Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'for-linus-5.14-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"A small cleanup patch and a fix of a rare race in the Xen evtchn
driver"
* tag 'for-linus-5.14-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/events: Fix race in set_evtchn_to_irq
xen/events: remove redundant initialization of variable irq
+15
-7
+15
-7
drivers/xen/events/events_base.c
+15
-7
drivers/xen/events/events_base.c
···
198
198
199
199
static DEFINE_PER_CPU(unsigned int, irq_epoch);
200
200
201
-
static void clear_evtchn_to_irq_row(unsigned row)
201
+
static void clear_evtchn_to_irq_row(int *evtchn_row)
202
202
{
203
203
unsigned col;
204
204
205
205
for (col = 0; col < EVTCHN_PER_ROW; col++)
206
-
WRITE_ONCE(evtchn_to_irq[row][col], -1);
206
+
WRITE_ONCE(evtchn_row[col], -1);
207
207
}
208
208
209
209
static void clear_evtchn_to_irq_all(void)
···
213
213
for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
214
214
if (evtchn_to_irq[row] == NULL)
215
215
continue;
216
-
clear_evtchn_to_irq_row(row);
216
+
clear_evtchn_to_irq_row(evtchn_to_irq[row]);
217
217
}
218
218
}
219
219
···
221
221
{
222
222
unsigned row;
223
223
unsigned col;
224
+
int *evtchn_row;
224
225
225
226
if (evtchn >= xen_evtchn_max_channels())
226
227
return -EINVAL;
···
234
233
if (irq == -1)
235
234
return 0;
236
235
237
-
evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
238
-
if (evtchn_to_irq[row] == NULL)
236
+
evtchn_row = (int *) __get_free_pages(GFP_KERNEL, 0);
237
+
if (evtchn_row == NULL)
239
238
return -ENOMEM;
240
239
241
-
clear_evtchn_to_irq_row(row);
240
+
clear_evtchn_to_irq_row(evtchn_row);
241
+
242
+
/*
243
+
* We've prepared an empty row for the mapping. If a different
244
+
* thread was faster inserting it, we can drop ours.
245
+
*/
246
+
if (cmpxchg(&evtchn_to_irq[row], NULL, evtchn_row) != NULL)
247
+
free_page((unsigned long) evtchn_row);
242
248
}
243
249
244
250
WRITE_ONCE(evtchn_to_irq[row][col], irq);
···
1017
1009
int xen_bind_pirq_gsi_to_irq(unsigned gsi,
1018
1010
unsigned pirq, int shareable, char *name)
1019
1011
{
1020
-
int irq = -1;
1012
+
int irq;
1021
1013
struct physdev_irq irq_op;
1022
1014
int ret;
1023
1015