From: Janosch Frank <fran...@linux.vnet.ibm.com> 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 <fran...@linux.vnet.ibm.com> Message-Id: <1452525484-32309-14-git-send-email-fran...@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- scripts/kvm/kvm_stat | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat index b5422f8..457624d 100755 --- a/scripts/kvm/kvm_stat +++ b/scripts/kvm/kvm_stat @@ -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 -- 1.8.3.1