On 12 December 2016 at 15:07, Jonathan Gray <jsg@xxxxxxxxx> wrote: > On Mon, Dec 12, 2016 at 02:10:31PM +0000, Emil Velikov wrote: >> On 10 December 2016 at 05:52, Jonathan Gray <jsg@xxxxxxxxx> wrote: >> > When constructing a path to a device node the minor number retrieved >> > from fstat needs to have the offset of the node type subtracted from it. >> > Control and render node types have the same major as the primary node >> > but each has their own block of minor types at fixed offsets. >> > >> > Signed-off-by: Jonathan Gray <jsg@xxxxxxxxx> >> > --- >> > xf86drm.c | 16 ++++++++++++---- >> > 1 file changed, 12 insertions(+), 4 deletions(-) >> > >> > diff --git a/xf86drm.c b/xf86drm.c >> > index 2e8c956..6705605 100644 >> > --- a/xf86drm.c >> > +++ b/xf86drm.c >> > @@ -2838,7 +2838,7 @@ out_close_dir: >> > char buf[PATH_MAX + 1]; >> > const char *dev_name; >> > unsigned int maj, min; >> > - int n; >> > + int n, base; >> > >> > if (fstat(fd, &sbuf)) >> > return NULL; >> > @@ -2863,7 +2863,11 @@ out_close_dir: >> > return NULL; >> > }; >> > >> > - n = snprintf(buf, sizeof(buf), dev_name, DRM_DIR_NAME, min); >> > + base = drmGetMinorBase(type); >> > + if (base < 0 || min < base) >> min < base seems bogus, since it will never be true, right ? If so can >> we drop it please. >> >> Same goes below and in 2/3. >> Emil > > For drmGetDevice2() and drmGetDeviceNameFromFd2() yes as it should be > caught by drmGetMinorType(). > > For drmGetMinorNameForFD() it would be possible for a minor number to be > wrong and have it not caught as the type comes from an argument not > inspection of the /dev node. A sanity check of the type argument > could be made based on the minor found on disk but that ends up > being the same kind of test. K-kind of ... There is no guarantee that that card0 relate to renderD128 and vice versa. Thus strictly speaking most/all the implementations that rely on drmGetMinorBase are buggy. IIIRC there was a discussion why those are not (and cannot) be made reliable, which inspired all the nasty sysfs parsing. Nothing [new] should rely on drmOpen and friends, so we can ignore the drmGetMinorNameForFD corner cases. ... I hope Thanks Emil _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
