tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 82e4255305c554b0bb18b7ccf2db86041b4c8b6e commit: ea929eb9121588cec720649ebac3caf75bab2df0 [9345/10049] signal: on exit skip waiting for an ack from the tracer if it is frozen config: x86_64-randconfig-123-20240702 (https://download.01.org/0day-ci/archive/20240702/202407021700.qhDbFwso-lkp@xxxxxxxxx/config) compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240702/202407021700.qhDbFwso-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202407021700.qhDbFwso-lkp@xxxxxxxxx/ sparse warnings: (new ones prefixed by >>) kernel/signal.c: note: in included file (through arch/x86/include/uapi/asm/signal.h, arch/x86/include/asm/signal.h, include/uapi/linux/signal.h, ...): include/uapi/asm-generic/signal-defs.h:83:29: sparse: sparse: multiple address spaces given kernel/signal.c:188:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:188:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:188:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:191:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:191:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:191:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:473:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:473:9: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:473:9: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:477:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:477:34: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:477:34: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:510:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:510:9: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:510:9: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:513:36: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:513:36: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:513:36: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:535:53: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct k_sigaction *ka @@ got struct k_sigaction [noderef] __rcu * @@ kernel/signal.c:535:53: sparse: expected struct k_sigaction *ka kernel/signal.c:535:53: sparse: got struct k_sigaction [noderef] __rcu * include/uapi/asm-generic/signal-defs.h:83:29: sparse: sparse: multiple address spaces given kernel/signal.c:695:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:695:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:695:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:697:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:697:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:697:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:762:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct lockdep_map const *lock @@ got struct lockdep_map [noderef] __rcu * @@ kernel/signal.c:762:9: sparse: expected struct lockdep_map const *lock kernel/signal.c:762:9: sparse: got struct lockdep_map [noderef] __rcu * kernel/signal.c:887:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct lockdep_map const *lock @@ got struct lockdep_map [noderef] __rcu * @@ kernel/signal.c:887:9: sparse: expected struct lockdep_map const *lock kernel/signal.c:887:9: sparse: got struct lockdep_map [noderef] __rcu * kernel/signal.c:1082:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct lockdep_map const *lock @@ got struct lockdep_map [noderef] __rcu * @@ kernel/signal.c:1082:9: sparse: expected struct lockdep_map const *lock kernel/signal.c:1082:9: sparse: got struct lockdep_map [noderef] __rcu * kernel/signal.c:1334:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:1334:9: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:1334:9: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:1335:16: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct k_sigaction *action @@ got struct k_sigaction [noderef] __rcu * @@ kernel/signal.c:1335:16: sparse: expected struct k_sigaction *action kernel/signal.c:1335:16: sparse: got struct k_sigaction [noderef] __rcu * kernel/signal.c:1356:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:1356:34: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:1356:34: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:1944:36: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:1944:36: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:1944:36: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2074:44: sparse: sparse: cast removes address space '__rcu' of expression kernel/signal.c:2093:65: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct task_struct *tsk @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2093:65: sparse: expected struct task_struct *tsk kernel/signal.c:2093:65: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2094:40: sparse: sparse: cast removes address space '__rcu' of expression kernel/signal.c:2112:14: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sighand_struct *psig @@ got struct sighand_struct [noderef] __rcu *[noderef] __rcu sighand @@ kernel/signal.c:2112:14: sparse: expected struct sighand_struct *psig kernel/signal.c:2112:14: sparse: got struct sighand_struct [noderef] __rcu *[noderef] __rcu sighand kernel/signal.c:2141:53: sparse: sparse: incorrect type in argument 3 (different address spaces) @@ expected struct task_struct *t @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2141:53: sparse: expected struct task_struct *t