From e02b6f344dd9cc4fe33100332649d6f4fe248fc9 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Wed, 30 Jun 2021 21:02:39 +0800
Subject: [PATCH] ACPI: GTDT: Don't corrupt interrupt mappings on watchdow
 probe failure

stable inclusion
from linux-4.19.191
commit 7b2162db1498c71962a4bb2f776fa4e76d4d305b

--------------------------------

commit 1ecd5b129252249b9bc03d7645a7bda512747277 upstream.

When failing the driver probe because of invalid firmware properties,
the GTDT driver unmaps the interrupt that it mapped earlier.

However, it never checks whether the mapping of the interrupt actially
succeeded. Even more, should the firmware report an illegal interrupt
number that overlaps with the GIC SGI range, this can result in an
IPI being unmapped, and subsequent fireworks (as reported by Dann
Frazier).

Rework the driver to have a slightly saner behaviour and actually
check whether the interrupt has been mapped before unmapping things.

Reported-by: dann frazier <dann.frazier@canonical.com>
Fixes: ca9ae5ec4ef0 ("acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/YH87dtTfwYgavusz@xps13.dannf
Cc: <stable@vger.kernel.org>
Cc: Fu Wei <wefu@redhat.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20210421164317.1718831-2-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/acpi/arm64/gtdt.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
index 92f9edf9d11e..c39b36c558d6 100644
--- a/drivers/acpi/arm64/gtdt.c
+++ b/drivers/acpi/arm64/gtdt.c
@@ -332,7 +332,7 @@ static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
 					int index)
 {
 	struct platform_device *pdev;
-	int irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);
+	int irq;
 
 	/*
 	 * According to SBSA specification the size of refresh and control
@@ -341,7 +341,7 @@ static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
 	struct resource res[] = {
 		DEFINE_RES_MEM(wd->control_frame_address, SZ_4K),
 		DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K),
-		DEFINE_RES_IRQ(irq),
+		{},
 	};
 	int nr_res = ARRAY_SIZE(res);
 
@@ -351,10 +351,11 @@ static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
 
 	if (!(wd->refresh_frame_address && wd->control_frame_address)) {
 		pr_err(FW_BUG "failed to get the Watchdog base address.\n");
-		acpi_unregister_gsi(wd->timer_interrupt);
 		return -EINVAL;
 	}
 
+	irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);
+	res[2] = (struct resource)DEFINE_RES_IRQ(irq);
 	if (irq <= 0) {
 		pr_warn("failed to map the Watchdog interrupt.\n");
 		nr_res--;
@@ -367,7 +368,8 @@ static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
 	 */
 	pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res);
 	if (IS_ERR(pdev)) {
-		acpi_unregister_gsi(wd->timer_interrupt);
+		if (irq > 0)
+			acpi_unregister_gsi(wd->timer_interrupt);
 		return PTR_ERR(pdev);
 	}
 
-- 
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