[RFC PATCH v1 0/9] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK

[RFC PATCH v1 0/9] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK

[Christophe Leroy]

The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are
leaked, making a number of attacks more difficult.

Christophe Leroy (9):
  timer: fix circular header dependency
  book3s/64: avoid circular header inclusion in mmu-hash.h
  powerpc: change name THREAD_INFO to TASK_STACK
  powerpc: Prepare for moving thread_info into task_struct
  powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
  powerpc: regain entire stack space
  powerpc: 'current_set' is now a table of task_struct pointers
  powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU
  powerpc/64: Modify CURRENT_THREAD_INFO()

 arch/powerpc/Kconfig                           |  1 +
 arch/powerpc/include/asm/asm-prototypes.h      |  4 +-
 arch/powerpc/include/asm/book3s/64/mmu-hash.h  |  2 +-
 arch/powerpc/include/asm/exception-64s.h       |  4 +-
 arch/powerpc/include/asm/irq.h                 | 14 +++---
 arch/powerpc/include/asm/livepatch.h           |  2 +-
 arch/powerpc/include/asm/processor.h           | 39 ++-------------
 arch/powerpc/include/asm/ptrace.h              |  2 +-
 arch/powerpc/include/asm/reg.h                 |  2 +-
 arch/powerpc/include/asm/smp.h                 |  3 +-
 arch/powerpc/include/asm/task_size.h           | 42 ++++++++++++++++
 arch/powerpc/include/asm/thread_info.h         | 17 +------
 arch/powerpc/kernel/asm-offsets.c              |  8 ++--
 arch/powerpc/kernel/entry_32.S                 | 66 +++++++++-----------------
 arch/powerpc/kernel/entry_64.S                 | 12 ++---
 arch/powerpc/kernel/epapr_hcalls.S             |  5 +-
 arch/powerpc/kernel/exceptions-64e.S           | 13 +----
 arch/powerpc/kernel/exceptions-64s.S           |  2 +-
 arch/powerpc/kernel/head_32.S                  | 14 +++---
 arch/powerpc/kernel/head_40x.S                 |  4 +-
 arch/powerpc/kernel/head_44x.S                 |  8 ++--
 arch/powerpc/kernel/head_64.S                  |  1 +
 arch/powerpc/kernel/head_8xx.S                 |  2 +-
 arch/powerpc/kernel/head_booke.h               | 12 ++---
 arch/powerpc/kernel/head_fsl_booke.S           | 16 +++----
 arch/powerpc/kernel/idle_6xx.S                 |  8 ++--
 arch/powerpc/kernel/idle_book3e.S              |  2 +-
 arch/powerpc/kernel/idle_e500.S                |  8 ++--
 arch/powerpc/kernel/idle_power4.S              |  2 +-
 arch/powerpc/kernel/irq.c                      | 66 ++++----------------------
 arch/powerpc/kernel/kgdb.c                     | 28 -----------
 arch/powerpc/kernel/machine_kexec_64.c         |  6 +--
 arch/powerpc/kernel/misc_32.S                  | 17 +++----
 arch/powerpc/kernel/process.c                  | 15 +++---
 arch/powerpc/kernel/setup-common.c             |  2 +-
 arch/powerpc/kernel/setup_32.c                 | 15 ++----
 arch/powerpc/kernel/setup_64.c                 | 29 ++---------
 arch/powerpc/kernel/smp.c                      | 16 +++----
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |  6 +--
 arch/powerpc/kvm/book3s_hv_hmi.c               |  1 +
 arch/powerpc/mm/hash_low_32.S                  | 14 ++----
 arch/powerpc/sysdev/6xx-suspend.S              |  5 +-
 arch/powerpc/xmon/xmon.c                       |  2 +-
 fs/timerfd.c                                   |  2 +-
 kernel/time/alarmtimer.c                       |  2 +-
 45 files changed, 194 insertions(+), 347 deletions(-)
 create mode 100644 arch/powerpc/include/asm/task_size.h

-- 
2.13.3

[RFC PATCH v1 1/9] timer: fix circular header dependency

[Christophe Leroy]

When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
has to be included in asm/smp.h for the following change, in order
to avoid uncomplete definition of task_struct:

-#define raw_smp_processor_id() (current_thread_info()->cpu)
+#define raw_smp_processor_id() (current->cpu)

But this generates the following compilation error, due to circular
header dependency.

  CC      kernel/time/alarmtimer.o
In file included from ./arch/powerpc/include/asm/smp.h:31,
                 from ./include/linux/smp.h:64,
                 from ./include/linux/percpu.h:7,
                 from ./include/linux/hrtimer.h:22,
                 from kernel/time/alarmtimer.c:19:
./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
  struct hrtimer   dl_timer;
                   ^~~~~~~~
./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
  struct hrtimer inactive_timer;
                 ^~~~~~~~~~~~~~
make[1]: *** [kernel/time/alarmtimer.o] Error 1
make: *** [kernel/time/alarmtimer.o] Error 2

  CC      fs/timerfd.o
In file included from ./arch/powerpc/include/asm/smp.h:31,
                 from ./include/linux/smp.h:64,
                 from ./include/linux/percpu.h:7,
                 from ./include/linux/hrtimer.h:22,
                 from ./include/linux/alarmtimer.h:6,
                 from fs/timerfd.c:12:
./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
  struct hrtimer   dl_timer;
                   ^~~~~~~~
./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
  struct hrtimer inactive_timer;
                 ^~~~~~~~~~~~~~
make[1]: *** [fs/timerfd.o] Error 1
make: *** [fs/timerfd.o] Error 2

This patch fixes it by including linux/hrtimer.h after linux/sched.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 Should it be fixed in powerpc instead ? In that case, how ? Any idea ?

 fs/timerfd.c             | 2 +-
 kernel/time/alarmtimer.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/timerfd.c b/fs/timerfd.c
index d69ad801eb80..0fc01b241382 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -9,12 +9,12 @@
  *
  */
 
-#include <linux/alarmtimer.h>
 #include <linux/file.h>
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/alarmtimer.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/list.h>
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index fa5de5e8de61..5fb75c9b3f06 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -16,11 +16,11 @@
  * published by the Free Software Foundation.
  */
 #include <linux/time.h>
-#include <linux/hrtimer.h>
 #include <linux/timerqueue.h>
 #include <linux/rtc.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/debug.h>
+#include <linux/hrtimer.h>
 #include <linux/alarmtimer.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
-- 
2.13.3

[RFC PATCH v1 2/9] book3s/64: avoid circular header inclusion in mmu-hash.h

[Christophe Leroy]

When activating CONFIG_THREAD_INFO_IN_TASK, linux/sched.h
includes asm/current.h. This generates a circular dependency.
To avoid that, asm/processor.h shall not be included in mmu-hash.h

In order to do that, this patch moves into a new header called
asm/task_size.h the information from asm/processor.h requires by
mmu-hash.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/book3s/64/mmu-hash.h |  2 +-
 arch/powerpc/include/asm/processor.h          | 34 +---------------------
 arch/powerpc/include/asm/task_size.h          | 42 +++++++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_hmi.c              |  1 +
 4 files changed, 45 insertions(+), 34 deletions(-)
 create mode 100644 arch/powerpc/include/asm/task_size.h

diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index bbeaf6adf93c..7788e35f19f0 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -23,7 +23,7 @@
  */
 #include <asm/book3s/64/pgtable.h>
 #include <asm/bug.h>
-#include <asm/processor.h>
+#include <asm/task_size.h>
 #include <asm/cpu_has_feature.h>
 
 /*
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 350c584ca179..353879db3e98 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -101,40 +101,8 @@ void release_thread(struct task_struct *);
 #endif
 
 #ifdef CONFIG_PPC64
-/*
- * 64-bit user address space can have multiple limits
- * For now supported values are:
- */
-#define TASK_SIZE_64TB  (0x0000400000000000UL)
-#define TASK_SIZE_128TB (0x0000800000000000UL)
-#define TASK_SIZE_512TB (0x0002000000000000UL)
-#define TASK_SIZE_1PB   (0x0004000000000000UL)
-#define TASK_SIZE_2PB   (0x0008000000000000UL)
-/*
- * With 52 bits in the address we can support
- * upto 4PB of range.
- */
-#define TASK_SIZE_4PB   (0x0010000000000000UL)
 
-/*
- * For now 512TB is only supported with book3s and 64K linux page size.
- */
-#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_64K_PAGES)
-/*
- * Max value currently used:
- */
-#define TASK_SIZE_USER64		TASK_SIZE_4PB
-#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_128TB
-#define TASK_CONTEXT_SIZE		TASK_SIZE_512TB
-#else
-#define TASK_SIZE_USER64		TASK_SIZE_64TB
-#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_64TB
-/*
- * We don't need to allocate extended context ids for 4K page size, because
- * we limit the max effective address on this config to 64TB.
- */
-#define TASK_CONTEXT_SIZE		TASK_SIZE_64TB
-#endif
+#include <asm/task_size.h>
 
 /*
  * 32-bit user address space is 4GB - 1 page
diff --git a/arch/powerpc/include/asm/task_size.h b/arch/powerpc/include/asm/task_size.h
new file mode 100644
index 000000000000..ca45638617b0
--- /dev/null
+++ b/arch/powerpc/include/asm/task_size.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_TASK_SIZE_H
+#define _ASM_POWERPC_TASK_SIZE_H
+
+#ifdef CONFIG_PPC64
+/*
+ * 64-bit user address space can have multiple limits
+ * For now supported values are:
+ */
+#define TASK_SIZE_64TB  (0x0000400000000000UL)
+#define TASK_SIZE_128TB (0x0000800000000000UL)
+#define TASK_SIZE_512TB (0x0002000000000000UL)
+#define TASK_SIZE_1PB   (0x0004000000000000UL)
+#define TASK_SIZE_2PB   (0x0008000000000000UL)
+/*
+ * With 52 bits in the address we can support
+ * upto 4PB of range.
+ */
+#define TASK_SIZE_4PB   (0x0010000000000000UL)
+
+/*
+ * For now 512TB is only supported with book3s and 64K linux page size.
+ */
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_64K_PAGES)
+/*
+ * Max value currently used:
+ */
+#define TASK_SIZE_USER64		TASK_SIZE_4PB
+#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_128TB
+#define TASK_CONTEXT_SIZE		TASK_SIZE_512TB
+#else
+#define TASK_SIZE_USER64		TASK_SIZE_64TB
+#define DEFAULT_MAP_WINDOW_USER64	TASK_SIZE_64TB
+/*
+ * We don't need to allocate extended context ids for 4K page size, because
+ * we limit the max effective address on this config to 64TB.
+ */
+#define TASK_CONTEXT_SIZE		TASK_SIZE_64TB
+#endif
+
+#endif /* CONFIG_PPC64 */
+#endif /* _ASM_POWERPC_TASK_SIZE_H */
diff --git a/arch/powerpc/kvm/book3s_hv_hmi.c b/arch/powerpc/kvm/book3s_hv_hmi.c
index e3f738eb1cac..64b5011475c7 100644
--- a/arch/powerpc/kvm/book3s_hv_hmi.c
+++ b/arch/powerpc/kvm/book3s_hv_hmi.c
@@ -24,6 +24,7 @@
 #include <linux/compiler.h>
 #include <asm/paca.h>
 #include <asm/hmi.h>
+#include <asm/processor.h>
 
 void wait_for_subcore_guest_exit(void)
 {
-- 
2.13.3

[RFC PATCH v1 3/9] powerpc: change name THREAD_INFO to TASK_STACK

[Christophe Leroy]

At the time being, the thread_info struct is located in the beginning
of the stack. There is an asm const called THREAD_INFO which is the
offset of the stack pointer in the task_struct.

In preparation of moving thread_info into task_struct, this patch
renames the THREAD_INFO const to TASK_STACK.

