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author | Thomas Gleixner <tglx@linutronix.de> | 2022-03-31 10:36:55 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2022-03-31 10:36:55 +0200 |
commit | 7dd5ad2d3e82fb55229e3fe18e09160878e77e20 (patch) | |
tree | ee452e1e6b8fb41a9b5e5339c7f152517567d376 | |
parent | 787af64d05cd528aac9ad16752d11bb1c6061bb9 (diff) | |
download | linux-stable-7dd5ad2d3e82fb55229e3fe18e09160878e77e20.tar.gz linux-stable-7dd5ad2d3e82fb55229e3fe18e09160878e77e20.tar.bz2 linux-stable-7dd5ad2d3e82fb55229e3fe18e09160878e77e20.zip |
Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels"
Revert commit bf9ad37dc8a. It needs to be better encapsulated and
generalized.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
-rw-r--r-- | arch/x86/Kconfig | 1 | ||||
-rw-r--r-- | include/linux/sched.h | 3 | ||||
-rw-r--r-- | kernel/Kconfig.preempt | 12 | ||||
-rw-r--r-- | kernel/entry/common.c | 14 | ||||
-rw-r--r-- | kernel/signal.c | 40 |
5 files changed, 1 insertions, 69 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7340d9f01b62..442a426e8a68 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -122,7 +122,6 @@ config X86 select ARCH_WANT_GENERAL_HUGETLB select ARCH_WANT_HUGE_PMD_SHARE select ARCH_WANT_LD_ORPHAN_WARN - select ARCH_WANTS_RT_DELAYED_SIGNALS select ARCH_WANTS_THP_SWAP if X86_64 select ARCH_HAS_PARANOID_L1D_FLUSH select BUILDTIME_TABLE_SORT diff --git a/include/linux/sched.h b/include/linux/sched.h index 4a6fdd2a679f..d5e3c00b74e1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1090,9 +1090,6 @@ struct task_struct { /* Restored if set_restore_sigmask() was used: */ sigset_t saved_sigmask; struct sigpending pending; -#ifdef CONFIG_RT_DELAYED_SIGNALS - struct kernel_siginfo forced_info; -#endif unsigned long sas_ss_sp; size_t sas_ss_size; unsigned int sas_ss_flags; diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 8c6de5a9ecc4..c2f1fd95a821 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -133,14 +133,4 @@ config SCHED_CORE which is the likely usage by Linux distributions, there should be no measurable impact on performance. -config ARCH_WANTS_RT_DELAYED_SIGNALS - bool - help - This option is selected by architectures where raising signals - can happen in atomic contexts on PREEMPT_RT enabled kernels. This - option delays raising the signal until the return to user space - loop where it is also delivered. X86 requires this to deliver - signals from trap handlers which run on IST stacks. - -config RT_DELAYED_SIGNALS - def_bool PREEMPT_RT && ARCH_WANTS_RT_DELAYED_SIGNALS + diff --git a/kernel/entry/common.c b/kernel/entry/common.c index ef8d94a98b7e..e57a224d6b79 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -142,18 +142,6 @@ void noinstr exit_to_user_mode(void) /* Workaround to allow gradual conversion of architecture code */ void __weak arch_do_signal_or_restart(struct pt_regs *regs) { } -#ifdef CONFIG_RT_DELAYED_SIGNALS -static inline void raise_delayed_signal(void) -{ - if (unlikely(current->forced_info.si_signo)) { - force_sig_info(¤t->forced_info); - current->forced_info.si_signo = 0; - } -} -#else -static inline void raise_delayed_signal(void) { } -#endif - static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, unsigned long ti_work) { @@ -168,8 +156,6 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, if (ti_work & _TIF_NEED_RESCHED) schedule(); - raise_delayed_signal(); - if (ti_work & _TIF_UPROBE) uprobe_notify_resume(regs); diff --git a/kernel/signal.c b/kernel/signal.c index 368a34c25bbf..30cd1ca43bcd 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1308,43 +1308,6 @@ enum sig_handler { }; /* - * On some archictectures, PREEMPT_RT has to delay sending a signal from a - * trap since it cannot enable preemption, and the signal code's - * spin_locks turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME - * which will send the signal on exit of the trap. - */ -#ifdef CONFIG_RT_DELAYED_SIGNALS -static inline bool force_sig_delayed(struct kernel_siginfo *info, - struct task_struct *t) -{ - if (!in_atomic()) - return false; - - if (WARN_ON_ONCE(t->forced_info.si_signo)) - return true; - - if (is_si_special(info)) { - WARN_ON_ONCE(info != SEND_SIG_PRIV); - t->forced_info.si_signo = info->si_signo; - t->forced_info.si_errno = 0; - t->forced_info.si_code = SI_KERNEL; - t->forced_info.si_pid = 0; - t->forced_info.si_uid = 0; - } else { - t->forced_info = *info; - } - set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); - return true; -} -#else -static inline bool force_sig_delayed(struct kernel_siginfo *info, - struct task_struct *t) -{ - return false; -} -#endif - -/* * Force a signal that the process can't ignore: if necessary * we unblock the signal and change any SIG_IGN to SIG_DFL. * @@ -1364,9 +1327,6 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, struct k_sigaction *action; int sig = info->si_signo; - if (force_sig_delayed(info, t)) - return 0; - spin_lock_irqsave(&t->sighand->siglock, flags); action = &t->sighand->action[sig-1]; ignored = action->sa.sa_handler == SIG_IGN; |