linux-kernel - [PATCH char-misc 1/1] Drivers: hv: vmbus: Cleanup synic memory free path

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Message-Id: <1533163513-10764-1-git-send-email-mikelley@microsoft.com>
Date:   Wed,  1 Aug 2018 15:45:13 -0700
From:   mhkelley58@...il.com
To:     gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
        devel@...uxdriverproject.org, olaf@...fle.de, apw@...onical.com,
        vkuznets@...hat.com, jasowang@...hat.com,
        marcelo.cerri@...onical.com, sthemmin@...rosoft.com,
        kys@...rosoft.com
Cc:     mikelley@...rosoft.com
Subject: [PATCH char-misc 1/1] Drivers: hv: vmbus: Cleanup synic memory free path

From: Michael Kelley <mikelley@...rosoft.com>

clk_evt memory is not being freed when the synic is shutdown
or when there is an allocation error.  Add the appropriate
kfree() call, along with a comment to clarify how the memory
gets freed after an allocation error.  Make the free path
consistent by removing checks for NULL since kfree() and
free_page() already do the check.

Signed-off-by: Michael Kelley <mikelley@...rosoft.com>
Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
---
 drivers/hv/hv.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 8d4fe0e..1fb9a6b 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -240,6 +240,10 @@ int hv_synic_alloc(void)
 
 	return 0;
 err:
+	/*
+	 * Any memory allocations that succeeded will be freed when
+	 * the caller cleans up by calling hv_synic_free()
+	 */
 	return -ENOMEM;
 }
 
@@ -252,12 +256,10 @@ void hv_synic_free(void)
 		struct hv_per_cpu_context *hv_cpu
 			= per_cpu_ptr(hv_context.cpu_context, cpu);
 
-		if (hv_cpu->synic_event_page)
-			free_page((unsigned long)hv_cpu->synic_event_page);
-		if (hv_cpu->synic_message_page)
-			free_page((unsigned long)hv_cpu->synic_message_page);
-		if (hv_cpu->post_msg_page)
-			free_page((unsigned long)hv_cpu->post_msg_page);
+		kfree(hv_cpu->clk_evt);
+		free_page((unsigned long)hv_cpu->synic_event_page);
+		free_page((unsigned long)hv_cpu->synic_message_page);
+		free_page((unsigned long)hv_cpu->post_msg_page);
 	}
 
 	kfree(hv_context.hv_numa_map);
-- 
1.8.3.1