kernel/signal.c:2141:53: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2142:34: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct task_struct *parent @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2142:34: sparse: expected struct task_struct *parent kernel/signal.c:2142:34: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2171:24: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct *parent @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2171:24: sparse: expected struct task_struct *parent kernel/signal.c:2171:24: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2174:24: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct *parent @@ got struct task_struct [noderef] __rcu *real_parent @@ kernel/signal.c:2174:24: sparse: expected struct task_struct *parent kernel/signal.c:2174:24: sparse: got struct task_struct [noderef] __rcu *real_parent kernel/signal.c:2207:17: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct sighand_struct *sighand @@ got struct sighand_struct [noderef] __rcu *sighand @@ kernel/signal.c:2207:17: sparse: expected struct sighand_struct *sighand kernel/signal.c:2207:17: sparse: got struct sighand_struct [noderef] __rcu *sighand kernel/signal.c:2247:41: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2247:41: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2247:41: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2249:39: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2249:39: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2249:39: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2306:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2306:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2306:33: sparse: got struct spinlock [noderef] __rcu * >> kernel/signal.c:2331:39: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct task_struct *task @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2331:39: sparse: expected struct task_struct *task kernel/signal.c:2331:39: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2378:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2378:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2378:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2418:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2418:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2418:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2420:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2420:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2420:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2518:41: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2518:41: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2518:41: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2602:41: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2602:41: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2602:41: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2614:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:2614:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:2614:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:2649:52: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct task_struct *tsk @@ got struct task_struct [noderef] __rcu *parent @@ kernel/signal.c:2649:52: sparse: expected struct task_struct *tsk kernel/signal.c:2649:52: sparse: got struct task_struct [noderef] __rcu *parent kernel/signal.c:2651:49: sparse: sparse: cast removes address space '__rcu' of expression kernel/signal.c:2689:49: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct sighand_struct *sighand @@ got struct sighand_struct [noderef] __rcu *sighand @@ kernel/signal.c:2689:49: sparse: expected struct sighand_struct *sighand kernel/signal.c:2689:49: sparse: got struct sighand_struct [noderef] __rcu *sighand kernel/signal.c:3023:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3023:27: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3023:27: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3044:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3044:29: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3044:29: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3111:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3111:27: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3111:27: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3113:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3113:29: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3113:29: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3264:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3264:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3264:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3267:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3267:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3267:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3656:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3656:27: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3656:27: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3668:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3668:37: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3668:37: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3673:35: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3673:35: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3673:35: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:3678:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:3678:29: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:3678:29: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:4154:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:4154:31: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:4154:31: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:4166:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:4166:33: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:4166:33: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:4184:11: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct