WSL2-Linux-Kernel/tools/perf/tests/bp_signal.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 17:07:57 +03:00
// SPDX-License-Identifier: GPL-2.0
/*
* Inspired by breakpoint overflow test done by
* Vince Weaver <vincent.weaver@maine.edu> for perf_event_tests
* (git://github.com/deater/perf_event_tests)
*/
/*
* Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
* 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
*/
#define __SANE_USERSPACE_TYPES__
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/mman.h>
#include <linux/compiler.h>
#include <linux/hw_breakpoint.h>
#include "tests.h"
#include "debug.h"
#include "event.h"
#include "perf-sys.h"
#include "cloexec.h"
static int fd1;
static int fd2;
static int fd3;
static int overflows;
static int overflows_2;
volatile long the_var;
/*
* Use ASM to ensure watchpoint and breakpoint can be triggered
* at one instruction.
*/
#if defined (__x86_64__)
extern void __test_function(volatile long *ptr);
asm (
".globl __test_function\n"
"__test_function:\n"
"incq (%rdi)\n"
"ret\n");
#else
static void __test_function(volatile long *ptr)
{
*ptr = 0x1234;
}
#endif
static noinline int test_function(void)
{
__test_function(&the_var);
the_var++;
return time(NULL);
}
static void sig_handler_2(int signum __maybe_unused,
siginfo_t *oh __maybe_unused,
void *uc __maybe_unused)
{
overflows_2++;
if (overflows_2 > 10) {
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
}
}
static void sig_handler(int signum __maybe_unused,
siginfo_t *oh __maybe_unused,
void *uc __maybe_unused)
{
overflows++;
if (overflows > 10) {
/*
* This should be executed only once during
* this test, if we are here for the 10th
* time, consider this the recursive issue.
*
* We can get out of here by disable events,
* so no new SIGIO is delivered.
*/
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
}
}
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
static int __event(bool is_x, void *addr, int sig)
{
struct perf_event_attr pe;
int fd;
memset(&pe, 0, sizeof(struct perf_event_attr));
pe.type = PERF_TYPE_BREAKPOINT;
pe.size = sizeof(struct perf_event_attr);
pe.config = 0;
pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
pe.bp_addr = (unsigned long) addr;
pe.bp_len = sizeof(long);
pe.sample_period = 1;
pe.sample_type = PERF_SAMPLE_IP;
pe.wakeup_events = 1;
pe.disabled = 1;
pe.exclude_kernel = 1;
pe.exclude_hv = 1;
fd = sys_perf_event_open(&pe, 0, -1, -1,
perf_event_open_cloexec_flag());
if (fd < 0) {
pr_debug("failed opening event %llx\n", pe.config);
return TEST_FAIL;
}
fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
fcntl(fd, F_SETSIG, sig);
fcntl(fd, F_SETOWN, getpid());
ioctl(fd, PERF_EVENT_IOC_RESET, 0);
return fd;
}
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
static int bp_event(void *addr, int sig)
{
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
return __event(true, addr, sig);
}
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
static int wp_event(void *addr, int sig)
{
perf tests: Fix build on older systems where 'signal' is reserved fixing the following problems, for instance, on RHEL6.7: CC /tmp/build/perf/tests/bp_signal.o cc1: warnings being treated as errors tests/bp_signal.c: In function ‘__event’: tests/bp_signal.c:106: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘bp_event’: tests/bp_signal.c:144: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here tests/bp_signal.c: In function ‘wp_event’: tests/bp_signal.c:149: error: declaration of ‘signal’ shadows a global declaration /usr/include/signal.h:101: error: shadowed declaration is here mv: cannot stat `/tmp/build/perf/tests/.bp_signal.o.tmp': No such file or directory make[3]: *** [/tmp/build/perf/tests/bp_signal.o] Error 1 make[2]: *** [tests] Error 2 make[1]: *** [/tmp/build/perf/perf-in.o] Error 2 make[1]: *** Waiting for unfinished jobs.... Reported-by: Vinson Lee <vlee@freedesktop.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Fixes: 8fd34e1cce18 ("perf test: Improve bp_signal") Link: http://lkml.kernel.org/n/tip-wlpx6tik1b0jirlkw64bv400@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-13 00:30:01 +03:00
return __event(false, addr, sig);
}
static long long bp_count(int fd)
{
long long count;
int ret;
ret = read(fd, &count, sizeof(long long));
if (ret != sizeof(long long)) {
pr_debug("failed to read: %d\n", ret);
return TEST_FAIL;
}
return count;
}
int test__bp_signal(struct test *test __maybe_unused, int subtest __maybe_unused)
{
struct sigaction sa;
long long count1, count2, count3;
/* setup SIGIO signal handler */
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_sigaction = (void *) sig_handler;
sa.sa_flags = SA_SIGINFO;
if (sigaction(SIGIO, &sa, NULL) < 0) {
pr_debug("failed setting up signal handler\n");
return TEST_FAIL;
}
sa.sa_sigaction = (void *) sig_handler_2;
if (sigaction(SIGUSR1, &sa, NULL) < 0) {
pr_debug("failed setting up signal handler 2\n");
return TEST_FAIL;
}
/*
* We create following events:
*
* fd1 - breakpoint event on __test_function with SIGIO
* signal configured. We should get signal
* notification each time the breakpoint is hit
*
* fd2 - breakpoint event on sig_handler with SIGUSR1
* configured. We should get SIGUSR1 each time when
* breakpoint is hit
*
* fd3 - watchpoint event on __test_function with SIGIO
* configured.
