scripts/kvm/kvm_stat: Fixup syscall error reporting

In 2008 a patch was written that introduced ctypes.get_errno() and
set_errno() as official interfaces to the libc errno variable. Using
them we can avoid accessing private libc variables.
The patch was included in python 2.6.

Also we need to raise the right exception, with the right parameters
and a helpful message.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Message-Id: <1452525484-32309-14-git-send-email-frankja@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Janosch Frank 2016-01-11 16:17:43 +01:00 committed by Paolo Bonzini
parent f4109dba21
commit 400b3cb519

View File

@ -287,10 +287,8 @@ filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)
if EXIT_REASONS:
filters['kvm_exit'] = ('exit_reason', EXIT_REASONS)
libc = ctypes.CDLL('libc.so.6')
libc = ctypes.CDLL('libc.so.6', use_errno=True)
syscall = libc.syscall
get_errno = libc.__errno_location
get_errno.restype = ctypes.POINTER(ctypes.c_int)
class perf_event_attr(ctypes.Structure):
_fields_ = [('type', ctypes.c_uint32),
@ -351,8 +349,9 @@ class Event(object):
group_leader = group.events[0].fd
fd = _perf_event_open(attr, -1, group.cpu, group_leader, 0)
if fd == -1:
err = get_errno()[0]
raise Exception('perf_event_open failed, errno = ' + err.__str__())
err = ctypes.get_errno()
raise OSError(err, os.strerror(err),
'while calling sys_perf_event_open().')
if tracefilter:
fcntl.ioctl(fd, IOCTL_NUMBERS['SET_FILTER'], tracefilter)
self.fd = fd