1142781e1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0 2142781e1SThomas Gleixner 3142781e1SThomas Gleixner #include <linux/context_tracking.h> 4142781e1SThomas Gleixner #include <linux/entry-common.h> 503248addSEric W. Biederman #include <linux/resume_user_mode.h> 65fbda3ecSThomas Gleixner #include <linux/highmem.h> 799cf983cSMark Rutland #include <linux/jump_label.h> 8a9f3a74aSThomas Gleixner #include <linux/livepatch.h> 9a9f3a74aSThomas Gleixner #include <linux/audit.h> 10f268c373SFrederic Weisbecker #include <linux/tick.h> 11142781e1SThomas Gleixner 1211894468SGabriel Krisman Bertazi #include "common.h" 1311894468SGabriel Krisman Bertazi 14142781e1SThomas Gleixner #define CREATE_TRACE_POINTS 15142781e1SThomas Gleixner #include <trace/events/syscalls.h> 16142781e1SThomas Gleixner 1796e2fbccSSven Schnelle /* See comment for enter_from_user_mode() in entry-common.h */ 186666bb71SSven Schnelle static __always_inline void __enter_from_user_mode(struct pt_regs *regs) 19142781e1SThomas Gleixner { 206d97af48SSven Schnelle arch_enter_from_user_mode(regs); 21142781e1SThomas Gleixner lockdep_hardirqs_off(CALLER_ADDR0); 22142781e1SThomas Gleixner 23142781e1SThomas Gleixner CT_WARN_ON(ct_state() != CONTEXT_USER); 24142781e1SThomas Gleixner user_exit_irqoff(); 25142781e1SThomas Gleixner 26142781e1SThomas Gleixner instrumentation_begin(); 27142781e1SThomas Gleixner trace_hardirqs_off_finish(); 28142781e1SThomas Gleixner instrumentation_end(); 29142781e1SThomas Gleixner } 30142781e1SThomas Gleixner 3196e2fbccSSven Schnelle void noinstr enter_from_user_mode(struct pt_regs *regs) 3296e2fbccSSven Schnelle { 3396e2fbccSSven Schnelle __enter_from_user_mode(regs); 3496e2fbccSSven Schnelle } 3596e2fbccSSven Schnelle 36142781e1SThomas Gleixner static inline void syscall_enter_audit(struct pt_regs *regs, long syscall) 37142781e1SThomas Gleixner { 38142781e1SThomas Gleixner if (unlikely(audit_context())) { 39142781e1SThomas Gleixner unsigned long args[6]; 40142781e1SThomas Gleixner 41142781e1SThomas Gleixner syscall_get_arguments(current, regs, args); 42142781e1SThomas Gleixner audit_syscall_entry(syscall, args[0], args[1], args[2], args[3]); 43142781e1SThomas Gleixner } 44142781e1SThomas Gleixner } 45142781e1SThomas Gleixner 46142781e1SThomas Gleixner static long syscall_trace_enter(struct pt_regs *regs, long syscall, 4729915524SGabriel Krisman Bertazi unsigned long work) 48142781e1SThomas Gleixner { 49142781e1SThomas Gleixner long ret = 0; 50142781e1SThomas Gleixner 5111894468SGabriel Krisman Bertazi /* 5211894468SGabriel Krisman Bertazi * Handle Syscall User Dispatch. This must comes first, since 5311894468SGabriel Krisman Bertazi * the ABI here can be something that doesn't make sense for 5411894468SGabriel Krisman Bertazi * other syscall_work features. 