*
* Following processing should happen:
* Exec: Action: Result:
* incq (%rdi) - fd1 event breakpoint hit -> count1 == 1
* - SIGIO is delivered
* sig_handler - fd2 event breakpoint hit -> count2 == 1
* - SIGUSR1 is delivered
* sig_handler_2 -> overflows_2 == 1 (nested signal)
* sys_rt_sigreturn - return from sig_handler_2
* overflows++ -> overflows = 1
* sys_rt_sigreturn - return from sig_handler
* incq (%rdi) - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
* - SIGIO is delivered
* sig_handler - fd2 event breakpoint hit -> count2 == 2
* - SIGUSR1 is delivered
* sig_handler_2 -> overflows_2 == 2 (nested signal)
* sys_rt_sigreturn - return from sig_handler_2
* overflows++ -> overflows = 2
* sys_rt_sigreturn - return from sig_handler
* the_var++ - fd3 event watchpoint hit -> count3 == 2 (standalone watchpoint)
* - SIGIO is delivered
* sig_handler - fd2 event breakpoint hit -> count2 == 3
* - SIGUSR1 is delivered
* sig_handler_2 -> overflows_2 == 3 (nested signal)
* sys_rt_sigreturn - return from sig_handler_2
* overflows++ -> overflows == 3
* sys_rt_sigreturn - return from sig_handler
*
* The test case check following error conditions:
* - we get stuck in signal handler because of debug
* exception being triggered receursively due to
* the wrong RF EFLAG management
*
* - we never trigger the sig_handler breakpoint due
* to the rong RF EFLAG management
*
*/
fd1 = bp_event(__test_function, SIGIO);
fd2 = bp_event(sig_handler, SIGUSR1);
fd3 = wp_event((void *)&the_var, SIGIO);
ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd3, PERF_EVENT_IOC_ENABLE, 0);
/*
* Kick off the test by trigering 'fd1'
* breakpoint.
*/
test_function();
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd3, PERF_EVENT_IOC_DISABLE, 0);
count1 = bp_count(fd1);
count2 = bp_count(fd2);
count3 = bp_count(fd3);
close(fd1);
close(fd2);
close(fd3);
pr_debug("count1 %lld, count2 %lld, count3 %lld, overflow %d, overflows_2 %d\n",
count1, count2, count3, overflows, overflows_2);
if (count1 != 1) {
if (count1 == 11)
pr_debug("failed: RF EFLAG recursion issue detected\n");
else
pr_debug("failed: wrong count for bp1%lld\n", count1);
}
if (overflows != 3)
pr_debug("failed: wrong overflow hit\n");
if (overflows_2 != 3)
pr_debug("failed: wrong overflow_2 hit\n");
if (count2 != 3)
pr_debug("failed: wrong count for bp2\n");
if (count3 != 2)
pr_debug("failed: wrong count for bp3\n");
return count1 == 1 && overflows == 3 && count2 == 3 && overflows_2 == 3 && count3 == 2 ?
TEST_OK : TEST_FAIL;
}
bool test__bp_signal_is_supported(void)
{
/*
* PowerPC and S390 do not support creation of instruction
* breakpoints using the perf_event interface.
*
* ARM requires explicit rounding down of the instruction
* pointer in Thumb mode, and then requires the single-step
* to be handled explicitly in the overflow handler to avoid
* stepping into the SIGIO handler and getting stuck on the
* breakpointed instruction.
