758d39ebd3
We have four different stack tracers of which three had bugs. So it's time to merge them to a single stack tracer which allows to specify a call back function which will be called for each step. This patch changes behavior a bit: - the "nosched" and "in_sched_functions" check within save_stack_trace_tsk did work only for the last stack frame within a context. Now it considers the check for each stack frame like it should. - both the oprofile variant and the perf_events variant did save a return address twice if a zero back chain was detected, which indicates an interrupt frame. The new dump_trace function will call the oprofile and perf_events backends with the psw address that is contained within the corresponding pt_regs structure instead. - the original show_trace and save_context_stack functions did already use the psw address of the pt_regs structure if a zero back chain was detected. However now we ignore the psw address if it is a user space address. After all we trace the kernel stack and not the user space stack. This way we also get rid of the garbage user space address in case of warnings and / or panic call traces. So this should make life easier since now there is only one stack tracer left which we can break. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
281 lines
6.8 KiB
C
281 lines
6.8 KiB
C
/*
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* Performance event support for s390x
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*
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* Copyright IBM Corp. 2012, 2013
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* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License (version 2 only)
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* as published by the Free Software Foundation.
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*/
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#define KMSG_COMPONENT "perf"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/perf_event.h>
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#include <linux/kvm_host.h>
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#include <linux/percpu.h>
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#include <linux/export.h>
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#include <linux/seq_file.h>
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#include <linux/spinlock.h>
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#include <linux/sysfs.h>
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#include <asm/irq.h>
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#include <asm/cpu_mf.h>
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#include <asm/lowcore.h>
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#include <asm/processor.h>
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#include <asm/sysinfo.h>
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const char *perf_pmu_name(void)
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{
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if (cpum_cf_avail() || cpum_sf_avail())
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return "CPU-Measurement Facilities (CPU-MF)";
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return "pmu";
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}
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EXPORT_SYMBOL(perf_pmu_name);
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int perf_num_counters(void)
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{
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int num = 0;
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if (cpum_cf_avail())
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num += PERF_CPUM_CF_MAX_CTR;
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if (cpum_sf_avail())
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num += PERF_CPUM_SF_MAX_CTR;
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return num;
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}
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EXPORT_SYMBOL(perf_num_counters);
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static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
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{
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struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
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if (!stack)
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return NULL;
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return (struct kvm_s390_sie_block *) stack->empty1[0];
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}
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static bool is_in_guest(struct pt_regs *regs)
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{
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if (user_mode(regs))
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return false;
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#if IS_ENABLED(CONFIG_KVM)
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return instruction_pointer(regs) == (unsigned long) &sie_exit;
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#else
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return false;
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#endif
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}
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static unsigned long guest_is_user_mode(struct pt_regs *regs)
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{
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return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
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}
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static unsigned long instruction_pointer_guest(struct pt_regs *regs)
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{
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return sie_block(regs)->gpsw.addr;
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}
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unsigned long perf_instruction_pointer(struct pt_regs *regs)
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{
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return is_in_guest(regs) ? instruction_pointer_guest(regs)
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: instruction_pointer(regs);
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}
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static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
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{
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return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
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: PERF_RECORD_MISC_GUEST_KERNEL;
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}
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static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
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{
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struct perf_sf_sde_regs *sde_regs;
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unsigned long flags;
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sde_regs = (struct perf_sf_sde_regs *) ®s->int_parm_long;
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if (sde_regs->in_guest)
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flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
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: PERF_RECORD_MISC_GUEST_KERNEL;
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else
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flags = user_mode(regs) ? PERF_RECORD_MISC_USER
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: PERF_RECORD_MISC_KERNEL;
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return flags;
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}
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unsigned long perf_misc_flags(struct pt_regs *regs)
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{
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/* Check if the cpum_sf PMU has created the pt_regs structure.
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* In this case, perf misc flags can be easily extracted. Otherwise,
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* do regular checks on the pt_regs content.
