| Message ID | 20240318071429.910454-1-xin@zytor.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/1] x86: Rename __{start,end}_init_task to __{start,end}_init_stack | expand |
On 18.03.24 08:14, 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) <xin@zytor.com> Reviewed-by: Juergen Gross <jgross@suse.com> Juergen
* Xin Li (Intel) <xin@zytor.com> 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) <xin@zytor.com> > --- > > Change since v1: > * Revert an accident insane change, init_task to init_stack (Jürgen Groß). > --- > 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 | 6 +++--- > 4 files changed, 7 insertions(+), 7 deletions(-) Note that this is now in conflict with this cleanup by Brian Gerst: 2cb16181a1d1 x86/boot: Simplify boot stack setup ... which removed __end_init_task[] entirely. Thanks, Ingo
On 3/21/2024 12:54 PM, Ingo Molnar wrote: > > * Xin Li (Intel) <xin@zytor.com> 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) <xin@zytor.com> >> --- >> >> Change since v1: >> * Revert an accident insane change, init_task to init_stack (Jürgen Groß). >> --- >> 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 | 6 +++--- >> 4 files changed, 7 insertions(+), 7 deletions(-) > > Note that this is now in conflict with this cleanup by Brian Gerst: > > 2cb16181a1d1 x86/boot: Simplify boot stack setup I like this patch, which does something that I'm also doing, further x86_64 doesn't have the concept of TOP_OF_KERNEL_STACK_PADDING, and I guess it was extended from x86_32 but defined to 0 just for code consistency. Yes, FRED code uses TOP_OF_KERNEL_STACK_PADDING, but a FRED event frame could contain different amount of information for different event types, e.g., #MCE could push extra bytes of information, or perhaps even for different instances of the same event type. Thus the size of an event frame pushed by a FRED CPU is not fixed and the address of the pt_regs structure that is used to save the user level context of current task is not at a fixed offset from the top of current task kernel stack. > > .. which removed __end_init_task[] entirely. Not really, but __end_init_task[] is only used to initialize __top_init_kernel_stack. I will rebase and send v3. Thanks! Xin
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 514d3002ad8a..cdfdcca23045 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_thread_info)) \ - . = __start_init_task + THREAD_SIZE; \ - __end_init_task = .; + . = __start_init_stack + THREAD_SIZE; \ + __end_init_stack = .; #define JUMP_TABLE_DATA \ . = ALIGN(8); \
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) <xin@zytor.com> --- Change since v1: * Revert an accident insane change, init_task to init_stack (Jürgen Groß). --- 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 | 6 +++--- 4 files changed, 7 insertions(+), 7 deletions(-) base-commit: 7e19a79344df2ed5e106091c29338962261b0290