From: Minfei Huang <mnfhuang@gmail.com>
To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com
Cc: x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] mm: Avoid overlap the fixmap area on i386
Date: Thu, 23 Oct 2014 23:36:17 +0800 [thread overview]
Message-ID: <6B680A9E-6CE9-4C96-934B-CB01DCB58278@gmail.com> (raw)
From: Minfei Huang <mnfhuang@gmail.com>
It is a problem when configuring high memory off where the vmalloc
reserve area could end up overlapping the early_ioremap fixmap
area on i386.
The ordering of the VMALLOC_RESERVE space is:
FIXADDR_TOP
fixed_addresses
FIXADDR_START
early_ioremap fixed addresses
FIXADDR_BOOT_START
Persistent kmap area
PKMAP_BASE
VMALLOC_END
Vmalloc area
VMALLOC_START
high_memory
The available address we can use is lower than FIXADDR_BOOT_START. So
We will set the kmap boundary below the FIXADDR_BOOT_START, if configure
the high memory.
If we configure the high memory, the vmalloc reserve area should end
up to PKMAP_BASE, otherwise should end up to FIXADDR_BOOT_START.
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
---
arch/x86/include/asm/pgtable_32_types.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h
index ed5903b..2ac5fc8 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -43,7 +43,7 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */
#ifdef CONFIG_HIGHMEM
# define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE)
#else
-# define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE)
+# define VMALLOC_END (FIXADDR_BOOT_START - 2 * PAGE_SIZE)
#endif
#define MODULES_VADDR VMALLOC_START
--
1.8.3.1
next reply other threads:[~2014-10-23 15:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-23 15:36 Minfei Huang [this message]
2014-10-28 11:06 ` Thomas Gleixner
2014-10-28 17:24 ` H. Peter Anvin
2014-10-28 17:29 ` Thomas Gleixner
2014-10-29 3:14 ` H. Peter Anvin
2014-10-29 4:30 ` Minfei Huang
2014-10-28 11:24 ` [tip:x86/mm] x86/mm: " tip-bot for Minfei Huang
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