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*/
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if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
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if (!regs->gprs[15])
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return perf_misc_flags_sf(regs);
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if (is_in_guest(regs))
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return perf_misc_guest_flags(regs);
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return user_mode(regs) ? PERF_RECORD_MISC_USER
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: PERF_RECORD_MISC_KERNEL;
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}
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static void print_debug_cf(void)
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{
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struct cpumf_ctr_info cf_info;
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int cpu = smp_processor_id();
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memset(&cf_info, 0, sizeof(cf_info));
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if (!qctri(&cf_info))
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pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
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cpu, cf_info.cfvn, cf_info.csvn,
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cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
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}
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static void print_debug_sf(void)
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{
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struct hws_qsi_info_block si;
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int cpu = smp_processor_id();
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memset(&si, 0, sizeof(si));
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if (qsi(&si))
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return;
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pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
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cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
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si.cpu_speed);
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if (si.as)
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pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
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" bsdes=%i tear=%016lx dear=%016lx\n", cpu,
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si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
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if (si.ad)
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pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
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" dsdes=%i tear=%016lx dear=%016lx\n", cpu,
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si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
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}
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void perf_event_print_debug(void)
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{
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unsigned long flags;
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local_irq_save(flags);
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if (cpum_cf_avail())
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print_debug_cf();
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if (cpum_sf_avail())
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print_debug_sf();
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local_irq_restore(flags);
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}
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/* Service level infrastructure */
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static void sl_print_counter(struct seq_file *m)
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{
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struct cpumf_ctr_info ci;
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memset(&ci, 0, sizeof(ci));
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if (qctri(&ci))
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return;
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seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
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"authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
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}
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static void sl_print_sampling(struct seq_file *m)
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{
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struct hws_qsi_info_block si;
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memset(&si, 0, sizeof(si));
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if (qsi(&si))
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return;
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if (!si.as && !si.ad)
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return;
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seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
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" cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
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si.cpu_speed);
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if (si.as)
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seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
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" sample_size=%u\n", si.bsdes);
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if (si.ad)
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seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
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" sample_size=%u\n", si.dsdes);
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}
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static void service_level_perf_print(struct seq_file *m,
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struct service_level *sl)
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{
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if (cpum_cf_avail())
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sl_print_counter(m);
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if (cpum_sf_avail())
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sl_print_sampling(m);
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}
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static struct service_level service_level_perf = {
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.seq_print = service_level_perf_print,
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};
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static int __init service_level_perf_register(void)
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{
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return register_service_level(&service_level_perf);
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}
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arch_initcall(service_level_perf_register);
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static int __perf_callchain_kernel(void *data, unsigned long address)
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{
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struct perf_callchain_entry *entry = data;
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perf_callchain_store(entry, address);
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return 0;
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}
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void perf_callchain_kernel(struct perf_callchain_entry *entry,
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struct pt_regs *regs)
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{
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if (user_mode(regs))
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return;
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dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]);
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}
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/* Perf defintions for PMU event attributes in sysfs */
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ssize_t cpumf_events_sysfs_show(struct device *dev,
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struct device_attribute *attr, char *page)
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{
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struct perf_pmu_events_attr *pmu_attr;
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pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
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return sprintf(page, "event=0x%04llx,name=%s\n",
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pmu_attr->id, attr->attr.name);
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}
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/* Reserve/release functions for sharing perf hardware */
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static DEFINE_SPINLOCK(perf_hw_owner_lock);
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static void *perf_sampling_owner;
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int perf_reserve_sampling(void)
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{
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int err;
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err = 0;
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spin_lock(&perf_hw_owner_lock);
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if (perf_sampling_owner) {
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pr_warn("The sampling facility is already reserved by %p\n",
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perf_sampling_owner);
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err = -EBUSY;
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} else
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perf_sampling_owner = __builtin_return_address(0);
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spin_unlock(&perf_hw_owner_lock);
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return err;
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}
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EXPORT_SYMBOL(perf_reserve_sampling);
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void perf_release_sampling(void)
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{
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spin_lock(&perf_hw_owner_lock);
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WARN_ON(!perf_sampling_owner);
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perf_sampling_owner = NULL;
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spin_unlock(&perf_hw_owner_lock);
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}
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EXPORT_SYMBOL(perf_release_sampling);
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