| Message ID | 20191215201321.7439-1-pakki001@umn.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/grant-table: remove unnecessary BUG_ON on gnttab_interface | expand |
On 15.12.19 21:13, Aditya Pakki wrote: > grow_gnttab_list() checks for NULL on gnttab_interface immediately > after gnttab_expand() check. The patch removes the redundant assertion > and replaces the BUG_ON call with recovery code. > > Signed-off-by: Aditya Pakki <pakki001@umn.edu> > --- > drivers/xen/grant-table.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 49b381e104ef..f59694c352be 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -664,7 +664,6 @@ static int grow_gnttab_list(unsigned int more_frames) > unsigned int nr_glist_frames, new_nr_glist_frames; > unsigned int grefs_per_frame; > > - BUG_ON(gnttab_interface == NULL); > grefs_per_frame = gnttab_interface->grefs_per_grant_frame; > > new_nr_grant_frames = nr_grant_frames + more_frames; > @@ -1388,7 +1387,9 @@ static int gnttab_expand(unsigned int req_entries) > int rc; > unsigned int cur, extra; > > - BUG_ON(gnttab_interface == NULL); > + if (!gnttab_interface) > + return -EINVAL; > + > cur = nr_grant_frames; > extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) / > gnttab_interface->grefs_per_grant_frame); > @@ -1423,7 +1424,9 @@ int gnttab_init(void) > /* Determine the maximum number of frames required for the > * grant reference free list on the current hypervisor. > */ > - BUG_ON(gnttab_interface == NULL); > + if (!gnttab_interface) > + return -EINVAL; > + I'd just remove the BUG_ON(). gnttab_request_version() called some lines up always sets gnttab_interface. The BUG_ON() in nr_status_frames() can be removed, too. It is either called by v2 specific functions (for those to be reached gnttab_interface must be set) or by gnttab_init() (reasoning see above). Juergen
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 49b381e104ef..f59694c352be 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -664,7 +664,6 @@ static int grow_gnttab_list(unsigned int more_frames) unsigned int nr_glist_frames, new_nr_glist_frames; unsigned int grefs_per_frame; - BUG_ON(gnttab_interface == NULL); grefs_per_frame = gnttab_interface->grefs_per_grant_frame; new_nr_grant_frames = nr_grant_frames + more_frames; @@ -1388,7 +1387,9 @@ static int gnttab_expand(unsigned int req_entries) int rc; unsigned int cur, extra; - BUG_ON(gnttab_interface == NULL); + if (!gnttab_interface) + return -EINVAL; + cur = nr_grant_frames; extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) / gnttab_interface->grefs_per_grant_frame); @@ -1423,7 +1424,9 @@ int gnttab_init(void) /* Determine the maximum number of frames required for the * grant reference free list on the current hypervisor. */ - BUG_ON(gnttab_interface == NULL); + if (!gnttab_interface) + return -EINVAL; + max_nr_glist_frames = (max_nr_grant_frames * gnttab_interface->grefs_per_grant_frame / RPP);
grow_gnttab_list() checks for NULL on gnttab_interface immediately after gnttab_expand() check. The patch removes the redundant assertion and replaces the BUG_ON call with recovery code. Signed-off-by: Aditya Pakki <pakki001@umn.edu> --- drivers/xen/grant-table.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)