It also makes it available to PPC64, as it will also be needed
there to get the stack pointer from current.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/asm-offsets.c    | 2 +-
 arch/powerpc/kernel/entry_32.S       | 2 +-
 arch/powerpc/kernel/head_32.S        | 2 +-
 arch/powerpc/kernel/head_40x.S       | 4 ++--
 arch/powerpc/kernel/head_8xx.S       | 2 +-
 arch/powerpc/kernel/head_booke.h     | 4 ++--
 arch/powerpc/kernel/head_fsl_booke.S | 2 +-
 7 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ba9d0fc98730..d1f161e48945 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -85,10 +85,10 @@ int main(void)
 	DEFINE(NMI_MASK, NMI_MASK);
 	OFFSET(TASKTHREADPPR, task_struct, thread.ppr);
 #else
-	OFFSET(THREAD_INFO, task_struct, stack);
 	DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16));
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
+	OFFSET(TASK_STACK, task_struct, stack);
 
 #ifdef CONFIG_LIVEPATCH
 	OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e58c3f467db5..12c0721f65ea 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1166,7 +1166,7 @@ ret_from_debug_exc:
 	mfspr	r9,SPRN_SPRG_THREAD
 	lwz	r10,SAVED_KSP_LIMIT(r1)
 	stw	r10,KSP_LIMIT(r9)
-	lwz	r9,THREAD_INFO-THREAD(r9)
+	lwz	r9,TASK_STACK-THREAD(r9)
 	CURRENT_THREAD_INFO(r10, r1)
 	lwz	r10,TI_PREEMPT(r10)
 	stw	r10,TI_PREEMPT(r9)
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 61ca27929355..dbb096c32332 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -261,7 +261,7 @@ __secondary_hold_acknowledge:
 	tophys(r11,r1);			/* use tophys(r1) if kernel */ \
 	beq	1f;		\
 	mfspr	r11,SPRN_SPRG_THREAD;	\
-	lwz	r11,THREAD_INFO-THREAD(r11);	\
+	lwz	r11,TASK_STACK-THREAD(r11);	\
 	addi	r11,r11,THREAD_SIZE;	\
 	tophys(r11,r11);	\
 1:	subi	r11,r11,INT_FRAME_SIZE	/* alloc exc. frame */
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index b19d78410511..3088c9f29f5e 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -115,7 +115,7 @@ _ENTRY(saved_ksp_limit)
 	andi.	r11,r11,MSR_PR;						     \
 	beq	1f;							     \
 	mfspr	r1,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack   */\
+	lwz	r1,TASK_STACK-THREAD(r1); /* this thread's kernel stack   */\
 	addi	r1,r1,THREAD_SIZE;					     \
 1:	subi	r1,r1,INT_FRAME_SIZE;	/* Allocate an exception frame     */\
 	tophys(r11,r1);							     \
@@ -158,7 +158,7 @@ _ENTRY(saved_ksp_limit)
 	beq	1f;							     \
 	/* COMING FROM USER MODE */					     \
 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+	lwz	r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
 1:	addi	r11,r11,THREAD_SIZE-INT_FRAME_SIZE; /* Alloc an excpt frm  */\
 	tophys(r11,r11);						     \
 	stw	r10,_CCR(r11);          /* save various registers	   */\
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 6582f824d620..e56e36aa2b3d 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -124,7 +124,7 @@ turn_on_mmu:
 	tophys(r11,r1);			/* use tophys(r1) if kernel */ \
 	beq	1f;		\
 	mfspr	r11,SPRN_SPRG_THREAD;	\
-	lwz	r11,THREAD_INFO-THREAD(r11);	\
+	lwz	r11,TASK_STACK-THREAD(r11);	\
 	addi	r11,r11,THREAD_SIZE;	\
 	tophys(r11,r11);	\
 1:	subi	r11,r11,INT_FRAME_SIZE	/* alloc exc. frame */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index d0862a100d29..20fe0c93a0bd 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -44,7 +44,7 @@
 	mr	r11, r1;						     \
 	beq	1f;							     \
 	/* if from user, start at top of this thread's kernel stack */       \
-	lwz	r11, THREAD_INFO-THREAD(r10);				     \
+	lwz	r11, TASK_STACK-THREAD(r10);				     \
 	ALLOC_STACK_FRAME(r11, THREAD_SIZE);				     \
 1 :	subi	r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */     \
 	stw	r13, _CCR(r11);		/* save various registers */	     \
@@ -130,7 +130,7 @@
 	DO_KVM	BOOKE_INTERRUPT_##intno exc_level_srr1;		             \
 	andi.	r11,r11,MSR_PR;						     \
 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
-	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
+	lwz	r11,TASK_STACK-THREAD(r11); /* this thread's kernel stack */\
 	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\
 	beq	1f;							     \
 	/* COMING FROM USER MODE */					     \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index e2750b856c8f..35d35067acf7 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -702,7 +702,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r12, THREAD_INFO-THREAD(r12)
+	lwz	r12, TASK_STACK-THREAD(r12)
 	lwz	r15, TI_CPU(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
-- 
2.13.3

[RFC PATCH v1 4/9] powerpc: Prepare for moving thread_info into task_struct

[Christophe Leroy]

This patch cleans the powerpc kernel before activating
CONFIG_THREAD_INFO_IN_TASK:
- The purpose of the pointer given to call_do_softirq() and
call_do_irq() is to point the new stack ==> change it to void*
- current_pt_regs() is in the stack, not in thread_info.
- Don't use CURRENT_THREAD_INFO() to locate the stack.
- Fixed a few comments.
- TI_CPU is only used when CONFIG_SMP is set.
- Replace current_thread_info()->task by current
- Remove unnecessary casts to thread_info, as they'll become
invalid once thread_info is not in stack anymore.
- Ensure task_struct 'cpu' fields is not used directly out of SMP code

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/irq.h       |  4 ++--
 arch/powerpc/include/asm/livepatch.h |  2 +-
 arch/powerpc/include/asm/processor.h |  4 ++--
 arch/powerpc/include/asm/ptrace.h    |  2 +-
 arch/powerpc/include/asm/reg.h       |  2 +-
 arch/powerpc/kernel/entry_64.S       |  2 +-
 arch/powerpc/kernel/head_32.S        |  2 +-
 arch/powerpc/kernel/head_44x.S       |  2 +-
 arch/powerpc/kernel/head_fsl_booke.S |  4 +++-
 arch/powerpc/kernel/misc_32.S        |  8 ++++++--
 arch/powerpc/kernel/process.c        |  6 +++---
 arch/powerpc/kernel/setup_32.c       | 15 +++++----------
 arch/powerpc/kernel/smp.c            |  4 +++-
 arch/powerpc/xmon/xmon.c             |  2 +-
 14 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index ee39ce56b2a2..8108d1fe33ca 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -63,8 +63,8 @@ extern struct thread_info *hardirq_ctx[NR_CPUS];
 extern struct thread_info *softirq_ctx[NR_CPUS];
 
 extern void irq_ctx_init(void);
-extern void call_do_softirq(struct thread_info *tp);
-extern void call_do_irq(struct pt_regs *regs, struct thread_info *tp);
+extern void call_do_softirq(void *tp);
+extern void call_do_irq(struct pt_regs *regs, void *tp);
 extern void do_IRQ(struct pt_regs *regs);
 extern void __init init_IRQ(void);
 extern void __do_irq(struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 47a03b9b528b..818451bf629c 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h
@@ -49,7 +49,7 @@ static inline void klp_init_thread_info(struct thread_info *ti)
 	ti->livepatch_sp = (unsigned long *)(ti + 1) + 1;
 }
 #else
-static void klp_init_thread_info(struct thread_info *ti) { }
+static inline void klp_init_thread_info(struct thread_info *ti) { }
 #endif /* CONFIG_LIVEPATCH */
 
 #endif /* _ASM_POWERPC_LIVEPATCH_H */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 353879db3e98..31873614392f 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -40,7 +40,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
-#include <asm/thread_info.h>
+#include <linux/thread_info.h>
 #include <asm/ptrace.h>
 #include <asm/hw_breakpoint.h>
 
@@ -333,7 +333,7 @@ struct thread_struct {
 
 #define INIT_SP		(sizeof(init_stack) + (unsigned long) &init_stack)
 #define INIT_SP_LIMIT \
-	(_ALIGN_UP(sizeof(init_thread_info), 16) + (unsigned long) &init_stack)
+	(_ALIGN_UP(sizeof(struct thread_info), 16) + (unsigned long) &init_stack)
 
 #ifdef CONFIG_SPE
 #define SPEFSCR_INIT \
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 447cbd1bee99..3a7e5561630b 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -120,7 +120,7 @@ extern int ptrace_put_reg(struct task_struct *task, int regno,
 			  unsigned long data);
 
 #define current_pt_regs() \
-	((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
+	((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 /*
  * We use the least-significant bit of the trap field to indicate
  * whether we have saved the full set of registers, or only a
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e5b314ed054e..f3a9cf19a986 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1053,7 +1053,7 @@
  *	- SPRG9 debug exception scratch
  *
  * All 32-bit:
- *	- SPRG3 current thread_info pointer
+ *	- SPRG3 current thread_struct physical addr pointer
  *        (virtual on BookE, physical on others)
  *
  * 32-bit classic:
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 77a888bfcb53..697406572592 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -680,7 +680,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 2:
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
-	CURRENT_THREAD_INFO(r7, r8)  /* base of new stack */
+	clrrdi	r7, r8, THREAD_SHIFT	/* base of new stack */
 	/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
 	   because we don't need to leave the 288-byte ABI gap at the
 	   top of the kernel stack. */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index dbb096c32332..dce6f2ff07e5 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -841,7 +841,7 @@ __secondary_start:
 	bl	init_idle_6xx
 #endif /* CONFIG_6xx */
 
-	/* get current_thread_info and current */
+	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	tophys(r1,r1)
 	lwz	r1,secondary_ti@l(r1)
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 37e4a7cf0065..15d39b2499de 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1020,7 +1020,7 @@ _GLOBAL(start_secondary_47x)
 
 	/* Now we can get our task struct and real stack pointer */
 
-	/* Get current_thread_info and current */
+	/* Get current's stack and current */
 	lis	r1,secondary_ti@ha
 	lwz	r1,secondary_ti@l(r1)
 	lwz	r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 35d35067acf7..239ad8a4754e 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -243,8 +243,10 @@ set_ivor:
 	li	r0,0
 	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
 
+#ifdef CONFIG_SMP
 	CURRENT_THREAD_INFO(r22, r1)
 	stw	r24, TI_CPU(r22)
+#endif
 
 	bl	early_init
 
@@ -1074,7 +1076,7 @@ __secondary_start:
 	mr	r4,r24		/* Why? */
 	bl	call_setup_cpu
 
-	/* get current_thread_info and current */
+	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	lwz	r1,secondary_ti@l(r1)
 	lwz	r2,TI_TASK(r1)
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 695b24a2d954..24a7f18ea10c 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -60,7 +60,7 @@ _GLOBAL(call_do_softirq)
 	blr
 
 /*
- * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
+ * void call_do_irq(struct pt_regs *regs, void *irqtp);
  */
 _GLOBAL(call_do_irq)
 	mflr	r0
@@ -183,10 +183,14 @@ _GLOBAL(low_choose_750fx_pll)
 	or	r4,r4,r5
 	mtspr	SPRN_HID1,r4
 
+#ifdef CONFIG_SMP
 	/* Store new HID1 image */
 	CURRENT_THREAD_INFO(r6, r1)
 	lwz	r6,TI_CPU(r6)
 	slwi	r6,r6,2
+#else
+	li	r6, 0
+#endif
 	addis	r6,r6,nap_save_hid1@ha
 	stw	r4,nap_save_hid1@l(r6)
 
@@ -599,7 +603,7 @@ EXPORT_SYMBOL(__bswapdi2)
 #ifdef CONFIG_SMP
 _GLOBAL(start_secondary_resume)
 	/* Reset stack */
-	CURRENT_THREAD_INFO(r1, r1)
+	rlwinm	r1, r1, 0, 0, 31 - THREAD_SHIFT
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
 	li	r3,0
 	stw	r3,0(r1)		/* Zero the stack frame pointer	*/
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 03c2e1f134bc..111abb4df2ec 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1240,8 +1240,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		batch->active = 1;
 	}
 
-	if (current_thread_info()->task->thread.regs) {
-		restore_math(current_thread_info()->task->thread.regs);
+	if (current->thread.regs) {
+		restore_math(current->thread.regs);
 
 		/*
 		 * The copy-paste buffer can only store into foreign real
@@ -1251,7 +1251,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 		 * mappings, we must issue a cp_abort to clear any state and
 		 * prevent snooping, corruption or a covert channel.
 		 */
-		if (current_thread_info()->task->thread.used_vas)
+		if (current->thread.used_vas)
 			asm volatile(PPC_CP_ABORT);
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 8c507be12c3c..81ebf7d6f526 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -205,10 +205,8 @@ void __init irqstack_early_init(void)
 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
 	 * as the memblock is limited to lowmem by default */
 	for_each_possible_cpu(i) {
-		softirq_ctx[i] = (struct thread_info *)
-			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
-		hardirq_ctx[i] = (struct thread_info *)
-			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+		softirq_ctx[i] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+		hardirq_ctx[i] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
 	}
 }
 
@@ -226,13 +224,10 @@ void __init exc_lvl_early_init(void)
 		hw_cpu = 0;
 #endif
 
-		critirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+		critirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
 #ifdef CONFIG_BOOKE
-		dbgirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
-		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
-			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+		dbgirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
+		mcheckirq_ctx[hw_cpu] = __va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
 #endif
 	}
 }
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 61c1fadbc644..19dd0ea55714 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
 #include <linux/sched/topology.h>
 #include <linux/smp.h>
 #include <linux/interrupt.h>
@@ -812,7 +813,8 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
-	paca_ptrs[cpu]->kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
+	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
+				  THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
 	ti->cpu = cpu;
 	secondary_ti = current_set[cpu] = ti;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 694c1d92e796..0d8d6fee892a 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2988,7 +2988,7 @@ static void show_task(struct task_struct *tsk)
 	printf("%px %016lx %6d %6d %c %2d %s\n", tsk,
 		tsk->thread.ksp,
 		tsk->pid, tsk->parent->pid,
-		state, task_thread_info(tsk)->cpu,
+		state, task_cpu(tsk),
 		tsk->comm);
 }
 
-- 
2.13.3

[RFC PATCH v1 5/9] powerpc: Activate CONFIG_THREAD_INFO_IN_TASK

[Christophe Leroy]

This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.

Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are
leaked, making a number of attacks more difficult.

This has the following consequences:
- thread_info is now located at the top of task_struct.
- The 'cpu' field is now in task_struct, and only exists when
CONFIG_SMP is active.
- thread_info doesn't have anymore the 'task' field.

This patch:
- Removes all recopy of thread_info struct when the stack changes.
- Changes the CURRENT_THREAD_INFO() macro to point to current.
- Selects CONFIG_THREAD_INFO_IN_TASK

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/Kconfig                   |  1 +
 arch/powerpc/include/asm/smp.h         |  3 ++-
 arch/powerpc/include/asm/thread_info.h | 17 ++----------
 arch/powerpc/kernel/asm-offsets.c      |  5 ++--
 arch/powerpc/kernel/entry_32.S         |  9 +++----
 arch/powerpc/kernel/exceptions-64e.S   | 11 --------
 arch/powerpc/kernel/head_32.S          |  6 ++---
 arch/powerpc/kernel/head_44x.S         |  4 +--
 arch/powerpc/kernel/head_64.S          |  1 +
 arch/powerpc/kernel/head_booke.h       |  8 +-----
 arch/powerpc/kernel/head_fsl_booke.S   |  7 +++--
 arch/powerpc/kernel/irq.c              | 49 ++--------------------------------
 arch/powerpc/kernel/kgdb.c             | 28 -------------------
 arch/powerpc/kernel/machine_kexec_64.c |  6 ++---
 arch/powerpc/kernel/setup-common.c     |  2 +-
 arch/powerpc/kernel/setup_64.c         | 21 ---------------
 arch/powerpc/kernel/smp.c              |  2 +-
 17 files changed, 28 insertions(+), 152 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a80669209155..c6c0b91ebd33 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -237,6 +237,7 @@ config PPC
 	select RTC_LIB
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
+	select THREAD_INFO_IN_TASK
 	select VIRT_TO_BUS			if !PPC64
 	#
 	# Please keep this list sorted alphabetically.
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 95b66a0c639b..7a197a669311 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -28,6 +28,7 @@
 #include <asm/paca.h>
 #endif
 #include <asm/percpu.h>
+#include <linux/sched.h>
 
 extern int boot_cpuid;
 extern int spinning_secondaries;
@@ -83,7 +84,7 @@ int is_cpu_dead(unsigned int cpu);
 /* 32-bit */
 extern int smp_hw_index[];
 
-#define raw_smp_processor_id()	(current_thread_info()->cpu)
+#define raw_smp_processor_id()	(current->cpu)
 #define hard_smp_processor_id() 	(smp_hw_index[smp_processor_id()])
 
 static inline int get_hard_smp_processor_id(int cpu)
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 406eb952b808..62eb9ff31292 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -18,9 +18,9 @@
 #define THREAD_SIZE		(1 << THREAD_SHIFT)
 
 #ifdef CONFIG_PPC64
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(clrrdi dest, sp, THREAD_SHIFT)
+#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
 #else
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT)
+#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(mr dest, r2)
 #endif
 
 #ifndef __ASSEMBLY__
@@ -34,8 +34,6 @@
  * low level task data.
  */
 struct thread_info {
-	struct task_struct *task;		/* main task structure */
-	int		cpu;			/* cpu we're on */
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
 	unsigned long	local_flags;		/* private flags for thread */
@@ -58,8 +56,6 @@ struct thread_info {
  */
 #define INIT_THREAD_INFO(tsk)			\
 {						\
-	.task =		&tsk,			\
-	.cpu =		0,			\
 	.preempt_count = INIT_PREEMPT_COUNT,	\
 	.flags =	0,			\
 }
@@ -67,15 +63,6 @@ struct thread_info {
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
 /* how to get the thread information struct from C */
-static inline struct thread_info *current_thread_info(void)
-{
-	unsigned long val;
-
-	asm (CURRENT_THREAD_INFO(%0,1) : "=r" (val));
-
-	return (struct thread_info *)val;
-}
-
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index d1f161e48945..b042d85325f5 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -89,6 +89,9 @@ int main(void)
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
+#ifdef CONFIG_SMP
+	OFFSET(TI_CPU, task_struct, cpu);
+#endif
 
 #ifdef CONFIG_LIVEPATCH
 	OFFSET(TI_livepatch_sp, thread_info, livepatch_sp);
@@ -156,8 +159,6 @@ int main(void)
 	OFFSET(TI_FLAGS, thread_info, flags);
 	OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags);
 	OFFSET(TI_PREEMPT, thread_info, preempt_count);
-	OFFSET(TI_TASK, thread_info, task);
-	OFFSET(TI_CPU, thread_info, cpu);
 
 #ifdef CONFIG_PPC64
 	OFFSET(DCACHEL1BLOCKSIZE, ppc64_caches, l1d.block_size);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 12c0721f65ea..a14f9b5f2762 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1166,10 +1166,6 @@ ret_from_debug_exc:
 	mfspr	r9,SPRN_SPRG_THREAD
 	lwz	r10,SAVED_KSP_LIMIT(r1)
 	stw	r10,KSP_LIMIT(r9)
-	lwz	r9,TASK_STACK-THREAD(r9)
-	CURRENT_THREAD_INFO(r10, r1)
-	lwz	r10,TI_PREEMPT(r10)
-	stw	r10,TI_PREEMPT(r9)
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_xSRR(CSRR0,CSRR1);
 	RESTORE_MMU_REGS;
@@ -1292,10 +1288,13 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_601)
 	lwz	r3,_TRAP(r1)
 	andi.	r0,r3,1
-	beq	4f
+	beq	5f
 	SAVE_NVGPRS(r1)
 	rlwinm	r3,r3,0,0,30
 	stw	r3,_TRAP(r1)
+5:	mfspr	r2,SPRN_SPRG_THREAD
+	addi	r2,r2,-THREAD
+	tovirt(r2,r2)			/* set back r2 to current */
 4:	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	nonrecoverable_exception
 	/* shouldn't return */
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 6d6e144a28ce..231d066b4a3d 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -77,17 +77,6 @@ special_reg_save:
 	andi.	r3,r3,MSR_PR
 	bnelr
 
-	/* Copy info into temporary exception thread info */
-	ld	r11,PACAKSAVE(r13)
-	CURRENT_THREAD_INFO(r11, r11)
-	CURRENT_THREAD_INFO(r12, r1)
-	ld	r10,TI_FLAGS(r11)
-	std	r10,TI_FLAGS(r12)
-	ld	r10,TI_PREEMPT(r11)
-	std	r10,TI_PREEMPT(r12)
-	ld	r10,TI_TASK(r11)
-	std	r10,TI_TASK(r12)
-
 	/*
 	 * Advance to the next TLB exception frame for handler
 	 * types that don't do it automatically.
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index dce6f2ff07e5..44dfd73b2a62 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -844,9 +844,9 @@ __secondary_start:
 	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
 	tophys(r1,r1)
-	lwz	r1,secondary_ti@l(r1)
-	tophys(r2,r1)
-	lwz	r2,TI_TASK(r2)
+	lwz	r2,secondary_ti@l(r1)
+	tophys(r1,r2)
+	lwz	r1,TASK_STACK(r1)
 
 	/* stack */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 15d39b2499de..2c7e90f36358 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1022,8 +1022,8 @@ _GLOBAL(start_secondary_47x)
 
 	/* Get current's stack and current */
 	lis	r1,secondary_ti@ha
-	lwz	r1,secondary_ti@l(r1)
-	lwz	r2,TI_TASK(r1)
+	lwz	r2,secondary_ti@l(r1)
+	lwz	r1,TASK_STACK(r2)
 
 	/* Current stack pointer */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 4898e9491a1c..c6a9bf7b34bf 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -805,6 +805,7 @@ __secondary_start:
 	LOAD_REG_ADDR(r3, current_set)
 	sldi	r28,r24,3		/* get current_set[cpu#]	 */
 	ldx	r14,r3,r28
+	ld	r14,TASK_STACK(r14)
 	addi	r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
 	std	r14,PACAKSAVE(r13)
 
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 20fe0c93a0bd..9f7f10896928 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -143,13 +143,7 @@
 	stw	r10,GPR11(r11);						     \
 	b	2f;							     \
 	/* COMING FROM PRIV MODE */					     \
-1:	lwz	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11);		     \
-	lwz	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11);		     \
-	stw	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8);			     \
-	stw	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8);		     \
-	lwz	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11);			     \
-	stw	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8);			     \
-	mr	r11,r8;							     \
+1:	mr	r11,r8;							     \
 2:	mfspr	r8,SPRN_SPRG_RSCRATCH_##exc_level;			     \
 	stw	r12,GPR12(r11);		/* save various registers	   */\
 	mflr	r10;							     \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 239ad8a4754e..b8a2b789677e 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -704,8 +704,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r12, TASK_STACK-THREAD(r12)
-	lwz	r15, TI_CPU(r12)
+	lwz	r15, TI_CPU-THREAD(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
 	rlwinm  r15, r15, 2, 0, 29
@@ -1078,8 +1077,8 @@ __secondary_start:
 
 	/* get current's stack and current */
 	lis	r1,secondary_ti@ha
-	lwz	r1,secondary_ti@l(r1)
-	lwz	r2,TI_TASK(r1)
+	lwz	r2,secondary_ti@l(r1)
+	lwz	r1,TASK_STACK(r2)
 
 	/* stack */
 	addi	r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 916ddc4aac44..699f0f816687 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -663,7 +663,7 @@ void do_IRQ(struct pt_regs *regs)
 	struct thread_info *curtp, *irqtp, *sirqtp;
 
 	/* Switch to the irq stack to handle this */
-	curtp = current_thread_info();
+	curtp = (void*)(current_stack_pointer() & ~(THREAD_SIZE - 1));
 	irqtp = hardirq_ctx[raw_smp_processor_id()];
 	sirqtp = softirq_ctx[raw_smp_processor_id()];
 
@@ -673,24 +673,9 @@ void do_IRQ(struct pt_regs *regs)
 		set_irq_regs(old_regs);
 		return;
 	}
-
-	/* Prepare the thread_info in the irq stack */
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
-
-	/* Copy the preempt_count so that the [soft]irq checks work. */
-	irqtp->preempt_count = curtp->preempt_count;
-
 	/* Switch stack and call */
 	call_do_irq(regs, irqtp);
 
-	/* Restore stack limit */
-	irqtp->task = NULL;
-
-	/* Copy back updates to the thread_info */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
-
 	set_irq_regs(old_regs);
 }
 
@@ -711,7 +696,6 @@ struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
 
 void exc_lvl_ctx_init(void)
 {
-	struct thread_info *tp;
 	int i, cpu_nr;
 
 	for_each_possible_cpu(i) {
@@ -726,20 +710,9 @@ void exc_lvl_ctx_init(void)
 #endif
 
 		memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = critirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
 #ifdef CONFIG_BOOKE
 		memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = dbgirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
 		memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = mcheckirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = HARDIRQ_OFFSET;
 #endif
 	}
 }
@@ -750,38 +723,20 @@ struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 
 void irq_ctx_init(void)
 {
-	struct thread_info *tp;
 	int i;
 
 	for_each_possible_cpu(i) {
 		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
-		tp = softirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
-
 		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
-		tp = hardirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
 	}
 }
 
 void do_softirq_own_stack(void)
 {
-	struct thread_info *curtp, *irqtp;
+	struct thread_info *irqtp;
 
