[IA64] access user RBS directly

Because the user RBS of a process is now completely stored in
user-mode when the process is ptrace-stopped, accesses to the
RBS should no longer augment any part of the kernel RBS.

This means we can get rid of most ia64_peek() and ia64_poke()
calls.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 14 insertions, 30 deletions

diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 331d6768b5d5..9d2591423eb7 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -908,7 +908,7 @@ static int
 access_uarea (struct task_struct *child, unsigned long addr,
               unsigned long *data, int write_access)
 {
-        unsigned long *ptr, regnum, urbs_end, rnat_addr, cfm;
+        unsigned long *ptr, regnum, urbs_end, cfm;
         struct switch_stack *sw;
         struct pt_regs *pt;
 #       define pt_reg_addr(pt, reg)     ((void *)                           \
@@ -1093,16 +1093,8 @@ access_uarea (struct task_struct *child, unsigned long addr,
                         return 0;
 
                       case PT_AR_RNAT:
-                        urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
-                        rnat_addr = (long) ia64_rse_rnat_addr((long *)
-                                                              urbs_end);
-                        if (write_access)
-                                return ia64_poke(child, sw, urbs_end,
-                                                 rnat_addr, *data);
-                        else
-                                return ia64_peek(child, sw, urbs_end,
-                                                 rnat_addr, data);
-
+                        ptr = pt_reg_addr(pt, ar_rnat);
+                        break;
                       case PT_R1:
                         ptr = pt_reg_addr(pt, r1);
                         break;
@@ -1541,11 +1533,10 @@ asmlinkage long
 sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
 {
         struct pt_regs *pt;
-        unsigned long urbs_end, peek_or_poke;
+        unsigned long peek_or_poke;
         struct task_struct *child;
         struct switch_stack *sw;
         long ret;
-        struct unw_frame_info info;
 
         lock_kernel();
         ret = -EPERM;
@@ -1593,26 +1584,19 @@ sys_ptrace (long request, pid_t pid, unsigned long addr, unsigned long data)
               case PTRACE_PEEKTEXT:
               case PTRACE_PEEKDATA:
                 /* read word at location addr */
-                urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
-                ret = ia64_peek(child, sw, urbs_end, addr, &data);
-                if (ret == 0) {
-                        ret = data;
-                        /* ensure "ret" is not mistaken as an error code: */
-                        force_successful_syscall_return();
+                if (access_process_vm(child, addr, &data, sizeof(data), 0)
+                    != sizeof(data)) {
+                        ret = -EIO;
+                        goto out_tsk;
                 }
+                ret = data;
+                /* ensure "ret" is not mistaken as an error code */
+                force_successful_syscall_return();
                 goto out_tsk;
 
-              case PTRACE_POKETEXT:
-              case PTRACE_POKEDATA:
-                /* write the word at location addr */
-                urbs_end = ia64_get_user_rbs_end(child, pt, NULL);
-                ret = ia64_poke(child, sw, urbs_end, addr, data);
-
-                /* Make sure user RBS has the latest data */
-                unw_init_from_blocked_task(&info, child);
-                do_sync_rbs(&info, ia64_sync_user_rbs);
-
-                goto out_tsk;
+        /* PTRACE_POKETEXT and PTRACE_POKEDATA is handled
+         * by the generic ptrace_request().
+         */
 
               case PTRACE_PEEKUSR:
                 /* read the word at addr in the USER area */