===================================================================
@@ -194,6 +194,12 @@ static ssize_t show_dscr_default(struct
return sprintf(buf, "%lx\n", dscr_default);
}
+static void update_dscr(void *dummy)
+{
+ if (!current->thread.dscr_inherit)
+ mtspr(SPRN_DSCR, dscr_default);
+}
+
static ssize_t __used store_dscr_default(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
@@ -206,6 +212,8 @@ static ssize_t __used store_dscr_default
return -EINVAL;
dscr_default = val;
+ on_each_cpu(update_dscr, NULL, 1);
+
return count;
}
Writing to dscr_default in sysfs doesn't actually change the DSCR - we rely on a context switch on each CPU to do the work. There is no guarantee we will get a context switch in a reasonable amount of time so fire off an IPI to force an immediate change. This issue was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Cc: <stable@kernel.org> # 3.0+ ---