-	curtp = current_thread_info();
 	irqtp = softirq_ctx[smp_processor_id()];
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
 	call_do_softirq(irqtp);
-	irqtp->task = NULL;
-
-	/* Set any flag that may have been set on the
-	 * alternate stack
-	 */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
 }
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 59c578f865aa..5056e54b5239 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -151,41 +151,13 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 	return 1;
 }
 
-static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
 static int kgdb_singlestep(struct pt_regs *regs)
 {
-	struct thread_info *thread_info, *exception_thread_info;
-	struct thread_info *backup_current_thread_info =
-		this_cpu_ptr(&kgdb_thread_info);
-
 	if (user_mode(regs))
 		return 0;
 
-	/*
-	 * On Book E and perhaps other processors, singlestep is handled on
-	 * the critical exception stack.  This causes current_thread_info()
-	 * to fail, since it it locates the thread_info by masking off
-	 * the low bits of the current stack pointer.  We work around
-	 * this issue by copying the thread_info from the kernel stack
-	 * before calling kgdb_handle_exception, and copying it back
-	 * afterwards.  On most processors the copy is avoided since
-	 * exception_thread_info == thread_info.
-	 */
-	thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
-	exception_thread_info = current_thread_info();
-
-	if (thread_info != exception_thread_info) {
-		/* Save the original current_thread_info. */
-		memcpy(backup_current_thread_info, exception_thread_info, sizeof *thread_info);
-		memcpy(exception_thread_info, thread_info, sizeof *thread_info);
-	}
-
 	kgdb_handle_exception(0, SIGTRAP, 0, regs);
 
-	if (thread_info != exception_thread_info)
-		/* Restore current_thread_info lastly. */
-		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
-
 	return 1;
 }
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index a0f6f45005bd..75692c327ba0 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -317,10 +317,8 @@ void default_machine_kexec(struct kimage *image)
 	 * We setup preempt_count to avoid using VMX in memcpy.
 	 * XXX: the task struct will likely be invalid once we do the copy!
 	 */
-	kexec_stack.thread_info.task = current_thread_info()->task;
-	kexec_stack.thread_info.flags = 0;
-	kexec_stack.thread_info.preempt_count = HARDIRQ_OFFSET;
-	kexec_stack.thread_info.cpu = current_thread_info()->cpu;
+	current_thread_info()->flags = 0;
+	current_thread_info()->preempt_count = HARDIRQ_OFFSET;
 
 	/* We need a static PACA, too; copy this CPU's PACA over and switch to
 	 * it. Also poison per_cpu_offset and NULL lppaca to catch anyone using
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 93fa0c99681e..d84351ad1379 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -939,7 +939,7 @@ void __init setup_arch(char **cmdline_p)
 	/* Reserve large chunks of memory for use by CMA for KVM. */
 	kvm_cma_reserve();
 
-	klp_init_thread_info(&init_thread_info);
+	klp_init_thread_info(&init_task.thread_info);
 
 	init_mm.start_code = (unsigned long)_stext;
 	init_mm.end_code = (unsigned long) _etext;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index faf00222b324..2d682f3e31c6 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -691,24 +691,6 @@ void __init exc_lvl_early_init(void)
 #endif
 
 /*
- * Emergency stacks are used for a range of things, from asynchronous
- * NMIs (system reset, machine check) to synchronous, process context.
- * We set preempt_count to zero, even though that isn't necessarily correct. To
- * get the right value we'd need to copy it from the previous thread_info, but
- * doing that might fault causing more problems.
- * TODO: what to do with accounting?
- */
-static void emerg_stack_init_thread_info(struct thread_info *ti, int cpu)
-{
-	ti->task = NULL;
-	ti->cpu = cpu;
-	ti->preempt_count = 0;
-	ti->local_flags = 0;
-	ti->flags = 0;
-	klp_init_thread_info(ti);
-}
-
-/*
  * Stack space used when we detect a bad kernel stack pointer, and
  * early in SMP boots before relocation is enabled. Exclusive emergency
  * stack for machine checks.
@@ -739,20 +721,17 @@ void __init emergency_stack_init(void)
 
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->emergency_sp = (void *)ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->nmi_emergency_sp = (void *)ti + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		emerg_stack_init_thread_info(ti, i);
 		paca_ptrs[i]->mc_emergency_sp = (void *)ti + THREAD_SIZE;
 #endif
 	}
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 19dd0ea55714..f22fcbeb9898 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -816,7 +816,7 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
 				  THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
-	ti->cpu = cpu;
+	idle->cpu = cpu;
 	secondary_ti = current_set[cpu] = ti;
 }
 
-- 
2.13.3

[RFC PATCH v1 6/9] powerpc: regain entire stack space

[Christophe Leroy]

thread_info is not anymore in the stack, so the entire stack
can now be used.

In the meantime, all pointers to the stacks are not anymore
pointers to thread_info so this patch changes them to void*

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/irq.h       | 10 +++++-----
 arch/powerpc/include/asm/processor.h |  3 +--
 arch/powerpc/kernel/asm-offsets.c    |  1 -
 arch/powerpc/kernel/entry_32.S       | 14 ++++----------
 arch/powerpc/kernel/irq.c            | 19 +++++++++----------
 arch/powerpc/kernel/misc_32.S        |  6 ++----
 arch/powerpc/kernel/process.c        |  9 +++------
 arch/powerpc/kernel/setup_64.c       |  8 ++++----
 8 files changed, 28 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index 8108d1fe33ca..3987929408d3 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -48,9 +48,9 @@ struct pt_regs;
  * Per-cpu stacks for handling critical, debug and machine check
  * level interrupts.
  */
-extern struct thread_info *critirq_ctx[NR_CPUS];
-extern struct thread_info *dbgirq_ctx[NR_CPUS];
-extern struct thread_info *mcheckirq_ctx[NR_CPUS];
+extern void *critirq_ctx[NR_CPUS];
+extern void *dbgirq_ctx[NR_CPUS];
+extern void *mcheckirq_ctx[NR_CPUS];
 extern void exc_lvl_ctx_init(void);
 #else
 #define exc_lvl_ctx_init()
@@ -59,8 +59,8 @@ extern void exc_lvl_ctx_init(void);
 /*
  * Per-cpu stacks for handling hard and soft interrupts.
  */
-extern struct thread_info *hardirq_ctx[NR_CPUS];
-extern struct thread_info *softirq_ctx[NR_CPUS];
+extern void *hardirq_ctx[NR_CPUS];
+extern void *softirq_ctx[NR_CPUS];
 
 extern void irq_ctx_init(void);
 extern void call_do_softirq(void *tp);
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 31873614392f..834d0d701e19 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -332,8 +332,7 @@ struct thread_struct {
 #define ARCH_MIN_TASKALIGN 16
 
 #define INIT_SP		(sizeof(init_stack) + (unsigned long) &init_stack)
-#define INIT_SP_LIMIT \
-	(_ALIGN_UP(sizeof(struct thread_info), 16) + (unsigned long) &init_stack)
+#define INIT_SP_LIMIT	((unsigned long) &init_stack)
 
 #ifdef CONFIG_SPE
 #define SPEFSCR_INIT \
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index b042d85325f5..ae7eda4ca09e 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -85,7 +85,6 @@ int main(void)
 	DEFINE(NMI_MASK, NMI_MASK);
 	OFFSET(TASKTHREADPPR, task_struct, thread.ppr);
 #else
-	DEFINE(THREAD_INFO_GAP, _ALIGN_UP(sizeof(struct thread_info), 16));
 	OFFSET(KSP_LIMIT, thread_struct, ksp_limit);
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index a14f9b5f2762..b45da00b01ef 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -97,14 +97,11 @@ crit_transfer_to_handler:
 	mfspr	r0,SPRN_SRR1
 	stw	r0,_SRR1(r11)
 
-	/* set the stack limit to the current stack
-	 * and set the limit to protect the thread_info
-	 * struct
-	 */
+	/* set the stack limit to the current stack */
 	mfspr	r8,SPRN_SPRG_THREAD
 	lwz	r0,KSP_LIMIT(r8)
 	stw	r0,SAVED_KSP_LIMIT(r11)
-	rlwimi	r0,r1,0,0,(31-THREAD_SHIFT)
+	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
 	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 #endif
@@ -121,14 +118,11 @@ crit_transfer_to_handler:
 	mfspr	r0,SPRN_SRR1
 	stw	r0,crit_srr1@l(0)
 
-	/* set the stack limit to the current stack
-	 * and set the limit to protect the thread_info
-	 * struct
-	 */
+	/* set the stack limit to the current stack */
 	mfspr	r8,SPRN_SPRG_THREAD
 	lwz	r0,KSP_LIMIT(r8)
 	stw	r0,saved_ksp_limit@l(0)
-	rlwimi	r0,r1,0,0,(31-THREAD_SHIFT)
+	rlwinm	r0,r1,0,0,(31 - THREAD_SHIFT)
 	stw	r0,KSP_LIMIT(r8)
 	/* fall through */
 #endif
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 699f0f816687..00dbee440bc2 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -618,9 +618,8 @@ static inline void check_stack_overflow(void)
 	sp = current_stack_pointer() & (THREAD_SIZE-1);
 
 	/* check for stack overflow: is there less than 2KB free? */
-	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
-		pr_err("do_IRQ: stack overflow: %ld\n",
-			sp - sizeof(struct thread_info));
+	if (unlikely(sp < 2048)) {
+		pr_err("do_IRQ: stack overflow: %ld\n", sp);
 		dump_stack();
 	}
 #endif
@@ -660,7 +659,7 @@ void __do_irq(struct pt_regs *regs)
 void do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
-	struct thread_info *curtp, *irqtp, *sirqtp;
+	void *curtp, *irqtp, *sirqtp;
 
 	/* Switch to the irq stack to handle this */
 	curtp = (void*)(current_stack_pointer() & ~(THREAD_SIZE - 1));
@@ -690,9 +689,9 @@ void __init init_IRQ(void)
 }
 
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
-struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
+void   *critirq_ctx[NR_CPUS] __read_mostly;
+void    *dbgirq_ctx[NR_CPUS] __read_mostly;
+void *mcheckirq_ctx[NR_CPUS] __read_mostly;
 
 void exc_lvl_ctx_init(void)
 {
@@ -718,8 +717,8 @@ void exc_lvl_ctx_init(void)
 }
 #endif
 
-struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
+void *softirq_ctx[NR_CPUS] __read_mostly;
+void *hardirq_ctx[NR_CPUS] __read_mostly;
 
 void irq_ctx_init(void)
 {
@@ -733,7 +732,7 @@ void irq_ctx_init(void)
 
 void do_softirq_own_stack(void)
 {
-	struct thread_info *irqtp;
+	void *irqtp;
 
 	irqtp = softirq_ctx[smp_processor_id()];
 	call_do_softirq(irqtp);
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 24a7f18ea10c..d3ba56307eb4 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -46,11 +46,10 @@ _GLOBAL(call_do_softirq)
 	mflr	r0
 	stw	r0,4(r1)
 	lwz	r10,THREAD+KSP_LIMIT(r2)
-	addi	r11,r3,THREAD_INFO_GAP
+	stw	r3, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
 	mr	r1,r3
 	stw	r10,8(r1)
-	stw	r11,THREAD+KSP_LIMIT(r2)
 	bl	__do_softirq
 	lwz	r10,8(r1)
 	lwz	r1,0(r1)
@@ -66,11 +65,10 @@ _GLOBAL(call_do_irq)
 	mflr	r0
 	stw	r0,4(r1)
 	lwz	r10,THREAD+KSP_LIMIT(r2)
-	addi	r11,r4,THREAD_INFO_GAP
+	stw	r4, THREAD+KSP_LIMIT(r2)
 	stwu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
 	mr	r1,r4
 	stw	r10,8(r1)
-	stw	r11,THREAD+KSP_LIMIT(r2)
 	bl	__do_irq
 	lwz	r10,8(r1)
 	lwz	r1,0(r1)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 111abb4df2ec..1e01bf42dc82 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1691,8 +1691,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	sp -= STACK_FRAME_OVERHEAD;
 	p->thread.ksp = sp;
 #ifdef CONFIG_PPC32
-	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
-				_ALIGN_UP(sizeof(struct thread_info), 16);
+	p->thread.ksp_limit = (unsigned long)task_stack_page(p);
 #endif
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	p->thread.ptrace_bps[0] = NULL;
@@ -2001,13 +2000,11 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 	 */
 	if (cpu < NR_CPUS && cpu_possible(cpu)) {
 		stack_page = (unsigned long) hardirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
+		if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
 			return 1;
 
 		stack_page = (unsigned long) softirq_ctx[cpu];
-		if (sp >= stack_page + sizeof(struct thread_struct)
-		    && sp <= stack_page + THREAD_SIZE - nbytes)
+		if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
 			return 1;
 	}
 	return 0;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 2d682f3e31c6..6792e9c90689 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -717,22 +717,22 @@ void __init emergency_stack_init(void)
 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
 
 	for_each_possible_cpu(i) {
-		struct thread_info *ti;
+		void *ti;
 
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		paca_ptrs[i]->emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->emergency_sp = ti + THREAD_SIZE;
 
 #ifdef CONFIG_PPC_BOOK3S_64
 		/* emergency stack for NMI exception handling. */
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		paca_ptrs[i]->nmi_emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->nmi_emergency_sp = ti + THREAD_SIZE;
 
 		/* emergency stack for machine check exception handling. */
 		ti = alloc_stack(limit, i);
 		memset(ti, 0, THREAD_SIZE);
-		paca_ptrs[i]->mc_emergency_sp = (void *)ti + THREAD_SIZE;
+		paca_ptrs[i]->mc_emergency_sp = ti + THREAD_SIZE;
 #endif
 	}
 }
-- 
2.13.3

[RFC PATCH v1 7/9] powerpc: 'current_set' is now a table of task_struct pointers

[Christophe Leroy]

The table of pointers 'current_set' has been used for retrieving
the stack and current. They used to be thread_info pointers as
they were pointing to the stack and current was taken from the
'task' field of the thread_info.