5511894468SGabriel Krisman Bertazi */ 5611894468SGabriel Krisman Bertazi if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) { 5711894468SGabriel Krisman Bertazi if (syscall_user_dispatch(regs)) 5811894468SGabriel Krisman Bertazi return -1L; 5911894468SGabriel Krisman Bertazi } 6011894468SGabriel Krisman Bertazi 61142781e1SThomas Gleixner /* Handle ptrace */ 6264eb35f7SGabriel Krisman Bertazi if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) { 630cfcb2b9SEric W. Biederman ret = ptrace_report_syscall_entry(regs); 6464eb35f7SGabriel Krisman Bertazi if (ret || (work & SYSCALL_WORK_SYSCALL_EMU)) 65142781e1SThomas Gleixner return -1L; 66142781e1SThomas Gleixner } 67142781e1SThomas Gleixner 68142781e1SThomas Gleixner /* Do seccomp after ptrace, to catch any tracer changes. */ 6923d67a54SGabriel Krisman Bertazi if (work & SYSCALL_WORK_SECCOMP) { 70142781e1SThomas Gleixner ret = __secure_computing(NULL); 71142781e1SThomas Gleixner if (ret == -1L) 72142781e1SThomas Gleixner return ret; 73142781e1SThomas Gleixner } 74142781e1SThomas Gleixner 75b6ec4134SKees Cook /* Either of the above might have changed the syscall number */ 76b6ec4134SKees Cook syscall = syscall_get_nr(current, regs); 77b6ec4134SKees Cook 78524666cbSGabriel Krisman Bertazi if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT)) 79142781e1SThomas Gleixner trace_sys_enter(regs, syscall); 80142781e1SThomas Gleixner 81142781e1SThomas Gleixner syscall_enter_audit(regs, syscall); 82142781e1SThomas Gleixner 83142781e1SThomas Gleixner return ret ? : syscall; 84142781e1SThomas Gleixner } 85142781e1SThomas Gleixner 864facb95bSThomas Gleixner static __always_inline long 874facb95bSThomas Gleixner __syscall_enter_from_user_work(struct pt_regs *regs, long syscall) 88142781e1SThomas Gleixner { 89b86678cfSGabriel Krisman Bertazi unsigned long work = READ_ONCE(current_thread_info()->syscall_work); 90142781e1SThomas Gleixner 9129915524SGabriel Krisman Bertazi if (work & SYSCALL_WORK_ENTER) 9229915524SGabriel Krisman Bertazi syscall = syscall_trace_enter(regs, syscall, work); 93142781e1SThomas Gleixner 94142781e1SThomas Gleixner return syscall; 95142781e1SThomas Gleixner } 96142781e1SThomas Gleixner 974facb95bSThomas Gleixner long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall) 984facb95bSThomas Gleixner { 994facb95bSThomas Gleixner return __syscall_enter_from_user_work(regs, syscall); 1004facb95bSThomas Gleixner } 1014facb95bSThomas Gleixner 1024facb95bSThomas Gleixner noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall) 1034facb95bSThomas Gleixner { 1044facb95bSThomas Gleixner long ret; 1054facb95bSThomas Gleixner 1066666bb71SSven Schnelle __enter_from_user_mode(regs); 1074facb95bSThomas Gleixner 1084facb95bSThomas Gleixner instrumentation_begin(); 1094facb95bSThomas Gleixner local_irq_enable(); 1104facb95bSThomas Gleixner ret = __syscall_enter_from_user_work(regs, syscall); 1114facb95bSThomas Gleixner instrumentation_end(); 1124facb95bSThomas Gleixner 1134facb95bSThomas Gleixner return ret; 1144facb95bSThomas Gleixner } 1154facb95bSThomas Gleixner 1164facb95bSThomas Gleixner noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs) 1174facb95bSThomas Gleixner { 1186666bb71SSven Schnelle __enter_from_user_mode(regs); 1194facb95bSThomas Gleixner instrumentation_begin(); 1204facb95bSThomas Gleixner local_irq_enable(); 1214facb95bSThomas Gleixner instrumentation_end(); 1224facb95bSThomas Gleixner } 1234facb95bSThomas Gleixner 124310de1a6SSven Schnelle /* See