*
perf tests: Disable bp_signal testing for arm64 As there are several discussions for enabling perf breakpoint signal testing on arm64 platform: arm64 needs to rely on single-step to execute the breakpointed instruction and then reinstall the breakpoint exception handler. But if we hook the breakpoint with a signal, the signal handler will do the stepping rather than the breakpointed instruction, this causes infinite loops as below: Kernel space | Userspace ---------------------------------|-------------------------------- | __test_function() -> hit | breakpoint breakpoint_handler() | `-> user_enable_single_step() | do_signal() | | sig_handler() -> Step one | instruction and | trap to kernel single_step_handler() | `-> reinstall_suspended_bps() | | __test_function() -> hit | breakpoint again and | repeat up flow infinitely As Will Deacon mentioned [1]: "that we require the overflow handler to do the stepping on arm/arm64, which is relied upon by GDB/ptrace. The hw_breakpoint code is a complete disaster so my preference would be to rip out the perf part and just implement something directly in ptrace, but it's a pretty horrible job". Though Will commented this on arm architecture, but the comment also can apply on arm64 architecture. For complete information, I searched online and found a few years back, Wang Nan sent one patch 'arm64: Store breakpoint single step state into pstate' [2]; the patch tried to resolve this issue by avoiding single stepping in signal handler and defer to enable the signal stepping when return to __test_function(). The fixing was not merged due to the concern for missing to handle different usage cases. Based on the info, the most feasible way is to skip Perf breakpoint signal testing for arm64 and this could avoid the duplicate investigation efforts when people see the failure. This patch skips this case on arm64 platform, which is same with arm architecture. [1] https://lkml.org/lkml/2018/11/15/205 [2] https://lkml.org/lkml/2015/12/23/477 Signed-off-by: Leo Yan <leo.yan@linaro.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Brajeswar Ghosh <brajeswar.linux@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Will Deacon <will@kernel.org> Link: http://lore.kernel.org/lkml/20191018085531.6348-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-10-18 11:55:31 +03:00
* Since arm64 has the same issue with arm for the single-step
* handling, this case also gets suck on the breakpointed
* instruction.
*
* Just disable the test for these architectures until these
* issues are resolved.
*/
perf tests: Disable bp_signal testing for arm64 As there are several discussions for enabling perf breakpoint signal testing on arm64 platform: arm64 needs to rely on single-step to execute the breakpointed instruction and then reinstall the breakpoint exception handler. But if we hook the breakpoint with a signal, the signal handler will do the stepping rather than the breakpointed instruction, this causes infinite loops as below: Kernel space | Userspace ---------------------------------|-------------------------------- | __test_function() -> hit | breakpoint breakpoint_handler() | `-> user_enable_single_step() | do_signal() | | sig_handler() -> Step one | instruction and | trap to kernel single_step_handler() | `-> reinstall_suspended_bps() | | __test_function() -> hit | breakpoint again and | repeat up flow infinitely As Will Deacon mentioned [1]: "that we require the overflow handler to do the stepping on arm/arm64, which is relied upon by GDB/ptrace. The hw_breakpoint code is a complete disaster so my preference would be to rip out the perf part and just implement something directly in ptrace, but it's a pretty horrible job". Though Will commented this on arm architecture, but the comment also can apply on arm64 architecture. For complete information, I searched online and found a few years back, Wang Nan sent one patch 'arm64: Store breakpoint single step state into pstate' [2]; the patch tried to resolve this issue by avoiding single stepping in signal handler and defer to enable the signal stepping when return to __test_function(). The fixing was not merged due to the concern for missing to handle different usage cases. Based on the info, the most feasible way is to skip Perf breakpoint signal testing for arm64 and this could avoid the duplicate investigation efforts when people see the failure. This patch skips this case on arm64 platform, which is same with arm architecture. [1] https://lkml.org/lkml/2018/11/15/205 [2] https://lkml.org/lkml/2015/12/23/477 Signed-off-by: Leo Yan <leo.yan@linaro.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Brajeswar Ghosh <brajeswar.linux@gmail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Will Deacon <will@kernel.org> Link: http://lore.kernel.org/lkml/20191018085531.6348-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-10-18 11:55:31 +03:00
#if defined(__powerpc__) || defined(__s390x__) || defined(__arm__) || \
defined(__aarch64__)
return false;
#else
return true;
#endif
}