LoongArch: Fix missing fcsr in ptrace's fpr_set

In file ptrace.c, function fpr_set does not copy fcsr data from ubuf to kbuf. That's the reason why fcsr cannot be modified by ptrace. This patch fixs this problem and allows users using ptrace to modify the fcsr. Co-developed-by: Xu Li <[email protected]> Signed-off-by: Qi Hu <[email protected]> Signed-off-by: Huacai Chen <[email protected]>
niw · Jul 29, 2022 · b0f3bdc · b0f3bdc
1 parent 1aea29d
commit b0f3bdc
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/arch/loongarch/kernel/ptrace.c b/arch/loongarch/kernel/ptrace.c
@@ -193,7 +193,7 @@ static int fpr_set(struct task_struct *target,
 		   const void *kbuf, const void __user *ubuf)
 {
 	const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
-	const int fcc_end = fcc_start + sizeof(u64);
+	const int fcsr_start = fcc_start + sizeof(u64);
 	int err;
 
 	BUG_ON(count % sizeof(elf_fpreg_t));
@@ -209,10 +209,12 @@ static int fpr_set(struct task_struct *target,
 	if (err)
 		return err;
 
-	if (count > 0)
-		err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-					  &target->thread.fpu.fcc,
-					  fcc_start, fcc_end);
+	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				  &target->thread.fpu.fcc, fcc_start,
+				  fcc_start + sizeof(u64));
+	err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				  &target->thread.fpu.fcsr, fcsr_start,
+				  fcsr_start + sizeof(u32));
 
 	return err;
 }