diff options
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/asm-offsets.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/calls.S | 4 | ||||
-rw-r--r-- | arch/arm/kernel/entry-common.S | 5 | ||||
-rw-r--r-- | arch/arm/kernel/head.S | 26 | ||||
-rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/kprobes.c | 6 | ||||
-rw-r--r-- | arch/arm/kernel/perf_event.c | 4 | ||||
-rw-r--r-- | arch/arm/kernel/perf_event_v7.c | 2 | ||||
-rw-r--r-- | arch/arm/kernel/signal.c | 160 | ||||
-rw-r--r-- | arch/arm/kernel/smp.c | 6 | ||||
-rw-r--r-- | arch/arm/kernel/smp_tlb.c | 12 | ||||
-rw-r--r-- | arch/arm/kernel/smp_twd.c | 4 | ||||
-rw-r--r-- | arch/arm/kernel/suspend.c | 1 | ||||
-rw-r--r-- | arch/arm/kernel/traps.c | 2 |
14 files changed, 103 insertions, 133 deletions
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index 5ce738b4350..923eec7105c 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -110,7 +110,7 @@ int main(void) BLANK(); #endif #ifdef CONFIG_CPU_HAS_ASID - DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id)); + DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id.counter)); BLANK(); #endif DEFINE(VMA_VM_MM, offsetof(struct vm_area_struct, vm_mm)); diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index a4fda4e7a37..c6ca7e37677 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -195,7 +195,7 @@ CALL(sys_getcwd) CALL(sys_capget) /* 185 */ CALL(sys_capset) - CALL(sys_sigaltstack_wrapper) + CALL(sys_sigaltstack) CALL(sys_sendfile) CALL(sys_ni_syscall) /* getpmsg */ CALL(sys_ni_syscall) /* putpmsg */ @@ -387,7 +387,7 @@ /* 375 */ CALL(sys_setns) CALL(sys_process_vm_readv) CALL(sys_process_vm_writev) - CALL(sys_ni_syscall) /* reserved for sys_kcmp */ + CALL(sys_kcmp) CALL(sys_finit_module) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index a6c301e90a3..3248cde504e 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -514,11 +514,6 @@ sys_rt_sigreturn_wrapper: b sys_rt_sigreturn ENDPROC(sys_rt_sigreturn_wrapper) -sys_sigaltstack_wrapper: - ldr r2, [sp, #S_OFF + S_SP] - b do_sigaltstack -ENDPROC(sys_sigaltstack_wrapper) - sys_statfs64_wrapper: teq r1, #88 moveq r1, #84 diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 486a15ae901..e0eb9a1cae7 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -184,13 +184,22 @@ __create_page_tables: orr r3, r3, #3 @ PGD block type mov r6, #4 @ PTRS_PER_PGD mov r7, #1 << (55 - 32) @ L_PGD_SWAPPER -1: str r3, [r0], #4 @ set bottom PGD entry bits +1: +#ifdef CONFIG_CPU_ENDIAN_BE8 str r7, [r0], #4 @ set top PGD entry bits + str r3, [r0], #4 @ set bottom PGD entry bits +#else + str r3, [r0], #4 @ set bottom PGD entry bits + str r7, [r0], #4 @ set top PGD entry bits +#endif add r3, r3, #0x1000 @ next PMD table subs r6, r6, #1 bne 1b add r4, r4, #0x1000 @ point to the PMD tables +#ifdef CONFIG_CPU_ENDIAN_BE8 + add r4, r4, #4 @ we only write the bottom word +#endif #endif ldr r7, [r10, #PROCINFO_MM_MMUFLAGS] @ mm_mmuflags @@ -258,6 +267,11 @@ __create_page_tables: addne r6, r6, #1 << SECTION_SHIFT strne r6, [r3] +#if defined(CONFIG_LPAE) && defined(CONFIG_CPU_ENDIAN_BE8) + sub r4, r4, #4 @ Fixup page table pointer + @ for 64-bit descriptors +#endif + #ifdef CONFIG_DEBUG_LL #if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING) /* @@ -276,13 +290,17 @@ __create_page_tables: orr r3, r7, r3, lsl #SECTION_SHIFT #ifdef CONFIG_ARM_LPAE mov r7, #1 << (54 - 32) @ XN +#ifdef CONFIG_CPU_ENDIAN_BE8 + str r7, [r0], #4 + str r3, [r0], #4 #else - orr r3, r3, #PMD_SECT_XN -#endif str r3, [r0], #4 -#ifdef CONFIG_ARM_LPAE str r7, [r0], #4 #endif +#else + orr r3, r3, #PMD_SECT_XN + str r3, [r0], #4 +#endif #else /* CONFIG_DEBUG_ICEDCC || CONFIG_DEBUG_SEMIHOSTING */ /* we don't need any serial debugging mappings */ diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 5eae53e7a2e..96093b75ab9 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1023,7 +1023,7 @@ out_mdbgen: static int __cpuinit dbg_reset_notify(struct notifier_block *self, unsigned long action, void *cpu) { - if (action == CPU_ONLINE) + if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE) smp_call_function_single((int)cpu, reset_ctrl_regs, NULL, 1); return NOTIFY_OK; diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c index 4dd41fc9e23..170e9f34003 100644 --- a/arch/arm/kernel/kprobes.c +++ b/arch/arm/kernel/kprobes.c @@ -395,7 +395,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) { struct kretprobe_instance *ri = NULL; struct hlist_head *head, empty_rp; - struct hlist_node *node, *tmp; + struct hlist_node *tmp; unsigned long flags, orig_ret_address = 0; unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; @@ -415,7 +415,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) * real return address, and all the rest will point to * kretprobe_trampoline */ - hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { + hlist_for_each_entry_safe(ri, tmp, head, hlist) { if (ri->task != current) /* another task is sharing our hash bucket */ continue; @@ -442,7 +442,7 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs) kretprobe_assert(ri, orig_ret_address, trampoline_address); kretprobe_hash_unlock(current, &flags); - hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { + hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { hlist_del(&ri->hlist); kfree(ri); } diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 31e0eb353cd..146157dfe27 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -400,7 +400,7 @@ __hw_perf_event_init(struct perf_event *event) } if (event->group_leader != event) { - if (validate_group(event) != 0); + if (validate_group(event) != 0) return -EINVAL; } @@ -484,7 +484,7 @@ const struct dev_pm_ops armpmu_dev_pm_ops = { SET_RUNTIME_PM_OPS(armpmu_runtime_suspend, armpmu_runtime_resume, NULL) }; -static void __init armpmu_init(struct arm_pmu *armpmu) +static void armpmu_init(struct arm_pmu *armpmu) { atomic_set(&armpmu->active_events, 0); mutex_init(&armpmu->reserve_mutex); diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c index 8c79a9e70b8..039cffb053a 100644 --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -774,7 +774,7 @@ static const unsigned armv7_a7_perf_cache_map[PERF_COUNT_HW_CACHE_MAX] /* * PMXEVTYPER: Event selection reg */ -#define ARMV7_EVTYPE_MASK 0xc00000ff /* Mask for writable bits */ +#define ARMV7_EVTYPE_MASK 0xc80000ff /* Mask for writable bits */ #define ARMV7_EVTYPE_EVENT 0xff /* Mask for EVENT bits */ /* diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 56f72d257eb..296786bdbb7 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -45,48 +45,6 @@ const unsigned long sigreturn_codes[7] = { MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN, }; -/* - * atomically swap in the new signal mask, and wait for a signal. - */ -asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask) -{ - sigset_t blocked; - siginitset(&blocked, mask); - return sigsuspend(&blocked); -} - -asmlinkage int -sys_sigaction(int sig, const struct old_sigaction __user *act, - struct old_sigaction __user *oact) -{ - struct k_sigaction new_ka, old_ka; - int ret; - - if (act) { - old_sigset_t mask; - if (!access_ok(VERIFY_READ, act, sizeof(*act)) || - __get_user(new_ka.sa.sa_handler, &act->sa_handler) || - __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) || - __get_user(new_ka.sa.sa_flags, &act->sa_flags) || - __get_user(mask, &act->sa_mask)) - return -EFAULT; - siginitset(&new_ka.sa.sa_mask, mask); - } - - ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); - - if (!ret && oact) { - if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || - __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || - __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) || - __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || - __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) - return -EFAULT; - } - - return ret; -} - #ifdef CONFIG_CRUNCH static int preserve_crunch_context(struct crunch_sigframe __user *frame) { @@ -300,7 +258,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) if (restore_sigframe(regs, &frame->sig)) goto badframe; - if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT) + if (restore_altstack(&frame->sig.uc.uc_stack)) goto badframe; return regs->ARM_r0; @@ -360,18 +318,12 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) } static inline void __user * -get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) +get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize) { - unsigned long sp = regs->ARM_sp; + unsigned long sp = sigsp(regs->ARM_sp, ksig); void __user *frame; /* - * This is the X/Open sanctioned signal stack switching. - */ - if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) - sp = current->sas_ss_sp + current->sas_ss_size; - - /* * ATPCS B01 mandates 8-byte alignment */ frame = (void __user *)((sp - framesize) & ~7); @@ -385,11 +337,22 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) return