#include "parse-events.h" #include "pmu.h" #include "util.h" #include "tests.h" /* Simulated format definitions. */ static struct test_format { const char *name; const char *value; } test_formats[] = { { "krava01", "config:0-1,62-63\n", }, { "krava02", "config:10-17\n", }, { "krava03", "config:5\n", }, { "krava11", "config1:0,2,4,6,8,20-28\n", }, { "krava12", "config1:63\n", }, { "krava13", "config1:45-47\n", }, { "krava21", "config2:0-3,10-13,20-23,30-33,40-43,50-53,60-63\n", }, { "krava22", "config2:8,18,48,58\n", }, { "krava23", "config2:28-29,38\n", }, }; /* Simulated users input. */ static struct parse_events_term test_terms[] = { { .config = (char *) "krava01", .val.num = 15, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava02", .val.num = 170, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava03", .val.num = 1, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava11", .val.num = 27, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava12", .val.num = 1, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava13", .val.num = 2, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava21", .val.num = 119, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava22", .val.num = 11, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, { .config = (char *) "krava23", .val.num = 2, .type_val = PARSE_EVENTS__TERM_TYPE_NUM, .type_term = PARSE_EVENTS__TERM_TYPE_USER, }, }; /* * Prepare format directory data, exported by kernel * at /sys/bus/event_source/devices//format. */ static char *test_format_dir_get(void) { static char dir[PATH_MAX]; unsigned int i; snprintf(dir, PATH_MAX, "/tmp/perf-pmu-test-format-XXXXXX"); if (!mkdtemp(dir)) return NULL; for (i = 0; i < ARRAY_SIZE(test_formats); i++) { static char name[PATH_MAX]; struct test_format *format = &test_formats[i]; FILE *file; snprintf(name, PATH_MAX, "%s/%s", dir, format->name); file = fopen(name, "w"); if (!file) return NULL; if (1 != fwrite(format->value, strlen(format->value), 1, file)) break; fclose(file); } return dir; } /* Cleanup format directory. */ static int test_format_dir_put(char *dir) { char buf[PATH_MAX]; snprintf(buf, PATH_MAX, "rm -f %s/*\n", dir); if (system(buf)) return -1; snprintf(buf, PATH_MAX, "rmdir %s\n", dir); return system(buf); } static struct list_head *test_terms_list(void) { static LIST_HEAD(terms); unsigned int i; for (i = 0; i < ARRAY_SIZE(test_terms); i++) list_add_tail(&test_terms[i].list, &terms); return &terms; } int test__pmu(int subtest __maybe_unused) { char *format = test_format_dir_get(); LIST_HEAD(formats); struct list_head *terms = test_terms_list(); int ret; if (!format) return -EINVAL; do { struct perf_event_attr attr; memset(&attr, 0, sizeof(attr)); ret = perf_pmu__format_parse(format, &formats); if (ret) break; ret = perf_pmu__config_terms(&formats, &attr, terms, false, NULL); if (ret) break; ret = -EINVAL; if (attr.config != 0xc00000000002a823) break; if (attr.config1 != 0x8000400000000145) break; if (attr.config2 != 0x0400000020041d07) break; ret = 0; } while (0); test_format_dir_put(format); return ret; } 15'>15space:mode:
authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /net/nfc/nci/ntf.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'net/nfc/nci/ntf.c')