Now, the pointers of 'current_set' table are now both pointers
to task_struct and pointers to thread_info.

As they are used to get current, and the stack pointer is
retrieved from current's stack field, this patch changes
their type to task_struct, and renames secondary_ti to
secondary_current.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/asm-prototypes.h |  4 ++--
 arch/powerpc/kernel/head_32.S             |  6 +++---
 arch/powerpc/kernel/head_44x.S            |  4 ++--
 arch/powerpc/kernel/head_fsl_booke.S      |  4 ++--
 arch/powerpc/kernel/smp.c                 | 10 ++++------
 5 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 78ed3c3f879a..e74d24821931 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -23,8 +23,8 @@
 #include <uapi/asm/ucontext.h>
 
 /* SMP */
-extern struct thread_info *current_set[NR_CPUS];
-extern struct thread_info *secondary_ti;
+extern struct task_struct *current_set[NR_CPUS];
+extern struct task_struct *secondary_current;
 void start_secondary(void *unused);
 
 /* kexec */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 44dfd73b2a62..ba0341bd5a00 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -842,9 +842,9 @@ __secondary_start:
 #endif /* CONFIG_6xx */
 
 	/* get current's stack and current */
-	lis	r1,secondary_ti@ha
-	tophys(r1,r1)
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	tophys(r2,r2)
+	lwz	r2,secondary_current@l(r2)
 	tophys(r1,r2)
 	lwz	r1,TASK_STACK(r1)
 
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 2c7e90f36358..48e4de4dfd0c 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1021,8 +1021,8 @@ _GLOBAL(start_secondary_47x)
 	/* Now we can get our task struct and real stack pointer */
 
 	/* Get current's stack and current */
-	lis	r1,secondary_ti@ha
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	lwz	r2,secondary_current@l(r2)
 	lwz	r1,TASK_STACK(r2)
 
 	/* Current stack pointer */
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index b8a2b789677e..0d27bfff52dd 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1076,8 +1076,8 @@ __secondary_start:
 	bl	call_setup_cpu
 
 	/* get current's stack and current */
-	lis	r1,secondary_ti@ha
-	lwz	r2,secondary_ti@l(r1)
+	lis	r2,secondary_current@ha
+	lwz	r2,secondary_current@l(r2)
 	lwz	r1,TASK_STACK(r2)
 
 	/* stack */
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index f22fcbeb9898..00193643f0da 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -74,7 +74,7 @@
 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
 #endif
 
-struct thread_info *secondary_ti;
+struct task_struct *secondary_current;
 
 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
 DEFINE_PER_CPU(cpumask_var_t, cpu_l2_cache_map);
@@ -644,7 +644,7 @@ void smp_send_stop(void)
 }
 #endif /* CONFIG_NMI_IPI */
 
-struct thread_info *current_set[NR_CPUS];
+struct task_struct *current_set[NR_CPUS];
 
 static void smp_store_cpu_info(int id)
 {
@@ -724,7 +724,7 @@ void smp_prepare_boot_cpu(void)
 	paca_ptrs[boot_cpuid]->__current = current;
 #endif
 	set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
-	current_set[boot_cpuid] = task_thread_info(current);
+	current_set[boot_cpuid] = current;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -809,15 +809,13 @@ static bool secondaries_inhibited(void)
 
 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 {
-	struct thread_info *ti = task_thread_info(idle);
-
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
 	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
 				  THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
 	idle->cpu = cpu;
-	secondary_ti = current_set[cpu] = ti;
+	secondary_current = current_set[cpu] = idle;
 }
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
-- 
2.13.3

[RFC PATCH v1 8/9] powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU

[Christophe Leroy]

Now that thread_info is similar to task_struct, it's address is in r2
so CURRENT_THREAD_INFO() macro is useless. This patch removes it.

At the same time, as the 'cpu' field is not anymore in thread_info,
this patch renames it to TASK_CPU.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/thread_info.h |  2 --
 arch/powerpc/kernel/asm-offsets.c      |  2 +-
 arch/powerpc/kernel/entry_32.S         | 43 ++++++++++++----------------------
 arch/powerpc/kernel/epapr_hcalls.S     |  5 ++--
 arch/powerpc/kernel/head_fsl_booke.S   |  5 ++--
 arch/powerpc/kernel/idle_6xx.S         |  8 +++----
 arch/powerpc/kernel/idle_e500.S        |  8 +++----
 arch/powerpc/kernel/misc_32.S          |  3 +--
 arch/powerpc/mm/hash_low_32.S          | 14 ++++-------
 arch/powerpc/sysdev/6xx-suspend.S      |  5 ++--
 10 files changed, 34 insertions(+), 61 deletions(-)

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 62eb9ff31292..1c42df627bf3 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -19,8 +19,6 @@
 
 #ifdef CONFIG_PPC64
 #define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
-#else
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(mr dest, r2)
 #endif
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ae7eda4ca09e..08b8bfd98737 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -89,7 +89,7 @@ int main(void)
 #endif /* CONFIG_PPC64 */
 	OFFSET(TASK_STACK, task_struct, stack);
 #ifdef CONFIG_SMP
-	OFFSET(TI_CPU, task_struct, cpu);
+	OFFSET(TASK_CPU, task_struct, cpu);
 #endif
 
 #ifdef CONFIG_LIVEPATCH
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index b45da00b01ef..5d12b26e20a4 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -168,8 +168,7 @@ transfer_to_handler:
 	tophys(r11,r11)
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_CPU(r9)
+	lwz	r9,TASK_CPU(r2)
 	slwi	r9,r9,3
 	add	r11,r11,r9
 #endif
@@ -180,8 +179,7 @@ transfer_to_handler:
 	stw	r12,4(r11)
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-	CURRENT_THREAD_INFO(r9, r1)
-	tophys(r9, r9)
+	tophys(r9, r2)
 	ACCOUNT_CPU_USER_ENTRY(r9, r11, r12)
 #endif
 
@@ -195,8 +193,7 @@ transfer_to_handler:
 	ble-	stack_ovf		/* then the kernel stack overflowed */
 5:
 #if defined(CONFIG_6xx) || defined(CONFIG_E500)
-	CURRENT_THREAD_INFO(r9, r1)
-	tophys(r9,r9)			/* check local flags */
+	tophys(r9,r2)			/* check local flags */
 	lwz	r12,TI_LOCAL_FLAGS(r9)
 	mtcrf	0x01,r12
 	bt-	31-TLF_NAPPING,4f
@@ -345,8 +342,7 @@ _GLOBAL(DoSyscall)
 	mtmsr	r11
 1:
 #endif /* CONFIG_TRACE_IRQFLAGS */
-	CURRENT_THREAD_INFO(r10, r1)
-	lwz	r11,TI_FLAGS(r10)
+	lwz	r11,TI_FLAGS(r2)
 	andi.	r11,r11,_TIF_SYSCALL_DOTRACE
 	bne-	syscall_dotrace
 syscall_dotrace_cont:
@@ -379,13 +375,12 @@ ret_from_syscall:
 	lwz	r3,GPR3(r1)
 #endif
 	mr	r6,r3
-	CURRENT_THREAD_INFO(r12, r1)
 	/* disable interrupts so current_thread_info()->flags can't change */
 	LOAD_MSR_KERNEL(r10,MSR_KERNEL)	/* doesn't include MSR_EE */
 	/* Note: We don't bother telling lockdep about it */
 	SYNC
 	MTMSRD(r10)
-	lwz	r9,TI_FLAGS(r12)
+	lwz	r9,TI_FLAGS(r2)
 	li	r8,-MAX_ERRNO
 	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
 	bne-	syscall_exit_work
@@ -432,8 +427,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	andi.	r4,r8,MSR_PR
 	beq	3f
-	CURRENT_THREAD_INFO(r4, r1)
-	ACCOUNT_CPU_USER_EXIT(r4, r5, r7)
+	ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
 3:
 #endif
 	lwz	r4,_LINK(r1)
@@ -526,7 +520,7 @@ syscall_exit_work:
 	/* Clear per-syscall TIF flags if any are set.  */
 
 	li	r11,_TIF_PERSYSCALL_MASK
-	addi	r12,r12,TI_FLAGS
+	addi	r12,r2,TI_FLAGS
 3:	lwarx	r8,0,r12
 	andc	r8,r8,r11
 #ifdef CONFIG_IBM405_ERR77
@@ -534,7 +528,6 @@ syscall_exit_work:
 #endif
 	stwcx.	r8,0,r12
 	bne-	3b
-	subi	r12,r12,TI_FLAGS
 	
 4:	/* Anything which requires enabling interrupts? */
 	andi.	r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
@@ -813,8 +806,7 @@ ret_from_except:
 
 user_exc_return:		/* r10 contains MSR_KERNEL here */
 	/* Check current_thread_info()->flags */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_FLAGS(r9)
+	lwz	r9,TI_FLAGS(r2)
 	andi.	r0,r9,_TIF_USER_WORK_MASK
 	bne	do_work
 
@@ -827,8 +819,7 @@ restore_user:
 	bnel-	load_dbcr0
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-	CURRENT_THREAD_INFO(r9, r1)
-	ACCOUNT_CPU_USER_EXIT(r9, r10, r11)
+	ACCOUNT_CPU_USER_EXIT(r2, r10, r11)
 #endif
 
 	b	restore
@@ -836,8 +827,7 @@ restore_user:
 /* N.B. the only way to get here is from the beq following ret_from_except. */
 resume_kernel:
 	/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r8,TI_FLAGS(r9)
+	lwz	r8,TI_FLAGS(r2)
 	andis.	r0,r8,_TIF_EMULATE_STACK_STORE@h
 	beq+	1f
 
@@ -863,7 +853,7 @@ resume_kernel:
 
 	/* Clear _TIF_EMULATE_STACK_STORE flag */
 	lis	r11,_TIF_EMULATE_STACK_STORE@h
-	addi	r5,r9,TI_FLAGS
+	addi	r5,r2,TI_FLAGS
 0:	lwarx	r8,0,r5
 	andc	r8,r8,r11
 #ifdef CONFIG_IBM405_ERR77
@@ -875,7 +865,7 @@ resume_kernel:
 
