From f156ffc439951b63cfa9f4d999a8d54267f13282 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Date: Tue, 8 May 2012 21:22:30 +0300 Subject: [PATCH] x86, realmode: Set permission for real mode pages Set proper permissions for rodata, text and data, removing the realmode trampoline area as a remaining RWX memory mapping in the kernel. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-8-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> --- arch/x86/kernel/realmode.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/realmode.c b/arch/x86/kernel/realmode.c index a465775b32f2..d85ac20bb4eb 100644 --- a/arch/x86/kernel/realmode.c +++ b/arch/x86/kernel/realmode.c @@ -86,7 +86,21 @@ static int __init set_real_mode_permissions(void) PAGE_ALIGN(real_mode_header.end) - __pa(real_mode_base); - set_memory_x((unsigned long) real_mode_base, all_size >> PAGE_SHIFT); + size_t ro_size = + PAGE_ALIGN(real_mode_header.ro_end) - + __pa(real_mode_base); + + size_t text_size = + PAGE_ALIGN(real_mode_header.ro_end) - + real_mode_header.text_start; + + unsigned long text_start = + (unsigned long) __va(real_mode_header.text_start); + + set_memory_nx((unsigned long) real_mode_base, all_size >> PAGE_SHIFT); + set_memory_ro((unsigned long) real_mode_base, ro_size >> PAGE_SHIFT); + set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT); + return 0; }