From 2ce4d4c937ce4c14704f02ae60e2e07e3906c68a Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Tue, 15 Dec 2009 16:48:18 -0800 Subject: gru: fix GRU interrupt race at deallocate Fix a race where an interrupt could be received for a GRU context that has been deallocated. Signed-off-by: Jack Steiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/misc/sgi-gru/grufault.c | 24 +++++++++++++++++------- drivers/misc/sgi-gru/gruprocfs.c | 1 + drivers/misc/sgi-gru/grutables.h | 1 + 3 files changed, 19 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c index 929d6073e60..6ff6dfb7516 100644 --- a/drivers/misc/sgi-gru/grufault.c +++ b/drivers/misc/sgi-gru/grufault.c @@ -360,7 +360,8 @@ static void gru_preload_tlb(struct gru_state *gru, * < 0 = error code * */ -static int gru_try_dropin(struct gru_thread_state *gts, +static int gru_try_dropin(struct gru_state *gru, + struct gru_thread_state *gts, struct gru_tlb_fault_handle *tfh, struct gru_instruction_bits *cbk) { @@ -432,7 +433,7 @@ static int gru_try_dropin(struct gru_thread_state *gts, } if (unlikely(cbe) && pageshift == PAGE_SHIFT) { - gru_preload_tlb(gts->ts_gru, gts, atomic, vaddr, asid, write, tlb_preload_count, tfh, cbe); + gru_preload_tlb(gru, gts, atomic, vaddr, asid, write, tlb_preload_count, tfh, cbe); gru_flush_cache_cbe(cbe); } @@ -442,7 +443,7 @@ static int gru_try_dropin(struct gru_thread_state *gts, gru_dbg(grudev, "%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, indexway 0x%x," " rw %d, ps %d, gpa 0x%lx\n", - atomic ? "atomic" : "non-atomic", gts->ts_gru->gs_gid, gts, tfh, vaddr, asid, + atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh, vaddr, asid, indexway, write, pageshift, gpa); STAT(tlb_dropin); return 0; @@ -528,6 +529,7 @@ static irqreturn_t gru_intr(int chiplet, int blade) struct gru_tlb_fault_map imap, dmap; struct gru_thread_state *gts; struct gru_tlb_fault_handle *tfh = NULL; + struct completion *cmp; int cbrnum, ctxnum; STAT(intr); @@ -547,9 +549,11 @@ static irqreturn_t gru_intr(int chiplet, int blade) for_each_cbr_in_tfm(cbrnum, dmap.fault_bits) { STAT(intr_cbr); - complete(gru->gs_blade->bs_async_wq); + cmp = gru->gs_blade->bs_async_wq; + if (cmp) + complete(cmp); gru_dbg(grudev, "gid %d, cbr_done %d, done %d\n", - gru->gs_gid, cbrnum, gru->gs_blade->bs_async_wq->done); + gru->gs_gid, cbrnum, cmp ? cmp->done : -1); } for_each_cbr_in_tfm(cbrnum, imap.fault_bits) { @@ -566,6 +570,12 @@ static irqreturn_t gru_intr(int chiplet, int blade) ctxnum = tfh->ctxnum; gts = gru->gs_gts[ctxnum]; + /* Spurious interrupts can cause this. Ignore. */ + if (!gts) { + STAT(intr_spurious); + continue; + } + /* * This is running in interrupt context. Trylock the mmap_sem. * If it fails, retry the fault in user context. @@ -573,7 +583,7 @@ static irqreturn_t gru_intr(int chiplet, int blade) if (!gts->ts_force_cch_reload && down_read_trylock(>s->ts_mm->mmap_sem)) { gts->ustats.fmm_tlbdropin++; - gru_try_dropin(gts, tfh, NULL); + gru_try_dropin(gru, gts, tfh, NULL); up_read(>s->ts_mm->mmap_sem); } else { tfh_user_polling_mode(tfh); @@ -619,7 +629,7 @@ static int gru_user_dropin(struct gru_thread_state *gts, wait_event(gms->ms_wait_queue, atomic_read(&gms->ms_range_active) == 0); prefetchw(tfh); /* Helps on hdw, required for emulator */ - ret = gru_try_dropin(gts, tfh, cb); + ret = gru_try_dropin(gts->ts_gru, gts, tfh, cb); if (ret <= 0) return ret; STAT(call_os_wait_queue); diff --git a/drivers/misc/sgi-gru/gruprocfs.c b/drivers/misc/sgi-gru/gruprocfs.c index 54a5a1c35ad..7768b87d995 100644 --- a/drivers/misc/sgi-gru/gruprocfs.c +++ b/drivers/misc/sgi-gru/gruprocfs.c @@ -66,6 +66,7 @@ static int statistics_show(struct seq_file *s, void *p) printstat(s, intr); printstat(s, intr_cbr); printstat(s, intr_tfh); + printstat(s, intr_spurious); printstat(s, intr_mm_lock_failed); printstat(s, call_os); printstat(s, call_os_wait_queue); diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h index adaf691d59f..54c3bb171ee 100644 --- a/drivers/misc/sgi-gru/grutables.h +++ b/drivers/misc/sgi-gru/grutables.h @@ -192,6 +192,7 @@ struct gru_stats_s { atomic_long_t intr; atomic_long_t intr_cbr; atomic_long_t intr_tfh; + atomic_long_t intr_spurious; atomic_long_t intr_mm_lock_failed; atomic_long_t call_os; atomic_long_t call_os_wait_queue; -- cgit v1.2.3-18-g5258