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From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
	yinghai@kernel.org, LKML <linux-kernel@vger.kernel.org>,
	x86@kernel.org
Subject: [PATCH] x86: fix system die when load with "reservetop" parameter
Date: Thu, 20 Aug 2009 20:23:11 +0800	[thread overview]
Message-ID: <4A8D402F.4080805@cn.fujitsu.com> (raw)

The system will die if the kernel is booted with "reservetop" parameter,
in present code, parse "reservetop" parameter after early_ioremap_init(),
and some function still use early_ioremap() after it.

The problem is, "reservetop" parameter can modify 'FIXADDR_TOP', then the
virtual address got by early_ioremap() is base on old 'FIXADDR_TOP', but
the page mapping is base on new 'FIXADDR_TOP', it will occur page fault,
and the IDT is not prepare yet, so, the system is dead.

So, put parse_early_param() in the front of early_ioremap_init() in this
patch.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
 arch/x86/kernel/setup.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 26fce55..aad6149 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -713,6 +713,11 @@ void __init setup_arch(char **cmdline_p)
 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
 #endif
 
+	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
+	*cmdline_p = command_line;
+
+	parse_early_param();
+
 	/* VMI may relocate the fixmap; do this before touching ioremap area */
 	vmi_init();
 
@@ -795,11 +800,6 @@ void __init setup_arch(char **cmdline_p)
 #endif
 #endif
 
-	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
-	*cmdline_p = command_line;
-
-	parse_early_param();
-
 #ifdef CONFIG_X86_64
 	check_efer();
 #endif
-- 
1.6.1.2



             reply	other threads:[~2009-08-20 12:23 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-20 12:23 Xiao Guangrong [this message]
2009-08-21 13:35 ` [PATCH] x86: fix system die when load with "reservetop" parameter Ingo Molnar
2009-08-24  1:21   ` Xiao Guangrong
2009-08-21 14:43 ` [tip:x86/urgent] x86: Fix system crash when loading " tip-bot for Xiao Guangrong

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