[S390] Introduce user_regset accessors for s390

Add the user_regset definitions for normal and compat processes, replace
the dump_regs core dump cruft with the generic CORE_DUMP_USER_REGSET and
replace binfmt_elf32.c with the generic compat_binfmt_elf.c implementation.

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

3 files changed, 38 insertions, 42 deletions

diff --git a/include/asm-s390/elf.h b/include/asm-s390/elf.h
index b3ac262c4582..3cad56923815 100644
--- a/include/asm-s390/elf.h
+++ b/include/asm-s390/elf.h
@@ -113,6 +113,9 @@
 typedef s390_fp_regs elf_fpregset_t;
 typedef s390_regs elf_gregset_t;
 
+typedef s390_fp_regs compat_elf_fpregset_t;
+typedef s390_compat_regs compat_elf_gregset_t;
+
 #include <linux/sched.h>        /* for task_struct */
 #include <asm/system.h>         /* for save_access_regs */
 #include <asm/mmu_context.h>
@@ -123,6 +126,10 @@ typedef s390_regs elf_gregset_t;
 #define elf_check_arch(x) \
         (((x)->e_machine == EM_S390 || (x)->e_machine == EM_S390_OLD) \
          && (x)->e_ident[EI_CLASS] == ELF_CLASS) 
+#define compat_elf_check_arch(x) \
+        (((x)->e_machine == EM_S390 || (x)->e_machine == EM_S390_OLD) \
+         && (x)->e_ident[EI_CLASS] == ELF_CLASS)
+#define compat_start_thread     start_thread31
 
 /* For SVR4/S390 the function pointer to be registered with `atexit` is
    passed in R14. */
@@ -131,6 +138,7 @@ typedef s390_regs elf_gregset_t;
                 _r->gprs[14] = 0; \
         } while (0)
 
+#define CORE_DUMP_USE_REGSET
 #define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE       4096
 
@@ -140,44 +148,6 @@ typedef s390_regs elf_gregset_t;
    that it will "exec", and that there is sufficient room for the brk.  */
 #define ELF_ET_DYN_BASE         (STACK_TOP / 3 * 2)
 
-/* Wow, the "main" arch needs arch dependent functions too.. :) */
-
-/* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
-   now struct_user_regs, they are different) */
-
-static inline int dump_regs(struct pt_regs *ptregs, elf_gregset_t *regs)
-{
-        memcpy(&regs->psw, &ptregs->psw, sizeof(regs->psw)+sizeof(regs->gprs));
-        save_access_regs(regs->acrs);
-        regs->orig_gpr2 = ptregs->orig_gpr2;
-        return 1;
-}
-
-#define ELF_CORE_COPY_REGS(pr_reg, regs) dump_regs(regs, &pr_reg);
-
-static inline int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
-{
-        struct pt_regs *ptregs = task_pt_regs(tsk);
-        memcpy(&regs->psw, &ptregs->psw, sizeof(regs->psw)+sizeof(regs->gprs));
-        memcpy(regs->acrs, tsk->thread.acrs, sizeof(regs->acrs));
-        regs->orig_gpr2 = ptregs->orig_gpr2;
-        return 1;
-}
-
-#define ELF_CORE_COPY_TASK_REGS(tsk, regs) dump_task_regs(tsk, regs)
-
-static inline int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
-{
-        if (tsk == current)
-                save_fp_regs(fpregs);
-        else
-                memcpy(fpregs, &tsk->thread.fp_regs, sizeof(elf_fpregset_t));
-        return 1;
-}
-
-#define ELF_CORE_COPY_FPREGS(tsk, fpregs) dump_task_fpu(tsk, fpregs)
-
-
 /* This yields a mask that user programs can use to figure out what
    instruction set this CPU supports. */
 
@@ -204,7 +174,10 @@ do {							\
                 set_personality(PER_SVR4);              \
         else if (current->personality != PER_LINUX32)   \
                 set_personality(PER_LINUX);             \
-        clear_thread_flag(TIF_31BIT);                   \
+        if ((ex).e_ident[EI_CLASS] == ELFCLASS32)       \
+                set_thread_flag(TIF_31BIT);             \
+        else                                            \
+                clear_thread_flag(TIF_31BIT);           \
 } while (0)
 #endif /* __s390x__ */
 
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index a00f79dd323b..5483c28b8bc3 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -143,11 +143,19 @@ struct stack_frame {
 /*
  * Do necessary setup to start up a new thread.
  */
-#define start_thread(regs, new_psw, new_stackp) do {            \
+#define start_thread(regs, new_psw, new_stackp) do {            \
         set_fs(USER_DS);                                        \
         regs->psw.mask  = psw_user_bits;                        \
-        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
-        regs->gprs[15]  = new_stackp ;                          \
+        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
+        regs->gprs[15]  = new_stackp;                           \
+} while (0)
+
+#define start_thread31(regs, new_psw, new_stackp) do {          \
+        set_fs(USER_DS);                                        \
+        regs->psw.mask  = psw_user32_bits;                      \
+        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
+        regs->gprs[15]  = new_stackp;                           \
+        crst_table_downgrade(current->mm, 1UL << 31);           \
 } while (0)
 
 /* Forward declaration, a strange C thing */
diff --git a/include/asm-s390/ptrace.h b/include/asm-s390/ptrace.h
index d7d4e2eb3e6f..af2c9ac28a07 100644
--- a/include/asm-s390/ptrace.h
+++ b/include/asm-s390/ptrace.h
@@ -215,6 +215,12 @@ typedef struct
         unsigned long addr;
 } __attribute__ ((aligned(8))) psw_t;
 
+typedef struct
+{
+        __u32   mask;
+        __u32   addr;
+} __attribute__ ((aligned(8))) psw_compat_t;
+
 #ifndef __s390x__
 
 #define PSW_MASK_PER            0x40000000UL
@@ -292,6 +298,15 @@ typedef struct
         unsigned long orig_gpr2;
 } s390_regs;
 
+typedef struct
+{
+        psw_compat_t    psw;
+        __u32           gprs[NUM_GPRS];
+        __u32           acrs[NUM_ACRS];
+        __u32           orig_gpr2;
+} s390_compat_regs;
+
+
 #ifdef __KERNEL__
 #include <asm/setup.h>
 #include <asm/page.h>