[RFC PATCH v1 16/19] powerpc/signal32: Switch handle_rt_signal32() to user_access_begin() logic

[Christophe Leroy]

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
 arch/powerpc/kernel/signal_32.c | 47 +++++++++++++++++++++------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 4ea83578ba9d..d03ba3d8eb68 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -58,8 +58,6 @@
 #define mcontext       mcontext32
 #define ucontext       ucontext32
 
-#define __save_altstack __compat_save_altstack
-
 /*
  * Userspace code may pass a ucontext which doesn't include VSX added
  * at the end.  We need to check for this case.
@@ -797,16 +795,36 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t 
*oldset,
        /* Set up Signal Frame */
        /* Put a Real Time Context onto stack */
        rt_sf = get_sigframe(ksig, tsk, sizeof(*rt_sf), 1);
-       if (!access_ok(rt_sf, sizeof(*rt_sf)))
+       if (!user_write_access_begin(rt_sf, sizeof(*rt_sf)))
                goto badframe;
 
        /* Put the siginfo & fill in most of the ucontext */
-       if (copy_siginfo_to_user(&rt_sf->info, &ksig->info)
-           || __put_user(0, &rt_sf->uc.uc_flags)
-           || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
-           || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
-                   &rt_sf->uc.uc_regs)
-           || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
+       unsafe_put_user(0, &rt_sf->uc.uc_flags, failed);
+#ifdef CONFIG_PPC64
+       unsafe_compat_save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1], failed);
+#else
+       unsafe_save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1], failed);
+#endif
+       unsafe_put_user(to_user_ptr(&rt_sf->uc.uc_mcontext), 
&rt_sf->uc.uc_regs, failed);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+       tm_frame = &rt_sf->uc_transact.uc_mcontext;
+       if (MSR_TM_ACTIVE(msr)) {
+               unsafe_put_user((unsigned long)&rt_sf->uc_transact,
+                               &rt_sf->uc.uc_link, failed);
+               unsafe_put_user((unsigned long)tm_frame,
+                               &rt_sf->uc_transact.uc_regs, failed);
+       }
+       else
+#endif
+       {
+               unsafe_put_user(0, &rt_sf->uc.uc_link, failed);
+       }
+       user_write_access_end();
+
+       if (put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
+               goto badframe;
+       if (copy_siginfo_to_user(&rt_sf->info, &ksig->info))
                goto badframe;
 
        /* Save user registers on the stack */
@@ -820,21 +838,13 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t 
*oldset,
        }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-       tm_frame = &rt_sf->uc_transact.uc_mcontext;
        if (MSR_TM_ACTIVE(msr)) {
-               if (__put_user((unsigned long)&rt_sf->uc_transact,
-                              &rt_sf->uc.uc_link) ||
-                   __put_user((unsigned long)tm_frame,
-                              &rt_sf->uc_transact.uc_regs))
-                       goto badframe;
                if (save_tm_user_regs(regs, frame, tm_frame, sigret, msr))
                        goto badframe;
        }
        else
 #endif
        {
-               if (__put_user(0, &rt_sf->uc.uc_link))
-                       goto badframe;
                if (save_user_regs(regs, frame, tm_frame, sigret, 1))
                        goto badframe;
        }
@@ -861,6 +871,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t 
*oldset,
        regs->msr |= (MSR_KERNEL & MSR_LE);
        return 0;
 
+failed:
+       user_write_access_end();
+
 badframe:
        signal_fault(tsk, regs, "handle_rt_signal32", rt_sf);
 
-- 
2.25.0