From 7f0a002b5a21302d9f4b29ba83c96cd433ff3769 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 1 Jun 2020 21:52:40 -0700 Subject: x86/mm: remove vmalloc faulting Remove fault handling on vmalloc areas, as the vmalloc code now takes care of synchronizing changes to all page-tables in the system. Signed-off-by: Joerg Roedel Signed-off-by: Andrew Morton Acked-by: Andy Lutomirski Acked-by: Peter Zijlstra (Intel) Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Dave Hansen Cc: "H . Peter Anvin" Cc: Ingo Molnar Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200515140023.25469-8-joro@8bytes.org Signed-off-by: Linus Torvalds --- arch/x86/include/asm/switch_to.h | 23 ----------------------- 1 file changed, 23 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 0e059b73437b..9f69cc497f4b 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -12,27 +12,6 @@ struct task_struct *__switch_to_asm(struct task_struct *prev, __visible struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next); -/* This runs runs on the previous thread's stack. */ -static inline void prepare_switch_to(struct task_struct *next) -{ -#ifdef CONFIG_VMAP_STACK - /* - * If we switch to a stack that has a top-level paging entry - * that is not present in the current mm, the resulting #PF will - * will be promoted to a double-fault and we'll panic. Probe - * the new stack now so that vmalloc_fault can fix up the page - * tables if needed. This can only happen if we use a stack - * in vmap space. - * - * We assume that the stack is aligned so that it never spans - * more than one top-level paging entry. - * - * To minimize cache pollution, just follow the stack pointer. - */ - READ_ONCE(*(unsigned char *)next->thread.sp); -#endif -} - asmlinkage void ret_from_fork(void); /* @@ -67,8 +46,6 @@ struct fork_frame { #define switch_to(prev, next, last) \ do { \ - prepare_switch_to(next); \ - \ ((last) = __switch_to_asm((prev), (next))); \ } while (0) -- cgit v1.2.3