diff options
| author | Brian Gerst <brgerst@gmail.com> | 2024-03-21 14:05:06 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2024-03-21 20:17:54 +0100 |
| commit | 2cb16181a1d1f93a88f2b4640e7638fc0549da93 (patch) | |
| tree | dbaada9d4d8b36039e5b3052db5e656ff9e0c956 | |
| parent | 4ae3dc83b047d51485cce1a72be277a110d77c91 (diff) | |
x86/boot: Simplify boot stack setup
Define the symbol __top_init_kernel_stack instead of duplicating
the offset from __end_init_task in multiple places.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20240321180506.89030-1-brgerst@gmail.com
| -rw-r--r-- | arch/x86/include/asm/processor.h | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/head_32.S | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 3 | ||||
| -rw-r--r-- | arch/x86/xen/xen-head.S | 2 |
5 files changed, 8 insertions, 16 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 811548f131f4..7fa01d951365 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -636,12 +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 __top_init_kernel_stack[]; #define INIT_THREAD { \ - .sp = (unsigned long)&__end_init_task - \ - TOP_OF_KERNEL_STACK_PADDING - \ - sizeof(struct pt_regs), \ + .sp = (unsigned long)&__top_init_kernel_stack, \ } extern unsigned long KSTK_ESP(struct task_struct *task); diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index b50f3641c4d6..a9de527ba5c4 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -44,9 +44,6 @@ #define X86_CAPABILITY new_cpu_data+CPUINFO_x86_capability #define X86_VENDOR_ID new_cpu_data+CPUINFO_x86_vendor_id - -#define SIZEOF_PTREGS 17*4 - /* * Worst-case size of the kernel mapping we need to make: * a relocatable kernel can live anywhere in lowmem, so we need to be able @@ -488,13 +485,7 @@ SYM_DATA_END(initial_page_table) .data .balign 4 -/* - * The SIZEOF_PTREGS gap is a convention which helps the in-kernel unwinder - * reliably detect the end of the stack. - */ -SYM_DATA(initial_stack, - .long init_thread_union + THREAD_SIZE - - SIZEOF_PTREGS - TOP_OF_KERNEL_STACK_PADDING) +SYM_DATA(initial_stack, .long __top_init_kernel_stack) __INITRODATA int_msg: diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index d8198fbd70e5..b11526869a40 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 __top_init_kernel_stack(%rip), %rsp /* Setup GSBASE to allow stack canary access for C code */ movl $MSR_GS_BASE, %ecx diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 56451fd2099e..91085c3430de 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -172,6 +172,9 @@ SECTIONS /* init_task */ INIT_TASK_DATA(THREAD_SIZE) + /* equivalent to task_pt_regs(&init_task) */ + __top_init_kernel_stack = __end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE; + #ifdef CONFIG_X86_32 /* 32 bit has nosave before _edata */ NOSAVE_DATA diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 04101b984f24..758bcd47b72d 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 __top_init_kernel_stack(%rip), %rsp /* Set up %gs. * |