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authorH. Peter Anvin <hpa@zytor.com>2014-05-04 19:36:22 +0200
committerH. Peter Anvin <hpa@zytor.com>2014-05-04 21:27:37 +0200
commit34273f41d57ee8d854dcd2a1d754cbb546cb548f (patch)
tree0f3fee911ac04263045d3c1557dd5ba452dc9658 /arch/x86/kernel/ldt.c
parentx86, espfix: Make espfix64 a Kconfig option, fix UML (diff)
downloadlinux-34273f41d57ee8d854dcd2a1d754cbb546cb548f.tar.xz
linux-34273f41d57ee8d854dcd2a1d754cbb546cb548f.zip
x86, espfix: Make it possible to disable 16-bit support
Embedded systems, which may be very memory-size-sensitive, are extremely unlikely to ever encounter any 16-bit software, so make it a CONFIG_EXPERT option to turn off support for any 16-bit software whatsoever. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Diffstat (limited to 'arch/x86/kernel/ldt.c')
-rw-r--r--arch/x86/kernel/ldt.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index ebc987398923..c37886d759cc 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -229,6 +229,11 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
}
}
+ if (!IS_ENABLED(CONFIG_X86_16BIT) && !ldt_info.seg_32bit) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
fill_ldt(&ldt, &ldt_info);
if (oldmode)
ldt.avl = 0;