comment for exit_to_user_mode() in entry-common.h */ 125bb793562SSven Schnelle static __always_inline void __exit_to_user_mode(void) 126a9f3a74aSThomas Gleixner { 127a9f3a74aSThomas Gleixner instrumentation_begin(); 128a9f3a74aSThomas Gleixner trace_hardirqs_on_prepare(); 1298b023accSNick Desaulniers lockdep_hardirqs_on_prepare(); 130a9f3a74aSThomas Gleixner instrumentation_end(); 131a9f3a74aSThomas Gleixner 132a9f3a74aSThomas Gleixner user_enter_irqoff(); 133a9f3a74aSThomas Gleixner arch_exit_to_user_mode(); 134a9f3a74aSThomas Gleixner lockdep_hardirqs_on(CALLER_ADDR0); 135a9f3a74aSThomas Gleixner } 136a9f3a74aSThomas Gleixner 137310de1a6SSven Schnelle void noinstr exit_to_user_mode(void) 138310de1a6SSven Schnelle { 139310de1a6SSven Schnelle __exit_to_user_mode(); 140310de1a6SSven Schnelle } 141310de1a6SSven Schnelle 142a9f3a74aSThomas Gleixner /* Workaround to allow gradual conversion of architecture code */ 1438ba62d37SEric W. Biederman void __weak arch_do_signal_or_restart(struct pt_regs *regs) { } 144a9f3a74aSThomas Gleixner 145a9f3a74aSThomas Gleixner static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, 146a9f3a74aSThomas Gleixner unsigned long ti_work) 147a9f3a74aSThomas Gleixner { 148a9f3a74aSThomas Gleixner /* 149a9f3a74aSThomas Gleixner * Before returning to user space ensure that all pending work 150a9f3a74aSThomas Gleixner * items have been completed. 151a9f3a74aSThomas Gleixner */ 152a9f3a74aSThomas Gleixner while (ti_work & EXIT_TO_USER_MODE_WORK) { 153a9f3a74aSThomas Gleixner 154a9f3a74aSThomas Gleixner local_irq_enable_exit_to_user(ti_work); 155a9f3a74aSThomas Gleixner 156a9f3a74aSThomas Gleixner if (ti_work & _TIF_NEED_RESCHED) 157a9f3a74aSThomas Gleixner schedule(); 158a9f3a74aSThomas Gleixner 159a9f3a74aSThomas Gleixner if (ti_work & _TIF_UPROBE) 160a9f3a74aSThomas Gleixner uprobe_notify_resume(regs); 161a9f3a74aSThomas Gleixner 162a9f3a74aSThomas Gleixner if (ti_work & _TIF_PATCH_PENDING) 163a9f3a74aSThomas Gleixner klp_update_patch_state(current); 164a9f3a74aSThomas Gleixner 16512db8b69SJens Axboe if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) 1668ba62d37SEric W. Biederman arch_do_signal_or_restart(regs); 167a9f3a74aSThomas Gleixner 168a68de80fSSean Christopherson if (ti_work & _TIF_NOTIFY_RESUME) 16903248addSEric W. Biederman resume_user_mode_work(regs); 170a9f3a74aSThomas Gleixner 171a9f3a74aSThomas Gleixner /* Architecture specific TIF work */ 172a9f3a74aSThomas Gleixner arch_exit_to_user_mode_work(regs, ti_work); 173a9f3a74aSThomas Gleixner 174a9f3a74aSThomas Gleixner /* 175a9f3a74aSThomas Gleixner * Disable interrupts and reevaluate the work flags as they 176a9f3a74aSThomas Gleixner * might have changed while interrupts and preemption was 177a9f3a74aSThomas Gleixner * enabled above. 