Commit 65e53f86 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Peter Zijlstra
Browse files

sched/isolation: Fix housekeeping_mask memory leak 



If "nohz_full=" or "isolcpus=nohz" are called with CONFIG_NO_HZ_FULL=n,
housekeeping_mask doesn't get freed despite it being unused if
housekeeping_setup() is called for the first time.

Check this scenario first to fix this, so that no useless allocation
is performed.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJuri Lelli <juri.lelli@redhat.com>
Reviewed-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarPhil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-8-frederic@kernel.org
parent 0cd3e59d

kernel/sched/isolation.c

+10 −9
Original line number Diff line number Diff line
@@ -94,6 +94,14 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) 
	cpumask_var_t non_housekeeping_mask, housekeeping_staging;

	int err = 0;



	if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {

		if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) {

			pr_warn("Housekeeping: nohz unsupported."

				" Build with CONFIG_NO_HZ_FULL\n");

			return 0;

		}

	}



	alloc_bootmem_cpumask_var(&non_housekeeping_mask);

	if (cpulist_parse(str, non_housekeeping_mask) < 0) {

		pr_warn("Housekeeping: nohz_full= or isolcpus= incorrect CPU range\n");
@@ -123,15 +131,8 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) 
		}

	}



	if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) {

		if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {

	if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK))

		tick_nohz_full_setup(non_housekeeping_mask);

		} else {

			pr_warn("Housekeeping: nohz unsupported."

				" Build with CONFIG_NO_HZ_FULL\n");

			goto free_housekeeping_staging;

		}

	}



	housekeeping_flags |= flags;

	err = 1;