[PATCH v2] x86: make DR*_RESERVED unsigned long

From: Oleg Nesterov
Date: Fri Apr 26 2013 - 12:41:24 EST

DR6_RESERVED and DR_CONTROL_RESERVED are used to clear the set
bits in the "unsigned long" data, make them long to ensure that
"&~" doesn't clear the upper bits.

This is only cleanup, the usage of ~DR*_RESERVED is safe but
doesn't look clean and the pattern is error prone.

- do_debug:

dr6 &= ~DR6_RESERVED;

this also wrongly clears 32-63 bits. Fortunately these
bits are reserved and must be zero.

- ptrace_write_dr7:


on __i386__ this mixes long/int but sizeof should be the

Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
arch/x86/include/uapi/asm/debugreg.h | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/uapi/asm/debugreg.h b/arch/x86/include/uapi/asm/debugreg.h
index 3c0874d..c0c1b89 100644
--- a/arch/x86/include/uapi/asm/debugreg.h
+++ b/arch/x86/include/uapi/asm/debugreg.h
@@ -15,7 +15,7 @@
are either reserved or not of interest to us. */

/* Define reserved bits in DR6 which are always set to 1 */
-#define DR6_RESERVED (0xFFFF0FF0)
+#define DR6_RESERVED (0xFFFF0FF0UL)

#define DR_TRAP0 (0x1) /* db0 */
#define DR_TRAP1 (0x2) /* db1 */
@@ -65,7 +65,7 @@
gdt or the ldt if we want to. I am not sure why this is an advantage */

#ifdef __i386__
-#define DR_CONTROL_RESERVED (0xFC00) /* Reserved by Intel */
+#define DR_CONTROL_RESERVED (0xFC00UL) /* Reserved by Intel */
#define DR_CONTROL_RESERVED (0xFFFFFFFF0000FC00UL) /* Reserved */

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