cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cacheflush.h (2039B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _ALPHA_CACHEFLUSH_H
      3#define _ALPHA_CACHEFLUSH_H
      4
      5#include <linux/mm.h>
      6
      7/* Note that the following two definitions are _highly_ dependent
      8   on the contexts in which they are used in the kernel.  I personally
      9   think it is criminal how loosely defined these macros are.  */
     10
     11/* We need to flush the kernel's icache after loading modules.  The
     12   only other use of this macro is in load_aout_interp which is not
     13   used on Alpha. 
     14
     15   Note that this definition should *not* be used for userspace
     16   icache flushing.  While functional, it is _way_ overkill.  The
     17   icache is tagged with ASNs and it suffices to allocate a new ASN
     18   for the process.  */
     19#ifndef CONFIG_SMP
     20#define flush_icache_range(start, end)		imb()
     21#else
     22#define flush_icache_range(start, end)		smp_imb()
     23extern void smp_imb(void);
     24#endif
     25
     26/* We need to flush the userspace icache after setting breakpoints in
     27   ptrace.
     28
     29   Instead of indiscriminately using imb, take advantage of the fact
     30   that icache entries are tagged with the ASN and load a new mm context.  */
     31/* ??? Ought to use this in arch/alpha/kernel/signal.c too.  */
     32
     33#ifndef CONFIG_SMP
     34#include <linux/sched.h>
     35
     36extern void __load_new_mm_context(struct mm_struct *);
     37static inline void
     38flush_icache_user_page(struct vm_area_struct *vma, struct page *page,
     39			unsigned long addr, int len)
     40{
     41	if (vma->vm_flags & VM_EXEC) {
     42		struct mm_struct *mm = vma->vm_mm;
     43		if (current->active_mm == mm)
     44			__load_new_mm_context(mm);
     45		else
     46			mm->context[smp_processor_id()] = 0;
     47	}
     48}
     49#define flush_icache_user_page flush_icache_user_page
     50#else /* CONFIG_SMP */
     51extern void flush_icache_user_page(struct vm_area_struct *vma,
     52		struct page *page, unsigned long addr, int len);
     53#define flush_icache_user_page flush_icache_user_page
     54#endif /* CONFIG_SMP */
     55
     56/* This is used only in __do_fault and do_swap_page.  */
     57#define flush_icache_page(vma, page) \
     58	flush_icache_user_page((vma), (page), 0, 0)
     59
     60#include <asm-generic/cacheflush.h>
     61
     62#endif /* _ALPHA_CACHEFLUSH_H */