[PATCH rcu 2/4] scftorture: Forgive memory-allocation failure if KASAN

From: Paul E. McKenney
Date: Mon Jul 17 2023 - 14:18:44 EST


Kernels built with CONFIG_KASAN=y quarantine newly freed memory in order
to better detect use-after-free errors. However, this can exhaust memory
more quickly in allocator-heavy tests, which can result in spurious
scftorture failure. This commit therefore forgives memory-allocation
failure in kernels built with CONFIG_KASAN=y, but continues counting
the errors for use in detailed test-result analyses.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/scftorture.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 5d113aa59e77..83c33ba0ca7e 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -171,7 +171,8 @@ static void scf_torture_stats_print(void)
scfs.n_all_wait += scf_stats_p[i].n_all_wait;
}
if (atomic_read(&n_errs) || atomic_read(&n_mb_in_errs) ||
- atomic_read(&n_mb_out_errs) || atomic_read(&n_alloc_errs))
+ atomic_read(&n_mb_out_errs) ||
+ (!IS_ENABLED(CONFIG_KASAN) && atomic_read(&n_alloc_errs)))
bangstr = "!!! ";
pr_alert("%s %sscf_invoked_count %s: %lld resched: %lld single: %lld/%lld single_ofl: %lld/%lld single_rpc: %lld single_rpc_ofl: %lld many: %lld/%lld all: %lld/%lld ",
SCFTORT_FLAG, bangstr, isdone ? "VER" : "ver", invoked_count, scfs.n_resched,
@@ -323,7 +324,8 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
preempt_disable();
if (scfsp->scfs_prim == SCF_PRIM_SINGLE || scfsp->scfs_wait) {
scfcp = kmalloc(sizeof(*scfcp), GFP_ATOMIC);
- if (WARN_ON_ONCE(!scfcp)) {
+ if (!scfcp) {
+ WARN_ON_ONCE(!IS_ENABLED(CONFIG_KASAN));
atomic_inc(&n_alloc_errs);
} else {
scfcp->scfc_cpu = -1;
--
2.40.1