From f5cdac274c62ab61874374abb60f2310ab979295 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 27 Jul 2010 19:29:37 +0200 Subject: [S390] Fix IRQ tracing in case of PER In case user space is single stepped (PER) the program check handler claims too early that IRQs are enabled on the return path. Subsequent checks will notice that the IRQ mask in the PSW and what lockdep thinks the IRQ mask should be do not correlate and therefore will print a warning to the console and disable lockdep. Fix this by doing all the work within the correct context. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 12 ++++++++++-- arch/s390/kernel/entry64.S | 12 ++++++++++-- 2 files changed, 20 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index d5e3e60..bea9ee3 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -535,8 +535,16 @@ pgm_no_vtime2: l %r3,__LC_PGM_ILC # load program interruption code la %r8,0x7f nr %r8,%r3 # clear per-event-bit and ilc - be BASED(pgm_exit) # only per or per+check ? - b BASED(pgm_do_call) + be BASED(pgm_exit2) # only per or per+check ? + l %r7,BASED(.Ljump_table) + sll %r8,2 + l %r7,0(%r8,%r7) # load address of handler routine + la %r2,SP_PTREGS(%r15) # address of register-save area + basr %r14,%r7 # branch to interrupt-handler +pgm_exit2: + TRACE_IRQS_ON + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + b BASED(sysc_return) # # it was a single stepped SVC that is causing all the trouble diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index e7192e1..8bccec1 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -544,8 +544,16 @@ pgm_no_vtime2: lgf %r3,__LC_PGM_ILC # load program interruption code lghi %r8,0x7f ngr %r8,%r3 # clear per-event-bit and ilc - je pgm_exit - j pgm_do_call + je pgm_exit2 + sll %r8,3 + larl %r1,pgm_check_table + lg %r1,0(%r8,%r1) # load address of handler routine + la %r2,SP_PTREGS(%r15) # address of register-save area + basr %r14,%r1 # branch to interrupt-handler +pgm_exit2: + TRACE_IRQS_ON + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + j sysc_return # # it was a single stepped SVC that is causing all the trouble -- cgit v1.1 From 33fea794b9deeb8ffb77e284eb37375b8f45a2c4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 27 Jul 2010 19:29:38 +0200 Subject: [S390] etr: fix clock synchronization race The etr events switch-to-local and sync-check disable the synchronous clock and schedule a work queue that tries to get the clock back into sync. If another switch-to-local or sync-check event occurs while the work queue function etr_work_fn still runs the eacr.es bit and the clock_sync_word can become inconsistent because check_sync_clock only uses the clock_sync_word to determine if the clock is in sync or not. The second pass of the etr_work_fn will reset the eacr.es bit but will leave the clock_sync_word intact. Fix this race by moving the reset of the eacr.es bit into the switch-to-local and sync-check functions and by checking the eacr.es bit as well to decide if the clock needs to be synced. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/time.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index a2163c9..15a7536 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -524,8 +524,11 @@ void etr_switch_to_local(void) if (!etr_eacr.sl) return; disable_sync_clock(NULL); - set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events); - queue_work(time_sync_wq, &etr_work); + if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) { + etr_eacr.es = etr_eacr.sl = 0; + etr_setr(&etr_eacr); + queue_work(time_sync_wq, &etr_work); + } } /* @@ -539,8 +542,11 @@ void etr_sync_check(void) if (!etr_eacr.es) return; disable_sync_clock(NULL); - set_bit(ETR_EVENT_SYNC_CHECK, &etr_events); - queue_work(time_sync_wq, &etr_work); + if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) { + etr_eacr.es = 0; + etr_setr(&etr_eacr); + queue_work(time_sync_wq, &etr_work); + } } /* @@ -902,7 +908,7 @@ static struct etr_eacr etr_handle_update(struct etr_aib *aib, * Do not try to get the alternate port aib if the clock * is not in sync yet. */ - if (!check_sync_clock()) + if (!eacr.es || !check_sync_clock()) return eacr; /* @@ -1064,7 +1070,7 @@ static void etr_work_fn(struct work_struct *work) * If the clock is in sync just update the eacr and return. * If there is no valid sync port wait for a port update. */ - if (check_sync_clock() || sync_port < 0) { + if ((eacr.es && check_sync_clock()) || sync_port < 0) { etr_update_eacr(eacr); etr_set_tolec_timeout(now); goto out_unlock; -- cgit v1.1