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 <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 9470303..ada7df7 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -96,7 +96,7 @@
vma = gru_find_vma(vaddr);
if (vma)
gts = gru_alloc_thread_state(vma, TSID(vaddr, vma));
- if (gts) {
+ if (!IS_ERR(gts)) {
mutex_lock(>s->ts_ctxlock);
downgrade_write(&mm->mmap_sem);
} else {
@@ -747,8 +747,8 @@
gru_dbg(grudev, "op %d, gseg 0x%lx, value1 0x%lx\n", req.op, req.gseg, req.val1);
gts = gru_alloc_locked_gts(req.gseg);
- if (!gts)
- return -EINVAL;
+ if (IS_ERR(gts))
+ return PTR_ERR(gts);
switch (req.op) {
case sco_blade_chiplet:
diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c
index 9ec54bd..9440288 100644
--- a/drivers/misc/sgi-gru/grumain.c
+++ b/drivers/misc/sgi-gru/grumain.c
@@ -27,6 +27,7 @@
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/list.h>
+#include <linux/err.h>
#include <asm/uv/uv_hub.h>
#include "gru.h"
#include "grutables.h"
@@ -286,7 +287,8 @@
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 @@
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 @@
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 @@
err:
gts_drop(gts);
- return NULL;
+ return ERR_CAST(gms);
}
/*
@@ -396,8 +400,8 @@
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);
diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index 1d12509..421c548 100644
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -299,6 +299,7 @@
{
struct gru_mm_struct *gms;
struct mmu_notifier *mn;
+ int err;
mn = mmu_find_ops(current->mm, &gru_mmuops);
if (mn) {
@@ -311,12 +312,17 @@
gms->ms_notifier.ops = &gru_mmuops;
atomic_set(&gms->ms_refcnt, 1);
init_waitqueue_head(&gms->ms_wait_queue);
- __mmu_notifier_register(&gms->ms_notifier, current->mm);
+ err = __mmu_notifier_register(&gms->ms_notifier, current->mm);
+ if (err)
+ goto error;
}
}
gru_dbg(grudev, "gms %p, refcnt %d\n", gms,
atomic_read(&gms->ms_refcnt));
return gms;
+error:
+ kfree(gms);
+ return ERR_PTR(err);
}
void gru_drop_mmu_notifier(struct gru_mm_struct *gms)