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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 <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jack Steiner 2009-12-15 16:48:18 -08:00 committed by Linus Torvalds
parent 74ccd09526
commit 2ce4d4c937
3 changed files with 19 additions and 7 deletions
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24
drivers/misc/sgi-gru/grufault.c
View File

@ -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(&gts->ts_mm->mmap_sem)) {
gts->ustats.fmm_tlbdropin++;
gru_try_dropin(gts, tfh, NULL);
gru_try_dropin(gru, gts, tfh, NULL);
up_read(&gts->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);

1
drivers/misc/sgi-gru/gruprocfs.c
View File

@ -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);

1
drivers/misc/sgi-gru/grutables.h
View File

@ -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;