frame; } +/* + * translate the signal + */ +static inline int map_sig(int sig) +{ + struct thread_info *thread = current_thread_info(); + if (sig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) + sig = thread->exec_domain->signal_invmap[sig]; + return sig; +} + static int -setup_return(struct pt_regs *regs, struct k_sigaction *ka, - unsigned long __user *rc, void __user *frame, int usig) +setup_return(struct pt_regs *regs, struct ksignal *ksig, + unsigned long __user *rc, void __user *frame) { - unsigned long handler = (unsigned long)ka->sa.sa_handler; + unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; unsigned long retcode; int thumb = 0; unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT); @@ -399,7 +362,7 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, /* * Maybe we need to deliver a 32-bit signal to a 26-bit task. */ - if (ka->sa.sa_flags & SA_THIRTYTWO) + if (ksig->ka.sa.sa_flags & SA_THIRTYTWO) cpsr = (cpsr & ~MODE_MASK) | USR_MODE; #ifdef CONFIG_ARM_THUMB @@ -421,12 +384,12 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, } #endif - if (ka->sa.sa_flags & SA_RESTORER) { - retcode = (unsigned long)ka->sa.sa_restorer; + if (ksig->ka.sa.sa_flags & SA_RESTORER) { + retcode = (unsigned long)ksig->ka.sa.sa_restorer; } else { unsigned int idx = thumb << 1; - if (ka->sa.sa_flags & SA_SIGINFO) + if (ksig->ka.sa.sa_flags & SA_SIGINFO) idx += 3; if (__put_user(sigreturn_codes[idx], rc) || @@ -451,7 +414,7 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, } } - regs->ARM_r0 = usig; + regs->ARM_r0 = map_sig(ksig->sig); regs->ARM_sp = (unsigned long)frame; regs->ARM_lr = retcode; regs->ARM_pc = handler; @@ -461,9 +424,9 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, } static int -setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) +setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { - struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); + struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); int err = 0; if (!frame) @@ -476,36 +439,29 @@ setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *reg err |= setup_sigframe(frame, regs, set); if (err == 0) - err = setup_return(regs, ka, frame->retcode, frame, usig); + err = setup_return(regs, ksig, frame->retcode, frame); return err; } static int -setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs *regs) +setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { - struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); - stack_t stack; + struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); int err = 0; if (!frame) return 1; - err |= copy_siginfo_to_user(&frame->info, info); + err |= copy_siginfo_to_user(&frame->info, &ksig->info); __put_user_error(0, &frame->sig.uc.uc_flags, err); __put_user_error(NULL, &frame->sig.uc.uc_link, err); - memset(&stack, 0, sizeof(stack)); - stack.ss_sp = (void __user *)current->sas_ss_sp; - stack.ss_flags = sas_ss_flags(regs->ARM_sp); - stack.ss_size = current->sas_ss_size; - err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack)); - + err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp); err |= setup_sigframe(&frame->sig, regs, set); if (err == 0) - err = setup_return(regs, ka, frame->sig.retcode, frame, usig); + err = setup_return(regs, ksig, frame->sig.retcode, frame); if (err == 0) { /* @@ -523,40 +479,25 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, /* * OK, we're invoking a handler */ -static void -handle_signal(unsigned long sig, struct k_sigaction *ka, - siginfo_t *info, struct pt_regs *regs) +static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) { - struct thread_info *thread = current_thread_info(); - struct task_struct *tsk = current; sigset_t *oldset = sigmask_to_save(); - int usig = sig; int ret; /* - * translate the signal - */ - if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) - usig = thread->exec_domain->signal_invmap[usig]; - - /* * Set up the stack frame */ - if (ka->sa.sa_flags & SA_SIGINFO) - ret = setup_rt_frame(usig, ka, info, oldset, regs); + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + ret = setup_rt_frame(ksig, oldset, regs); else - ret = setup_frame(usig, ka, oldset, regs); + ret = setup_frame(ksig, oldset, regs); /* * Check that the resulting registers are actually sane. */ ret |= !valid_user_regs(regs); - if (ret != 0) { - force_sigsegv(sig, tsk); - return; - } - signal_delivered(sig, info, ka, regs, 