linux-kernel - [PATCH v2] sparc32: Limit memblock allocation to low memory

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>] [day] [month] [year] [list]

Message-Id: <20210205132031.25407-1-andreas@gaisler.com>
Date:   Fri,  5 Feb 2021 14:20:31 +0100
From:   Andreas Larsson <andreas@...sler.com>
To:     David Miller <davem@...emloft.net>, sparclinux@...r.kernel.org
Cc:     Mike Rapoport <rppt@...ux.ibm.com>,
        Sam Ravnborg <sam@...nborg.org>, linux-kernel@...r.kernel.org,
        software@...sler.com
Subject: [PATCH v2] sparc32: Limit memblock allocation to low memory

Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 changed sparc32 to use
memblocks instead of bootmem, but also made high memory available via
memblock allocation which does not work together with e.g. phys_to_virt
and can lead to kernel panic.

This changes back to only low memory being allocatable in the early
stages, now using memblock allocation.

Signed-off-by: Andreas Larsson <andreas@...sler.com>
Acked-by: Mike Rapoport <rppt@...ux.ibm.com>
---
Changes, in commit message, since v1:
- Added a missing "not" in "does not work"
- Clarified crash to kernel panic.
- Added Acked-by

arch/sparc/mm/init_32.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index eb2946b1df8a..6139c5700ccc 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -197,6 +197,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
 	size = memblock_phys_mem_size() - memblock_reserved_size();
 	*pages_avail = (size >> PAGE_SHIFT) - high_pages;
 
+	/* Only allow low memory to be allocated via memblock allocation */
+	memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
+
 	return max_pfn;
 }
 
-- 
2.17.1