Rodrigo Arias
37a567299e
The test creates tasks that pause until the children task have finished. The value of the perf_event_paranoid file is checked to determine if we can run the test.
62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
/* Copyright (c) 2024 Barcelona Supercomputing Center (BSC)
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* SPDX-License-Identifier: GPL-3.0-or-later */
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#include "common.h"
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#include "compat.h"
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#include <stdio.h>
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#include <stdlib.h>
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static long
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fib(long index)
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{
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long a, b;
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if (index <= 1)
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return index;
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#pragma oss task shared(a) label("fibonacci")
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a = fib(index-1);
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#pragma oss task shared(b) label("fibonacci")
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b = fib(index-2);
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#pragma oss taskwait
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return a + b;
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}
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int
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main(void)
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{
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FILE *f = fopen("/proc/sys/kernel/perf_event_paranoid", "r");
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if (f == NULL)
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die("cannot open /proc/sys/kernel/perf_event_paranoid:");
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char buf[16] = {0};
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if (fread(buf, 1, 16, f) <= 0)
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die("cannot read /proc/sys/kernel/perf_event_paranoid:");
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fclose(f);
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/* We need the value 1 or less:
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* Access to performance monitoring and observability operations is limited.
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* Consider adjusting /proc/sys/kernel/perf_event_paranoid setting to open
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* access to performance monitoring and observability operations for processes
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* without CAP_PERFMON, CAP_SYS_PTRACE or CAP_SYS_ADMIN Linux capability.
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* More information can be found at 'Perf events and tool security' document:
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* https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html
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* perf_event_paranoid setting is 3:
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* -1: Allow use of (almost) all events by all users
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* Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
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* >= 0: Disallow raw and ftrace function tracepoint access
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* >= 1: Disallow CPU event access
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* >= 2: Disallow kernel profiling
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* To make the adjusted perf_event_paranoid setting permanent preserve it
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* in /etc/sysctl.conf (e.g. kernel.perf_event_paranoid = <setting>)
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*/
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int level = atoi(buf);
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if (level > 1)
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die("requires perf_event_paranoid = 1 or less");
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for (int i = 0; i < 30; i++)
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fib(5);
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#pragma oss taskwait
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return 0;
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}
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