On Mon,  1 Oct 2018 12:30:21 +0000 (UTC)
Christophe Leroy <christophe.le...@c-s.fr> wrote:

> 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*
> - 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
> - Rename THREAD_INFO to TASK_STASK: As it is in fact the offset of the
> pointer to the stack in task_struct, this pointer will not be impacted
> by the move of THREAD_INFO.
> - Makes TASK_STACK available to PPC64 which will need it to the get
> stack pointer from current once the thread_info have been moved.
> 
> Signed-off-by: Christophe Leroy <christophe.le...@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/reg.h       |  2 +-
>  arch/powerpc/kernel/asm-offsets.c    |  2 +-
>  arch/powerpc/kernel/entry_32.S       |  2 +-
>  arch/powerpc/kernel/entry_64.S       |  2 +-
>  arch/powerpc/kernel/head_32.S        |  4 ++--
>  arch/powerpc/kernel/head_40x.S       |  4 ++--
>  arch/powerpc/kernel/head_44x.S       |  2 +-
>  arch/powerpc/kernel/head_8xx.S       |  2 +-
>  arch/powerpc/kernel/head_booke.h     |  4 ++--
>  arch/powerpc/kernel/head_fsl_booke.S |  6 ++++--
>  arch/powerpc/kernel/irq.c            |  2 +-
>  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 +-
>  19 files changed, 40 insertions(+), 37 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);

void *sp for these ?

This all seems okay to me except the 32-bit code which I don't know.
Would it be any trouble for you to put the TI_CPU bits into their own
patch?

Reviewed-by: Nicholas Piggin <npig...@gmail.com>


>  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/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/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/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 61ca27929355..dce6f2ff07e5 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 */
> @@ -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_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_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_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..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
>  
> @@ -702,7 +704,7 @@ 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
> @@ -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/irq.c b/arch/powerpc/kernel/irq.c
> index 916ddc4aac44..aa53db3ba6e7 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()];
>  
> 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
> 

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