k_sigaction *k @@ got struct k_sigaction [noderef] __rcu * @@ kernel/signal.c:4184:11: sparse: expected struct k_sigaction *k kernel/signal.c:4184:11: sparse: got struct k_sigaction [noderef] __rcu * kernel/signal.c:4186:25: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:4186:25: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:4186:25: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:4188:35: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:4188:35: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:4188:35: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:4236:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/signal.c:4236:27: sparse: expected struct spinlock [usertype] *lock kernel/signal.c:4236:27: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:72:34: sparse: sparse: dereference of noderef expression kernel/signal.c:522:35: sparse: sparse: dereference of noderef expression kernel/signal.c:550:52: sparse: sparse: dereference of noderef expression kernel/signal.c:1035:13: sparse: sparse: dereference of noderef expression kernel/signal.c: note: in included file: include/linux/signalfd.h:21:13: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct wait_queue_head *wq_head @@ got struct wait_queue_head [noderef] __rcu * @@ include/linux/signalfd.h:21:13: sparse: expected struct wait_queue_head *wq_head include/linux/signalfd.h:21:13: sparse: got struct wait_queue_head [noderef] __rcu * include/linux/signalfd.h:22:17: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct wait_queue_head *wq_head @@ got struct wait_queue_head [noderef] __rcu * @@ include/linux/signalfd.h:22:17: sparse: expected struct wait_queue_head *wq_head include/linux/signalfd.h:22:17: sparse: got struct wait_queue_head [noderef] __rcu * kernel/signal.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h, ...): include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true kernel/signal.c: note: in included file (through include/linux/sched/cputime.h): include/linux/sched/signal.h:754:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:754:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:754:37: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c:1305:9: sparse: sparse: context imbalance in 'do_send_sig_info' - different lock contexts for basic block kernel/signal.c: note: in included file (through include/linux/rbtree.h, include/linux/mm_types.h, include/linux/mmzone.h, ...): include/linux/rcupdate.h:809:9: sparse: sparse: context imbalance in '__lock_task_sighand' - different lock contexts for basic block kernel/signal.c: note: in included file (through include/linux/sched/cputime.h): include/linux/sched/signal.h:754:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:754:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:754:37: sparse: got struct spinlock [noderef] __rcu * kernel/signal.c: note: in included file: vim +2331 kernel/signal.c 2218 2219 /* 2220 * This must be called with current->sighand->siglock held. 2221 * 2222 * This should be the path for all ptrace stops. 2223 * We always set current->last_siginfo while stopped here. 2224 * That makes it a way to test a stopped process for 2225 * being ptrace-stopped vs being job-control-stopped. 2226 * 2227 * Returns the signal the ptracer requested the code resume 2228 * with. If the code did not stop because the tracer is gone, 2229 * the stop signal remains unchanged unless clear_code. 2230 */ 2231 static int ptrace_stop(int exit_code, int why, unsigned long message, 2232 kernel_siginfo_t *info) 2233 __releases(¤t->sighand->siglock) 2234 __acquires(¤t->sighand->siglock) 2235 { 2236 bool gstop_done = false; 2237 2238 if (arch_ptrace_stop_needed()) { 2239 /* 2240 * The arch code has something special to do before a 2241 * ptrace stop. This is allowed to block, e.g. for faults 2242 * on user stack pages. We can't keep the siglock while 2243 * calling arch_ptrace_stop, so we must release it now. 2244 * To preserve proper semantics, we must do this before 2245 * any signal bookkeeping like checking group_stop_count. 2246 */ 2247 spin_unlock_irq(¤t->sighand->siglock); 2248 arch_ptrace_stop(); 2249 spin_lock_irq(¤t->sighand->siglock); 2250 } 2251 2252 /* 2253 * After this point ptrace_signal_wake_up or signal_wake_up 2254 * will clear TASK_TRACED if ptrace_unlink happens or a fatal 2255 * signal comes in. Handle previous ptrace_unlinks and fatal 2256 * signals here to prevent ptrace_stop sleeping in schedule. 2257 */ 2258 if (!current->ptrace || __fatal_signal_pending(current)) 2259 return exit_code; 2260 2261 set_special_state(TASK_TRACED); 2262 current->jobctl |= JOBCTL_TRACED; 2263 2264 /* 2265 * We're committing to trapping. TRACED should be visible before 2266 * TRAPPING is cleared; otherwise, the tracer might fail do_wait(). 