0); + signal_setup_done(ret, ksig, 0); } /* @@ -571,9 +512,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, static int do_signal(struct pt_regs *regs, int syscall) { unsigned int retval = 0, continue_addr = 0, restart_addr = 0; - struct k_sigaction ka; - siginfo_t info; - int signr; + struct ksignal ksig; int restart = 0; /* @@ -605,33 +544,32 @@ static int do_signal(struct pt_regs *regs, int syscall) * Get the signal to deliver. When running under ptrace, at this * point the debugger may change all our registers ... */ - signr = get_signal_to_deliver(&info, &ka, regs, NULL); /* * Depending on the signal settings we may need to revert the * decision to restart the system call. But skip this if a * debugger has chosen to restart at a different PC. */ - if (regs->ARM_pc != restart_addr) - restart = 0; - if (signr > 0) { - if (unlikely(restart)) { + if (get_signal(&ksig)) { + /* handler */ + if (unlikely(restart) && regs->ARM_pc == restart_addr) { if (retval == -ERESTARTNOHAND || retval == -ERESTART_RESTARTBLOCK || (retval == -ERESTARTSYS - && !(ka.sa.sa_flags & SA_RESTART))) { + && !(ksig.ka.sa.sa_flags & SA_RESTART))) { regs->ARM_r0 = -EINTR; regs->ARM_pc = continue_addr; } } - - handle_signal(signr, &ka, &info, regs); - return 0; + handle_signal(&ksig, regs); + } else { + /* no handler */ + restore_saved_sigmask(); + if (unlikely(restart) && regs->ARM_pc == restart_addr) { + regs->ARM_pc = continue_addr; + return restart; + } } - - restore_saved_sigmask(); - if (unlikely(restart)) - regs->ARM_pc = continue_addr; - return restart; + return 0; } asmlinkage int diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 5f73f7018f5..31644f1978d 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -285,6 +285,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) * switch away from it before attempting any exclusive accesses. */ cpu_switch_mm(mm->pgd, mm); + local_flush_bp_all(); enter_lazy_tlb(mm, current); local_flush_tlb_all(); @@ -466,8 +467,6 @@ void tick_broadcast(const struct cpumask *mask) { smp_cross_call(mask, IPI_TIMER); } -#else -#define smp_timer_broadcast NULL #endif static void broadcast_timer_set_mode(enum clock_event_mode mode, @@ -674,6 +673,9 @@ static int cpufreq_callback(struct notifier_block *nb, if (freq->flags & CPUFREQ_CONST_LOOPS) return NOTIFY_OK; + if (arm_delay_ops.const_clock) + return NOTIFY_OK; + if (!per_cpu(l_p_j_ref, cpu)) { per_cpu(l_p_j_ref, cpu) = per_cpu(cpu_data, cpu).loops_per_jiffy; diff --git a/arch/arm/kernel/smp_tlb.c b/arch/arm/kernel/smp_tlb.c index 02c5d2ce23b..bd030053139 100644 --- a/arch/arm/kernel/smp_tlb.c +++ b/arch/arm/kernel/smp_tlb.c @@ -64,6 +64,11 @@ static inline void ipi_flush_tlb_kernel_range(void *arg) local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end); } +static inline void ipi_flush_bp_all(void *ignored) +{ + local_flush_bp_all(); +} + void flush_tlb_all(void) { if (tlb_ops_need_broadcast()) @@ -127,3 +132,10 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end) local_flush_tlb_kernel_range(start, end); } +void flush_bp_all(void) +{ + if (tlb_ops_need_broadcast()) + on_each_cpu(ipi_flush_bp_all, NULL, 1); + else + local_flush_bp_all(); +} diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index c092115d903..3f256503748 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -22,6 +22,7 @@ #include <linux/of_irq.h> #include <linux/of_address.h> +#include <asm/smp_plat.h> #include <asm/smp_twd.h> #include <asm/localtimer.h> @@ -373,6 +374,9 @@ void __init twd_local_timer_of_register(void) struct device_node *np; int err; + if (!is_smp() || !setup_max_cpus) + return; + np = of_find_matching_node(NULL, twd_of_match); if (!np) return; diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c index 358bca3a995..c59c97ea826 100644 --- a/arch/arm/kernel/suspend.c +++ b/arch/arm/kernel/suspend.c @@ -68,6 +68,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) ret = __cpu_suspend(arg, fn); if (ret == 0) { cpu_switch_mm(mm->pgd, mm); + local_flush_bp_all(); local_flush_tlb_all(); } diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index b0179b89a04..1c089119b2d 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -296,7 +296,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) bust_spinlocks(0); die_owner = -1; - add_taint(TAINT_DIE); + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); die_nest_count--; if (!die_nest_count) /* Nest count reaches zero, release the lock. */ |