2024-03-13 06:07:05

by Xin Li (Intel)

[permalink] [raw]
Subject: [PATCH v1 1/1] x86: Rename __{start,end}_init_task to __{start,end}_init_stack

The stack of a task has been separated from the memory of a task_struct
struture for a long time on x86, as a result __{start,end}_init_task no
longer mark the start and end of the init_task structure, but its stack
only.

Rename __{start,end}_init_task to __{start,end}_init_stack.

Note other architectures are not affected because __{start,end}_init_task
are used on x86 only.

Signed-off-by: Xin Li (Intel) <[email protected]>
---
arch/x86/include/asm/processor.h | 4 ++--
arch/x86/kernel/head_64.S | 2 +-
arch/x86/xen/xen-head.S | 2 +-
include/asm-generic/vmlinux.lds.h | 8 ++++----
4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 811548f131f4..8b3a3f3bb859 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -636,10 +636,10 @@ static __always_inline void prefetchw(const void *x)
#define KSTK_ESP(task) (task_pt_regs(task)->sp)

#else
-extern unsigned long __end_init_task[];
+extern unsigned long __end_init_stack[];

#define INIT_THREAD { \
- .sp = (unsigned long)&__end_init_task - \
+ .sp = (unsigned long)&__end_init_stack - \
TOP_OF_KERNEL_STACK_PADDING - \
sizeof(struct pt_regs), \
}
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index d8198fbd70e5..c7babd7ebb0f 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -66,7 +66,7 @@ SYM_CODE_START_NOALIGN(startup_64)
mov %rsi, %r15

/* Set up the stack for verify_cpu() */
- leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
+ leaq (__end_init_stack - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp

/* Setup GSBASE to allow stack canary access for C code */
movl $MSR_GS_BASE, %ecx
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 04101b984f24..43eadf03f46d 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -49,7 +49,7 @@ SYM_CODE_START(startup_xen)
ANNOTATE_NOENDBR
cld

- leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
+ leaq (__end_init_stack - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp

/* Set up %gs.
*
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 5dd3a61d673d..a168be99d522 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -399,13 +399,13 @@

#define INIT_TASK_DATA(align) \
. = ALIGN(align); \
- __start_init_task = .; \
+ __start_init_stack = .; \
init_thread_union = .; \
init_stack = .; \
- KEEP(*(.data..init_task)) \
+ KEEP(*(.data..init_stack)) \
KEEP(*(.data..init_thread_info)) \
- . = __start_init_task + THREAD_SIZE; \
- __end_init_task = .;
+ . = __start_init_stack + THREAD_SIZE; \
+ __end_init_stack = .;

#define JUMP_TABLE_DATA \
. = ALIGN(8); \

base-commit: 626856ae97054963e7b8c35335d4418271c8d0c4
--
2.44.0



2024-03-13 07:10:10

by Juergen Gross

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] x86: Rename __{start,end}_init_task to __{start,end}_init_stack

On 13.03.24 07:05, Xin Li (Intel) wrote:
> The stack of a task has been separated from the memory of a task_struct
> struture for a long time on x86, as a result __{start,end}_init_task no
> longer mark the start and end of the init_task structure, but its stack
> only.
>
> Rename __{start,end}_init_task to __{start,end}_init_stack.
>
> Note other architectures are not affected because __{start,end}_init_task
> are used on x86 only.
>
> Signed-off-by: Xin Li (Intel) <[email protected]>
> ---
> arch/x86/include/asm/processor.h | 4 ++--
> arch/x86/kernel/head_64.S | 2 +-
> arch/x86/xen/xen-head.S | 2 +-
> include/asm-generic/vmlinux.lds.h | 8 ++++----
> 4 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index 811548f131f4..8b3a3f3bb859 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -636,10 +636,10 @@ static __always_inline void prefetchw(const void *x)
> #define KSTK_ESP(task) (task_pt_regs(task)->sp)
>
> #else
> -extern unsigned long __end_init_task[];
> +extern unsigned long __end_init_stack[];
>
> #define INIT_THREAD { \
> - .sp = (unsigned long)&__end_init_task - \
> + .sp = (unsigned long)&__end_init_stack - \
> TOP_OF_KERNEL_STACK_PADDING - \
> sizeof(struct pt_regs), \
> }
> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index d8198fbd70e5..c7babd7ebb0f 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -66,7 +66,7 @@ SYM_CODE_START_NOALIGN(startup_64)
> mov %rsi, %r15
>
> /* Set up the stack for verify_cpu() */
> - leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
> + leaq (__end_init_stack - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
>
> /* Setup GSBASE to allow stack canary access for C code */
> movl $MSR_GS_BASE, %ecx
> diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
> index 04101b984f24..43eadf03f46d 100644
> --- a/arch/x86/xen/xen-head.S
> +++ b/arch/x86/xen/xen-head.S
> @@ -49,7 +49,7 @@ SYM_CODE_START(startup_xen)
> ANNOTATE_NOENDBR
> cld
>
> - leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
> + leaq (__end_init_stack - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
>
> /* Set up %gs.
> *
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index 5dd3a61d673d..a168be99d522 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -399,13 +399,13 @@
>
> #define INIT_TASK_DATA(align) \
> . = ALIGN(align); \
> - __start_init_task = .; \
> + __start_init_stack = .; \
> init_thread_union = .; \
> init_stack = .; \
> - KEEP(*(.data..init_task)) \
> + KEEP(*(.data..init_stack)) \

Is this modification really correct?

> KEEP(*(.data..init_thread_info)) \
> - . = __start_init_task + THREAD_SIZE; \
> - __end_init_task = .;
> + . = __start_init_stack + THREAD_SIZE; \
> + __end_init_stack = .;
>
> #define JUMP_TABLE_DATA \
> . = ALIGN(8); \
>
> base-commit: 626856ae97054963e7b8c35335d4418271c8d0c4


Juergen


2024-03-13 19:22:11

by Xin Li (Intel)

[permalink] [raw]
Subject: Re: [PATCH v1 1/1] x86: Rename __{start,end}_init_task to __{start,end}_init_stack

On 3/13/2024 12:09 AM, Jürgen Groß wrote:
> On 13.03.24 07:05, Xin Li (Intel) wrote:
>> The stack of a task has been separated from the memory of a task_struct
>> struture for a long time on x86, as a result __{start,end}_init_task no
>> longer mark the start and end of the init_task structure, but its stack
>> only.
>>
>> Rename __{start,end}_init_task to __{start,end}_init_stack.
>>
>> Note other architectures are not affected because __{start,end}_init_task
>> are used on x86 only.
>>

>> diff --git a/include/asm-generic/vmlinux.lds.h
>> b/include/asm-generic/vmlinux.lds.h
>> index 5dd3a61d673d..a168be99d522 100644
>> --- a/include/asm-generic/vmlinux.lds.h
>> +++ b/include/asm-generic/vmlinux.lds.h
>> @@ -399,13 +399,13 @@
>>   #define INIT_TASK_DATA(align)                        \
>>       . = ALIGN(align);                        \
>> -    __start_init_task = .;                        \
>> +    __start_init_stack = .;                        \
>>       init_thread_union = .;                        \
>>       init_stack = .;                            \
>> -    KEEP(*(.data..init_task))                    \
>> +    KEEP(*(.data..init_stack))                    \
>
> Is this modification really correct?
>

Good catch, I should not change it.

Thanks!
Xin