![Benjamin LaHaise](/assets/img/avatar_default.png)
This patch fixes a fairly serious tlb flushing bug that makes aio use under uml very unreliable -- SEGVs, Oops and panic()s occur as a result of stale tlb entires being used by uml when aio switches mms due to the fact that uml does not implement the activate_mm() hook. This patch introduces a simple but correct approach (read: hammer) for implementing activate_mm() in uml by doing a force_flush_all() if the new mm is different from old. With this patch in place, uml is able to succeed at the aio test case that was randomly faulting for me before. Cc: Jeff Dike <jdike@addtoit.com> Cc: <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
/*
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* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#ifndef __UM_MMU_CONTEXT_H
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#define __UM_MMU_CONTEXT_H
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#include "linux/sched.h"
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#include "linux/config.h"
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#include "choose-mode.h"
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#include "um_mmu.h"
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#define get_mmu_context(task) do ; while(0)
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#define activate_context(tsk) do ; while(0)
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#define deactivate_mm(tsk,mm) do { } while (0)
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extern void force_flush_all(void);
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static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
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{
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if (old != new)
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force_flush_all();
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}
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static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
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struct task_struct *tsk)
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{
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unsigned cpu = smp_processor_id();
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if(prev != next){
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cpu_clear(cpu, prev->cpu_vm_mask);
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cpu_set(cpu, next->cpu_vm_mask);
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if(next != &init_mm)
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CHOOSE_MODE((void) 0,
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switch_mm_skas(&next->context.skas.id));
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}
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}
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static inline void enter_lazy_tlb(struct mm_struct *mm,
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struct task_struct *tsk)
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{
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}
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extern int init_new_context_skas(struct task_struct *task,
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struct mm_struct *mm);
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static inline int init_new_context_tt(struct task_struct *task,
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struct mm_struct *mm)
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{
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return(0);
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}
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static inline int init_new_context(struct task_struct *task,
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struct mm_struct *mm)
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{
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return(CHOOSE_MODE_PROC(init_new_context_tt, init_new_context_skas,
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task, mm));
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}
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extern void destroy_context_skas(struct mm_struct *mm);
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static inline void destroy_context(struct mm_struct *mm)
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{
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CHOOSE_MODE((void) 0, destroy_context_skas(mm));
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}
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#endif
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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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