[RFC PATCH v3 2/7] powerpc: Prepare for moving thread_info into task_struct
Christophe LEROY
christophe.leroy at c-s.fr
Wed Oct 3 15:49:44 AEST 2018
Le 03/10/2018 à 07:02, Nicholas Piggin a écrit :
> On Mon, 1 Oct 2018 12:30:21 +0000 (UTC)
> Christophe Leroy <christophe.leroy at 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.leroy at 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 ?
Yes, why not but it means changing the code. I wanted to minimise the
changes and avoid cosmetic. Or maybe should add a cosmetic patch at the
end ?
>
> 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?
No problem, I can put the TI_CPU bits in a separate patch.
>
> Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
>
Thanks
Christophe
>
>> 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 at ha
>> tophys(r1,r1)
>> lwz r1,secondary_ti at 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 at ha
>> lwz r1,secondary_ti at 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 at h
>> ori r14, r14, __per_cpu_offset at 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 at ha
>> lwz r1,secondary_ti at 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 at ha
>> stw r4,nap_save_hid1 at 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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