From: Marc Zyngier <marc.zyngier@arm.com>
Date: Tue, 29 Jan 2019 15:19:23 +0000 (+0000)
Subject: irqchip/gic-v3-its: Gracefully fail on LPI exhaustion
X-Git-Tag: v4.20.16~72
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=61d0518dd102d99948b3552c48f0bca88e2d6276;p=thirdparty%2Fkernel%2Fstable.git

irqchip/gic-v3-its: Gracefully fail on LPI exhaustion

[ Upstream commit 45725e0fc3e7fe52fedb94f59806ec50e9618682 ]

In the unlikely event that we cannot find any available LPI in the
system, we should gracefully return an error instead of carrying
on with no LPI allocated at all.

Fixes: 38dd7c494cf6 ("irqchip/gic-v3-its: Drop chunk allocation compatibility")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index f25ec92f23ee2..c3aba3fc818d3 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1586,6 +1586,9 @@ static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
 		nr_irqs /= 2;
 	} while (nr_irqs > 0);
 
+	if (!nr_irqs)
+		err = -ENOSPC;
+
 	if (err)
 		goto out;