178a9f3a74aSThomas Gleixner */ 179a9f3a74aSThomas Gleixner local_irq_disable_exit_to_user(); 18047b8ff19SFrederic Weisbecker 18147b8ff19SFrederic Weisbecker /* Check if any of the above work has queued a deferred wakeup */ 182f268c373SFrederic Weisbecker tick_nohz_user_enter_prepare(); 18347b8ff19SFrederic Weisbecker 1846ce89512SMark Rutland ti_work = read_thread_flags(); 185a9f3a74aSThomas Gleixner } 186a9f3a74aSThomas Gleixner 187a9f3a74aSThomas Gleixner /* Return the latest work state for arch_exit_to_user_mode() */ 188a9f3a74aSThomas Gleixner return ti_work; 189a9f3a74aSThomas Gleixner } 190a9f3a74aSThomas Gleixner 191a9f3a74aSThomas Gleixner static void exit_to_user_mode_prepare(struct pt_regs *regs) 192a9f3a74aSThomas Gleixner { 1936ce89512SMark Rutland unsigned long ti_work = read_thread_flags(); 194a9f3a74aSThomas Gleixner 195a9f3a74aSThomas Gleixner lockdep_assert_irqs_disabled(); 196a9f3a74aSThomas Gleixner 19747b8ff19SFrederic Weisbecker /* Flush pending rcuog wakeup before the last need_resched() check */ 198f268c373SFrederic Weisbecker tick_nohz_user_enter_prepare(); 19947b8ff19SFrederic Weisbecker 200a9f3a74aSThomas Gleixner if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) 201a9f3a74aSThomas Gleixner ti_work = exit_to_user_mode_loop(regs, ti_work); 202a9f3a74aSThomas Gleixner 203a9f3a74aSThomas Gleixner arch_exit_to_user_mode_prepare(regs, ti_work); 204a9f3a74aSThomas Gleixner 205a9f3a74aSThomas Gleixner /* Ensure that the address limit is intact and no locks are held */ 206a9f3a74aSThomas Gleixner addr_limit_user_check(); 2075fbda3ecSThomas Gleixner kmap_assert_nomap(); 208a9f3a74aSThomas Gleixner lockdep_assert_irqs_disabled(); 209a9f3a74aSThomas Gleixner lockdep_sys_exit(); 210a9f3a74aSThomas Gleixner } 211a9f3a74aSThomas Gleixner 212a9f3a74aSThomas Gleixner /* 21364eb35f7SGabriel Krisman Bertazi * If SYSCALL_EMU is set, then the only reason to report is when 2146342adcaSGabriel Krisman Bertazi * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall 215900ffe39SKees Cook * instruction has been already reported in syscall_enter_from_user_mode(). 216a9f3a74aSThomas Gleixner */ 21764eb35f7SGabriel Krisman Bertazi static inline bool report_single_step(unsigned long work) 218a9f3a74aSThomas Gleixner { 21941c1a06dSYuxuan Shui if (work & SYSCALL_WORK_SYSCALL_EMU) 22064eb35f7SGabriel Krisman Bertazi return false; 22164eb35f7SGabriel Krisman Bertazi 2226342adcaSGabriel Krisman Bertazi return work & SYSCALL_WORK_SYSCALL_EXIT_TRAP; 223a9f3a74aSThomas Gleixner } 22429915524SGabriel Krisman Bertazi 22529915524SGabriel Krisman Bertazi static void syscall_exit_work(struct pt_regs *regs, unsigned long work) 226a9f3a74aSThomas Gleixner { 227a9f3a74aSThomas Gleixner bool step; 228a9f3a74aSThomas Gleixner 22911894468SGabriel Krisman Bertazi /* 23011894468SGabriel Krisman Bertazi * If the syscall was rolled back due to syscall user dispatching, 23111894468SGabriel Krisman Bertazi * then the tracers below are not invoked for the same reason as 23211894468SGabriel Krisman Bertazi * the entry side was not invoked in syscall_trace_enter(): The ABI 23311894468SGabriel Krisman Bertazi * of these syscalls is unknown. 