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author | Ingo Molnar <mingo@kernel.org> | 2015-04-12 11:11:21 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2015-04-12 11:21:15 +0200 |
commit | 066450be419fa48007a9f29e19828f2a86198754 (patch) | |
tree | 8dcc666fb88b9e6f472ccad4fed9f1d57d538938 /arch/x86 | |
parent | 5dafd7cb96ec75454eb1fcbf993000bf41175f13 (diff) | |
download | op-kernel-dev-066450be419fa48007a9f29e19828f2a86198754.zip op-kernel-dev-066450be419fa48007a9f29e19828f2a86198754.tar.gz |
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: Dan 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_pt.c | 53 |
1 files changed, 30 insertions, 23 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index f5a3afc..f277064 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -119,48 +119,55 @@ static int __init pt_pmu_hw_init(void) struct dev_ext_attribute *de_attrs; struct attribute **attrs; size_t size; + int ret; long i; - if (test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) { - for (i = 0; i < PT_CPUID_LEAVES; i++) - cpuid_count(20, i, - &pt_pmu.caps[CR_EAX + i * 4], - &pt_pmu.caps[CR_EBX + i * 4], - &pt_pmu.caps[CR_ECX + i * 4], - &pt_pmu.caps[CR_EDX + i * 4]); - } else { - return -ENODEV; + attrs = NULL; + 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, + &pt_pmu.caps[CR_EAX + i*4], + &pt_pmu.caps[CR_EBX + i*4], + &pt_pmu.caps[CR_ECX + i*4], + &pt_pmu.caps[CR_EDX + i*4]); } - size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps) + 1); + ret = -ENOMEM; + size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1); attrs = kzalloc(size, GFP_KERNEL); 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); if (!de_attrs) - goto err_de_attrs; + goto fail; 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->attr.attr); - sysfs_attr_init(&de_attrs[i].attr.attr); - de_attrs[i].attr.attr.mode = S_IRUGO; - de_attrs[i].attr.show = pt_cap_show; - de_attrs[i].var = (void *)i; - attrs[i] = &de_attrs[i].attr.attr; + de_attr->attr.attr.mode = S_IRUGO; + de_attr->attr.show = pt_cap_show; + de_attr->var = (void *)i; + + attrs[i] = &de_attr->attr.attr; } pt_cap_group.attrs = attrs; + return 0; -err_de_attrs: - kfree(de_attrs); -err_attrs: +fail: kfree(attrs); - return -ENOMEM; + return ret; } #define PT_CONFIG_MASK (RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC) |