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x86/fred: Fix init_task thread stack pointer initialization 

As TOP_OF_KERNEL_STACK_PADDING was defined as 0 on x86_64, it went
unnoticed that the initialization of the .sp field in INIT_THREAD and some
calculations in the low level startup code do not take the padding into
account.

FRED enabled kernels require a 16 byte padding, which means that the init
task initialization and the low level startup code use the wrong stack
offset.

Subtract TOP_OF_KERNEL_STACK_PADDING in all affected places to adjust for
this.

Fixes: 65c9cc9e2c ("x86/fred: Reserve space for the FRED stack frame")
Fixes: 3adee777ad ("x86/smpboot: Remove initial_stack on 64-bit")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/oe-lkp/202402262159.183c2a37-lkp@intel.com
Link: https://lore.kernel.org/r/20240304083333.449322-1-xin@zytor.com
This commit is contained in:
Xin Li (Intel) 2024-03-04 00:33:33 -08:00 committed by Thomas Gleixner
parent e13841907b
commit c416b5bac6
3 changed files with 7 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/x86/include/asm/processor.h
View File

@ -664,8 +664,10 @@ static __always_inline void prefetchw(const void *x)
#else
extern unsigned long __end_init_task[];
#define INIT_THREAD { \
.sp = (unsigned long)&__end_init_task - sizeof(struct pt_regs), \
#define INIT_THREAD { \
.sp = (unsigned long)&__end_init_task - \
TOP_OF_KERNEL_STACK_PADDING - \
sizeof(struct pt_regs), \
}
extern unsigned long KSTK_ESP(struct task_struct *task);

3
arch/x86/kernel/head_64.S
View File

@ -26,6 +26,7 @@
#include <asm/apicdef.h>
#include <asm/fixmap.h>
#include <asm/smp.h>
#include <asm/thread_info.h>
/*
* We are not able to switch in one step to the final KERNEL ADDRESS SPACE
@ -66,7 +67,7 @@ SYM_CODE_START_NOALIGN(startup_64)
mov %rsi, %r15
/* Set up the stack for verify_cpu() */
leaq (__end_init_task - PTREGS_SIZE)(%rip), %rsp
leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
leaq _text(%rip), %rdi

2
arch/x86/xen/xen-head.S
View File

@ -49,7 +49,7 @@ SYM_CODE_START(startup_xen)
ANNOTATE_NOENDBR
cld
leaq (__end_init_task - PTREGS_SIZE)(%rip), %rsp
leaq (__end_init_task - TOP_OF_KERNEL_STACK_PADDING - PTREGS_SIZE)(%rip), %rsp
/* Set up %gs.
*