From 0eb5085c38749f2a91e5bd8cbebb1ebf3398343c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 16 Nov 2023 14:36:38 +0100 Subject: [PATCH] arch: remove ARCH_TASK_STRUCT_ON_STACK IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ON_STACK. IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Therefore remove support for ARCH_TASK_STRUCT_ON_STACK as well. Note: this also reveals a potential bug in powerpc code, which makes use of __init_task_data without selecting ARCH_TASK_STRUCT_ON_STACK which makes __init_task_data a no-op. This is broken since commit d11ed3ab3166 ("Expand INIT_TASK() in init/init_task.c and remove") from 2018 and needs to be addressed separately. Link: https://lkml.kernel.org/r/20231116133638.1636277-4-hca@linux.ibm.com Signed-off-by: Heiko Carstens Reviewed-by: Arnd Bergmann Cc: Michael Ellerman Cc: Nicholas Piggin Signed-off-by: Andrew Morton --- arch/Kconfig | 4 ---- arch/powerpc/kexec/core_64.c | 3 +-- include/linux/init_task.h | 7 ------- include/linux/sched.h | 2 -- init/init_task.c | 10 ++-------- 5 files changed, 3 insertions(+), 23 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index c2f87ef9f0ae..bfcc7c2dc039 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -301,10 +301,6 @@ config ARCH_HAS_DMA_CLEAR_UNCACHED config ARCH_HAS_CPU_FINALIZE_INIT bool -# Select if arch init_task must go in the __init_task_data section -config ARCH_TASK_STRUCT_ON_STACK - bool - config HAVE_ARCH_THREAD_STRUCT_WHITELIST bool help diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c index 0bee7ca9a77c..762e4d09aacf 100644 --- a/arch/powerpc/kexec/core_64.c +++ b/arch/powerpc/kexec/core_64.c @@ -283,8 +283,7 @@ static void kexec_prepare_cpus(void) * We could use a smaller stack if we don't care about anything using * current, but that audit has not been performed. */ -static union thread_union kexec_stack __init_task_data = - { }; +static union thread_union kexec_stack = { }; /* * For similar reasons to the stack above, the kexecing CPU needs to be on a diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 40fc5813cf93..bccb3f1f6262 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -37,13 +37,6 @@ extern struct cred init_cred; #define INIT_TASK_COMM "swapper" -/* Attach to the init_task data structure for proper alignment */ -#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK -#define __init_task_data __section(".data..init_task") -#else -#define __init_task_data /**/ -#endif - /* Attach to the thread_info data structure for proper alignment */ #define __init_thread_info __section(".data..init_thread_info") diff --git a/include/linux/sched.h b/include/linux/sched.h index 292c31697248..c2ecb2e06046 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1955,9 +1955,7 @@ extern void ia64_set_curr_task(int cpu, struct task_struct *p); void yield(void); union thread_union { -#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK struct task_struct task; -#endif #ifndef CONFIG_THREAD_INFO_IN_TASK struct thread_info thread_info; #endif diff --git a/init/init_task.c b/init/init_task.c index 5727d42149c3..6f6485d554df 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -51,8 +51,7 @@ static struct sighand_struct init_sighand = { }; #ifdef CONFIG_SHADOW_CALL_STACK -unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] - __init_task_data = { +unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = { [(SCS_SIZE / sizeof(long)) - 1] = SCS_END_MAGIC }; #endif @@ -61,12 +60,7 @@ unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] * Set up the first task table, touch at your own risk!. Base=0, * limit=0x1fffff (=2MB) */ -struct task_struct init_task -#ifdef CONFIG_ARCH_TASK_STRUCT_ON_STACK - __init_task_data -#endif - __aligned(L1_CACHE_BYTES) -= { +struct task_struct init_task __aligned(L1_CACHE_BYTES) = { #ifdef CONFIG_THREAD_INFO_IN_TASK .thread_info = INIT_THREAD_INFO(init_task), .stack_refcount = REFCOUNT_INIT(1),