23411894468SGabriel Krisman Bertazi */ 23511894468SGabriel Krisman Bertazi if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) { 23611894468SGabriel Krisman Bertazi if (unlikely(current->syscall_dispatch.on_dispatch)) { 23711894468SGabriel Krisman Bertazi current->syscall_dispatch.on_dispatch = false; 23811894468SGabriel Krisman Bertazi return; 23911894468SGabriel Krisman Bertazi } 24011894468SGabriel Krisman Bertazi } 24111894468SGabriel Krisman Bertazi 242a9f3a74aSThomas Gleixner audit_syscall_exit(regs); 243a9f3a74aSThomas Gleixner 244524666cbSGabriel Krisman Bertazi if (work & SYSCALL_WORK_SYSCALL_TRACEPOINT) 245a9f3a74aSThomas Gleixner trace_sys_exit(regs, syscall_get_return_value(current, regs)); 246a9f3a74aSThomas Gleixner 24764eb35f7SGabriel Krisman Bertazi step = report_single_step(work); 24864c19ba2SGabriel Krisman Bertazi if (step || work & SYSCALL_WORK_SYSCALL_TRACE) 2490cfcb2b9SEric W. Biederman ptrace_report_syscall_exit(regs, step); 250a9f3a74aSThomas Gleixner } 251a9f3a74aSThomas Gleixner 252a9f3a74aSThomas Gleixner /* 253a9f3a74aSThomas Gleixner * Syscall specific exit to user mode preparation. Runs with interrupts 254a9f3a74aSThomas Gleixner * enabled. 255a9f3a74aSThomas Gleixner */ 256a9f3a74aSThomas Gleixner static void syscall_exit_to_user_mode_prepare(struct pt_regs *regs) 257a9f3a74aSThomas Gleixner { 258b86678cfSGabriel Krisman Bertazi unsigned long work = READ_ONCE(current_thread_info()->syscall_work); 259a9f3a74aSThomas Gleixner unsigned long nr = syscall_get_nr(current, regs); 260a9f3a74aSThomas Gleixner 261a9f3a74aSThomas Gleixner CT_WARN_ON(ct_state() != CONTEXT_KERNEL); 262a9f3a74aSThomas Gleixner 263a9f3a74aSThomas Gleixner if (IS_ENABLED(CONFIG_PROVE_LOCKING)) { 264a9f3a74aSThomas Gleixner if (WARN(irqs_disabled(), "syscall %lu left IRQs disabled", nr)) 265a9f3a74aSThomas Gleixner local_irq_enable(); 266a9f3a74aSThomas Gleixner } 267a9f3a74aSThomas Gleixner 268a9f3a74aSThomas Gleixner rseq_syscall(regs); 269a9f3a74aSThomas Gleixner 270a9f3a74aSThomas Gleixner /* 271a9f3a74aSThomas Gleixner * Do one-time syscall specific work. If these work items are 272a9f3a74aSThomas Gleixner * enabled, we want to run them exactly once per syscall exit with 273a9f3a74aSThomas Gleixner * interrupts enabled. 274a9f3a74aSThomas Gleixner */ 27529915524SGabriel Krisman Bertazi if (unlikely(work & SYSCALL_WORK_EXIT)) 27629915524SGabriel Krisman Bertazi syscall_exit_work(regs, work); 277a9f3a74aSThomas Gleixner } 278a9f3a74aSThomas Gleixner 279c6156e1dSSven Schnelle static __always_inline void __syscall_exit_to_user_mode_work(struct pt_regs *regs) 280a9f3a74aSThomas Gleixner { 281a9f3a74aSThomas Gleixner syscall_exit_to_user_mode_prepare(regs); 282a9f3a74aSThomas Gleixner local_irq_disable_exit_to_user(); 283a9f3a74aSThomas Gleixner exit_to_user_mode_prepare(regs); 284c6156e1dSSven Schnelle } 285c6156e1dSSven Schnelle 286c6156e1dSSven Schnelle void syscall_exit_to_user_mode_work(struct pt_regs *regs) 287c6156e1dSSven Schnelle { 288c6156e1dSSven Schnelle __syscall_exit_to_user_mode_work(regs); 289c6156e1dSSven Schnelle } 290c6156e1dSSven Schnelle 291c6156e1dSSven Schnelle __visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs) 292c6156e1dSSven Schnelle { 293c6156e1dSSven Schnelle instrumentation_begin(); 294c6156e1dSSven Schnelle __syscall_exit_to_user_mode_work(regs); 295a9f3a74aSThomas Gleixner instrumentation_end(); 296bb793562SSven Schnelle __exit_to_user_mode(); 297a9f3a74aSThomas Gleixner } 