linux-kernel - [PATCH hyperv-next v4 09/16] Drivers: hv: Check message and event pages for non-NULL before iounmap()

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Message-ID: <20250714221545.5615-10-romank@linux.microsoft.com>
Date: Mon, 14 Jul 2025 15:15:38 -0700
From: Roman Kisel <romank@...ux.microsoft.com>
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Subject: [PATCH hyperv-next v4 09/16] Drivers: hv: Check message and event pages for non-NULL before iounmap()

It might happen that some hyp SynIC pages aren't allocated.

Check for that and only then call iounmap().

Signed-off-by: Roman Kisel <romank@...ux.microsoft.com>
---
 drivers/hv/hv.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 820711e954d1..a8669843c56e 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -367,8 +367,10 @@ void hv_synic_disable_regs(unsigned int cpu)
 	 */
 	simp.simp_enabled = 0;
 	if (ms_hyperv.paravisor_present || hv_root_partition()) {
-		iounmap(hv_cpu->hyp_synic_message_page);
-		hv_cpu->hyp_synic_message_page = NULL;
+		if (hv_cpu->hyp_synic_message_page) {
+			iounmap(hv_cpu->hyp_synic_message_page);
+			hv_cpu->hyp_synic_message_page = NULL;
+		}
 	} else {
 		simp.base_simp_gpa = 0;
 	}
@@ -379,8 +381,10 @@ void hv_synic_disable_regs(unsigned int cpu)
 	siefp.siefp_enabled = 0;
 
 	if (ms_hyperv.paravisor_present || hv_root_partition()) {
-		iounmap(hv_cpu->hyp_synic_event_page);
-		hv_cpu->hyp_synic_event_page = NULL;
+		if (hv_cpu->hyp_synic_event_page) {
+			iounmap(hv_cpu->hyp_synic_event_page);
+			hv_cpu->hyp_synic_event_page = NULL;
+		}
 	} else {
 		siefp.base_siefp_gpa = 0;
 	}
-- 
2.43.0