powerpc/signal: Refactor bad frame logging

The logging of bad frame appears half a dozen of times
and is pretty similar.

Create signal_fault() fonction to perform that logging.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fa094445c119fc00315e1c13783b493346306c6a.1597770847.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/signal.c

@@ -351,3 +351,14 @@ static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 #endif
 	return ret;
 }
+
+static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
+static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
+
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr)
+{
+	if (show_unhandled_signals)
+		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
+				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
+}

arch/powerpc/kernel/signal.h

@@ -93,4 +93,7 @@ static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 
 #endif /* !defined(CONFIG_PPC64) */
 
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr);
+
 #endif  /* _POWERPC_ARCH_SIGNAL_H */

arch/powerpc/kernel/signal_32.c

@@ -835,12 +835,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_rt_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_rt_signal32", addr);
 
 	return 1;
 }
@@ -1092,12 +1087,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
  bad:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_rt_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   rt_sf, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -1181,12 +1171,7 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
 	 * We kill the task with a SIGSEGV in this situation.
 	 */
 	if (do_setcontext(ctx, regs, 1)) {
-		if (show_unhandled_signals)
-			printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
-					   "sys_debug_setcontext: %p nip %08lx "
-					   "lr %08lx\n",
-					   current->comm, current->pid,
-					   ctx, regs->nip, regs->link);
+		signal_fault(current, regs, "sys_debug_setcontext", ctx);
 
 		force_sig(SIGSEGV);
 		goto out;
@@ -1287,12 +1272,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in handle_signal32: "
-				   "%p nip %08lx lr %08lx\n",
-				   tsk->comm, tsk->pid,
-				   frame, regs->nip, regs->link);
+	signal_fault(tsk, regs, "handle_signal32", frame);
 
 	return 1;
 }
@@ -1363,12 +1343,7 @@ SYSCALL_DEFINE0(sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(KERN_INFO
-				   "%s[%d]: bad frame in sys_sigreturn: "
-				   "%p nip %08lx lr %08lx\n",
-				   current->comm, current->pid,
-				   addr, regs->nip, regs->link);
+	signal_fault(current, regs, "sys_sigreturn", addr);
 
 	force_sig(SIGSEGV);
 	return 0;

arch/powerpc/kernel/signal_64.c

@@ -66,11 +66,6 @@ struct rt_sigframe {
 	char abigap[USER_REDZONE_SIZE];
 } __attribute__ ((aligned (16)));
 
-static const char fmt32[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
-static const char fmt64[] = KERN_INFO \
-	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
-
 /*
  * This computes a quad word aligned pointer inside the vmx_reserve array
  * element. For historical reasons sigcontext might not be quad word aligned,
@@ -801,10 +796,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   current->comm, current->pid, "rt_sigreturn",
-				   (long)uc, regs->nip, regs->link);
+	signal_fault(current, regs, "rt_sigreturn", uc);
 
 	force_sig(SIGSEGV);
 	return 0;
@@ -911,10 +903,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 	return 0;
 
 badframe:
-	if (show_unhandled_signals)
-		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-				   tsk->comm, tsk->pid, "setup_rt_frame",
-				   (long)frame, regs->nip, regs->link);
+	signal_fault(current, regs, "handle_rt_signal64", frame);
 
 	return 1;
 }