cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

init-common.c (4649B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  PowerPC version
      4 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
      5 *
      6 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
      7 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
      8 *    Copyright (C) 1996 Paul Mackerras
      9 *
     10 *  Derived from "arch/i386/mm/init.c"
     11 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
     12 *
     13 *  Dave Engebretsen <engebret@us.ibm.com>
     14 *      Rework for PPC64 port.
     15 */
     16
     17#undef DEBUG
     18
     19#include <linux/string.h>
     20#include <linux/pgtable.h>
     21#include <asm/pgalloc.h>
     22#include <asm/kup.h>
     23#include <asm/smp.h>
     24
     25phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
     26EXPORT_SYMBOL_GPL(memstart_addr);
     27phys_addr_t kernstart_addr __ro_after_init;
     28EXPORT_SYMBOL_GPL(kernstart_addr);
     29unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
     30EXPORT_SYMBOL_GPL(kernstart_virt_addr);
     31
     32bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
     33bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
     34
     35static int __init parse_nosmep(char *p)
     36{
     37	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
     38		return 0;
     39
     40	disable_kuep = true;
     41	pr_warn("Disabling Kernel Userspace Execution Prevention\n");
     42	return 0;
     43}
     44early_param("nosmep", parse_nosmep);
     45
     46static int __init parse_nosmap(char *p)
     47{
     48	disable_kuap = true;
     49	pr_warn("Disabling Kernel Userspace Access Protection\n");
     50	return 0;
     51}
     52early_param("nosmap", parse_nosmap);
     53
     54void __weak setup_kuep(bool disabled)
     55{
     56	if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled)
     57		return;
     58
     59	if (smp_processor_id() != boot_cpuid)
     60		return;
     61
     62	pr_info("Activating Kernel Userspace Execution Prevention\n");
     63}
     64
     65void setup_kup(void)
     66{
     67	setup_kuap(disable_kuap);
     68	setup_kuep(disable_kuep);
     69}
     70
     71#define CTOR(shift) static void ctor_##shift(void *addr) \
     72{							\
     73	memset(addr, 0, sizeof(void *) << (shift));	\
     74}
     75
     76CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
     77CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
     78
     79static inline void (*ctor(int shift))(void *)
     80{
     81	BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
     82
     83	switch (shift) {
     84	case 0: return ctor_0;
     85	case 1: return ctor_1;
     86	case 2: return ctor_2;
     87	case 3: return ctor_3;
     88	case 4: return ctor_4;
     89	case 5: return ctor_5;
     90	case 6: return ctor_6;
     91	case 7: return ctor_7;
     92	case 8: return ctor_8;
     93	case 9: return ctor_9;
     94	case 10: return ctor_10;
     95	case 11: return ctor_11;
     96	case 12: return ctor_12;
     97	case 13: return ctor_13;
     98	case 14: return ctor_14;
     99	case 15: return ctor_15;
    100	}
    101	return NULL;
    102}
    103
    104struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
    105EXPORT_SYMBOL_GPL(pgtable_cache);	/* used by kvm_hv module */
    106
    107/*
    108 * Create a kmem_cache() for pagetables.  This is not used for PTE
    109 * pages - they're linked to struct page, come from the normal free
    110 * pages pool and have a different entry size (see real_pte_t) to
    111 * everything else.  Caches created by this function are used for all
    112 * the higher level pagetables, and for hugepage pagetables.
    113 */
    114void pgtable_cache_add(unsigned int shift)
    115{
    116	char *name;
    117	unsigned long table_size = sizeof(void *) << shift;
    118	unsigned long align = table_size;
    119
    120	/* When batching pgtable pointers for RCU freeing, we store
    121	 * the index size in the low bits.  Table alignment must be
    122	 * big enough to fit it.
    123	 *
    124	 * Likewise, hugeapge pagetable pointers contain a (different)
    125	 * shift value in the low bits.  All tables must be aligned so
    126	 * as to leave enough 0 bits in the address to contain it. */
    127	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
    128				     HUGEPD_SHIFT_MASK + 1);
    129	struct kmem_cache *new;
    130
    131	/* It would be nice if this was a BUILD_BUG_ON(), but at the
    132	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
    133	 * constant expression, so so much for that. */
    134	BUG_ON(!is_power_of_2(minalign));
    135	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
    136
    137	if (PGT_CACHE(shift))
    138		return; /* Already have a cache of this size */
    139
    140	align = max_t(unsigned long, align, minalign);
    141	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
    142	new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
    143	if (!new)
    144		panic("Could not allocate pgtable cache for order %d", shift);
    145
    146	kfree(name);
    147	pgtable_cache[shift] = new;
    148
    149	pr_debug("Allocated pgtable cache for order %d\n", shift);
    150}
    151EXPORT_SYMBOL_GPL(pgtable_cache_add);	/* used by kvm_hv module */
    152
    153void pgtable_cache_init(void)
    154{
    155	pgtable_cache_add(PGD_INDEX_SIZE);
    156
    157	if (PMD_CACHE_INDEX)
    158		pgtable_cache_add(PMD_CACHE_INDEX);
    159	/*
    160	 * In all current configs, when the PUD index exists it's the
    161	 * same size as either the pgd or pmd index except with THP enabled
    162	 * on book3s 64
    163	 */
    164	if (PUD_CACHE_INDEX)
    165		pgtable_cache_add(PUD_CACHE_INDEX);
    166}