signal/powerpc: Use force_sig_mceerr as appropriate

In do_sigbus isolate the mceerr signaling code and call
force_sig_mceerr instead of falling through to the force_sig_info that
works for all of the other signals.

Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

arch/powerpc/mm/fault.c

@@ -158,7 +158,6 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address,
 		     vm_fault_t fault)
 {
 	siginfo_t info;
-	unsigned int lsb = 0;
 
 	if (!user_mode(regs))
 		return SIGBUS;
@@ -171,17 +170,22 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address,
 	info.si_addr = (void __user *)address;
 #ifdef CONFIG_MEMORY_FAILURE
 	if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
+		unsigned int lsb = 0; /* shutup gcc */
+
 		pr_err("MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",
 			current->comm, current->pid, address);
-		info.si_code = BUS_MCEERR_AR;
+
+		if (fault & VM_FAULT_HWPOISON_LARGE)
+			lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+		if (fault & VM_FAULT_HWPOISON)
+			lsb = PAGE_SHIFT;
+
+		force_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb,
+				 current);
+		return 0;
 	}
 
-	if (fault & VM_FAULT_HWPOISON_LARGE)
-		lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
-	if (fault & VM_FAULT_HWPOISON)
-		lsb = PAGE_SHIFT;
 #endif
-	info.si_addr_lsb = lsb;
 	force_sig_info(SIGBUS, &info, current);
 	return 0;
 }