Messages in this thread |  | | Subject | Re: [PATCH] xen/grant-table: remove unnecessary BUG_ON on gnttab_interface | From | Jürgen Groß <> | Date | Mon, 16 Dec 2019 08:38:19 +0100 |
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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
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