[tip: x86/asm] x86/irq/32: Use current_stack_pointer to avoid asm() in check_stack_overflow()

["tip-bot2 for Uros Bizjak" <tip-bot2@linutronix.de>]

The following commit has been merged into the x86/asm branch of tip:

Commit-ID:     70e8a96f5408e409dc71b08a366d6d705e9d9fb8
Gitweb:        https://git.kernel.org/tip/70e8a96f5408e409dc71b08a366d6d705e9d9fb8
Author:        Uros Bizjak <ubizjak@gmail.com>
AuthorDate:    Mon, 03 Mar 2025 16:54:24 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 04 Mar 2025 10:53:51 +01:00

x86/irq/32: Use current_stack_pointer to avoid asm() in check_stack_overflow()

Make code more readable by using the 'current_stack_pointer' global variable.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250303155446.112769-4-ubizjak@gmail.com
---
 arch/x86/kernel/irq_32.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index f351fa1..2428d66 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -31,10 +31,7 @@ int sysctl_panic_on_stackoverflow __read_mostly;
 /* Debugging check for stack overflow: is there less than 1KB free? */
 static int check_stack_overflow(void)
 {
-	long sp;
-
-	__asm__ __volatile__("andl %%esp,%0" :
-			     "=r" (sp) : "0" (THREAD_SIZE - 1));
+	unsigned long sp = current_stack_pointer & (THREAD_SIZE - 1);
 
 	return sp < (sizeof(struct thread_info) + STACK_WARN);
 }