linux-kernel - [PATCH] arm64: mm: update max

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 28 Sep 2021 11:51:49 -0700
From:   Chris Goldsworthy <quic_cgoldswo@...cinc.com>
To:     Andrew Morton <akpm@...ux-foundation.org>
CC:     David Hildenbrand <david@...hat.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        "Sudarshan Rajagopalan" <quic_sudaraja@...cinc.com>,
        Georgi Djakov <quic_c_gdjako@...cinc.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org>,
        Chris Goldsworthy <quic_cgoldswo@...cinc.com>,
        Florian Fainelli <f.fainelli@...il.com>
Subject: [PATCH] arm64: mm: update max_pfn after memory hotplug

From: Sudarshan Rajagopalan <quic_sudaraja@...cinc.com>

After new memory blocks have been hotplugged, max_pfn and max_low_pfn
needs updating to reflect on new PFNs being hot added to system.
Without this patch, debug-related functions that use max_pfn such as
get_max_dump_pfn() or read_page_owner() will not work with any page in
memory that is hot-added after boot. 

Fixes: 4ab215061554 ("arm64: Add memory hotplug support")
Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@...cinc.com>
Signed-off-by: Chris Goldsworthy <quic_cgoldswo@...cinc.com>
Acked-by: David Hildenbrand <david@...hat.com>
Cc: Florian Fainelli <f.fainelli@...il.com>
Cc: Georgi Djakov <quic_c_gdjako@...cinc.com>
---
 arch/arm64/mm/mmu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index cfd9deb..fd85b51 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
 	if (ret)
 		__remove_pgd_mapping(swapper_pg_dir,
 				     __phys_to_virt(start), size);
+	else {
+		max_pfn = PFN_UP(start + size);
+		max_low_pfn = max_pfn;
+	}
+
 	return ret;
 }
 
-- 
2.7.4