oprofile/x86: rework error handler in nmi_setup()

This patch improves the error handler in nmi_setup(). Most parts of
the code are moved to allocate_msrs(). In case of an error
allocate_msrs() also frees already allocated memory. nmi_setup()
becomes easier and better extendable.

Signed-off-by: Robert Richter <robert.richter@amd.com>

1 files changed, 19 insertions, 14 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 2c505ee71014..c0c21f200faf 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -295,6 +295,7 @@ static void free_msrs(void)
                 kfree(per_cpu(cpu_msrs, i).controls);
                 per_cpu(cpu_msrs, i).controls = NULL;
         }
+        nmi_shutdown_mux();
 }
 
 static int allocate_msrs(void)
@@ -307,14 +308,21 @@ static int allocate_msrs(void)
                 per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
                                                         GFP_KERNEL);
                 if (!per_cpu(cpu_msrs, i).counters)
-                        return 0;
+                        goto fail;
                 per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
                                                         GFP_KERNEL);
                 if (!per_cpu(cpu_msrs, i).controls)
-                        return 0;
+                        goto fail;
         }
 
+        if (!nmi_setup_mux())
+                goto fail;
+
         return 1;
+
+fail:
+        free_msrs();
+        return 0;
 }
 
 static void nmi_cpu_setup(void *dummy)
@@ -342,17 +350,7 @@ static int nmi_setup(void)
         int cpu;
 
         if (!allocate_msrs())
-                err = -ENOMEM;
-        else if (!nmi_setup_mux())
-                err = -ENOMEM;
-        else
-                err = register_die_notifier(&profile_exceptions_nb);
-
-        if (err) {
-                free_msrs();
-                nmi_shutdown_mux();
-                return err;
-        }
+                return -ENOMEM;
 
         /* We need to serialize save and setup for HT because the subset
          * of msrs are distinct for save and setup operations
@@ -374,9 +372,17 @@ static int nmi_setup(void)
 
                 mux_clone(cpu);
         }
+
+        err = register_die_notifier(&profile_exceptions_nb);
+        if (err)
+                goto fail;
+
         on_each_cpu(nmi_cpu_setup, NULL, 1);
         nmi_enabled = 1;
         return 0;
+fail:
+        free_msrs();
+        return err;
 }
 
 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
@@ -421,7 +427,6 @@ static void nmi_shutdown(void)
         nmi_enabled = 0;
         on_each_cpu(nmi_cpu_shutdown, NULL, 1);
         unregister_die_notifier(&profile_exceptions_nb);
-        nmi_shutdown_mux();
         msrs = &get_cpu_var(cpu_msrs);
         model->shutdown(msrs);
         free_msrs();