298a9f3a74aSThomas Gleixner 299142781e1SThomas Gleixner noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs) 300142781e1SThomas Gleixner { 3016666bb71SSven Schnelle __enter_from_user_mode(regs); 302142781e1SThomas Gleixner } 303a9f3a74aSThomas Gleixner 304a9f3a74aSThomas Gleixner noinstr void irqentry_exit_to_user_mode(struct pt_regs *regs) 305a9f3a74aSThomas Gleixner { 306a9f3a74aSThomas Gleixner instrumentation_begin(); 307a9f3a74aSThomas Gleixner exit_to_user_mode_prepare(regs); 308a9f3a74aSThomas Gleixner instrumentation_end(); 309bb793562SSven Schnelle __exit_to_user_mode(); 310a9f3a74aSThomas Gleixner } 311a5497babSThomas Gleixner 312aadfc2f9SIngo Molnar noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) 313a5497babSThomas Gleixner { 314a5497babSThomas Gleixner irqentry_state_t ret = { 315a5497babSThomas Gleixner .exit_rcu = false, 316a5497babSThomas Gleixner }; 317a5497babSThomas Gleixner 318a5497babSThomas Gleixner if (user_mode(regs)) { 319a5497babSThomas Gleixner irqentry_enter_from_user_mode(regs); 320a5497babSThomas Gleixner return ret; 321a5497babSThomas Gleixner } 322a5497babSThomas Gleixner 323a5497babSThomas Gleixner /* 324*6f0e6c15SFrederic Weisbecker * If this entry hit the idle task invoke ct_irq_enter() whether 325a5497babSThomas Gleixner * RCU is watching or not. 326a5497babSThomas Gleixner * 32778a56e04SIra Weiny * Interrupts can nest when the first interrupt invokes softirq 328a5497babSThomas Gleixner * processing on return which enables interrupts. 329a5497babSThomas Gleixner * 330a5497babSThomas Gleixner * Scheduler ticks in the idle task can mark quiescent state and 331a5497babSThomas Gleixner * terminate a grace period, if and only if the timer interrupt is 332a5497babSThomas Gleixner * not nested into another interrupt. 333a5497babSThomas Gleixner * 3347f2a53c2SPaul E. McKenney * Checking for rcu_is_watching() here would prevent the nesting 335*6f0e6c15SFrederic Weisbecker * interrupt to invoke ct_irq_enter(). If that nested interrupt is 336a5497babSThomas Gleixner * the tick then rcu_flavor_sched_clock_irq() would wrongfully 33797258ce9SIngo Molnar * assume that it is the first interrupt and eventually claim 33878a56e04SIra Weiny * quiescent state and end grace periods prematurely. 339a5497babSThomas Gleixner * 340*6f0e6c15SFrederic Weisbecker * Unconditionally invoke ct_irq_enter() so RCU state stays 341a5497babSThomas Gleixner * consistent. 342a5497babSThomas Gleixner * 343a5497babSThomas Gleixner * TINY_RCU does not support EQS, so let the compiler eliminate 344a5497babSThomas Gleixner * this part when enabled. 345a5497babSThomas Gleixner */ 346a5497babSThomas Gleixner if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) { 347a5497babSThomas Gleixner /* 348a5497babSThomas Gleixner * If RCU is not watching then the same careful 349a5497babSThomas Gleixner * sequence vs. lockdep and tracing is required 35045ff5105SIra Weiny * as in irqentry_enter_from_user_mode(). 