From 996bd8ea64e5cc1bf07842ada63638fc574ac117 Mon Sep 17 00:00:00 2001 From: Patrick Fay Date: Sat, 1 Apr 2017 14:29:27 -0700 Subject: [PATCH] Perf: arm64: Add Snapshot of perf tracepoints Snapshot of perf tracepoint framework taken straight of msm-4.4 commit (Merge "qpnp-fg-gen3: prime CC_SOC_SW when capacity learning begins") [Fixing coding style issues] [Switch perf_trace_counters.c to new hotplug notifier method] [Replace inline assembly with read/write_sysreg()] [Change perf_trace_user.h to display 7 counters like perf_trace_counters.h] [Change perf_trace_user.c to use debugfs_create_dir() instead of obsolete perf_create_debug_dir()] It contains the following squashed commit: Perf: arm64: avoid use of uninitialized variable Variable "buf" is not initialized. It may contain the data from stack when "count == 0". Kernel information leak is possible due to different code path execution. The commit also includes the squashed patch from Olav as follows: Perf: arm64: Use proper API to get task cpu Instead of directly accessing thread_info structure to get the task cpu use the appropriate wrapper API. This is needed for subsequent patches refactors the location of task cpu. Change-Id: I83c3ca3fbc9237c9109735f5fb2398cb4e9f6de9 Signed-off-by: Olav Haugan Signed-off-by: Patrick Fay Signed-off-by: Raghavendra Rao Ananta Signed-off-by: Rishabh Bhatnagar --- arch/arm64/kernel/Makefile | 3 +- arch/arm64/kernel/perf_trace_counters.c | 171 ++++++++++++++++++++++++ arch/arm64/kernel/perf_trace_counters.h | 103 ++++++++++++++ arch/arm64/kernel/perf_trace_user.c | 89 ++++++++++++ arch/arm64/kernel/perf_trace_user.h | 77 +++++++++++ 5 files changed, 442 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/kernel/perf_trace_counters.c create mode 100644 arch/arm64/kernel/perf_trace_counters.h create mode 100644 arch/arm64/kernel/perf_trace_user.c create mode 100644 arch/arm64/kernel/perf_trace_user.h diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 4c8b13bede80..1ceb932b7f17 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -33,7 +33,8 @@ arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o arm64-obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o -arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o +arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o perf_trace_counters.o \ + perf_trace_user.o arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o arm64-obj-$(CONFIG_CPU_PM) += sleep.o suspend.o arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o diff --git a/arch/arm64/kernel/perf_trace_counters.c b/arch/arm64/kernel/perf_trace_counters.c new file mode 100644 index 000000000000..488e8143abc7 --- /dev/null +++ b/arch/arm64/kernel/perf_trace_counters.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2013-2014, 2017-2018, The Linux Foundation. All rights reserved. + */ +#include +#include +#include +#include +#include +#define CREATE_TRACE_POINTS +#include "perf_trace_counters.h" + +static unsigned int tp_pid_state; + +DEFINE_PER_CPU(u32, cntenset_val); +DEFINE_PER_CPU(u32, previous_ccnt); +DEFINE_PER_CPU(u32[NUM_L1_CTRS], previous_l1_cnts); +DEFINE_PER_CPU(u32, old_pid); +DEFINE_PER_CPU(u32, hotplug_flag); + +#define USE_CPUHP_STATE CPUHP_AP_ONLINE + +static int tracectr_cpu_hotplug_coming_up(unsigned int cpu) +{ + per_cpu(hotplug_flag, cpu) = 1; + + return 0; +} + +static void setup_prev_cnts(u32 cpu, u32 cnten_val) +{ + int i; + + if (cnten_val & CC) + per_cpu(previous_ccnt, cpu) = + read_sysreg(pmccntr_el0); + + for (i = 0; i < NUM_L1_CTRS; i++) { + if (cnten_val & (1 << i)) { + /* Select */ + write_sysreg(i, pmselr_el0); + isb(); + /* Read value */ + per_cpu(previous_l1_cnts[i], cpu) = + read_sysreg(pmxevcntr_el0); + } + } +} + +void tracectr_notifier(void *ignore, bool preempt, + struct task_struct *prev, struct task_struct *next) +{ + u32 cnten_val; + int current_pid; + u32 cpu = task_cpu(next); + + if (tp_pid_state != 1) + return; + current_pid = next->pid; + if (per_cpu(old_pid, cpu) != -1) { + cnten_val = read_sysreg(pmcntenset_el0); + per_cpu(cntenset_val, cpu) = cnten_val; + /* Disable all the counters that were enabled */ + write_sysreg(cnten_val, pmcntenclr_el0); + + if (per_cpu(hotplug_flag, cpu) == 1) { + per_cpu(hotplug_flag, cpu) = 0; + setup_prev_cnts(cpu, cnten_val); + } else { + trace_sched_switch_with_ctrs(per_cpu(old_pid, cpu), + current_pid); + } + + /* Enable all the counters that were disabled */ + write_sysreg(cnten_val, pmcntenset_el0); + } + per_cpu(old_pid, cpu) = current_pid; +} + +static void enable_tp_pid(void) +{ + if (tp_pid_state == 0) { + tp_pid_state = 1; + register_trace_sched_switch(tracectr_notifier, NULL); + } +} + +static void disable_tp_pid(void) +{ + if (tp_pid_state == 1) { + tp_pid_state = 0; + unregister_trace_sched_switch(tracectr_notifier, NULL); + } +} + +static ssize_t read_enabled_perftp_file_bool(struct file *file, + char __user *user_buf, size_t count, loff_t *ppos) +{ + char buf[2]; + + buf[1] = '\n'; + if (tp_pid_state == 0) + buf[0] = '0'; + else + buf[0] = '1'; + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static ssize_t write_enabled_perftp_file_bool(struct file *file, + const char __user *user_buf, size_t count, loff_t *ppos) +{ + char buf[32]; + size_t buf_size; + + buf[0] = 0; + buf_size = min(count, (sizeof(buf)-1)); + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + switch (buf[0]) { + case 'y': + case 'Y': + case '1': + enable_tp_pid(); + break; + case 'n': + case 'N': + case '0': + disable_tp_pid(); + break; + } + + return count; +} + +static const struct file_operations fops_perftp = { + .read = read_enabled_perftp_file_bool, + .write = write_enabled_perftp_file_bool, + .llseek = default_llseek, +}; + +int __init init_tracecounters(void) +{ + struct dentry *dir; + struct dentry *file; + unsigned int value = 1; + int cpu, rc; + + dir = debugfs_create_dir("perf_debug_tp", NULL); + if (!dir) + return -ENOMEM; + file = debugfs_create_file("enabled", 0660, dir, + &value, &fops_perftp); + if (!file) { + debugfs_remove(dir); + return -ENOMEM; + } + for_each_possible_cpu(cpu) + per_cpu(old_pid, cpu) = -1; + rc = cpuhp_setup_state_nocalls(USE_CPUHP_STATE, + "tracectr_cpu_hotplug", + tracectr_cpu_hotplug_coming_up, + NULL); + return 0; +} + +int __exit exit_tracecounters(void) +{ + cpuhp_remove_state_nocalls(USE_CPUHP_STATE); + return 0; +} +late_initcall(init_tracecounters); diff --git a/arch/arm64/kernel/perf_trace_counters.h b/arch/arm64/kernel/perf_trace_counters.h new file mode 100644 index 000000000000..de6a882549c3 --- /dev/null +++ b/arch/arm64/kernel/perf_trace_counters.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2013-2014, 2017-2018, The Linux Foundation. All rights reserved. + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM perf_trace_counters + +#if !defined(_PERF_TRACE_COUNTERS_H_) || defined(TRACE_HEADER_MULTI_READ) +#define _PERF_TRACE_COUNTERS_H_ + +/* Ctr index for PMCNTENSET/CLR */ +#define CC 0x80000000 +#define C0 0x1 +#define C1 0x2 +#define C2 0x4 +#define C3 0x8 +#define C4 0x10 +#define C5 0x20 +#define C_ALL (CC | C0 | C1 | C2 | C3 | C4 | C5) +#define NUM_L1_CTRS 6 + +#include +#include +#include + +DECLARE_PER_CPU(u32, cntenset_val); +DECLARE_PER_CPU(u32, previous_ccnt); +DECLARE_PER_CPU(u32[NUM_L1_CTRS], previous_l1_cnts); +TRACE_EVENT(sched_switch_with_ctrs, + + TP_PROTO(pid_t prev, pid_t next), + + TP_ARGS(prev, next), + + TP_STRUCT__entry( + __field(pid_t, old_pid) + __field(pid_t, new_pid) + __field(u32, cctr) + __field(u32, ctr0) + __field(u32, ctr1) + __field(u32, ctr2) + __field(u32, ctr3) + __field(u32, ctr4) + __field(u32, ctr5) + ), + + TP_fast_assign( + u32 cpu = smp_processor_id(); + u32 i; + u32 cnten_val; + u32 total_ccnt = 0; + u32 total_cnt = 0; + u32 delta_l1_cnts[NUM_L1_CTRS]; + + __entry->old_pid = prev; + __entry->new_pid = next; + + cnten_val = per_cpu(cntenset_val, cpu); + + if (cnten_val & CC) { + /* Read value */ + total_ccnt = read_sysreg(pmccntr_el0); + __entry->cctr = total_ccnt - + per_cpu(previous_ccnt, cpu); + per_cpu(previous_ccnt, cpu) = total_ccnt; + } + for (i = 0; i < NUM_L1_CTRS; i++) { + if (cnten_val & (1 << i)) { + /* Select */ + write_sysreg(i, pmselr_el0); + isb(); + /* Read value */ + total_cnt = read_sysreg(pmxevcntr_el0); + delta_l1_cnts[i] = total_cnt - + per_cpu(previous_l1_cnts[i], cpu); + per_cpu(previous_l1_cnts[i], cpu) = + total_cnt; + } else + delta_l1_cnts[i] = 0; + } + + __entry->ctr0 = delta_l1_cnts[0]; + __entry->ctr1 = delta_l1_cnts[1]; + __entry->ctr2 = delta_l1_cnts[2]; + __entry->ctr3 = delta_l1_cnts[3]; + __entry->ctr4 = delta_l1_cnts[4]; + __entry->ctr5 = delta_l1_cnts[5]; + ), + + TP_printk("prev_pid=%d, next_pid=%d, CCNTR: %u, CTR0: %u, CTR1: %u, CTR2: %u, CTR3: %u, CTR4: %u, CTR5: %u", + __entry->old_pid, __entry->new_pid, + __entry->cctr, + __entry->ctr0, __entry->ctr1, + __entry->ctr2, __entry->ctr3, + __entry->ctr4, __entry->ctr5) +); + +#endif +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH ../../arch/arm64/kernel +#define TRACE_INCLUDE_FILE perf_trace_counters +#include diff --git a/arch/arm64/kernel/perf_trace_user.c b/arch/arm64/kernel/perf_trace_user.c new file mode 100644 index 000000000000..8892a526ca6e --- /dev/null +++ b/arch/arm64/kernel/perf_trace_user.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2014,2017-2018, The Linux Foundation. All rights reserved. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#define CREATE_TRACE_POINTS +#include "perf_trace_user.h" + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM perf_trace_counters + +#define TRACE_USER_MAX_BUF_SIZE 100 + +static ssize_t perf_trace_write(struct file *file, + const char __user *user_string_in, + size_t len, loff_t *ppos) +{ + u32 cnten_val; + int rc; + char buf[TRACE_USER_MAX_BUF_SIZE + 1]; + ssize_t length; + + if (len == 0) + return 0; + + length = len > TRACE_USER_MAX_BUF_SIZE ? TRACE_USER_MAX_BUF_SIZE : len; + + rc = copy_from_user(buf, user_string_in, length); + if (rc) { + pr_err("%s copy_from_user failed, rc=%d\n", __func__, rc); + return -EFAULT; + } + + /* Remove any trailing newline and make sure string is terminated */ + if (buf[length - 1] == '\n') + buf[length - 1] = '\0'; + else + buf[length] = '\0'; + + /* + * Disable preemption to ensure that all the performance counter + * accesses happen on the same cpu + */ + preempt_disable(); + /* stop counters, call the trace function, restart them */ + + cnten_val = read_sysreg(pmcntenset_el0); + /* Disable all the counters that were enabled */ + write_sysreg(cnten_val, pmcntenclr_el0); + + trace_perf_trace_user(buf, cnten_val); + + /* Enable all the counters that were disabled */ + write_sysreg(cnten_val, pmcntenset_el0); + preempt_enable(); + + return length; +} + +static const struct file_operations perf_trace_fops = { + .write = perf_trace_write +}; + +static int __init init_perf_trace(void) +{ + struct dentry *dir; + struct dentry *file; + unsigned int value = 1; + + dir = debugfs_create_dir("msm_perf", NULL); + if (!dir) + return -ENOMEM; + file = debugfs_create_file("trace_marker", 0220, dir, + &value, &perf_trace_fops); + if (!file) + return -ENOMEM; + + return 0; +} + +late_initcall(init_perf_trace); diff --git a/arch/arm64/kernel/perf_trace_user.h b/arch/arm64/kernel/perf_trace_user.h new file mode 100644 index 000000000000..376909cb1982 --- /dev/null +++ b/arch/arm64/kernel/perf_trace_user.h @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2014, 2017-2018, The Linux Foundation. All rights reserved. + */ +#if !defined(_PERF_TRACE_USER_H_) || defined(TRACE_HEADER_MULTI_READ) +#define _PERF_TRACE_USER_H_ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM perf_trace_counters + +#include + +#define CNTENSET_CC 0x80000000 +#define NUM_L1_CTRS 6 + +TRACE_EVENT(perf_trace_user, + TP_PROTO(char *string, u32 cnten_val), + TP_ARGS(string, cnten_val), + + TP_STRUCT__entry( + __field(u32, cctr) + __field(u32, ctr0) + __field(u32, ctr1) + __field(u32, ctr2) + __field(u32, ctr3) + __field(u32, ctr4) + __field(u32, ctr5) + __string(user_string, string) + ), + + TP_fast_assign( + u32 cnt; + u32 l1_cnts[NUM_L1_CTRS]; + int i; + + if (cnten_val & CNTENSET_CC) { + /* Read value */ + cnt = read_sysreg(pmccntr_el0); + __entry->cctr = cnt; + } else + __entry->cctr = 0; + for (i = 0; i < NUM_L1_CTRS; i++) { + if (cnten_val & (1 << i)) { + /* Select */ + write_sysreg(i, pmselr_el0); + isb(); + /* Read value */ + cnt = read_sysreg(pmxevcntr_el0); + l1_cnts[i] = cnt; + } else { + l1_cnts[i] = 0; + } + } + + __entry->ctr0 = l1_cnts[0]; + __entry->ctr1 = l1_cnts[1]; + __entry->ctr2 = l1_cnts[2]; + __entry->ctr3 = l1_cnts[3]; + __entry->ctr4 = l1_cnts[4]; + __entry->ctr5 = l1_cnts[5]; + __assign_str(user_string, string); + ), + + TP_printk("CCNTR: %u, CTR0: %u, CTR1: %u, CTR2: %u, CTR3: %u, CTR4: %u, CTR5: %u, MSG=%s", + __entry->cctr, + __entry->ctr0, __entry->ctr1, + __entry->ctr2, __entry->ctr3, + __entry->ctr4, __entry->ctr5, + __get_str(user_string) + ) +); + +#endif +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH ../../arch/arm64/kernel +#define TRACE_INCLUDE_FILE perf_trace_user +#include