From 066450be419fa48007a9f29e19828f2a86198754 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 12 Apr 2015 11:11:21 +0200 Subject: [PATCH] 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 Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150409090805.GG17605@mwanda Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel_pt.c | 53 +++++++++++++---------- 1 file 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 f5a3afc65371..f2770641c0fd 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) -- 2.20.1