4 files changed, 27 insertions, 7 deletions

diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index a34a9d612fc0..18cd6b592650 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -20,7 +20,7 @@
 #define PSW32_MASK_CC           0x00003000UL
 #define PSW32_MASK_PM           0x00000f00UL
 
-#define PSW32_MASK_USER         0x00003F00UL
+#define PSW32_MASK_USER         0x0000FF00UL
 
 #define PSW32_ADDR_AMODE        0x80000000UL
 #define PSW32_ADDR_INSN         0x7FFFFFFFUL
diff --git a/arch/s390/include/uapi/asm/ptrace.h b/arch/s390/include/uapi/asm/ptrace.h
index 705588a16d70..a5ca214b34fd 100644
--- a/arch/s390/include/uapi/asm/ptrace.h
+++ b/arch/s390/include/uapi/asm/ptrace.h
@@ -239,7 +239,7 @@ typedef struct
 #define PSW_MASK_EA             0x00000000UL
 #define PSW_MASK_BA             0x00000000UL
 
-#define PSW_MASK_USER           0x00003F00UL
+#define PSW_MASK_USER           0x0000FF00UL
 
 #define PSW_ADDR_AMODE          0x80000000UL
 #define PSW_ADDR_INSN           0x7FFFFFFFUL
@@ -269,7 +269,7 @@ typedef struct
 #define PSW_MASK_EA             0x0000000100000000UL
 #define PSW_MASK_BA             0x0000000080000000UL
 
-#define PSW_MASK_USER           0x00003F8180000000UL
+#define PSW_MASK_USER           0x0000FF8180000000UL
 
 #define PSW_ADDR_AMODE          0x0000000000000000UL
 #define PSW_ADDR_INSN           0xFFFFFFFFFFFFFFFFUL
diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index a1e8a8694bb7..593fcc9253fc 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -309,6 +309,10 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
                 (__u64)(regs32.psw.mask & PSW32_MASK_USER) << 32 |
                 (__u64)(regs32.psw.addr & PSW32_ADDR_AMODE);
+        /* Check for invalid user address space control. */
+        if ((regs->psw.mask & PSW_MASK_ASC) >= (psw_kernel_bits & PSW_MASK_ASC))
+                regs->psw.mask = (psw_user_bits & PSW_MASK_ASC) |
+                        (regs->psw.mask & ~PSW_MASK_ASC);
         regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
         for (i = 0; i < NUM_GPRS; i++)
                 regs->gprs[i] = (__u64) regs32.gprs[i];
@@ -481,7 +485,10 @@ static int setup_frame32(int sig, struct k_sigaction *ka,
 
         /* Set up registers for signal handler */
         regs->gprs[15] = (__force __u64) frame;
-        regs->psw.mask |= PSW_MASK_BA;          /* force amode 31 */
+        /* Force 31 bit amode and default user address space control. */
+        regs->psw.mask = PSW_MASK_BA |
+                (psw_user_bits & PSW_MASK_ASC) |
+                (regs->psw.mask & ~PSW_MASK_ASC);
         regs->psw.addr = (__force __u64) ka->sa.sa_handler;
 
         regs->gprs[2] = map_signal(sig);
@@ -549,7 +556,10 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* Set up registers for signal handler */
         regs->gprs[15] = (__force __u64) frame;
-        regs->psw.mask |= PSW_MASK_BA;          /* force amode 31 */
+        /* Force 31 bit amode and default user address space control. */
+        regs->psw.mask = PSW_MASK_BA |
+                (psw_user_bits & PSW_MASK_ASC) |
+                (regs->psw.mask & ~PSW_MASK_ASC);
         regs->psw.addr = (__u64) ka->sa.sa_handler;
 
         regs->gprs[2] = map_signal(sig);
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index c13a2a37ef00..d1259d875074 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -136,6 +136,10 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
         /* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
                 (user_sregs.regs.psw.mask & PSW_MASK_USER);
+        /* Check for invalid user address space control. */
+        if ((regs->psw.mask & PSW_MASK_ASC) >= (psw_kernel_bits & PSW_MASK_ASC))
+                regs->psw.mask = (psw_user_bits & PSW_MASK_ASC) |
+                        (regs->psw.mask & ~PSW_MASK_ASC);
         /* Check for invalid amode */
         if (regs->psw.mask & PSW_MASK_EA)
                 regs->psw.mask |= PSW_MASK_BA;
@@ -273,7 +277,10 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 
         /* Set up registers for signal handler */
         regs->gprs[15] = (unsigned long) frame;
-        regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;    /* 64 bit amode */
+        /* Force default amode and default user address space control. */
+        regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
+                (psw_user_bits & PSW_MASK_ASC) |
+                (regs->psw.mask & ~PSW_MASK_ASC);
         regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
         regs->gprs[2] = map_signal(sig);
@@ -346,7 +353,10 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* Set up registers for signal handler */
         regs->gprs[15] = (unsigned long) frame;
-        regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA;    /* 64 bit amode */
+        /* Force default amode and default user address space control. */
+        regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
+                (psw_user_bits & PSW_MASK_ASC) |
+                (regs->psw.mask & ~PSW_MASK_ASC);
         regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
 
         regs->gprs[2] = map_signal(sig);