From 7f2251b1bcdd3d2971b2fde3008b270ea11b8780 Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Tue, 15 Dec 2009 16:48:08 -0800 Subject: gru: handle failures to mmu_notifier_register Under some conditions, mmu_notifier_register() will fail to register a mmu_notifier. Fix the GRU driver to correctly handle these failures. Signed-off-by: Jack Steiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/misc/sgi-gru/grumain.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) (limited to 'drivers/misc/sgi-gru/grumain.c') diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index 9ec54bde4472..944028871884 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include "gru.h" #include "grutables.h" @@ -286,7 +287,8 @@ static void gru_unload_mm_tracker(struct gru_state *gru, void gts_drop(struct gru_thread_state *gts) { if (gts && atomic_dec_return(>s->ts_refcnt) == 0) { - gru_drop_mmu_notifier(gts->ts_gms); + if (gts->ts_gms) + gru_drop_mmu_notifier(gts->ts_gms); kfree(gts); STAT(gts_free); } @@ -313,13 +315,14 @@ struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma, int cbr_au_count, int dsr_au_count, int options, int tsid) { struct gru_thread_state *gts; + struct gru_mm_struct *gms; int bytes; bytes = DSR_BYTES(dsr_au_count) + CBR_BYTES(cbr_au_count); bytes += sizeof(struct gru_thread_state); gts = kmalloc(bytes, GFP_KERNEL); if (!gts) - return NULL; + return ERR_PTR(-ENOMEM); STAT(gts_alloc); memset(gts, 0, sizeof(struct gru_thread_state)); /* zero out header */ @@ -338,9 +341,10 @@ struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma, if (vma) { gts->ts_mm = current->mm; gts->ts_vma = vma; - gts->ts_gms = gru_register_mmu_notifier(); - if (!gts->ts_gms) + gms = gru_register_mmu_notifier(); + if (IS_ERR(gms)) goto err; + gts->ts_gms = gms; } gru_dbg(grudev, "alloc gts %p\n", gts); @@ -348,7 +352,7 @@ struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma, err: gts_drop(gts); - return NULL; + return ERR_CAST(gms); } /* @@ -396,8 +400,8 @@ struct gru_thread_state *gru_alloc_thread_state(struct vm_area_struct *vma, gts = gru_alloc_gts(vma, vdata->vd_cbr_au_count, vdata->vd_dsr_au_count, vdata->vd_user_options, tsid); - if (!gts) - return NULL; + if (IS_ERR(gts)) + return gts; spin_lock(&vdata->vd_lock); ngts = gru_find_current_gts_nolock(vdata, tsid); -- cgit v1.2.3