From: Nathan Fontenot <nfont@austin.ibm.com>
Date: Mon, 13 Oct 2008 08:42:00 +0000 (+0000)
Subject: powerpc/pseries: Validate PFN in pseries_remove_lmb()
X-Git-Tag: firefly_0821_release~17166^2~26
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=04badfd2936333a23e0fc233f31a760d0dc9424f;p=firefly-linux-kernel-4.4.55.git

powerpc/pseries: Validate PFN in pseries_remove_lmb()

The pfn of the memory to be removed should be validated prior to
attempting to remove the memory.  In cases where the probe of a
memory section fails during hotplug add, the pfn for the lmb may
not be valid.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 140d02a5232a..a623ad256e9e 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -22,6 +22,12 @@ static int pseries_remove_lmb(unsigned long base, unsigned int lmb_size)
 	int ret;
 
 	start_pfn = base >> PAGE_SHIFT;
+
+	if (!pfn_valid(start_pfn)) {
+		lmb_remove(base, lmb_size);
+		return 0;
+	}
+
 	zone = page_zone(pfn_to_page(start_pfn));
 
 	/*