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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pgtable_32.c (2314B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/sched.h>
      3#include <linux/kernel.h>
      4#include <linux/errno.h>
      5#include <linux/mm.h>
      6#include <linux/nmi.h>
      7#include <linux/swap.h>
      8#include <linux/smp.h>
      9#include <linux/highmem.h>
     10#include <linux/pagemap.h>
     11#include <linux/spinlock.h>
     12
     13#include <asm/cpu_entry_area.h>
     14#include <asm/fixmap.h>
     15#include <asm/e820/api.h>
     16#include <asm/tlb.h>
     17#include <asm/tlbflush.h>
     18#include <asm/io.h>
     19#include <linux/vmalloc.h>
     20
     21unsigned int __VMALLOC_RESERVE = 128 << 20;
     22
     23/*
     24 * Associate a virtual page frame with a given physical page frame 
     25 * and protection flags for that frame.
     26 */ 
     27void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
     28{
     29	pgd_t *pgd;
     30	p4d_t *p4d;
     31	pud_t *pud;
     32	pmd_t *pmd;
     33	pte_t *pte;
     34
     35	pgd = swapper_pg_dir + pgd_index(vaddr);
     36	if (pgd_none(*pgd)) {
     37		BUG();
     38		return;
     39	}
     40	p4d = p4d_offset(pgd, vaddr);
     41	if (p4d_none(*p4d)) {
     42		BUG();
     43		return;
     44	}
     45	pud = pud_offset(p4d, vaddr);
     46	if (pud_none(*pud)) {
     47		BUG();
     48		return;
     49	}
     50	pmd = pmd_offset(pud, vaddr);
     51	if (pmd_none(*pmd)) {
     52		BUG();
     53		return;
     54	}
     55	pte = pte_offset_kernel(pmd, vaddr);
     56	if (!pte_none(pteval))
     57		set_pte_at(&init_mm, vaddr, pte, pteval);
     58	else
     59		pte_clear(&init_mm, vaddr, pte);
     60
     61	/*
     62	 * It's enough to flush this one mapping.
     63	 * (PGE mappings get flushed as well)
     64	 */
     65	flush_tlb_one_kernel(vaddr);
     66}
     67
     68unsigned long __FIXADDR_TOP = 0xfffff000;
     69EXPORT_SYMBOL(__FIXADDR_TOP);
     70
     71/*
     72 * vmalloc=size forces the vmalloc area to be exactly 'size'
     73 * bytes. This can be used to increase (or decrease) the
     74 * vmalloc area - the default is 128m.
     75 */
     76static int __init parse_vmalloc(char *arg)
     77{
     78	if (!arg)
     79		return -EINVAL;
     80
     81	/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
     82	__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
     83	return 0;
     84}
     85early_param("vmalloc", parse_vmalloc);
     86
     87/*
     88 * reservetop=size reserves a hole at the top of the kernel address space which
     89 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
     90 * so relocating the fixmap can be done before paging initialization.
     91 */
     92static int __init parse_reservetop(char *arg)
     93{
     94	unsigned long address;
     95
     96	if (!arg)
     97		return -EINVAL;
     98
     99	address = memparse(arg, &arg);
    100	reserve_top_address(address);
    101	early_ioremap_init();
    102	return 0;
    103}
    104early_param("reservetop", parse_reservetop);