diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h
index bc4f562bd4594762a04dc7a845be8b0fcfa6b763..7594764d8a69c69040bfd18a2ccb0a8e17c84464 100644
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -100,9 +100,14 @@ extern void cpu_idle_on_new_stack(struct thread_info *old_ti,
#else /* __ASSEMBLY__ */
-/* how to get the thread information struct from ASM */
+/*
+ * How to get the thread information struct from assembly.
+ * Note that we use different macros since different architectures
+ * have different semantics in their "mm" instruction and we would
+ * like to guarantee that the macro expands to exactly one instruction.
+ */
#ifdef __tilegx__
-#define GET_THREAD_INFO(reg) move reg, sp; mm reg, zero, LOG2_THREAD_SIZE, 63
+#define EXTRACT_THREAD_INFO(reg) mm reg, zero, LOG2_THREAD_SIZE, 63
#else
#define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
#endif
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S
index 5d56a1ef5ba5212e6cffe97e0fe14223bc0d116b..6943515100f8518cbe3b6f37c4eae8440c6a4e6d 100644
--- a/arch/tile/kernel/intvec_32.S
+++ b/arch/tile/kernel/intvec_32.S
@@ -838,6 +838,18 @@ STD_ENTRY(interrupt_return)
.Lresume_userspace:
FEEDBACK_REENTER(interrupt_return)
+ /*
+ * Use r33 to hold whether we have already loaded the callee-saves
+ * into ptregs. We don't want to do it twice in this loop, since
+ * then we'd clobber whatever changes are made by ptrace, etc.
+ * Get base of stack in r32.
+ */
+ {
+ GET_THREAD_INFO(r32)
+ movei r33, 0
+ }
+
+.Lretry_work_pending:
/*
* Disable interrupts so as to make sure we don't
* miss an interrupt that sets any of the thread flags (like
@@ -848,9 +860,6 @@ STD_ENTRY(interrupt_return)
IRQ_DISABLE(r20, r21)
TRACE_IRQS_OFF /* Note: clobbers registers r0-r29 */
- /* Get base of stack in r32; note r30/31 are used as arguments here. */
- GET_THREAD_INFO(r32)
-
/* Check to see if there is any work to do before returning to user. */
{
@@ -866,16 +875,18 @@ STD_ENTRY(interrupt_return)
/*
* Make sure we have all the registers saved for signal
- * handling or single-step. Call out to C code to figure out
- * exactly what we need to do for each flag bit, then if
- * necessary, reload the flags and recheck.
+ * handling, notify-resume, or single-step. Call out to C
+ * code to figure out exactly what we need to do for each flag bit,
+ * then if necessary, reload the flags and recheck.
*/
- push_extra_callee_saves r0
{
PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
- jal do_work_pending
+ bnz r33, 1f
}
- bnz r0, .Lresume_userspace
+ push_extra_callee_saves r0
+ movei r33, 1
+1: jal do_work_pending
+ bnz r0, .Lretry_work_pending
/*
* In the NMI case we
@@ -1180,10 +1191,12 @@ handle_syscall:
add r20, r20, tp
lw r21, r20
addi r21, r21, 1
- sw r20, r21
+ {
+ sw r20, r21
+ GET_THREAD_INFO(r31)
+ }
/* Trace syscalls, if requested. */
- GET_THREAD_INFO(r31)
addi r31, r31, THREAD_INFO_FLAGS_OFFSET
lw r30, r31
andi r30, r30, _TIF_SYSCALL_TRACE
@@ -1362,7 +1375,10 @@ handle_ill:
3:
/* set PC and continue */
lw r26, r24
- sw r28, r26
+ {
+ sw r28, r26
+ GET_THREAD_INFO(r0)
+ }
/*
* Clear TIF_SINGLESTEP to prevent recursion if we execute an ill.
@@ -1370,7 +1386,6 @@ handle_ill:
* need to clear it here and can't really impose on all other arches.
* So what's another write between friends?
*/
- GET_THREAD_INFO(r0)
addi r1, r0, THREAD_INFO_FLAGS_OFFSET
{
diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 49d9d66216822a463a4e905f3425e8eb2a4f77e8..30ae76e50c44e458fc5b87e2d8712de3219383a5 100644
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -646,6 +646,20 @@ STD_ENTRY(interrupt_return)
.Lresume_userspace:
FEEDBACK_REENTER(interrupt_return)
+ /*
+ * Use r33 to hold whether we have already loaded the callee-saves
+ * into ptregs. We don't want to do it twice in this loop, since
+ * then we'd clobber whatever changes are made by ptrace, etc.
+ */
+ {
+ movei r33, 0
+ move r32, sp
+ }
+
+ /* Get base of stack in r32. */
+ EXTRACT_THREAD_INFO(r32)
+
+.Lretry_work_pending:
/*
* Disable interrupts so as to make sure we don't
* miss an interrupt that sets any of the thread flags (like
@@ -656,9 +670,6 @@ STD_ENTRY(interrupt_return)
IRQ_DISABLE(r20, r21)
TRACE_IRQS_OFF /* Note: clobbers registers r0-r29 */
- /* Get base of stack in r32; note r30/31 are used as arguments here. */
- GET_THREAD_INFO(r32)
-
/* Check to see if there is any work to do before returning to user. */
{
@@ -674,16 +685,18 @@ STD_ENTRY(interrupt_return)
/*
* Make sure we have all the registers saved for signal
- * handling or single-step. Call out to C code to figure out
+ * handling or notify-resume. Call out to C code to figure out
* exactly what we need to do for each flag bit, then if
* necessary, reload the flags and recheck.
*/
- push_extra_callee_saves r0
{
PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
- jal do_work_pending
+ bnez r33, 1f
}
- bnez r0, .Lresume_userspace
+ push_extra_callee_saves r0
+ movei r33, 1
+1: jal do_work_pending
+ bnez r0, .Lretry_work_pending
/*
* In the NMI case we
@@ -968,11 +981,16 @@ handle_syscall:
shl16insli r20, r20, hw0(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET)
add r20, r20, tp
ld4s r21, r20
- addi r21, r21, 1
- st4 r20, r21
+ {
+ addi r21, r21, 1
+ move r31, sp
+ }
+ {
+ st4 r20, r21
+ EXTRACT_THREAD_INFO(r31)
+ }
/* Trace syscalls, if requested. */
- GET_THREAD_INFO(r31)
addi r31, r31, THREAD_INFO_FLAGS_OFFSET
ld r30, r31
andi r30, r30, _TIF_SYSCALL_TRACE
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 2d5ef617bb3906cfcf1f9846af10b9d87e8d53e0..54e6c64b85cc5ee398be55e110b30d98114eb6cb 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -567,6 +567,10 @@ struct task_struct *__sched _switch_to(struct task_struct *prev,
*/
int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
{
+ /* If we enter in kernel mode, do nothing and exit the caller loop. */
+ if (!user_mode(regs))
+ return 0;
+
if (thread_info_flags & _TIF_NEED_RESCHED) {
schedule();
return 1;
@@ -589,8 +593,7 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
return 1;
}
if (thread_info_flags & _TIF_SINGLESTEP) {
- if ((regs->ex1 & SPR_EX_CONTEXT_1_1__PL_MASK) == 0)
- single_step_once(regs);
+ single_step_once(regs);
return 0;
}
panic("work_pending: bad flags %#x\n", thread_info_flags);