 #ifdef CONFIG_PREEMPT
 	/* check current_thread_info->preempt_count */
-	lwz	r0,TI_PREEMPT(r9)
+	lwz	r0,TI_PREEMPT(r2)
 	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
 	bne	restore
 	andi.	r8,r8,_TIF_NEED_RESCHED
@@ -891,8 +881,7 @@ resume_kernel:
 	bl	trace_hardirqs_off
 #endif
 1:	bl	preempt_schedule_irq
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r3,TI_FLAGS(r9)
+	lwz	r3,TI_FLAGS(r2)
 	andi.	r0,r3,_TIF_NEED_RESCHED
 	bne-	1b
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -1191,8 +1180,7 @@ load_dbcr0:
 	lis	r11,global_dbcr0@ha
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_CPU(r9)
+	lwz	r9,TASK_CPU(r2)
 	slwi	r9,r9,3
 	add	r11,r11,r9
 #endif
@@ -1232,8 +1220,7 @@ recheck:
 	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
 	SYNC
 	MTMSRD(r10)		/* disable interrupts */
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r9,TI_FLAGS(r9)
+	lwz	r9,TI_FLAGS(r2)
 	andi.	r0,r9,_TIF_NEED_RESCHED
 	bne-	do_resched
 	andi.	r0,r9,_TIF_USER_WORK_MASK
diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
index 52ca2471ee1a..d252f4663a23 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -21,10 +21,9 @@
 #ifndef CONFIG_PPC64
 /* epapr_ev_idle() was derived from e500_idle() */
 _GLOBAL(epapr_ev_idle)
-	CURRENT_THREAD_INFO(r3, r1)
-	PPC_LL	r4, TI_LOCAL_FLAGS(r3)	/* set napping bit */
+	PPC_LL	r4, TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
-	PPC_STL	r4, TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
+	PPC_STL	r4, TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 
 	wrteei	1
 
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 0d27bfff52dd..38918f82bc5b 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -244,8 +244,7 @@ set_ivor:
 	stwu	r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r22, r1)
-	stw	r24, TI_CPU(r22)
+	stw	r24, TASK_CPU(r2)
 #endif
 
 	bl	early_init
@@ -704,7 +703,7 @@ finish_tlb_load:
 
 	/* Get the next_tlbcam_idx percpu var */
 #ifdef CONFIG_SMP
-	lwz	r15, TI_CPU-THREAD(r12)
+	lwz	r15, TASK_CPU-THREAD(r12)
 	lis     r14, __per_cpu_offset@h
 	ori     r14, r14, __per_cpu_offset@l
 	rlwinm  r15, r15, 2, 0, 29
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index ff026c9d3cab..5afd2e236990 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -136,10 +136,9 @@ BEGIN_FTR_SECTION
 	DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	CURRENT_THREAD_INFO(r9, r1)
-	lwz	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
+	lwz	r8,TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
-	stw	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
+	stw	r8,TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 	mfmsr	r7
 	ori	r7,r7,MSR_EE
 	oris	r7,r7,MSR_POW@h
@@ -159,8 +158,7 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r12, r11)
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TASK_CPU(r2)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 583e55ac7d26..69dfcd2ca011 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -22,10 +22,9 @@
 	.text
 
 _GLOBAL(e500_idle)
-	CURRENT_THREAD_INFO(r3, r1)
-	lwz	r4,TI_LOCAL_FLAGS(r3)	/* set napping bit */
+	lwz	r4,TI_LOCAL_FLAGS(r2)	/* set napping bit */
 	ori	r4,r4,_TLF_NAPPING	/* so when we take an exception */
-	stw	r4,TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
+	stw	r4,TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
 
 #ifdef CONFIG_PPC_E500MC
 	wrteei	1
@@ -88,8 +87,7 @@ _GLOBAL(power_save_ppc32_restore)
 	stw	r9,_NIP(r11)		/* make it do a blr */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r12, r1)
-	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	lwz	r11,TASK_CPU(r2)		/* get cpu number * 4 */
 	slwi	r11,r11,2
 #else
 	li	r11,0
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index d3ba56307eb4..0509c9a215a7 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -183,8 +183,7 @@ _GLOBAL(low_choose_750fx_pll)
 
 #ifdef CONFIG_SMP
 	/* Store new HID1 image */
-	CURRENT_THREAD_INFO(r6, r1)
-	lwz	r6,TI_CPU(r6)
+	lwz	r6,TASK_CPU(r2)
 	slwi	r6,r6,2
 #else
 	li	r6, 0
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index 26acf6c8c20c..27edbfddebaa 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -185,8 +185,7 @@ _GLOBAL(add_hash_page)
 	add	r3,r3,r0		/* note create_hpte trims to 24 bits */
 
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r8, r1)	/* use cpu number to make tag */
-	lwz	r8,TI_CPU(r8)		/* to go in mmu_hash_lock */
+	lwz	r8,TASK_CPU(r2)		/* to go in mmu_hash_lock */
 	oris	r8,r8,12
 #endif /* CONFIG_SMP */
 
@@ -546,9 +545,8 @@ _GLOBAL(flush_hash_pages)
 #ifdef CONFIG_SMP
 	addis	r9,r7,mmu_hash_lock@ha
 	addi	r9,r9,mmu_hash_lock@l
-	CURRENT_THREAD_INFO(r8, r1)
-	add	r8,r8,r7
-	lwz	r8,TI_CPU(r8)
+	add	r8,r2,r7
+	lwz	r8,TASK_CPU(r8)
 	oris	r8,r8,9
 10:	lwarx	r0,0,r9
 	cmpi	0,r0,0
@@ -641,8 +639,7 @@ EXPORT_SYMBOL(flush_hash_pages)
  */
 _GLOBAL(_tlbie)
 #ifdef CONFIG_SMP
-	CURRENT_THREAD_INFO(r8, r1)
-	lwz	r8,TI_CPU(r8)
+	lwz	r8,TASK_CPU(r2)
 	oris	r8,r8,11
 	mfmsr	r10
 	SYNC
@@ -679,8 +676,7 @@ _GLOBAL(_tlbie)
  */
 _GLOBAL(_tlbia)
 #if defined(CONFIG_SMP)
-	CURRENT_THREAD_INFO(r8, r1)
-	lwz	r8,TI_CPU(r8)
+	lwz	r8,TASK_CPU(r2)
 	oris	r8,r8,10
 	mfmsr	r10
 	SYNC
diff --git a/arch/powerpc/sysdev/6xx-suspend.S b/arch/powerpc/sysdev/6xx-suspend.S
index cf48e9cb2575..6c4aec25c4ba 100644
--- a/arch/powerpc/sysdev/6xx-suspend.S
+++ b/arch/powerpc/sysdev/6xx-suspend.S
@@ -29,10 +29,9 @@ _GLOBAL(mpc6xx_enter_standby)
 	ori	r5, r5, ret_from_standby@l
 	mtlr	r5
 
-	CURRENT_THREAD_INFO(r5, r1)
-	lwz	r6, TI_LOCAL_FLAGS(r5)
+	lwz	r6, TI_LOCAL_FLAGS(r2)
 	ori	r6, r6, _TLF_SLEEPING
-	stw	r6, TI_LOCAL_FLAGS(r5)
+	stw	r6, TI_LOCAL_FLAGS(r2)
 
 	mfmsr	r5
 	ori	r5, r5, MSR_EE
-- 
2.13.3

[RFC PATCH v1 9/9] powerpc/64: Modify CURRENT_THREAD_INFO()

[Christophe Leroy]

CURRENT_THREAD_INFO() now uses the PACA to retrieve 'current' pointer,
it doesn't use 'sp' anymore.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/exception-64s.h       |  4 ++--
 arch/powerpc/include/asm/thread_info.h         |  2 +-
 arch/powerpc/kernel/entry_64.S                 | 10 +++++-----
 arch/powerpc/kernel/exceptions-64e.S           |  2 +-
 arch/powerpc/kernel/exceptions-64s.S           |  2 +-
 arch/powerpc/kernel/idle_book3e.S              |  2 +-
 arch/powerpc/kernel/idle_power4.S              |  2 +-
 arch/powerpc/kernel/trace/ftrace_64_mprofile.S |  6 +++---
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 47578b79f0fb..e38d84c267b8 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -672,7 +672,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 #define RUNLATCH_ON				\
 BEGIN_FTR_SECTION				\
-	CURRENT_THREAD_INFO(r3, r1);		\
+	CURRENT_THREAD_INFO(r3);		\
 	ld	r4,TI_LOCAL_FLAGS(r3);		\
 	andi.	r0,r4,_TLF_RUNLATCH;		\
 	beql	ppc64_runlatch_on_trampoline;	\
@@ -722,7 +722,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
 #ifdef CONFIG_PPC_970_NAP
 #define FINISH_NAP				\
 BEGIN_FTR_SECTION				\
-	CURRENT_THREAD_INFO(r11, r1);		\
+	CURRENT_THREAD_INFO(r11);		\
 	ld	r9,TI_LOCAL_FLAGS(r11);		\
 	andi.	r10,r9,_TLF_NAPPING;		\
 	bnel	power4_fixup_nap;		\
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 1c42df627bf3..a339de87806b 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -18,7 +18,7 @@
 #define THREAD_SIZE		(1 << THREAD_SHIFT)
 
 #ifdef CONFIG_PPC64
-#define CURRENT_THREAD_INFO(dest, sp)	stringify_in_c(ld dest, PACACURRENT(r13))
+#define CURRENT_THREAD_INFO(dest)	stringify_in_c(ld dest, PACACURRENT(r13))
 #endif
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 697406572592..331b9e9b6d78 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -158,7 +158,7 @@ system_call:			/* label this so stack traces look sane */
 	li	r10,IRQS_ENABLED
 	std	r10,SOFTE(r1)
 
-	CURRENT_THREAD_INFO(r11, r1)
+	CURRENT_THREAD_INFO(r11)
 	ld	r10,TI_FLAGS(r11)
 	andi.	r11,r10,_TIF_SYSCALL_DOTRACE
 	bne	.Lsyscall_dotrace		/* does not return */
@@ -205,7 +205,7 @@ system_call:			/* label this so stack traces look sane */
 	ld	r3,RESULT(r1)
 #endif
 
-	CURRENT_THREAD_INFO(r12, r1)
+	CURRENT_THREAD_INFO(r12)
 
 	ld	r8,_MSR(r1)
 #ifdef CONFIG_PPC_BOOK3S
@@ -336,7 +336,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
 	/* Repopulate r9 and r10 for the syscall path */
 	addi	r9,r1,STACK_FRAME_OVERHEAD
-	CURRENT_THREAD_INFO(r10, r1)
+	CURRENT_THREAD_INFO(r10)
 	ld	r10,TI_FLAGS(r10)
 
 	cmpldi	r0,NR_syscalls
@@ -731,7 +731,7 @@ _GLOBAL(ret_from_except_lite)
 	mtmsrd	r10,1		  /* Update machine state */
 #endif /* CONFIG_PPC_BOOK3E */
 
-	CURRENT_THREAD_INFO(r9, r1)
+	CURRENT_THREAD_INFO(r9)
 	ld	r3,_MSR(r1)
 #ifdef CONFIG_PPC_BOOK3E
 	ld	r10,PACACURRENT(r13)
@@ -845,7 +845,7 @@ resume_kernel:
 1:	bl	preempt_schedule_irq
 
 	/* Re-test flags and eventually loop */
-	CURRENT_THREAD_INFO(r9, r1)
+	CURRENT_THREAD_INFO(r9)
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 231d066b4a3d..f48d9aa07a73 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -469,7 +469,7 @@ exc_##n##_bad_stack:							    \
  * interrupts happen before the wait instruction.
  */
 #define CHECK_NAPPING()							\
-	CURRENT_THREAD_INFO(r11, r1);					\
+	CURRENT_THREAD_INFO(r11);					\
 	ld	r10,TI_LOCAL_FLAGS(r11);				\
 	andi.	r9,r10,_TLF_NAPPING;					\
 	beq+	1f;							\
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 89d32bb79d5e..07701063d36e 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1620,7 +1620,7 @@ do_hash_page:
 	ori	r0,r0,DSISR_BAD_FAULT_64S@l
 	and.	r0,r4,r0		/* weird error? */
 	bne-	handle_page_fault	/* if not, try to insert a HPTE */
-	CURRENT_THREAD_INFO(r11, r1)
+	CURRENT_THREAD_INFO(r11)
 	lwz	r0,TI_PREEMPT(r11)	/* If we're in an "NMI" */
 	andis.	r0,r0,NMI_MASK@h	/* (i.e. an irq when soft-disabled) */
 	bne	77f			/* then don't call hash_page now */
diff --git a/arch/powerpc/kernel/idle_book3e.S b/arch/powerpc/kernel/idle_book3e.S
index 4e0d94d02030..23f3d927ea4f 100644
--- a/arch/powerpc/kernel/idle_book3e.S
+++ b/arch/powerpc/kernel/idle_book3e.S
@@ -63,7 +63,7 @@ _GLOBAL(\name)
 1:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
 	 * to the right spot
 	*/
-	CURRENT_THREAD_INFO(r11, r1)
+	CURRENT_THREAD_INFO(r11)
 	ld	r10,TI_LOCAL_FLAGS(r11)
 	ori	r10,r10,_TLF_NAPPING
 	std	r10,TI_LOCAL_FLAGS(r11)
diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index a09b3c7ca176..80e09f4ec056 100644
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -68,7 +68,7 @@ BEGIN_FTR_SECTION
 	DSSALL
 	sync
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
-	CURRENT_THREAD_INFO(r9, r1)
+	CURRENT_THREAD_INFO(r9)
 	ld	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
 	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
 	std	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
index 32476a6e4e9c..5ba39ec48cdd 100644
--- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
@@ -229,7 +229,7 @@ ftrace_call:
 	 *  - r0, r11 & r12 are free
 	 */
 livepatch_handler:
-	CURRENT_THREAD_INFO(r12, r1)
+	CURRENT_THREAD_INFO(r12)
 
 	/* Allocate 3 x 8 bytes */
 	ld	r11, TI_livepatch_sp(r12)
@@ -256,7 +256,7 @@ livepatch_handler:
 	 * restore it.
 	 */
 
-	CURRENT_THREAD_INFO(r12, r1)
+	CURRENT_THREAD_INFO(r12)
 
 	ld	r11, TI_livepatch_sp(r12)
 
@@ -273,7 +273,7 @@ livepatch_handler:
 	ld	r2,  -24(r11)
 
 	/* Pop livepatch stack frame */
-	CURRENT_THREAD_INFO(r12, r1)
+	CURRENT_THREAD_INFO(r12)
 	subi	r11, r11, 24
 	std	r11, TI_livepatch_sp(r12)
 
-- 
2.13.3

Re: [RFC PATCH v1 1/9] timer: fix circular header dependency

[Christophe LEROY]

Le 24/09/2018 à 17:52, Christophe Leroy a écrit :
> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
> has to be included in asm/smp.h for the following change, in order
> to avoid uncomplete definition of task_struct:
> 
> -#define raw_smp_processor_id() (current_thread_info()->cpu)
> +#define raw_smp_processor_id() (current->cpu)
> 
> But this generates the following compilation error, due to circular
> header dependency.
> 
>    CC      kernel/time/alarmtimer.o
> In file included from ./arch/powerpc/include/asm/smp.h:31,
>                   from ./include/linux/smp.h:64,
>                   from ./include/linux/percpu.h:7,
>                   from ./include/linux/hrtimer.h:22,
>                   from kernel/time/alarmtimer.c:19:
> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
>    struct hrtimer   dl_timer;
>                     ^~~~~~~~
> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
>    struct hrtimer inactive_timer;
>                   ^~~~~~~~~~~~~~
> make[1]: *** [kernel/time/alarmtimer.o] Error 1
> make: *** [kernel/time/alarmtimer.o] Error 2
> 
>    CC      fs/timerfd.o
> In file included from ./arch/powerpc/include/asm/smp.h:31,
>                   from ./include/linux/smp.h:64,
>                   from ./include/linux/percpu.h:7,
>                   from ./include/linux/hrtimer.h:22,
>                   from ./include/linux/alarmtimer.h:6,
>                   from fs/timerfd.c:12:
> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
>    struct hrtimer   dl_timer;
>                     ^~~~~~~~
> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
>    struct hrtimer inactive_timer;
>                   ^~~~~~~~~~~~~~
> make[1]: *** [fs/timerfd.o] Error 1
> make: *** [fs/timerfd.o] Error 2
> 
> This patch fixes it by including linux/hrtimer.h after linux/sched.h
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>   Should it be fixed in powerpc instead ? In that case, how ? Any idea ?


Looks like there are several other places where the problem occurs, so 
it has to be fixed in the powerpc headers instead.

Seems like RISC arch faced the same issue, and fixed it the following way:

/*
  * This is particularly ugly: it appears we can't actually get the 
definition
  * of task_struct here, but we need access to the CPU this task is 
running on.
  * Instead of using C we're using asm-offsets.h to get the current 
processor
  * ID.
  */
#define raw_smp_processor_id() (*((int*)((char*)get_current() + 
TASK_TI_CPU)))


Unless someone has a better idea, I'll fixed it that way.

Christophe


> 
>   fs/timerfd.c             | 2 +-
>   kernel/time/alarmtimer.c | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/timerfd.c b/fs/timerfd.c
> index d69ad801eb80..0fc01b241382 100644
> --- a/fs/timerfd.c
> +++ b/fs/timerfd.c
> @@ -9,12 +9,12 @@
>    *
>    */
>   
> -#include <linux/alarmtimer.h>
>   #include <linux/file.h>
>   #include <linux/poll.h>
>   #include <linux/init.h>
>   #include <linux/fs.h>
>   #include <linux/sched.h>
> +#include <linux/alarmtimer.h>
>   #include <linux/kernel.h>
>   #include <linux/slab.h>
>   #include <linux/list.h>
> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
> index fa5de5e8de61..5fb75c9b3f06 100644
> --- a/kernel/time/alarmtimer.c
> +++ b/kernel/time/alarmtimer.c
> @@ -16,11 +16,11 @@
>    * published by the Free Software Foundation.
>    */
>   #include <linux/time.h>
> -#include <linux/hrtimer.h>
>   #include <linux/timerqueue.h>
>   #include <linux/rtc.h>
>   #include <linux/sched/signal.h>
>   #include <linux/sched/debug.h>
> +#include <linux/hrtimer.h>
>   #include <linux/alarmtimer.h>
>   #include <linux/mutex.h>
>   #include <linux/platform_device.h>
> 

Re: [RFC PATCH v1 1/9] timer: fix circular header dependency

[Christophe LEROY]

Le 25/09/2018 à 07:34, Christophe LEROY a écrit :
> 
> 
> Le 24/09/2018 à 17:52, Christophe Leroy a écrit :
>> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
>> has to be included in asm/smp.h for the following change, in order
>> to avoid uncomplete definition of task_struct:
>>
>> -#define raw_smp_processor_id() (current_thread_info()->cpu)
>> +#define raw_smp_processor_id() (current->cpu)
>>
>> But this generates the following compilation error, due to circular
>> header dependency.
>>
>>    CC      kernel/time/alarmtimer.o
>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>                   from ./include/linux/smp.h:64,
>>                   from ./include/linux/percpu.h:7,
>>                   from ./include/linux/hrtimer.h:22,
>>                   from kernel/time/alarmtimer.c:19:
>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete 
>> type
>>    struct hrtimer   dl_timer;
>>                     ^~~~~~~~
>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has 
>> incomplete type
>>    struct hrtimer inactive_timer;
>>                   ^~~~~~~~~~~~~~
>> make[1]: *** [kernel/time/alarmtimer.o] Error 1
>> make: *** [kernel/time/alarmtimer.o] Error 2
>>
>>    CC      fs/timerfd.o
>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>                   from ./include/linux/smp.h:64,
>>                   from ./include/linux/percpu.h:7,
>>                   from ./include/linux/hrtimer.h:22,
>>                   from ./include/linux/alarmtimer.h:6,
>>                   from fs/timerfd.c:12:
>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete 
>> type
>>    struct hrtimer   dl_timer;
>>                     ^~~~~~~~
>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has 
>> incomplete type
>>    struct hrtimer inactive_timer;
>>                   ^~~~~~~~~~~~~~
>> make[1]: *** [fs/timerfd.o] Error 1
>> make: *** [fs/timerfd.o] Error 2
>>
>> This patch fixes it by including linux/hrtimer.h after linux/sched.h
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>>   Should it be fixed in powerpc instead ? In that case, how ? Any idea ?
> 
> 
> Looks like there are several other places where the problem occurs, so 
> it has to be fixed in the powerpc headers instead.
> 
> Seems like RISC arch faced the same issue, and fixed it the following way:
> 
> /*
>   * This is particularly ugly: it appears we can't actually get the 
> definition
>   * of task_struct here, but we need access to the CPU this task is 
> running on.
>   * Instead of using C we're using asm-offsets.h to get the current 
> processor
>   * ID.
>   */
> #define raw_smp_processor_id() (*((int*)((char*)get_current() + 
> TASK_TI_CPU)))
> 
> 
> Unless someone has a better idea, I'll fixed it that way.


Not easy. I'm stuck at the moment, because asm-offsets.h redefines a lot 
of things with the same name as in C, so when including asm-offsets.h in 
C it conflicts. Argh !. Need to fix all those duplicates ?

Christophe

> 
> Christophe
> 
> 
>>
>>   fs/timerfd.c             | 2 +-
>>   kernel/time/alarmtimer.c | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/timerfd.c b/fs/timerfd.c
>> index d69ad801eb80..0fc01b241382 100644
>> --- a/fs/timerfd.c
>> +++ b/fs/timerfd.c
>> @@ -9,12 +9,12 @@
>>    *
>>    */
>> -#include <linux/alarmtimer.h>
>>   #include <linux/file.h>
>>   #include <linux/poll.h>
>>   #include <linux/init.h>
>>   #include <linux/fs.h>
>>   #include <linux/sched.h>
>> +#include <linux/alarmtimer.h>
>>   #include <linux/kernel.h>
>>   #include <linux/slab.h>
>>   #include <linux/list.h>
>> diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
>> index fa5de5e8de61..5fb75c9b3f06 100644
>> --- a/kernel/time/alarmtimer.c
>> +++ b/kernel/time/alarmtimer.c
>> @@ -16,11 +16,11 @@
>>    * published by the Free Software Foundation.
>>    */
>>   #include <linux/time.h>
>> -#include <linux/hrtimer.h>
>>   #include <linux/timerqueue.h>
>>   #include <linux/rtc.h>
>>   #include <linux/sched/signal.h>
>>   #include <linux/sched/debug.h>
>> +#include <linux/hrtimer.h>
>>   #include <linux/alarmtimer.h>
>>   #include <linux/mutex.h>
>>   #include <linux/platform_device.h>
>>

Re: [RFC PATCH v1 1/9] timer: fix circular header dependency

[Mark Rutland]

On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote:
> 
> 
> Le 24/09/2018 à 17:52, Christophe Leroy a écrit :
> > When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
> > has to be included in asm/smp.h for the following change, in order
> > to avoid uncomplete definition of task_struct:
> > 
> > -#define raw_smp_processor_id() (current_thread_info()->cpu)
> > +#define raw_smp_processor_id() (current->cpu)
> > 
> > But this generates the following compilation error, due to circular
> > header dependency.
> > 
> >    CC      kernel/time/alarmtimer.o
> > In file included from ./arch/powerpc/include/asm/smp.h:31,
> >                   from ./include/linux/smp.h:64,
> >                   from ./include/linux/percpu.h:7,
> >                   from ./include/linux/hrtimer.h:22,
> >                   from kernel/time/alarmtimer.c:19:
> > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
> >    struct hrtimer   dl_timer;
> >                     ^~~~~~~~
> > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
> >    struct hrtimer inactive_timer;
> >                   ^~~~~~~~~~~~~~
> > make[1]: *** [kernel/time/alarmtimer.o] Error 1
> > make: *** [kernel/time/alarmtimer.o] Error 2
> > 
> >    CC      fs/timerfd.o
> > In file included from ./arch/powerpc/include/asm/smp.h:31,
> >                   from ./include/linux/smp.h:64,
> >                   from ./include/linux/percpu.h:7,
> >                   from ./include/linux/hrtimer.h:22,
> >                   from ./include/linux/alarmtimer.h:6,
> >                   from fs/timerfd.c:12:
> > ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
> >    struct hrtimer   dl_timer;
> >                     ^~~~~~~~
> > ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
> >    struct hrtimer inactive_timer;
> >                   ^~~~~~~~~~~~~~
> > make[1]: *** [fs/timerfd.o] Error 1
> > make: *** [fs/timerfd.o] Error 2
> > 
> > This patch fixes it by including linux/hrtimer.h after linux/sched.h
> > 
> > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> > ---
> >   Should it be fixed in powerpc instead ? In that case, how ? Any idea ?
> 
> 
> Looks like there are several other places where the problem occurs, so it
> has to be fixed in the powerpc headers instead.
> 
> Seems like RISC arch faced the same issue, and fixed it the following way:
> 
> /*
>  * This is particularly ugly: it appears we can't actually get the
> definition
>  * of task_struct here, but we need access to the CPU this task is running
> on.
>  * Instead of using C we're using asm-offsets.h to get the current processor
>  * ID.
>  */
> #define raw_smp_processor_id() (*((int*)((char*)get_current() +
> TASK_TI_CPU)))
> 
> 
> Unless someone has a better idea, I'll fixed it that way.

