From bf5882abab773afd1277415e2f826b21de28f30d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 14 Apr 2019 17:59:51 +0200 Subject: [PATCH] x86/irq/64: Use cpu entry area instead of orig_ist The orig_ist[] array is a shadow copy of the IST array in the TSS. The reason why it exists is that older kernels used two TSS variants with different pointers into the debug stack. orig_ist[] contains the real starting points. There is no point anymore to do so because the same information can be retrieved using the base address of the cpu entry area mapping and the offsets of the various exception stacks. No functional change. Preparation for removing orig_ist. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Nicolai Stange Cc: Sean Christopherson Cc: x86-ml Link: https://lkml.kernel.org/r/20190414160144.885741626@linutronix.de --- arch/x86/kernel/irq_64.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 182e8b245e063..7eb6f8d11bfd3 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -18,6 +18,8 @@ #include #include #include + +#include #include #include @@ -43,10 +45,9 @@ static inline void stack_overflow_check(struct pt_regs *regs) { #ifdef CONFIG_DEBUG_STACKOVERFLOW #define STACK_MARGIN 128 - struct orig_ist *oist; - u64 irq_stack_top, irq_stack_bottom; - u64 estack_top, estack_bottom; + u64 irq_stack_top, irq_stack_bottom, estack_top, estack_bottom; u64 curbase = (u64)task_stack_page(current); + struct cea_exception_stacks *estacks; if (user_mode(regs)) return; @@ -60,9 +61,9 @@ static inline void stack_overflow_check(struct pt_regs *regs) if (regs->sp >= irq_stack_bottom && regs->sp <= irq_stack_top) return; - oist = this_cpu_ptr(&orig_ist); - estack_top = (u64)oist->ist[ESTACK_DB]; - estack_bottom = estack_top - DEBUG_STKSZ + STACK_MARGIN; + estacks = __this_cpu_read(cea_exception_stacks); + estack_top = CEA_ESTACK_TOP(estacks, DB); + estack_bottom = CEA_ESTACK_BOT(estacks, DB) + STACK_MARGIN; if (regs->sp >= estack_bottom && regs->sp <= estack_top) return; -- 2.30.2