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Commit 066450be authored by Ingo Molnar's avatar Ingo Molnar
Browse files

perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init() 



Dan Carpenter pointed out that the control flow in pt_pmu_hw_init()
is a bit messy: for example the kfree(de_attrs) is entirely
superfluous.

Another problem is the inconsistent mixing of label based and
direct return error handling.

Add modern, label based error handling instead and clean up the code
a bit as well.

Note that we'll still do a kfree(NULL) in the normal case - this does
not matter as this is an init path and kfree() returns early if it
sees a NULL.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150409090805.GG17605@mwanda


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5dafd7cb

arch/x86/kernel/cpu/perf_event_intel_pt.c

+30 −23
Original line number Original line Diff line number Diff line
@@ -119,48 +119,55 @@ static int __init pt_pmu_hw_init(void) 
	struct dev_ext_attribute *de_attrs;

	struct dev_ext_attribute *de_attrs;

	struct attribute **attrs;

	struct attribute **attrs;

	size_t size;

	size_t size;

	int ret;

	long i;

	long i;





	if (test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) {

	attrs = NULL;

		for (i = 0; i < PT_CPUID_LEAVES; i++)

	ret = -ENODEV;

	if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT))

		goto fail;



	for (i = 0; i < PT_CPUID_LEAVES; i++) {

		cpuid_count(20, i,

		cpuid_count(20, i,

			    &pt_pmu.caps[CR_EAX + i*4],

			    &pt_pmu.caps[CR_EAX + i*4],

			    &pt_pmu.caps[CR_EBX + i*4],

			    &pt_pmu.caps[CR_EBX + i*4],

			    &pt_pmu.caps[CR_ECX + i*4],

			    &pt_pmu.caps[CR_ECX + i*4],

			    &pt_pmu.caps[CR_EDX + i*4]);

			    &pt_pmu.caps[CR_EDX + i*4]);

	} else {

		return -ENODEV;

	}

	}





	ret = -ENOMEM;

	size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1);

	size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1);

	attrs = kzalloc(size, GFP_KERNEL);

	attrs = kzalloc(size, GFP_KERNEL);

	if (!attrs)

	if (!attrs)

		goto err_attrs;

		goto fail;





	size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps)+1);

	size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps)+1);

	de_attrs = kzalloc(size, GFP_KERNEL);

	de_attrs = kzalloc(size, GFP_KERNEL);

	if (!de_attrs)

	if (!de_attrs)

		goto err_de_attrs;

		goto fail;





	for (i = 0; i < ARRAY_SIZE(pt_caps); i++) {

	for (i = 0; i < ARRAY_SIZE(pt_caps); i++) {

		de_attrs[i].attr.attr.name = pt_caps[i].name;

		struct dev_ext_attribute *de_attr = de_attrs + i;



		de_attr->attr.attr.name = pt_caps[i].name;





		sysfs_attr_init(&de_attrs[i].attr.attr);

		sysfs_attr_init(&de_attrs->attr.attr);

		de_attrs[i].attr.attr.mode = S_IRUGO;



		de_attrs[i].attr.show = pt_cap_show;

		de_attr->attr.attr.mode		= S_IRUGO;

		de_attrs[i].var = (void *)i;

		de_attr->attr.show		= pt_cap_show;

		attrs[i] = &de_attrs[i].attr.attr;

		de_attr->var			= (void *)i;



		attrs[i] = &de_attr->attr.attr;

	}

	}





	pt_cap_group.attrs = attrs;

	pt_cap_group.attrs = attrs;



	return 0;

	return 0;





err_de_attrs:

fail:

	kfree(de_attrs);

err_attrs:

	kfree(attrs);

	kfree(attrs);





	return -ENOMEM;

	return ret;

}

}





#define PT_CONFIG_MASK (RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC)

#define PT_CONFIG_MASK (RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC)