[LTP] [PATCH ltp] Add Intel PT full trace mode basic test case

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> +++ b/testcases/kernel/tracing/pt_test/Makefile
> @@ -0,0 +1,21 @@
> +# Copyright (c) 2013 Oracle and/or its affiliates. All Rights Reserved.
                       ^
		       This looks like obvious copy&paste mistake

> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation; either version 2 of
> +# the License, or (at your option) any later version.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +
> +top_srcdir		?= ../../../..
> +
> +include $(top_srcdir)/include/mk/testcases.mk
> +include $(top_srcdir)/testcases/kernel/mem/include/libmem.mk
   ^
   I doubt that this is needed here
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> \ No newline at end of file
^
Missing newline at the end of file

> diff --git a/testcases/kernel/tracing/pt_test/pt_test.c b/testcases/kernel/tracing/pt_test/pt_test.c
> new file mode 100644
> index 000000000..0e85652e5
> --- /dev/null
> +++ b/testcases/kernel/tracing/pt_test/pt_test.c
> @@ -0,0 +1,207 @@
> +/*
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + *
> + * author: Ammy Yi (ammy.yi@intel.com)
> + * date:   8/20/2018
> + */
> +
> +/*
> + * This test will check if Intel PT(Intel Processer Trace) full trace mode is
> + * working. It is only applied on X86 platforms.
> + */
> +
> +#include "tst_test.h"
> +#include <linux/perf_event.h>
> +#include <sys/syscall.h>
> +#include <sched.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +
> +#define PAGESIZE 4096
> +#define INTEL_PT_MEMSIZE 17*PAGESIZE
> +
> +#define BIT(nr)                 (1UL << (nr))
> +
> +#define INTEL_PT_PMU_TYPE "/sys/devices/intel_pt/type"
> +#define INTEL_PT_FORMAT_TSC "/sys/devices/intel_pt/format/tsc"
> +#define INTEL_PT_FORMAT_NRT "/sys/devices/intel_pt/format/noretcomp"
> +
> +//Intel PT event handle
> +int FDE = -1;
> +//map head and size
> +uint64_t ** BUFM = NULL;
> +long BUFSZ = 0;
> +
> +/*
> + * mapping management
> + */

Please avoid commenting the obvious.

> +uint64_t ** creaMap(int fde,long bufsize)
> +{
> +	int PROTo;
> +	long pbufSz;
> +	uint64_t **bufEv;
> +	struct perf_event_mmap_page *pc;
> +
> +	bufEv = malloc(2*sizeof(uint64_t *));
> +	if (!bufEv) {
> +		return NULL;
> +	}

You should use SAFE_MALLOC() instead.

> +	PROTo = PROT_READ | PROT_WRITE;
> +
> +	pbufSz = INTEL_PT_MEMSIZE;
> +
> +	bufEv[0] = mmap(NULL, pbufSz, PROT_READ | PROT_WRITE, MAP_SHARED, fde, 0);

SAFE_MMAP() here.

> +	if (bufEv[0]!=MAP_FAILED) {
> +		pc=(struct perf_event_mmap_page *)bufEv[0];
> +		pc->aux_offset=pbufSz;
> +		pc->aux_size=bufsize;
> +		bufEv[1] = mmap(NULL, bufsize, PROTo, MAP_SHARED, fde, pbufSz);

And here.

> +
> +	}
> +	return bufEv;
> +}
> +
> +
> +/*
> + * get sysfs value
> + */

Here as well, do not comment the obvious.

> +int Intel_PT_pmu_value(char *dir)
> +{
> +	char *value;
> +	int temp = 0, val = 0;
> +	char delims[] = ":";
> +	FILE *f = fopen(dir, "r");
> +
> +	if (f) {
> +		temp = fscanf(f, "%m[^\n]", &value);
> +		if (temp != 1){
> +			tst_res(TINFO, "Read value fail!");
> +        }
> +		else {
> +			if (strstr(value, delims) == NULL){
> +				val = atoi(value);
> +			}
> +			else {
> +				strsep(&value, delims);
> +				val = atoi(value);
> +			}
> +		}
> +		fclose(f);
> +	}
> +
> +	return val;
> +}

We do have SAFE_FILE_SCANF() that does exactly this.

> +void delMap(uint64_t **bufEv,long bufsize)
> +{
> +	long pbufSz;
> +
> +	pbufSz = INTEL_PT_MEMSIZE;
> +
> +	munmap(bufEv[0],pbufSz);
> +	munmap(bufEv[1],bufsize);
> +
> +	free(bufEv);
> +}
> +
> +/*
> + * Will test Intel PT Full Trace mode working normal
> + */

And here as well.

> +static void INTEL_PT_FULL_TRACE_CHECK(void)
> +{
> +	struct perf_event_attr attr = {};
> +	struct perf_event_mmap_page *pmp;
> +	uint64_t aux_head = 0;
> +	BUFSZ = 2 * PAGESIZE;
> +	//set attr for Intel PT trace
> +	attr.type			= Intel_PT_pmu_value(INTEL_PT_PMU_TYPE);
> +	attr.read_format		= PERF_FORMAT_ID | PERF_FORMAT_TOTAL_TIME_RUNNING | PERF_FORMAT_TOTAL_TIME_ENABLED;
> +	attr.disabled			= 1;
> +	attr.config			= BIT(Intel_PT_pmu_value(INTEL_PT_FORMAT_TSC)) | BIT(Intel_PT_pmu_value(INTEL_PT_FORMAT_NRT));
> +	attr.size			= sizeof(struct perf_event_attr);
> +	attr.exclude_kernel		= 0;
> +	attr.exclude_user		= 0;
> +	attr.mmap			= 1;
> +
> +	//only get trace for own pid
> +	FDE = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);

You have to use tst_syscall() here and include lapi/syscalls.h instead
of sys/syscall.h.

> +	if (FDE < 0) {
> +		tst_res(TINFO,"Open Intel PT event failed!");
> +		tst_res(TFAIL, "perf trace full mode is failed!");
> +		return;
> +	}
> +
> +	/* allocate memory for trace */
> +	BUFM =  creaMap(FDE,BUFSZ);
> +
> +	if (!BUFM || (BUFM)[0]==MAP_FAILED || (BUFM)[1]==MAP_FAILED) {
> +		tst_res(TINFO,"creaMap failed!");
> +		tst_res(TFAIL, "perf trace full mode is failed!");
> +		return;
> +	}
> +
> +	/* enable tracing */
> +	if(ioctl(FDE, PERF_EVENT_IOC_RESET) != 0) {
> +		tst_res(TFAIL, "ioctl with PERF_EVENT_IOC_RESET is failed!");
> +		return;
> +	}
> +	if(ioctl(FDE, PERF_EVENT_IOC_ENABLE) != 0) {
> +		tst_res(TFAIL, "ioctl with PERF_EVENT_IOC_ENABLE is failed!");
> +		return;
> +	}

We do have SAFE_IOCTL() as well.

> +	/* stop tracing */
> +	if(ioctl(FDE, PERF_EVENT_IOC_DISABLE) != 0) {
> +		tst_res(TFAIL, "ioctl with PERF_EVENT_IOC_DISABLE is failed!");
> +		return;
> +	}
> +
> +	// check if there is some trace generated
> +	pmp = (struct perf_event_mmap_page *)BUFM[0];
> +	aux_head = *(volatile uint64_t *)&pmp->aux_head;
> +	if(aux_head == 0) {
> +		tst_res(TFAIL, "There is no trace, so failed!");
> +		return;
> +	}
> +
> +	tst_res(TPASS, "perf trace full mode is passed!");
> +
> +}
> +
> +/*
> +* clean up for Intel PT test.
> +*/

And here as well.

> +void Cleanup(void) {
> +
> +	//close device id

This is even more obvious comment, please avoid adding comments like
that.

> +	if(FDE != -1){
> +		close(FDE);
> +	}
> +	// free memory

Here as well.

> +	if (!BUFM || (BUFM)[0]==MAP_FAILED || (BUFM)[1]==MAP_FAILED){
> +		delMap(BUFM,BUFSZ);
> +	}
> +}
> +
> +static struct tst_test test = {
> +	.test_all = INTEL_PT_FULL_TRACE_CHECK,
> +	.min_kver = "4.1",
> +	.cleanup = Cleanup,
> +	.needs_root = 1,
> +};

There are various coding-style violations in the code that should be
fixed, you can check for these with the chechpatch.pl script that is
shipped with linux kernel sources.

-- 
Cyril Hrubis
chrubis@suse.cz