[S390] 64-bit register support for 31-bit processes

From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index a8738676b26c..653c6a178740 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -57,6 +57,7 @@
 enum s390_regset {
         REGSET_GENERAL,
         REGSET_FP,
+        REGSET_GENERAL_EXTENDED,
 };
 
 static void
@@ -879,6 +880,67 @@ static int s390_compat_regs_set(struct task_struct *target,
         return rc;
 }
 
+static int s390_compat_regs_high_get(struct task_struct *target,
+                                     const struct user_regset *regset,
+                                     unsigned int pos, unsigned int count,
+                                     void *kbuf, void __user *ubuf)
+{
+        compat_ulong_t *gprs_high;
+
+        gprs_high = (compat_ulong_t *)
+                &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
+        if (kbuf) {
+                compat_ulong_t *k = kbuf;
+                while (count > 0) {
+                        *k++ = *gprs_high;
+                        gprs_high += 2;
+                        count -= sizeof(*k);
+                }
+        } else {
+                compat_ulong_t __user *u = ubuf;
+                while (count > 0) {
+                        if (__put_user(*gprs_high, u++))
+                                return -EFAULT;
+                        gprs_high += 2;
+                        count -= sizeof(*u);
+                }
+        }
+        return 0;
+}
+
+static int s390_compat_regs_high_set(struct task_struct *target,
+                                     const struct user_regset *regset,
+                                     unsigned int pos, unsigned int count,
+                                     const void *kbuf, const void __user *ubuf)
+{
+        compat_ulong_t *gprs_high;
+        int rc = 0;
+
+        gprs_high = (compat_ulong_t *)
+                &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
+        if (kbuf) {
+                const compat_ulong_t *k = kbuf;
+                while (count > 0) {
+                        *gprs_high = *k++;
+                        *gprs_high += 2;
+                        count -= sizeof(*k);
+                }
+        } else {
+                const compat_ulong_t  __user *u = ubuf;
+                while (count > 0 && !rc) {
+                        unsigned long word;
+                        rc = __get_user(word, u++);
+                        if (rc)
+                                break;
+                        *gprs_high = word;
+                        *gprs_high += 2;
+                        count -= sizeof(*u);
+                }
+        }
+
+        return rc;
+}
+
 static const struct user_regset s390_compat_regsets[] = {
         [REGSET_GENERAL] = {
                 .core_note_type = NT_PRSTATUS,
@@ -896,6 +958,14 @@ static const struct user_regset s390_compat_regsets[] = {
                 .get = s390_fpregs_get,
                 .set = s390_fpregs_set,
         },
+        [REGSET_GENERAL_EXTENDED] = {
+                .core_note_type = NT_PRXSTATUS,
+                .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
+                .size = sizeof(compat_long_t),
+                .align = sizeof(compat_long_t),
+                .get = s390_compat_regs_high_get,
+                .set = s390_compat_regs_high_set,
+        },
 };
 
 static const struct user_regset_view user_s390_compat_view = {