The patch titled
gru: fix GRU interrupt race at deallocate
has been added to the -mm tree. Its filename is
gru-fix-gru-interrupt-race-at-deallocate.patch
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------------------------------------------------------
Subject: gru: fix GRU interrupt race at deallocate
From: Jack Steiner <steiner@xxxxxxx>
Fix a race where an interrupt could be received for a GRU context that has
been deallocated.
Signed-off-by: Jack Steiner <steiner@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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(-)
diff -puN drivers/misc/sgi-gru/grufault.c~gru-fix-gru-interrupt-race-at-deallocate drivers/misc/sgi-gru/grufault.c
--- a/drivers/misc/sgi-gru/grufault.c~gru-fix-gru-interrupt-race-at-deallocate
+++ a/drivers/misc/sgi-gru/grufault.c
@@ -360,7 +360,8 @@ static void gru_preload_tlb(struct gru_s
* < 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_thr
}
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_thr
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,
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,
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,
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,
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_th
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 -puN drivers/misc/sgi-gru/gruprocfs.c~gru-fix-gru-interrupt-race-at-deallocate drivers/misc/sgi-gru/gruprocfs.c
--- a/drivers/misc/sgi-gru/gruprocfs.c~gru-fix-gru-interrupt-race-at-deallocate
+++ a/drivers/misc/sgi-gru/gruprocfs.c
@@ -66,6 +66,7 @@ static int statistics_show(struct seq_fi
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 -puN drivers/misc/sgi-gru/grutables.h~gru-fix-gru-interrupt-race-at-deallocate drivers/misc/sgi-gru/grutables.h
--- a/drivers/misc/sgi-gru/grutables.h~gru-fix-gru-interrupt-race-at-deallocate
+++ a/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;
_
Patches currently in -mm which might be from steiner@xxxxxxx are
linux-next.patch
x86-uv-introduce-a-means-to-translate-from-gpa-socket_paddr.patch
x86-uv-xpc-needs-to-provide-an-abstraction-for-uv_gpa.patch
x86-uv-introduce-uv_gpa_is_mmr.patch
x86-uv-implement-a-gru_read_gpa-kernel-function.patch
x86-uv-update-xpc-to-handle-updated-bios-interface.patch
x86-uv-xpc-null-deref-when-mesq-becomes-empty.patch
x86-uv-xpc_make_first_contact-hang-due-to-not-accepting-active-state.patch
x86-uv-xpc-receive-message-reuse-triggers-invalid-bug_on.patch
gru-initial-gru-based-on-blade-topology.patch
gru-add-comments-raised-in-previous-code-reviews.patch
gru-fix-istatus-race-in-gru-tlb-dropin.patch
gru-handle-blades-without-memory.patch
gru-allow-users-to-specify-gru-chiplet-1.patch
gru-allow-users-to-specify-gru-chiplet-2.patch
gru-allow-users-to-specify-gru-chiplet-3.patch
gru-fix-bug-in-module-unload.patch
gru-improve-messages-for-malfunctioning-grus.patch
gru-support-64-bit-gru-addresses.patch
gru-handle-failures-to-mmu_notifier_register.patch
gru-add-debug-option-for-cache-flushing.patch
gru-add-test-for-gru_copy_gpa.patch
gru-check-for-valid-vma.patch
gru-fix-prefetch-and-speculation-bugs.patch
gru-update-irq-infrastructure.patch
gru-add-additional-gru-statistics.patch
gru-expicitly-set-instruction-status-to-active.patch
gru-preload-tlb-for-bcopy-instructions.patch
gru-fix-bug-in-exception-handling.patch
gru-add-symbolic-names-for-gru-error-code.patch
gru-remove-stray-local_irq_enable.patch
gru-check-for-correct-gru-chiplet-assignment.patch
gru-update-gru-structures-to-match-latest-hardware-spec.patch
gru-fix-bug-in-allocation-of-kernel-contexts.patch
gru-add-hugepage-support.patch
gru-fix-gru-interrupt-race-at-deallocate.patch
gru-improve-gru-tlb-dropin-statistics.patch
gru-update-driver-version-number.patch
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