To solve this on arm64 we made the cpu number a percpu variable; see
commit:

  57c82954e77fa12c ("arm64: make cpu number a percpu variable")

IIUC, you could do that by placing it in paca_struct.

Thanks,
Mark.

Re: [RFC PATCH v1 1/9] timer: fix circular header dependency

[Christophe LEROY]

Le 25/09/2018 à 14:11, Mark Rutland a écrit :
> On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote:
>>
>>
>> Le 24/09/2018 à 17:52, Christophe Leroy a écrit :
>>> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
>>> has to be included in asm/smp.h for the following change, in order
>>> to avoid uncomplete definition of task_struct:
>>>
>>> -#define raw_smp_processor_id() (current_thread_info()->cpu)
>>> +#define raw_smp_processor_id() (current->cpu)
>>>
>>> But this generates the following compilation error, due to circular
>>> header dependency.
>>>
>>>     CC      kernel/time/alarmtimer.o
>>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>>                    from ./include/linux/smp.h:64,
>>>                    from ./include/linux/percpu.h:7,
>>>                    from ./include/linux/hrtimer.h:22,
>>>                    from kernel/time/alarmtimer.c:19:
>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
>>>     struct hrtimer   dl_timer;
>>>                      ^~~~~~~~
>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
>>>     struct hrtimer inactive_timer;
>>>                    ^~~~~~~~~~~~~~
>>> make[1]: *** [kernel/time/alarmtimer.o] Error 1
>>> make: *** [kernel/time/alarmtimer.o] Error 2
>>>
>>>     CC      fs/timerfd.o
>>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>>                    from ./include/linux/smp.h:64,
>>>                    from ./include/linux/percpu.h:7,
>>>                    from ./include/linux/hrtimer.h:22,
>>>                    from ./include/linux/alarmtimer.h:6,
>>>                    from fs/timerfd.c:12:
>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has incomplete type
>>>     struct hrtimer   dl_timer;
>>>                      ^~~~~~~~
>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has incomplete type
>>>     struct hrtimer inactive_timer;
>>>                    ^~~~~~~~~~~~~~
>>> make[1]: *** [fs/timerfd.o] Error 1
>>> make: *** [fs/timerfd.o] Error 2
>>>
>>> This patch fixes it by including linux/hrtimer.h after linux/sched.h
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>> ---
>>>    Should it be fixed in powerpc instead ? In that case, how ? Any idea ?
>>
>>
>> Looks like there are several other places where the problem occurs, so it
>> has to be fixed in the powerpc headers instead.
>>
>> Seems like RISC arch faced the same issue, and fixed it the following way:
>>
>> /*
>>   * This is particularly ugly: it appears we can't actually get the
>> definition
>>   * of task_struct here, but we need access to the CPU this task is running
>> on.
>>   * Instead of using C we're using asm-offsets.h to get the current processor
>>   * ID.
>>   */
>> #define raw_smp_processor_id() (*((int*)((char*)get_current() +
>> TASK_TI_CPU)))
>>
>>
>> Unless someone has a better idea, I'll fixed it that way.
> 
> To solve this on arm64 we made the cpu number a percpu variable; see
> commit:
> 
>    57c82954e77fa12c ("arm64: make cpu number a percpu variable")

Thanks, I'll have a look

> IIUC, you could do that by placing it in paca_struct.

By the way, it is already in PACA struct for PPC64.
The issue is with PPC32, up to now it was in current_thread_info:

#ifdef CONFIG_PPC64
#define raw_smp_processor_id()	(local_paca->paca_index)
#define hard_smp_processor_id() (get_paca()->hw_cpu_id)
#else
/* 32-bit */
extern int smp_hw_index[];

#define raw_smp_processor_id()	(current_thread_info()->cpu)
#define hard_smp_processor_id() 	(smp_hw_index[smp_processor_id()])

[..]

#endif


Christophe

Re: [RFC PATCH v1 1/9] timer: fix circular header dependency

[Christophe Leroy]

On 09/25/2018 12:15 PM, Christophe LEROY wrote:
> 
> 
> Le 25/09/2018 à 14:11, Mark Rutland a écrit :
>> On Tue, Sep 25, 2018 at 07:34:15AM +0200, Christophe LEROY wrote:
>>>
>>>
>>> Le 24/09/2018 à 17:52, Christophe Leroy a écrit :
>>>> When switching powerpc to CONFIG_THREAD_INFO_IN_TASK, include/sched.h
>>>> has to be included in asm/smp.h for the following change, in order
>>>> to avoid uncomplete definition of task_struct:
>>>>
>>>> -#define raw_smp_processor_id() (current_thread_info()->cpu)
>>>> +#define raw_smp_processor_id() (current->cpu)
>>>>
>>>> But this generates the following compilation error, due to circular
>>>> header dependency.
>>>>
>>>>     CC      kernel/time/alarmtimer.o
>>>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>>>                    from ./include/linux/smp.h:64,
>>>>                    from ./include/linux/percpu.h:7,
>>>>                    from ./include/linux/hrtimer.h:22,
>>>>                    from kernel/time/alarmtimer.c:19:
>>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has 
>>>> incomplete type
>>>>     struct hrtimer   dl_timer;
>>>>                      ^~~~~~~~
>>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has 
>>>> incomplete type
>>>>     struct hrtimer inactive_timer;
>>>>                    ^~~~~~~~~~~~~~
>>>> make[1]: *** [kernel/time/alarmtimer.o] Error 1
>>>> make: *** [kernel/time/alarmtimer.o] Error 2
>>>>
>>>>     CC      fs/timerfd.o
>>>> In file included from ./arch/powerpc/include/asm/smp.h:31,
>>>>                    from ./include/linux/smp.h:64,
>>>>                    from ./include/linux/percpu.h:7,
>>>>                    from ./include/linux/hrtimer.h:22,
>>>>                    from ./include/linux/alarmtimer.h:6,
>>>>                    from fs/timerfd.c:12:
>>>> ./include/linux/sched.h:558:19: error: field 'dl_timer' has 
>>>> incomplete type
>>>>     struct hrtimer   dl_timer;
>>>>                      ^~~~~~~~
>>>> ./include/linux/sched.h:567:17: error: field 'inactive_timer' has 
>>>> incomplete type
>>>>     struct hrtimer inactive_timer;
>>>>                    ^~~~~~~~~~~~~~
>>>> make[1]: *** [fs/timerfd.o] Error 1
>>>> make: *** [fs/timerfd.o] Error 2
>>>>
>>>> This patch fixes it by including linux/hrtimer.h after linux/sched.h
>>>>
>>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>>> ---
>>>>    Should it be fixed in powerpc instead ? In that case, how ? Any 
>>>> idea ?
>>>
>>>
>>> Looks like there are several other places where the problem occurs, 
>>> so it
>>> has to be fixed in the powerpc headers instead.
>>>
>>> Seems like RISC arch faced the same issue, and fixed it the following 
>>> way:
>>>
>>> /*
>>>   * This is particularly ugly: it appears we can't actually get the
>>> definition
>>>   * of task_struct here, but we need access to the CPU this task is 
>>> running
>>> on.
>>>   * Instead of using C we're using asm-offsets.h to get the current 
>>> processor
>>>   * ID.
>>>   */
>>> #define raw_smp_processor_id() (*((int*)((char*)get_current() +
>>> TASK_TI_CPU)))
>>>
>>>
>>> Unless someone has a better idea, I'll fixed it that way.
>>
>> To solve this on arm64 we made the cpu number a percpu variable; see
>> commit:
>>
>>    57c82954e77fa12c ("arm64: make cpu number a percpu variable")
> 
> Thanks, I'll have a look
> 
>> IIUC, you could do that by placing it in paca_struct.
> 
> By the way, it is already in PACA struct for PPC64.
> The issue is with PPC32, up to now it was in current_thread_info:
> 
> #ifdef CONFIG_PPC64
> #define raw_smp_processor_id()    (local_paca->paca_index)
> #define hard_smp_processor_id() (get_paca()->hw_cpu_id)
> #else
> /* 32-bit */
> extern int smp_hw_index[];
> 
> #define raw_smp_processor_id()    (current_thread_info()->cpu)
> #define hard_smp_processor_id()     (smp_hw_index[smp_processor_id()])
> 
> [..]
> 
> #endif
> 

It seems not that easy. Adding the following leads to the below failure. 
I'm having a hard time identifying and fixing the issue. Looks again 
like a circular thing, because linux/percpu-defs.h is where 
raw_cpu_ptr() is defined.

--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -83,7 +83,14 @@ int is_cpu_dead(unsigned int cpu);
  /* 32-bit */
  extern int smp_hw_index[];

-#define raw_smp_processor_id() (current_thread_info()->cpu)
+DECLARE_PER_CPU_READ_MOSTLY(unsigned int, cpu_number);
+
+/*
+ * We don't use this_cpu_read(cpu_number) as that has implicit writes to
+ * preempt_count, and associated (compiler) barriers, that we'd like to 
avoid
+ * the expense of. If we're preemptible, the value can be stale at use 
anyway.
+ */
+#define raw_smp_processor_id()         (*this_cpu_ptr(&cpu_number))
  #define hard_smp_processor_id()        (smp_hw_index[smp_processor_id()])

  static inline int get_hard_smp_processor_id(int cpu)


   CC      arch/powerpc/kernel/asm-offsets.s
In file included from ././include/linux/compiler_types.h:64:0,
                  from <command-line>:0:
./include/linux/percpu-rwsem.h: In function 
'percpu_down_read_preempt_disable':
./include/linux/percpu-defs.h:254:27: error: implicit declaration of 
function 'raw_cpu_ptr' [-Werror=implicit-function-declaration]
  #define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
                            ^
./include/linux/compiler-gcc.h:58:26: note: in definition of macro 
'RELOC_HIDE'
   (typeof(ptr)) (__ptr + (off));     \
                           ^
./include/asm-generic/percpu.h:44:31: note: in expansion of macro 
'SHIFT_PERCPU_PTR'
  #define arch_raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
                                ^
./include/asm-generic/percpu.h:31:25: note: in expansion of macro 
'per_cpu_offset'
  #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
                          ^
./arch/powerpc/include/asm/smp.h:93:35: note: in expansion of macro 
'this_cpu_ptr'
  #define raw_smp_processor_id()  (*this_cpu_ptr(&cpu_number))
                                    ^
./include/asm-generic/percpu.h:31:40: note: in expansion of macro 
'raw_smp_processor_id'
  #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
                                         ^
./include/asm-generic/percpu.h:44:53: note: in expansion of macro 
'__my_cpu_offset'
  #define arch_raw_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
                                                      ^
./include/linux/percpu-defs.h:244:2: note: in expansion of macro 
'arch_raw_cpu_ptr'
   arch_raw_cpu_ptr(ptr);      \
   ^
./include/asm-generic/percpu.h:76:3: note: in expansion of macro 
'raw_cpu_ptr'
   *raw_cpu_ptr(&(pcp)) op val;     \
    ^
./include/asm-generic/percpu.h:225:34: note: in expansion of macro 
'raw_cpu_generic_to_op'
  #define raw_cpu_add_1(pcp, val)  raw_cpu_generic_to_op(pcp, val, +=)
                                   ^
./include/linux/percpu-defs.h:379:11: note: in expansion of macro 
'raw_cpu_add_1'
    case 1: stem##1(variable, __VA_ARGS__);break;  \
            ^
./include/linux/percpu-defs.h:424:32: note: in expansion of macro 
'__pcpu_size_call'
  #define raw_cpu_add(pcp, val)  __pcpu_size_call(raw_cpu_add_, pcp, val)
                                 ^
./include/linux/percpu-defs.h:460:2: note: in expansion of macro 
'raw_cpu_add'
   raw_cpu_add(pcp, val);      \
   ^
./include/linux/percpu-defs.h:499:30: note: in expansion of macro 
'__this_cpu_add'
  #define __this_cpu_inc(pcp)  __this_cpu_add(pcp, 1)
                               ^
./include/linux/percpu-rwsem.h:47:2: note: in expansion of macro 
'__this_cpu_inc'
   __this_cpu_inc(*sem->read_count);
   ^
./arch/powerpc/include/asm/smp.h:93:34: error: invalid type argument of 
unary '*' (have 'int')
  #define raw_smp_processor_id()  (*this_cpu_ptr(&cpu_number))
                                   ^


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