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Subject[PATCH v3 2/7] x86/ldt: use a common value for read_default_ldt()
Date
From: "H. Peter Anvin" <hpa@linux.intel.com>

There is no point in having two different sizes for the "default ldt";
a concept which is obsolete anyway. Since this is kernel-dependent
and not user-space dependent, a 32-bit app needs to be able to accept
the 64-bit value anyway, so use that value, which is the larger of the
two.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Markus T. Metzger <markus.t.metzger@intel.com>
---
arch/x86/kernel/ldt.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 18e9f4c0633d..601d24268a99 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -383,12 +383,8 @@ static int read_ldt(void __user *ptr, unsigned long bytecount)

static int read_default_ldt(void __user *ptr, unsigned long bytecount)
{
- /* CHECKME: Can we use _one_ random number ? */
-#ifdef CONFIG_X86_32
- unsigned long size = 5 * sizeof(struct desc_struct);
-#else
- unsigned long size = 128;
-#endif
+ const unsigned long size = 128;
+
if (bytecount > size)
bytecount = size;
if (clear_user(ptr, bytecount))
--
2.14.4
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