custom .eh_frame section).
unwind_info.add_saved_register('rsp', sp)
else:
# Our parent frame is not jitted, so we're in enterTCHelper, and we
# can restore our parent's %rsp as usual.
unwind_info.add_saved_register('rsp', fp + 16)
return unwind_info
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 2:
print('Usage: walkfp [fp] [rip]')
return
fp_type = T('uintptr_t').pointer()
fp = gdb.parse_and_eval('$rbp').cast(fp_type)
rip = gdb.parse_and_eval('$rip').cast(T('uintptr_t'))
if len(argv) >= 1:
fp = argv[0].cast(fp_type)
if len(argv) == 2:
rip = argv[1].cast(T('uintptr_t'))
i = 0
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
try:
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
print(
frame.stringify(
frame.create_php(idx=i,
ar=fp.cast(ar_type),
rip=rip)))
else:
print(
frame.stringify(
frame.create_native(idx=i,
fp=fp,
rip=rip,
name=_function_for(rip))))
except:
print(
frame.stringify(frame.create_native(idx=i, fp=fp,
rip=rip)))
i += 1
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 2:
print('Usage: walkfp [fp] [rip]')
return
fp_type = T('uintptr_t').pointer()
try:
arch = gdb.newest_frame().architecture().name()
except:
arch = 'i386:x86-64'
frame_reg = '$x29' if arch == 'aarch64' else '$rbp'
pc_reg = '$pc' if arch == 'aarch64' else '$rip'
fp = (argv[0] if len(argv) >= 1 else
gdb.parse_and_eval(frame_reg)).cast(fp_type)
rip = (argv[1] if len(argv) == 2 else
gdb.parse_and_eval(pc_reg)).cast(T('uintptr_t'))
i = 0
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
try:
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
print(frame.stringify(frame.create_php(
idx=i, ar=fp.cast(ar_type), rip=rip)))
else:
print(frame.stringify(frame.create_native(
idx=i, fp=fp, rip=rip, name=_function_for(rip))))
except:
print(frame.stringify(frame.create_native(idx=i, fp=fp, rip=rip)))
i += 1
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 2:
print('Usage: walkfp [fp] [rip]')
return
fp_type = T('uintptr_t').pointer()
fp = gdb.parse_and_eval('$rbp').cast(fp_type)
rip = gdb.parse_and_eval('$rip').cast(T('uintptr_t'))
if len(argv) >= 1:
fp = argv[0].cast(fp_type)
if len(argv) == 2:
rip = argv[1].cast(T('uintptr_t'))
i = 0
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
try:
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
print(frame.stringify(frame.create_php(
idx=i, ar=fp.cast(ar_type), rip=rip)))
else:
print(frame.stringify(frame.create_native(
idx=i, fp=fp, rip=rip, name=_function_for(rip))))
except:
print(frame.stringify(frame.create_native(idx=i, fp=fp, rip=rip)))
i += 1
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 1:
print('Usage: walkstk [fp]')
return
# Bail early if the custom unwinder has not been set up.
if not unwind.try_unwinder_init():
print('walkstk: Could not initialize the HHVM unwinder.')
# Find the starting native frame.
native_frame = gdb.newest_frame()
if native_frame is None:
print('walkstk: Cannot find any frames: corrupt stack?')
return
# Set fp = $rbp, rip = $rip.
fp_type = T('uintptr_t').pointer()
fp = native_frame.read_register('rbp').cast(fp_type)
rip = native_frame.pc()
if len(argv) == 1:
# Start walking the stack from the user-provided `fp'.
fp = argv[0].cast(fp_type)[0]
rip = argv[0].cast(fp_type)[1]
# Try to find a corresponding native frame.
while (native_frame is not None and rip != native_frame.pc()):
native_frame = native_frame.older()
