[PATCH] x86: fix system die when load with "reservetop" parameter

From: Xiao Guangrong
Date: Thu Aug 20 2009 - 08:23:48 EST


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@xxxxxxxxxxxxxx>
---
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


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