/*
* proc_info_list_kthreads
*
* list 64 bit thread ids of kernel_task
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <err.h>
#include <libproc.h>
#include <strings.h>
#include <darwintest.h>
#include <TargetConditionals.h>
T_GLOBAL_META(T_META_RUN_CONCURRENTLY(true));
#define MAX_TRIES 20
#define EXTRA_THREADS 15
#if TARGET_OS_OSX
T_DECL(proc_info_list_kthreads,
"Test to verify PROC_PIDLISTTHREADIDS returns kernel thread IDs for pid 0",
T_META_ASROOT(true),
T_META_CHECK_LEAKS(false))
#else
T_DECL(proc_info_list_kthreads,
"Test to verify PROC_PIDLISTTHREADIDS returns kernel thread IDs for pid 0",
T_META_ASROOT(false),
T_META_CHECK_LEAKS(false))
#endif /* TARGET_OS_OSX */
{
int buf_used = 0;
int thread_count = 0;
uint64_t *thread_list = NULL;
/*
* To use PROC_PIDLISTTHREADIDS, we must pass a buffer of uint64_t's for each thread ID.
* However, there is a TOCTOU race between asking for the thread count
* and asking for the array of identifiers.
*
* Because the process could have allocated more threads since last we asked
* how many threads there are, we instead pass an extra slot in the array,
* and try again if it used that slot.
*/
int attempt = 1;
while (!thread_count && (attempt < MAX_TRIES)) {
struct proc_taskinfo ti;
buf_used = proc_pidinfo(0, PROC_PIDTASKINFO, 0, &ti, sizeof(ti));
T_QUIET; T_WITH_ERRNO; T_ASSERT_GT(buf_used, 0, "proc_pidinfo(PROC_PIDTASKINFO) returned a value > 0");
T_QUIET; T_ASSERT_EQ(buf_used, (int)sizeof(ti), "proc_pidinfo(PROC_PIDTASKINFO) returned size %d == %lu", buf_used, sizeof(ti));
T_LOG("The kernel says it has %d threads", ti.pti_threadnum);
int expected_size = ti.pti_threadnum * (int)sizeof(uint64_t);
/* tack on five extra to detect newly allocated threads */
int allocated_size = expected_size + EXTRA_THREADS * (int)sizeof(uint64_t);
uint64_t *thread_list_tmp = malloc((size_t)allocated_size);
T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list_tmp, "malloc(size = %d) failed", allocated_size);
buf_used = proc_pidinfo(0, PROC_PIDLISTTHREADIDS, 0, thread_list_tmp, (int)allocated_size);
T_LOG("proc_pidinfo(PROC_PIDLISTTHREADIDS) buf_used = %d, expected_size = %d", buf_used, expected_size);
if (buf_used == 0) {
T_WITH_ERRNO; T_ASSERT_FAIL("proc_pidinfo(PROC_PIDLISTTHREADIDS) failed");
}
if (buf_used == expected_size) {
/* success, we found the expected number of threads */
thread_list = thread_list_tmp;
thread_count = expected_size / (int)sizeof(uint64_t);
} else if (buf_used < expected_size) {
/* there were fewer threads than we expected, fix up the allocation */
thread_list = realloc(thread_list_tmp, (size_t)buf_used);
thread_count = buf_used / (int)sizeof(uint64_t);
T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list, "realloc(size = %d) failed", buf_used);
} else if (buf_used > expected_size) {
if (buf_used < allocated_size) {
thread_list = realloc(thread_list_tmp, (size_t)buf_used);
thread_count = buf_used / (int)sizeof(uint64_t);
T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list, "realloc(size = %d) failed", buf_used);
} else {
/*
* it used all the extra slots, meaning there are more
* threads than we thought, try again!
*/
T_LOG("expected %d threads, but saw an extra thread: %d",
expected_size / (int)sizeof(uint64_t), buf_used / (int)sizeof(uint64_t));
free(thread_list_tmp);
}
}
attempt++;
}
T_QUIET; T_ASSERT_LE(attempt, MAX_TRIES, "attempt <= MAX_TRIES");
T_QUIET; T_ASSERT_NOTNULL(thread_list, "thread_list != NULL");
T_QUIET; T_ASSERT_GT(thread_count, 0, "thread_count > 0");
struct proc_threadinfo pthinfo_64;
for (int i = 0; i < thread_count; i++) {
bzero(&pthinfo_64, sizeof(struct proc_threadinfo));
int retval = proc_pidinfo(0, PROC_PIDTHREADID64INFO, thread_list[i],
(void *)&pthinfo_64, (uint32_t)sizeof(pthinfo_64));
T_QUIET; T_WITH_ERRNO; T_EXPECT_GT(retval, 0, "proc_pidinfo(PROC_PIDTASKINFO) returned %d", retval);
T_QUIET; T_EXPECT_EQ(retval, (int)sizeof(pthinfo_64), "proc_pidinfo(PROC_PIDTASKINFO) returned size %d == %lu",
retval, sizeof(pthinfo_64));
}
}