351a5497babSThomas Gleixner */ 352a5497babSThomas Gleixner lockdep_hardirqs_off(CALLER_ADDR0); 353*6f0e6c15SFrederic Weisbecker ct_irq_enter(); 354a5497babSThomas Gleixner instrumentation_begin(); 355a5497babSThomas Gleixner trace_hardirqs_off_finish(); 356a5497babSThomas Gleixner instrumentation_end(); 357a5497babSThomas Gleixner 358a5497babSThomas Gleixner ret.exit_rcu = true; 359a5497babSThomas Gleixner return ret; 360a5497babSThomas Gleixner } 361a5497babSThomas Gleixner 362a5497babSThomas Gleixner /* 363a5497babSThomas Gleixner * If RCU is watching then RCU only wants to check whether it needs 364a5497babSThomas Gleixner * to restart the tick in NOHZ mode. rcu_irq_enter_check_tick() 365a5497babSThomas Gleixner * already contains a warning when RCU is not watching, so no point 366a5497babSThomas Gleixner * in having another one here. 367a5497babSThomas Gleixner */ 3689d820f68SThomas Gleixner lockdep_hardirqs_off(CALLER_ADDR0); 369a5497babSThomas Gleixner instrumentation_begin(); 370a5497babSThomas Gleixner rcu_irq_enter_check_tick(); 3719d820f68SThomas Gleixner trace_hardirqs_off_finish(); 372a5497babSThomas Gleixner instrumentation_end(); 373a5497babSThomas Gleixner 374a5497babSThomas Gleixner return ret; 375a5497babSThomas Gleixner } 376a5497babSThomas Gleixner 3774624a14fSMark Rutland void raw_irqentry_exit_cond_resched(void) 378a5497babSThomas Gleixner { 379a5497babSThomas Gleixner if (!preempt_count()) { 380a5497babSThomas Gleixner /* Sanity check RCU and thread stack */ 381a5497babSThomas Gleixner rcu_irq_exit_check_preempt(); 382a5497babSThomas Gleixner if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) 383a5497babSThomas Gleixner WARN_ON_ONCE(!on_thread_stack()); 384a5497babSThomas Gleixner if (need_resched()) 385a5497babSThomas Gleixner preempt_schedule_irq(); 386a5497babSThomas Gleixner } 387a5497babSThomas Gleixner } 38840607ee9SPeter Zijlstra (Intel) #ifdef CONFIG_PREEMPT_DYNAMIC 38999cf983cSMark Rutland #if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 3904624a14fSMark Rutland DEFINE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched); 39199cf983cSMark Rutland #elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 39299cf983cSMark Rutland DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); 39399cf983cSMark Rutland void dynamic_irqentry_exit_cond_resched(void) 39499cf983cSMark Rutland { 3950a70045eSSven Schnelle if (!static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched)) 39699cf983cSMark Rutland return; 39799cf983cSMark Rutland raw_irqentry_exit_cond_resched(); 39899cf983cSMark Rutland } 39999cf983cSMark Rutland #endif 40040607ee9SPeter Zijlstra (Intel) #endif 401a5497babSThomas Gleixner 402aadfc2f9SIngo Molnar noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) 403a5497babSThomas Gleixner { 404a5497babSThomas Gleixner lockdep_assert_irqs_disabled(); 405a5497babSThomas Gleixner 406a5497babSThomas Gleixner /* Check whether this returns to user mode */ 407a5497babSThomas Gleixner if (user_mode(regs)) { 408a5497babSThomas Gleixner irqentry_exit_to_user_mode(regs); 409a5497babSThomas Gleixner } else if (!regs_irqs_disabled(regs)) { 410a5497babSThomas Gleixner /* 411a5497babSThomas Gleixner * If RCU was not watching on entry this needs to be done 412a5497babSThomas Gleixner * carefully and needs the same ordering of