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-rw-r--r--arch/s390/kernel/ptrace.c33
1 files changed, 22 insertions, 11 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 252ed61..a5f8f0c 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -1171,26 +1171,37 @@ static int s390_gs_cb_set(struct task_struct *target,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
- struct gs_cb *data = target->thread.gs_cb;
+ struct gs_cb gs_cb = { }, *data = NULL;
int rc;
if (!MACHINE_HAS_GS)
return -ENODEV;
- if (!data) {
+ if (!target->thread.gs_cb) {
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
- data->gsd = 25;
- target->thread.gs_cb = data;
- if (target == current)
- __ctl_set_bit(2, 4);
- } else if (target == current) {
- save_gs_cb(data);
}
+ if (!target->thread.gs_cb)
+ gs_cb.gsd = 25;
+ else if (target == current)
+ save_gs_cb(&gs_cb);
+ else
+ gs_cb = *target->thread.gs_cb;
rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- data, 0, sizeof(struct gs_cb));
- if (target == current)
- restore_gs_cb(data);
+ &gs_cb, 0, sizeof(gs_cb));
+ if (rc) {
+ kfree(data);
+ return -EFAULT;
+ }
+ preempt_disable();
+ if (!target->thread.gs_cb)
+ target->thread.gs_cb = data;
+ *target->thread.gs_cb = gs_cb;
+ if (target == current) {
+ __ctl_set_bit(2, 4);
+ restore_gs_cb(target->thread.gs_cb);
+ }
+ preempt_enable();
return rc;
}
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