From: Heiko Carstens <hca@linux.ibm.com>
Date: Thu, 16 Nov 2023 13:36:38 +0000 (+0100)
Subject: arch: remove ARCH_TASK_STRUCT_ON_STACK
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0eb5085c38749f2a91e5bd8cbebb1ebf3398343c;p=linux.git
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 <hca@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
diff --git a/arch/Kconfig b/arch/Kconfig
index c2f87ef9f0ae3..bfcc7c2dc039b 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 0bee7ca9a77c6..762e4d09aacfa 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 40fc5813cf932..bccb3f1f62621 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 292c316972485..c2ecb2e060462 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 5727d42149c33..6f6485d554df1 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),