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authorDave Martin <Dave.Martin@arm.com>2017-01-18 16:25:20 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2017-01-18 18:05:02 +0000
commit9a17b876b573441bfb3387ad55d98bf7184daf9d (patch)
tree8756fec6c654dd65fb7e6783e7d7fc7db4761617 /arch
parent1c8a946bf3754a59cba1fc373949a8114bfe5aaa (diff)
downloadlinux-9a17b876b573441bfb3387ad55d98bf7184daf9d.tar.gz
arm64/ptrace: Preserve previous registers for short regset write
Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.

Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2cdb23 ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/ptrace.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index fc35e06ccaac..8c0bc3434f55 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -596,7 +596,7 @@ static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	struct user_pt_regs newregs;
+	struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 	if (ret)
@@ -626,7 +626,8 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	struct user_fpsimd_state newstate;
+	struct user_fpsimd_state newstate =
+		target->thread.fpsimd_state.user_fpsimd;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 	if (ret)
@@ -650,7 +651,7 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	unsigned long tls;
+	unsigned long tls = target->thread.tp_value;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 	if (ret)