linux-kernel - [PATCH] ARM: mm: Fix the memblock allocation for LPAE machines

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-next>] [day] [month] [year] [list]

Message-ID: <1391285687-20534-1-git-send-email-santosh.shilimkar@ti.com>
Date:	Sat, 1 Feb 2014 15:14:47 -0500
From:	Santosh Shilimkar <santosh.shilimkar@...com>
To:	<linux-arm-kernel@...ts.infradead.org>
CC:	<linux-kernel@...r.kernel.org>,
	Santosh Shilimkar <santosh.shilimkar@...com>,
	Yinghai Lu <yinghai@...nel.org>,
	Russell King <linux@....linux.org.uk>,
	"Strashko, Grygorii" <grygorii.strashko@...com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] ARM: mm: Fix the memblock allocation for LPAE machines

Commit ad6492b8 added much needed memblock_virt_alloc_low() and further
commit 07bacb3 {memblock, bootmem: restore goal for alloc_low} fixed the
issue with low memory limit thansk to Yinghai. But even after all these fixes,
there is still one case where the limit check done with ARCH_LOW_ADDRESS_LIMIT
for low memory fails. Russell pointed out the issue with 32 bit LPAE machines
in below thread.
	https://lkml.org/lkml/2014/1/28/364

Since on some LPAE machines where memory start address is beyond 4GB,
the low memory marker in memblock will be set to default
ARCH_LOW_ADDRESS_LIMIT which is wrong. We can fix this by letting
architectures set the ARCH_LOW_ADDRESS_LIMIT using another export
similar to memblock_set_current_limit() but am not sure whether
its worth the trouble. Tell me if you think otherwise.

Rather am just trying to fix that one broken case using memblock_virt_alloc()
in setup code since the memblock.current_limit is updated appropriately
makes it work on all ARM 32 bit machines.

Cc: Yinghai Lu <yinghai@...nel.org>
Cc: Russell King <linux@....linux.org.uk>
Cc: Strashko, Grygorii <grygorii.strashko@...com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@...com>
---
 arch/arm/kernel/setup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index b0df976..1e8b030 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -731,7 +731,7 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
 	kernel_data.end     = virt_to_phys(_end - 1);
 
 	for_each_memblock(memory, region) {
-		res = memblock_virt_alloc_low(sizeof(*res), 0);
+		res = memblock_virt_alloc(sizeof(*res), 0);
 		res->name  = "System RAM";
 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/