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70b27c756f
The default breakpoint length is "sizeof(long)" however this is incorrect on platforms like Aarch64 where sizeof(long) is 8 but the breakpoint length is 4. Add a helper function that can be used to determine the correct breakpoint length, in this change it just returns the existing default sizeof(long) value. Use the helper in the bp_account test so that, when modifying the event from a watchpoint to a breakpoint, the breakpoint length is appropriate for the architecture and not just sizeof(long). Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: Colin Ian King <colin.i.king@gmail.com> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Junhao He <hejunhao3@huawei.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Yang Jihong <yangjihong@bytedance.com> Link: https://lore.kernel.org/r/20240904050606.752788-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
225 lines
4.9 KiB
C
225 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
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* 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
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*/
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#define __SANE_USERSPACE_TYPES__
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <fcntl.h>
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#include <linux/hw_breakpoint.h>
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#include "tests.h"
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#include "debug.h"
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#include "event.h"
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#include "parse-events.h"
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#include "../perf-sys.h"
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#include "cloexec.h"
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/*
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* PowerPC and S390 do not support creation of instruction breakpoints using the
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* perf_event interface.
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*
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* Just disable the test for these architectures until these issues are
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* resolved.
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*/
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#if defined(__powerpc__) || defined(__s390x__)
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#define BP_ACCOUNT_IS_SUPPORTED 0
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#else
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#define BP_ACCOUNT_IS_SUPPORTED 1
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#endif
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static volatile long the_var;
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static noinline int test_function(void)
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{
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return 0;
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}
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static int __event(bool is_x, void *addr, struct perf_event_attr *attr)
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{
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int fd;
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memset(attr, 0, sizeof(struct perf_event_attr));
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attr->type = PERF_TYPE_BREAKPOINT;
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attr->size = sizeof(struct perf_event_attr);
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attr->config = 0;
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attr->bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
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attr->bp_addr = (unsigned long) addr;
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attr->bp_len = is_x ? default_breakpoint_len() : sizeof(long);
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attr->sample_period = 1;
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attr->sample_type = PERF_SAMPLE_IP;
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attr->exclude_kernel = 1;
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attr->exclude_hv = 1;
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fd = sys_perf_event_open(attr, -1, 0, -1,
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perf_event_open_cloexec_flag());
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if (fd < 0) {
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pr_debug("failed opening event %llx\n", attr->config);
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return TEST_FAIL;
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}
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return fd;
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}
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static int wp_event(void *addr, struct perf_event_attr *attr)
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{
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return __event(false, addr, attr);
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}
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static int bp_event(void *addr, struct perf_event_attr *attr)
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{
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return __event(true, addr, attr);
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}
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static int bp_accounting(int wp_cnt, int share)
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{
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struct perf_event_attr attr, attr_mod, attr_new;
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int i, fd[wp_cnt], fd_wp, ret;
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for (i = 0; i < wp_cnt; i++) {
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fd[i] = wp_event((void *)&the_var, &attr);
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TEST_ASSERT_VAL("failed to create wp\n", fd[i] != -1);
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pr_debug("wp %d created\n", i);
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}
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attr_mod = attr;
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attr_mod.bp_type = HW_BREAKPOINT_X;
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attr_mod.bp_addr = (unsigned long) test_function;
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attr_mod.bp_len = default_breakpoint_len();
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ret = ioctl(fd[0], PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr_mod);
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TEST_ASSERT_VAL("failed to modify wp\n", ret == 0);
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pr_debug("wp 0 modified to bp\n");
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if (!share) {
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fd_wp = wp_event((void *)&the_var, &attr_new);
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TEST_ASSERT_VAL("failed to create max wp\n", fd_wp != -1);
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pr_debug("wp max created\n");
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}
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for (i = 0; i < wp_cnt; i++)
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close(fd[i]);
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return 0;
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}
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static int detect_cnt(bool is_x)
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{
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struct perf_event_attr attr;
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void *addr = is_x ? (void *)test_function : (void *)&the_var;
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int fd[100], cnt = 0, i;
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while (1) {
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if (cnt == 100) {
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pr_debug("way too many debug registers, fix the test\n");
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return 0;
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}
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fd[cnt] = __event(is_x, addr, &attr);
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if (fd[cnt] < 0)
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break;
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cnt++;
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}
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for (i = 0; i < cnt; i++)
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close(fd[i]);
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return cnt;
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}
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static int detect_ioctl(void)
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{
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struct perf_event_attr attr;
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int fd, ret = 1;
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fd = wp_event((void *) &the_var, &attr);
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if (fd > 0) {
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ret = ioctl(fd, PERF_EVENT_IOC_MODIFY_ATTRIBUTES, &attr);
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close(fd);
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}
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return ret ? 0 : 1;
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}
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static int detect_share(int wp_cnt, int bp_cnt)
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{
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struct perf_event_attr attr;
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int i, *fd = NULL, ret = -1;
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if (wp_cnt + bp_cnt == 0)
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return 0;
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fd = malloc(sizeof(int) * (wp_cnt + bp_cnt));
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if (!fd)
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return -1;
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for (i = 0; i < wp_cnt; i++) {
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fd[i] = wp_event((void *)&the_var, &attr);
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if (fd[i] == -1) {
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pr_err("failed to create wp\n");
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goto out;
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}
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}
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for (; i < (bp_cnt + wp_cnt); i++) {
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fd[i] = bp_event((void *)test_function, &attr);
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if (fd[i] == -1)
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break;
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}
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ret = i != (bp_cnt + wp_cnt);
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out:
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while (i--)
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close(fd[i]);
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free(fd);
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return ret;
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}
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/*
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* This test does following:
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* - detects the number of watch/break-points,
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* skip test if any is missing
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* - detects PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl,
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* skip test if it's missing
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* - detects if watchpoints and breakpoints share
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* same slots
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* - create all possible watchpoints on cpu 0
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* - change one of it to breakpoint
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* - in case wp and bp do not share slots,
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* we create another watchpoint to ensure
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* the slot accounting is correct
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*/
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static int test__bp_accounting(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
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{
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int has_ioctl = detect_ioctl();
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int wp_cnt = detect_cnt(false);
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int bp_cnt = detect_cnt(true);
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int share = detect_share(wp_cnt, bp_cnt);
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if (!BP_ACCOUNT_IS_SUPPORTED) {
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pr_debug("Test not supported on this architecture");
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return TEST_SKIP;
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}
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pr_debug("watchpoints count %d, breakpoints count %d, has_ioctl %d, share %d\n",
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wp_cnt, bp_cnt, has_ioctl, share);
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if (!wp_cnt || !bp_cnt || !has_ioctl)
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return TEST_SKIP;
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return bp_accounting(wp_cnt, share);
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}
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DEFINE_SUITE("Breakpoint accounting", bp_accounting);
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