[patch] i386: Don't let ptrace set the nested task bit

From: Chuck Ebbert
Date: Tue Feb 21 2006 - 05:18:08 EST


There's no good reason for allowing ptrace to set the NT
bit in EFLAGS, so mask it off.

Signed-off-by: Chuck Ebbert <76306.1226@xxxxxxxxxxxxxx>

--- 2.6.16-rc4-nb.orig/arch/i386/kernel/ptrace.c
+++ 2.6.16-rc4-nb/arch/i386/kernel/ptrace.c
@@ -34,10 +34,10 @@

/*
* Determines which flags the user has access to [1 = access, 0 = no access].
- * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
+ * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).
* Also masks reserved bits (31-22, 15, 5, 3, 1).
*/
-#define FLAG_MASK 0x00054dd5
+#define FLAG_MASK 0x00050dd5

/* set's the trap flag. */
#define TRAP_FLAG 0x100
--
Chuck
"Equations are the Devil's sentences." --Stephen Colbert
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