i = 0
# Make a fake frame for our `fp' and `rip'. This lets us pop a frame
# at the top of the loop, which makes it easier to include the final
# frame.
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
# Try to get the PHP function name from the ActRec at `fp' if we're
# executing in the TC.
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
try:
print(
frame.stringify(
frame.create_php(idx=i,
ar=fp.cast(ar_type),
rip=rip)))
except gdb.MemoryError:
print(
frame.stringify(
frame.create_native(idx=i,
fp=fp,
rip=rip,
native_frame=native_frame)))
if native_frame is not None:
native_frame = native_frame.older()
i += 1
else:
if native_frame is None:
# If we couldn't find a native frame, then `walkstk' was
# invoked with a non-native `fp' argument. Now that we
# don't seem to be in the TC, try to find the corresponding
# native frame.
native_frame = gdb.newest_frame()
while (native_frame is not None
and rip != native_frame.pc()):
native_frame = native_frame.older()
if native_frame is not None:
# Pop native frames until we hit our caller's rip.
frames = []
while (native_frame is not None
and (fp == 0x0 or fp[1] != native_frame.pc())):
frames.append(
frame.create_native(idx=i,
fp='{inline frame}',
rip=native_frame.pc(),
native_frame=native_frame))
native_frame = native_frame.older()
i += 1
if frames:
# Associate the frame pointer with the un-inlined frame.
frames[-1]['fp'] = str(fp)
for f in frames:
print(frame.stringify(f))
else:
# We only hit this case if gdb undercounted the TC's
# frames---which shouldn't happen unless the custom
# unwinder (or gdb's unwinder API) is malfunctioning.
#
# Just guess that the name of the frame is the same as the
# name of the block we're in.
try:
block = gdb.block_for_pc(int(rip))
name = block.function.name
print(
frame.stringify(
frame.create_native(idx=i,
fp=fp,
rip=rip,
name='? ' + name)))
except:
print(
frame.stringify(
frame.create_native(idx=i,
fp=fp,
rip=rip,
native_frame=None)))
i += 1
def invoke(self, args, from_tty):
argv = parse_argv(args)
if len(argv) > 1:
print('Usage: walkstk [fp]')
return
# Bail early if the custom unwinder has not been set up.
if not unwind.try_unwinder_init():
print('walkstk: Could not initialize the HHVM unwinder.')
# Find the starting native frame.
native_frame = gdb.newest_frame()
if native_frame is None:
print('walkstk: Cannot find any frames: corrupt stack?')
return
# Set fp = $rbp, rip = $rip.
fp_type = T('uintptr_t').pointer()
fp = native_frame.read_register('rbp').cast(fp_type)
rip = native_frame.pc()
if len(argv) == 1:
# Start walking the stack from the user-provided `fp'.
fp = argv[0].cast(fp_type)[0]
rip = argv[0].cast(fp_type)[1]
# Try to find a corresponding native frame.
while (native_frame is not None
and rip != native_frame.pc()):
native_frame = native_frame.older()
i = 0
# Make a fake frame for our `fp' and `rip'. This lets us pop a frame
# at the top of the loop, which makes it easier to include the final
# frame.
fp = (fp, rip)
while fp:
rip = fp[1]
fp = fp[0].cast(fp_type)
# Try to get the PHP function name from the ActRec at `fp' if we're
# executing in the TC.
if frame.is_jitted(fp, rip):
ar_type = T('HPHP::ActRec').pointer()
try:
print(frame.stringify(frame.create_php(
idx=i, ar=fp.cast(ar_type), rip=rip)))
except gdb.MemoryError:
print(frame.stringify(frame.create_native(
idx=i, fp=fp, rip=rip, native_frame=native_frame)))
if native_frame is not None:
native_frame = native_frame.older()
i += 1
else:
if native_frame is None:
# If we couldn't find a native frame, then `walkstk' was
# invoked with a non-native `fp' argument. Now that we
# don't seem to be in the TC, try to find the corresponding
# native frame.
native_frame = gdb.newest_frame()
while (native_frame is not None
and rip != native_frame.pc()):
native_frame = native_frame.older()
if native_frame is not None:
# Pop native frames until we hit our caller's rip.
frames = []
while (native_frame is not None
and (fp == 0x0 or fp[1] != native_frame.pc())):
frames.append(frame.create_native(
idx=i,
fp='{inline frame}',
rip=native_frame.pc(),
native_frame=native_frame))
native_frame = native_frame.older()
i += 1
if frames:
# Associate the frame pointer with the un-inlined frame.
frames[-1]['fp'] = str(fp)
for f in frames:
print(frame.stringify(f))
else:
# We only hit this case if gdb undercounted the TC's
# frames---which shouldn't happen unless the custom
# unwinder (or gdb's unwinder API) is malfunctioning.
#
# Just guess that the name of the frame is the same as the
# name of the block we're in.
try:
print(frame.stringify(frame.create_native(
idx=i, fp=fp, rip=rip, name=_function_for(rip))))
except:
print(frame.stringify(frame.create_native(
idx=i, fp=fp, rip=rip, native_frame=None)))
i += 1
