From 3633c7308005e8c1dab594f69ef904424f8b639a Mon Sep 17 00:00:00 2001 From: Hidetoshi Seto Date: Fri, 9 May 2008 15:26:35 +0900 Subject: [PATCH] [IA64] fix interrupt masking for pending works on kernel leave [Bug-fix for "[BUG?][2.6.25-mm1] sleeping during IRQ disabled"] This patch does: - enable interrupts before calling schedule() as same as others, ex. x86 - enable interrupts during ia64_do_signal() and ia64_sync_krbs() - do_notify_resume_user() is still called with interrupts disabled, since we can take short path of fsys_mode if-statement quickly. - pfm_handle_work() is also called with interrupts disabled, since it can deal interrupt mask within itself. - fix/add some comments/notes Reported-by: KOSAKI Motohiro Signed-off-by: Hidetoshi Seto Signed-off-by: Tony Luck --- arch/ia64/kernel/entry.S | 14 ++++++++++---- arch/ia64/kernel/process.c | 25 +++++++++++++++++++++---- 2 files changed, 31 insertions(+), 8 deletions(-) diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S index e49ad8c5dc..ef6b0313c8 100644 --- a/arch/ia64/kernel/entry.S +++ b/arch/ia64/kernel/entry.S @@ -1156,6 +1156,9 @@ skip_rbs_switch: * r31 = current->thread_info->flags * On exit: * p6 = TRUE if work-pending-check needs to be redone + * + * Interrupts are disabled on entry, reenabled depend on work, and + * disabled on exit. */ .work_pending_syscall: add r2=-8,r2 @@ -1170,8 +1173,8 @@ skip_rbs_switch: (pKStk) dep r21=-1,r0,PREEMPT_ACTIVE_BIT,1 ;; (pKStk) st4 [r20]=r21 - ssm psr.i // enable interrupts #endif + ssm psr.i // enable interrupts br.call.spnt.many rp=schedule .ret9: cmp.eq p6,p0=r0,r0 // p6 <- 1 rsm psr.i // disable interrupts @@ -1234,9 +1237,12 @@ GLOBAL_ENTRY(ia64_invoke_schedule_tail) END(ia64_invoke_schedule_tail) /* - * Setup stack and call do_notify_resume_user(). Note that pSys and pNonSys need to - * be set up by the caller. We declare 8 input registers so the system call - * args get preserved, in case we need to restart a system call. + * Setup stack and call do_notify_resume_user(), keeping interrupts + * disabled. + * + * Note that pSys and pNonSys need to be set up by the caller. + * We declare 8 input registers so the system call args get preserved, + * in case we need to restart a system call. */ ENTRY(notify_resume_user) .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8) diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 58dcfac5ea..a3a34b4eb0 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -167,11 +167,18 @@ void tsk_clear_notify_resume(struct task_struct *tsk) clear_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME); } +/* + * do_notify_resume_user(): + * Called from notify_resume_user at entry.S, with interrupts disabled. + */ void -do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall) +do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) { if (fsys_mode(current, &scr->pt)) { - /* defer signal-handling etc. until we return to privilege-level 0. */ + /* + * defer signal-handling etc. until we return to + * privilege-level 0. + */ if (!ia64_psr(&scr->pt)->lp) ia64_psr(&scr->pt)->lp = 1; return; @@ -179,16 +186,26 @@ do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall #ifdef CONFIG_PERFMON if (current->thread.pfm_needs_checking) + /* + * Note: pfm_handle_work() allow us to call it with interrupts + * disabled, and may enable interrupts within the function. + */ pfm_handle_work(); #endif /* deal with pending signal delivery */ - if (test_thread_flag(TIF_SIGPENDING)) + if (test_thread_flag(TIF_SIGPENDING)) { + local_irq_enable(); /* force interrupt enable */ ia64_do_signal(scr, in_syscall); + } /* copy user rbs to kernel rbs */ - if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) + if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) { + local_irq_enable(); /* force interrupt enable */ ia64_sync_krbs(); + } + + local_irq_disable(); /* force interrupt disable */ } static int pal_halt = 1; -- 2.39.5