[patch V3 02/28] x86/perf/intel/uncore: Simplify error rollback

From: Thomas Gleixner
Date: Mon Feb 22 2016 - 17:26:52 EST


No point in doing partial rollbacks. Robustify uncore_exit_type() so it does
not dereference type->pmus unconditionally and remove all the partial rollback
hackery.

Preparatory patch for proper error handling.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 45 +++++++++++++-------------
1 file changed, 24 insertions(+), 21 deletions(-)

--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -767,10 +767,12 @@ static void __init uncore_type_exit(stru
{
int i;

- for (i = 0; i < type->num_boxes; i++)
- free_percpu(type->pmus[i].box);
- kfree(type->pmus);
- type->pmus = NULL;
+ if (type->pmus) {
+ for (i = 0; i < type->num_boxes; i++)
+ free_percpu(type->pmus[i].box);
+ kfree(type->pmus);
+ type->pmus = NULL;
+ }
kfree(type->events_group);
type->events_group = NULL;
}
@@ -778,6 +780,7 @@ static void __init uncore_type_exit(stru
static void __init uncore_types_exit(struct intel_uncore_type **types)
{
int i;
+
for (i = 0; types[i]; i++)
uncore_type_exit(types[i]);
}
@@ -806,7 +809,7 @@ static int __init uncore_type_init(struc
INIT_LIST_HEAD(&pmus[i].box_list);
pmus[i].box = alloc_percpu(struct intel_uncore_box *);
if (!pmus[i].box)
- goto fail;
+ return -ENOMEM;
}

if (type->event_descs) {
@@ -817,7 +820,7 @@ static int __init uncore_type_init(struc
attr_group = kzalloc(sizeof(struct attribute *) * (i + 1) +
sizeof(*attr_group), GFP_KERNEL);
if (!attr_group)
- goto fail;
+ return -ENOMEM;

attrs = (struct attribute **)(attr_group + 1);
attr_group->name = "events";
@@ -831,9 +834,6 @@ static int __init uncore_type_init(struc

type->pmu_group = &uncore_pmu_attr_group;
return 0;
-fail:
- uncore_type_exit(type);
- return -ENOMEM;
}

static int __init uncore_types_init(struct intel_uncore_type **types)
@@ -843,13 +843,9 @@ static int __init uncore_types_init(stru
for (i = 0; types[i]; i++) {
ret = uncore_type_init(types[i]);
if (ret)
- goto fail;
+ return ret;
}
return 0;
-fail:
- while (--i >= 0)
- uncore_type_exit(types[i]);
- return ret;
}

/*
@@ -1007,17 +1003,21 @@ static int __init uncore_pci_init(void)

ret = uncore_types_init(uncore_pci_uncores);
if (ret)
- return ret;
+ goto err;

uncore_pci_driver->probe = uncore_pci_probe;
uncore_pci_driver->remove = uncore_pci_remove;

ret = pci_register_driver(uncore_pci_driver);
- if (ret == 0)
- pcidrv_registered = true;
- else
- uncore_types_exit(uncore_pci_uncores);
+ if (ret)
+ goto err;
+
+ pcidrv_registered = true;
+ return 0;

+err:
+ uncore_types_exit(uncore_pci_uncores);
+ uncore_pci_uncores = empty_uncore;
return ret;
}

@@ -1316,9 +1316,12 @@ static int __init uncore_cpu_init(void)

ret = uncore_types_init(uncore_msr_uncores);
if (ret)
- return ret;
-
+ goto err;
return 0;
+err:
+ uncore_types_exit(uncore_msr_uncores);
+ uncore_msr_uncores = empty_uncore;
+ return ret;
}

static int __init uncore_pmus_register(void)