2267 * Also, transition to TRACED and updates to ->jobctl should be 2268 * atomic with respect to siglock and should be done after the arch 2269 * hook as siglock is released and regrabbed across it. 2270 * 2271 * TRACER TRACEE 2272 * 2273 * ptrace_attach() 2274 * [L] wait_on_bit(JOBCTL_TRAPPING) [S] set_special_state(TRACED) 2275 * do_wait() 2276 * set_current_state() smp_wmb(); 2277 * ptrace_do_wait() 2278 * wait_task_stopped() 2279 * task_stopped_code() 2280 * [L] task_is_traced() [S] task_clear_jobctl_trapping(); 2281 */ 2282 smp_wmb(); 2283 2284 current->ptrace_message = message; 2285 current->last_siginfo = info; 2286 current->exit_code = exit_code; 2287 2288 /* 2289 * If @why is CLD_STOPPED, we're trapping to participate in a group 2290 * stop. Do the bookkeeping. Note that if SIGCONT was delievered 2291 * across siglock relocks since INTERRUPT was scheduled, PENDING 2292 * could be clear now. We act as if SIGCONT is received after 2293 * TASK_TRACED is entered - ignore it. 2294 */ 2295 if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING)) 2296 gstop_done = task_participate_group_stop(current); 2297 2298 /* any trap clears pending STOP trap, STOP trap clears NOTIFY */ 2299 task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP); 2300 if (info && info->si_code >> 8 == PTRACE_EVENT_STOP) 2301 task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY); 2302 2303 /* entering a trap, clear TRAPPING */ 2304 task_clear_jobctl_trapping(current); 2305 2306 spin_unlock_irq(¤t->sighand->siglock); 2307 read_lock(&tasklist_lock); 2308 /* 2309 * Notify parents of the stop. 2310 * 2311 * While ptraced, there are two parents - the ptracer and 2312 * the real_parent of the group_leader. The ptracer should 2313 * know about every stop while the real parent is only 2314 * interested in the completion of group stop. The states 2315 * for the two don't interact with each other. Notify 2316 * separately unless they're gonna be duplicates. 2317 */ 2318 if (current->ptrace) 2319 do_notify_parent_cldstop(current, true, why); 2320 if (gstop_done && (!current->ptrace || ptrace_reparented(current))) 2321 do_notify_parent_cldstop(current, false, why); 2322 2323 /* 2324 * If tracer is frozen, it won't ack until it gets unfrozen and if the 2325 * tracee is exiting this means its resources do not get freed until 2326 * the tracer is thawed. Skip waiting for the tracer. Per ptrace(2) 2327 * manual, the tracer cannot assume that the ptrace-stopped tracee 2328 * exists, so exiting now should not be an issue. 2329 */ 2330 if (current->ptrace && (exit_code >> 8) == PTRACE_EVENT_EXIT && > 2331 cgroup_task_frozen(current->parent)) { 2332 read_unlock(&tasklist_lock); 2333 goto skip_wait; 2334 } 2335 2336 /* 2337 * The previous do_notify_parent_cldstop() invocation woke ptracer. 2338 * One a PREEMPTION kernel this can result in preemption requirement 2339 * which will be fulfilled after read_unlock() and the ptracer will be 2340 * put on the CPU. 2341 * The ptracer is in wait_task_inactive(, __TASK_TRACED) waiting for 2342 * this task wait in schedule(). If this task gets preempted then it 2343 * remains enqueued on the runqueue. The ptracer will observe this and 2344 * then sleep for a delay of one HZ tick. In the meantime this task 2345 * gets scheduled, enters schedule() and will wait for the ptracer. 2346 * 2347 * This preemption point is not bad from a correctness point of 2348 * view but extends the runtime by one HZ tick time due to the 2349 * ptracer's sleep. The preempt-disable section ensures that there 2350 * will be no preemption between unlock and schedule() and so 2351 * improving the performance since the ptracer will observe that 2352 * the tracee is scheduled out once it gets on the CPU. 2353 * 2354 * On PREEMPT_RT locking tasklist_lock does not disable preemption. 2355 * Therefore the task can be preempted after do_notify_parent_cldstop() 2356 * before unlocking tasklist_lock so there is no benefit in doing this. 2357 * 2358 * In fact disabling preemption is harmful on PREEMPT_RT because 2359 * the spinlock_t in cgroup_enter_frozen() must not be acquired 2360 * with preemption disabled due to the 'sleeping' spinlock 2361 * substitution of RT. 2362 */ 2363 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 2364 preempt_disable(); 2365 read_unlock(&tasklist_lock); 2366 cgroup_enter_frozen(); 2367 if (!IS_ENABLED(CONFIG_PREEMPT_RT)) 2368 preempt_enable_no_resched(); 2369 schedule(); 2370 cgroup_leave_frozen(true); 2371 2372 skip_wait: 2373 /* 2374 * We are back. Now reacquire the siglock before touching 2375 * last_siginfo, so that we are sure to have synchronized with 2376 * any signal-sending on another CPU that wants to examine it. 2377 */ 2378 spin_lock_irq(¤t->sighand->siglock); 2379 exit_code = current->exit_code; 2380 current->last_siginfo = NULL; 2381 current->ptrace_message = 0; 2382 current->exit_code = 0; 2383 2384 /* LISTENING can be set only during STOP traps, clear it */ 2385 current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN); 2386 2387 /* 2388 * Queued signals ignored us while we were stopped for tracing. 2389 * So check for any that we should take before resuming user mode. 2390 * This sets TIF_SIGPENDING, but never clears it. 2391 */ 2392 recalc_sigpending_tsk(current); 2393 return exit_code; 2394 } 2395 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
