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From: Yinghai Lu <yinghai@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	"H. Peter Anvin" <hpa@zytor.com>, Jacob Shin <jacob.shin@amd.com>,
	Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 6/8] x86: if kernel .text .data .bss are not marked as E820_RAM, complain and fix
Date: Thu, 30 Aug 2012 16:06:13 -0700	[thread overview]
Message-ID: <1346367975-6446-7-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1346367975-6446-1-git-send-email-yinghai@kernel.org>

From: Jacob Shin <jacob.shin@amd.com>

There could be cases where user supplied memmap=exactmap memory
mappings do not mark the region where the kernel .text .data and
.bss reside as E820_RAM, as reported here:

https://lkml.org/lkml/2012/8/14/86

Handle it by complaining, and adding the range back into the e820.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
---
 arch/x86/kernel/setup.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c30c78c..587dcd9 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -831,6 +831,20 @@ void __init setup_arch(char **cmdline_p)
 	insert_resource(&iomem_resource, &data_resource);
 	insert_resource(&iomem_resource, &bss_resource);
 
+	/*
+	 * Complain if .text .data and .bss are not marked as E820_RAM and
+	 * attempt to fix it by adding the range. We may have a confused BIOS,
+	 * or the user may have incorrectly supplied it via memmap=exactmap. If
+	 * we really are running on top non-RAM, we will crash later anyways.
+	 */
+	if (!e820_all_mapped(code_resource.start, __pa(__brk_limit), E820_RAM)) {
+		pr_warn(".text .data .bss are not marked as E820_RAM!\n");
+
+		e820_add_region(code_resource.start,
+				__pa(__brk_limit) - code_resource.start + 1,
+				E820_RAM);
+	}
+
 	trim_bios_range();
 #ifdef CONFIG_X86_32
 	if (ppro_with_ram_bug()) {
-- 
1.7.7


  parent reply	other threads:[~2012-08-30 23:07 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-29 19:04 [PATCH V5 0/6] x86: Create direct mappings for E820_RAM only Jacob Shin
2012-08-29 19:04 ` [PATCH 1/6] x86, mm: Add page_size_mask() Jacob Shin
2012-08-29 19:04 ` [PATCH 2/6] x86, mm: Split out split_mem_range Jacob Shin
2012-08-29 19:04 ` [PATCH 3/6] x86/mm: find_early_table_space based on memory ranges that are being mapped Jacob Shin
2012-08-29 19:04 ` [PATCH 4/6] x86: Only direct map addresses that are marked as E820_RAM Jacob Shin
2012-08-29 21:17   ` Yinghai Lu
2012-08-29 21:32     ` Borislav Petkov
2012-08-30  6:28       ` H. Peter Anvin
2012-08-30 23:06         ` [PATCH 0/8] x86, mm: init_memory_mapping cleanup Yinghai Lu
2012-08-30 23:06           ` [PATCH 1/8] x86, mm: Add global page_size_mask Yinghai Lu
2012-08-30 23:06           ` [PATCH 2/8] x86, mm: Split out split_mem_range Yinghai Lu
2012-08-30 23:06           ` [PATCH 3/8] x86, mm: Moving init_memory_mapping calling Yinghai Lu
2012-08-30 23:06           ` [PATCH 4/8] x86, mm: Revert back good_end setting for 64bit Yinghai Lu
2012-08-30 23:06           ` [PATCH 5/8] x86, mm: Find early page table only one time Yinghai Lu
2012-08-30 23:06           ` Yinghai Lu [this message]
2012-08-30 23:06           ` [PATCH 7/8] x86: Fixup code testing if a pfn is direct mapped Yinghai Lu
2012-08-30 23:06           ` [PATCH 8/8] x86: Only direct map addresses that are marked as E820_RAM Yinghai Lu
2012-08-30 23:14           ` [PATCH 0/8] x86, mm: init_memory_mapping cleanup Yinghai Lu
2012-08-30 23:22           ` Jacob Shin
2012-08-29 21:46     ` [PATCH 4/6] x86: Only direct map addresses that are marked as E820_RAM Jacob Shin
2012-08-29 19:04 ` [PATCH 5/6] x86: Fixup code testing if a pfn is direct mapped Jacob Shin
2012-08-29 21:02   ` Yinghai Lu
2012-08-29 19:04 ` [PATCH 6/6] x86: if kernel .text .data .bss are not marked as E820_RAM, complain and fix Jacob Shin

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