lockdep/tracing 413a5497babSThomas Gleixner * and RCU as the return to user mode path. 414a5497babSThomas Gleixner */ 415a5497babSThomas Gleixner if (state.exit_rcu) { 416a5497babSThomas Gleixner instrumentation_begin(); 417a5497babSThomas Gleixner /* Tell the tracer that IRET will enable interrupts */ 418a5497babSThomas Gleixner trace_hardirqs_on_prepare(); 4198b023accSNick Desaulniers lockdep_hardirqs_on_prepare(); 420a5497babSThomas Gleixner instrumentation_end(); 421*6f0e6c15SFrederic Weisbecker ct_irq_exit(); 422a5497babSThomas Gleixner lockdep_hardirqs_on(CALLER_ADDR0); 423a5497babSThomas Gleixner return; 424a5497babSThomas Gleixner } 425a5497babSThomas Gleixner 426a5497babSThomas Gleixner instrumentation_begin(); 4274624a14fSMark Rutland if (IS_ENABLED(CONFIG_PREEMPTION)) 428a5497babSThomas Gleixner irqentry_exit_cond_resched(); 4294624a14fSMark Rutland 430a5497babSThomas Gleixner /* Covers both tracing and lockdep */ 431a5497babSThomas Gleixner trace_hardirqs_on(); 432a5497babSThomas Gleixner instrumentation_end(); 433a5497babSThomas Gleixner } else { 434a5497babSThomas Gleixner /* 435a5497babSThomas Gleixner * IRQ flags state is correct already. Just tell RCU if it 436a5497babSThomas Gleixner * was not watching on entry. 437a5497babSThomas Gleixner */ 438a5497babSThomas Gleixner if (state.exit_rcu) 439*6f0e6c15SFrederic Weisbecker ct_irq_exit(); 440a5497babSThomas Gleixner } 441a5497babSThomas Gleixner } 442b6be002bSThomas Gleixner 443b6be002bSThomas Gleixner irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs) 444b6be002bSThomas Gleixner { 445b6be002bSThomas Gleixner irqentry_state_t irq_state; 446b6be002bSThomas Gleixner 447b6be002bSThomas Gleixner irq_state.lockdep = lockdep_hardirqs_enabled(); 448b6be002bSThomas Gleixner 449b6be002bSThomas Gleixner __nmi_enter(); 450b6be002bSThomas Gleixner lockdep_hardirqs_off(CALLER_ADDR0); 451b6be002bSThomas Gleixner lockdep_hardirq_enter(); 452b6be002bSThomas Gleixner rcu_nmi_enter(); 453b6be002bSThomas Gleixner 454b6be002bSThomas Gleixner instrumentation_begin(); 455b6be002bSThomas Gleixner trace_hardirqs_off_finish(); 456b6be002bSThomas Gleixner ftrace_nmi_enter(); 457b6be002bSThomas Gleixner instrumentation_end(); 458b6be002bSThomas Gleixner 459b6be002bSThomas Gleixner return irq_state; 460b6be002bSThomas Gleixner } 461b6be002bSThomas Gleixner 462b6be002bSThomas Gleixner void noinstr irqentry_nmi_exit(struct pt_regs *regs, irqentry_state_t irq_state) 463b6be002bSThomas Gleixner { 464b6be002bSThomas Gleixner instrumentation_begin(); 465b6be002bSThomas Gleixner ftrace_nmi_exit(); 466b6be002bSThomas Gleixner if (irq_state.lockdep) { 467b6be002bSThomas Gleixner trace_hardirqs_on_prepare(); 4688b023accSNick Desaulniers lockdep_hardirqs_on_prepare(); 469b6be002bSThomas Gleixner } 470b6be002bSThomas Gleixner instrumentation_end(); 471b6be002bSThomas Gleixner 472b6be002bSThomas Gleixner rcu_nmi_exit(); 473b6be002bSThomas Gleixner lockdep_hardirq_exit(); 474b6be002bSThomas Gleixner if (irq_state.lockdep) 475b6be002bSThomas Gleixner lockdep_hardirqs_on(CALLER_ADDR0); 476b6be002bSThomas Gleixner __nmi_exit(); 477b6be002bSThomas Gleixner } 478