Messages in this thread Patch in this message | | | From | Jinyang He <> | Subject | [PATCH v2] LoongArch: Remove unused kernel stack padding | Date | Wed, 21 Sep 2022 15:41:13 +0800 |
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Kernel stack padding looks like obey MIPS o32 Calling Convention, as LoongArch is inspired by MIPS and keep it. Remove it avoid not clear code.
Link: https://lore.kernel.org/loongarch/1662130897-13156-1-git-send-email-hejinyang@loongson.cn/
Signed-off-by: Jinyang He <hejinyang@loongson.cn> --- v2: Remove TOP_OF_KERNEL_STACK_PADDING Remove 'init stack pointer' in head.S
arch/loongarch/include/asm/processor.h | 2 +- arch/loongarch/include/asm/ptrace.h | 2 +- arch/loongarch/kernel/head.S | 3 +-- arch/loongarch/kernel/process.c | 4 ++-- arch/loongarch/kernel/switch.S | 2 +- 5 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/arch/loongarch/include/asm/processor.h b/arch/loongarch/include/asm/processor.h index 1c4b4308378d..780e0d39f638 100644 --- a/arch/loongarch/include/asm/processor.h +++ b/arch/loongarch/include/asm/processor.h @@ -194,7 +194,7 @@ static inline void flush_thread(void) unsigned long __get_wchan(struct task_struct *p); #define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + \ - THREAD_SIZE - 32 - sizeof(struct pt_regs)) + THREAD_SIZE - sizeof(struct pt_regs)) #define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk)) #define KSTK_EIP(tsk) (task_pt_regs(tsk)->csr_era) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[3]) diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/asm/ptrace.h index 17838c6b7ccd..82649a78fec1 100644 --- a/arch/loongarch/include/asm/ptrace.h +++ b/arch/loongarch/include/asm/ptrace.h @@ -133,7 +133,7 @@ static inline void die_if_kernel(const char *str, struct pt_regs *regs) #define current_pt_regs() \ ({ \ unsigned long sp = (unsigned long)__builtin_frame_address(0); \ - (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1 - 32) - 1; \ + (struct pt_regs *)((sp | (THREAD_SIZE - 1)) + 1) - 1; \ }) /* Helpers for working with the user stack pointer */ diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S index 4d352230fbc3..0e1752fbc857 100644 --- a/arch/loongarch/kernel/head.S +++ b/arch/loongarch/kernel/head.S @@ -81,10 +81,9 @@ SYM_CODE_START(kernel_entry) # kernel entry point la.pcrel tp, init_thread_union /* Set the SP after an empty pt_regs. */ - PTR_LI sp, (_THREAD_SIZE - 32 - PT_SIZE) + PTR_LI sp, (_THREAD_SIZE - PT_SIZE) PTR_ADD sp, sp, tp set_saved_sp sp, t0, t1 - PTR_ADDI sp, sp, -4 * SZREG # init stack pointer bl start_kernel diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c index 660492f064e7..dae087d6c458 100644 --- a/arch/loongarch/kernel/process.c +++ b/arch/loongarch/kernel/process.c @@ -129,7 +129,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) unsigned long clone_flags = args->flags; struct pt_regs *childregs, *regs = current_pt_regs(); - childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; + childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE; /* set up new TSS. */ childregs = (struct pt_regs *) childksp - 1; @@ -236,7 +236,7 @@ bool in_task_stack(unsigned long stack, struct task_struct *task, struct stack_info *info) { unsigned long begin = (unsigned long)task_stack_page(task); - unsigned long end = begin + THREAD_SIZE - 32; + unsigned long end = begin + THREAD_SIZE; if (stack < begin || stack >= end) return false; diff --git a/arch/loongarch/kernel/switch.S b/arch/loongarch/kernel/switch.S index 43ebbc3990f7..202a163cb32f 100644 --- a/arch/loongarch/kernel/switch.S +++ b/arch/loongarch/kernel/switch.S @@ -26,7 +26,7 @@ SYM_FUNC_START(__switch_to) move tp, a2 cpu_restore_nonscratch a1 - li.w t0, _THREAD_SIZE - 32 + li.w t0, _THREAD_SIZE PTR_ADD t0, t0, tp set_saved_sp t0, t1, t2 -- 2.31.1
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