[PATCH v1 1/1] x86/fred: Fix init_task thread stack pointer initialization
From: Xin Li (Intel)
Date: Fri Mar 01 2024 - 03:42:13 EST
As TOP_OF_KERNEL_STACK_PADDING is defined as 0 on x86_64, no one noticed
it's missing in the calculation of the .sp field in INIT_THREAD until it
is defined to 16 with CONFIG_X86_FRED=y.
Subtract TOP_OF_KERNEL_STACK_PADDING from the .sp field of INIT_THREAD.
Fixes: 65c9cc9e2c14 ("x86/fred: Reserve space for the FRED stack frame")
Fixes: 3adee777ad0d ("x86/smpboot: Remove initial_stack on 64-bit")
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-lkp/202402262159.183c2a37-lkp@xxxxxxxxx
Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
---
arch/x86/include/asm/processor.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 26620d7642a9..17fe81998ce4 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -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);
base-commit: e13841907b8fda0ae0ce1ec03684665f578416a8
--
2.44.0