[PATCH 4.4 30/42] arm64/ptrace: Preserve previous registers for short regset write

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Dave Martin 

commit 9a17b876b573441bfb3387ad55d98bf7184daf9d upstream.

Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.

Fixes: 478fcb2cdb23 ("arm64: Debugging support")
Signed-off-by: Dave Martin 
Acked-by: Will Deacon 
Signed-off-by: Catalin Marinas 
Signed-off-by: Greg Kroah-Hartman 

---
 arch/arm64/kernel/ptrace.c |7 ---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -495,7 +495,7 @@ static int gpr_set(struct task_struct *t
   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(, , , , , 0, -1);
if (ret)
@@ -525,7 +525,8 @@ static int fpr_set(struct task_struct *t
   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(, , , , , 0, -1);
if (ret)
@@ -549,7 +550,7 @@ static int tls_set(struct task_struct *t
   const void *kbuf, const void __user *ubuf)
 {
int ret;
-   unsigned long tls;
+   unsigned long tls = target->thread.tp_value;
 
ret = user_regset_copyin(, , , , , 0, -1);
if (ret)

[PATCH 4.4 30/42] arm64/ptrace: Preserve previous registers for short regset write

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Dave Martin 

commit 9a17b876b573441bfb3387ad55d98bf7184daf9d upstream.

Ensure that if userspace supplies insufficient data to
PTRACE_SETREGSET to fill all the registers, the thread's old
registers are preserved.

Fixes: 478fcb2cdb23 ("arm64: Debugging support")
Signed-off-by: Dave Martin 
Acked-by: Will Deacon 
Signed-off-by: Catalin Marinas 
Signed-off-by: Greg Kroah-Hartman 

---
 arch/arm64/kernel/ptrace.c |7 ---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -495,7 +495,7 @@ static int gpr_set(struct task_struct *t
   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(, , , , , 0, -1);
if (ret)
@@ -525,7 +525,8 @@ static int fpr_set(struct task_struct *t
   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(, , , , , 0, -1);
if (ret)
@@ -549,7 +550,7 @@ static int tls_set(struct task_struct *t
   const void *kbuf, const void __user *ubuf)
 {
int ret;
-   unsigned long tls;
+   unsigned long tls = target->thread.tp_value;
 
ret = user_regset_copyin(, , , , , 0, -1);
if (ret)