[PATCH] Alpha: Rearrange thread info flags fixing two regressions

From: Michael Cree
Date: Fri Oct 30 2009 - 22:33:59 EST


The removal of the TIF_NOTIFY_RESUME flag, commit a583f1b54249b
"remove unused TIF_NOTIFY_RESUME flag," resulted in incorrect
setting of the unaligned access control flags by the prctl syscall.

The re-addition of the TIF_NOTIFY_RESUME flag, commit d0420c83f39f
"KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6]"
further caused problems, namely incorrect operands to assembler code
as evidenced by:

AS arch/alpha/kernel/entry.o
arch/alpha/kernel/entry.S: Assembler messages:
arch/alpha/kernel/entry.S:326: Warning: operand out of range (0x0000000000000406 is not between 0x0000000000000000 and 0x00000000000000ff)

Both regressions fixed by (1) rearranging TIF_NOTIFY_RESUME flag to be
in lower 8 bits of the thread info flags, and (2) making sure that
ALPHA_UAC_SHIFT matches the rearrangement of the thread info flags.

Signed-off-by: Michael Cree <mcree@xxxxxxxxxxxx>
---
arch/alpha/include/asm/thread_info.h | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index e7a07f6..3ba4ded 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -61,21 +61,24 @@ register struct thread_info *__current_thread_info __asm__("$8");
/*
* Thread information flags:
* - these are process state flags and used from assembly
- * - pending work-to-be-done flags come first to fit in and immediate operand.
+ * - pending work-to-be-done flags come first and must be assigned to be
+ * within bits 0 to 7 to fit in and immediate operand.
+ * - ALPHA_UAC_SHIFT below must be kept consistent with the unaligned
+ * control flags.
*
* TIF_SYSCALL_TRACE is known to be 0 via blbs.
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
-#define TIF_SIGPENDING 1 /* signal pending */
-#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
-#define TIF_POLLING_NRFLAG 3 /* poll_idle is polling NEED_RESCHED */
-#define TIF_DIE_IF_KERNEL 4 /* dik recursion lock */
-#define TIF_UAC_NOPRINT 5 /* see sysinfo.h */
-#define TIF_UAC_NOFIX 6
-#define TIF_UAC_SIGBUS 7
-#define TIF_MEMDIE 8
-#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal */
-#define TIF_NOTIFY_RESUME 10 /* callback before returning to user */
+#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
+#define TIF_SIGPENDING 2 /* signal pending */
+#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
+#define TIF_POLLING_NRFLAG 8 /* poll_idle is polling NEED_RESCHED */
+#define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */
+#define TIF_UAC_NOPRINT 10 /* see sysinfo.h */
+#define TIF_UAC_NOFIX 11
+#define TIF_UAC_SIGBUS 12
+#define TIF_MEMDIE 13
+#define TIF_RESTORE_SIGMASK 14 /* restore signal mask in do_signal */
#define TIF_FREEZE 16 /* is freezing for suspend */

#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -94,7 +97,7 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define _TIF_ALLWORK_MASK (_TIF_WORK_MASK \
| _TIF_SYSCALL_TRACE)

-#define ALPHA_UAC_SHIFT 6
+#define ALPHA_UAC_SHIFT 10
#define ALPHA_UAC_MASK (1 << TIF_UAC_NOPRINT | 1 << TIF_UAC_NOFIX | \
1 << TIF_UAC_SIGBUS)

--
1.6.3.3

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