arm: switch to generic sigaltstack

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 4 insertions, 14 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b82a4ed..caf0ba73ea38 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -56,6 +56,7 @@ config ARM
         select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
         select MODULES_USE_ELF_REL
         select CLONE_BACKWARDS
+        select GENERIC_SIGALTSTACK
         help
           The ARM series is a line of low-power-consumption RISC chip designs
           licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index a4fda4e7a372..0cc57611fc4f 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -195,7 +195,7 @@
                 CALL(sys_getcwd)
                 CALL(sys_capget)
 /* 185 */       CALL(sys_capset)
-                CALL(sys_sigaltstack_wrapper)
+                CALL(sys_sigaltstack)
                 CALL(sys_sendfile)
                 CALL(sys_ni_syscall)            /* getpmsg */
                 CALL(sys_ni_syscall)            /* putpmsg */
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index a6c301e90a3b..3248cde504ed 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -514,11 +514,6 @@ sys_rt_sigreturn_wrapper:
                 b       sys_rt_sigreturn
 ENDPROC(sys_rt_sigreturn_wrapper)
 
-sys_sigaltstack_wrapper:
-                ldr     r2, [sp, #S_OFF + S_SP]
-                b       do_sigaltstack
-ENDPROC(sys_sigaltstack_wrapper)
-
 sys_statfs64_wrapper:
                 teq     r1, #88
                 moveq   r1, #84
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 56f72d257ebd..f1f6d214050f 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -300,7 +300,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
         if (restore_sigframe(regs, &frame->sig))
                 goto badframe;
 
-        if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
+        if (restore_altstack(&frame->sig.uc.uc_stack))
                 goto badframe;
 
         return regs->ARM_r0;
@@ -486,7 +486,6 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
                sigset_t *set, struct pt_regs *regs)
 {
         struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
-        stack_t stack;
         int err = 0;
 
         if (!frame)
@@ -497,12 +496,7 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
         __put_user_error(0, &frame->sig.uc.uc_flags, err);
         __put_user_error(NULL, &frame->sig.uc.uc_link, err);
 
-        memset(&stack, 0, sizeof(stack));
-        stack.ss_sp = (void __user *)current->sas_ss_sp;
-        stack.ss_flags = sas_ss_flags(regs->ARM_sp);
-        stack.ss_size = current->sas_ss_size;
-        err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
-
+        err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp);
         err |= setup_sigframe(&frame->sig, regs, set);
         if (err == 0)
                 err = setup_return(regs, ka, frame->sig.retcode, frame, usig);