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![Jason Yan](/assets/img/avatar_default.png)
Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we need a variable to store the kernel base. Signed-off-by: Jason Yan <yanaijie@huawei.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Diana Craciun <diana.craciun@nxp.com> Tested-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
151 lines
4.3 KiB
C
151 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* PowerPC version
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Dave Engebretsen <engebret@us.ibm.com>
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* Rework for PPC64 port.
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*/
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#undef DEBUG
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#include <linux/string.h>
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#include <asm/pgalloc.h>
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#include <asm/pgtable.h>
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#include <asm/kup.h>
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phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
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EXPORT_SYMBOL_GPL(memstart_addr);
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phys_addr_t kernstart_addr __ro_after_init;
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EXPORT_SYMBOL_GPL(kernstart_addr);
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unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
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EXPORT_SYMBOL_GPL(kernstart_virt_addr);
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static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
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static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
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static int __init parse_nosmep(char *p)
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{
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disable_kuep = true;
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pr_warn("Disabling Kernel Userspace Execution Prevention\n");
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return 0;
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}
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early_param("nosmep", parse_nosmep);
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static int __init parse_nosmap(char *p)
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{
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disable_kuap = true;
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pr_warn("Disabling Kernel Userspace Access Protection\n");
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return 0;
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}
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early_param("nosmap", parse_nosmap);
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void __ref setup_kup(void)
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{
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setup_kuep(disable_kuep);
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setup_kuap(disable_kuap);
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}
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#define CTOR(shift) static void ctor_##shift(void *addr) \
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{ \
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memset(addr, 0, sizeof(void *) << (shift)); \
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}
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CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
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CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
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static inline void (*ctor(int shift))(void *)
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{
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BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
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switch (shift) {
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case 0: return ctor_0;
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case 1: return ctor_1;
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case 2: return ctor_2;
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case 3: return ctor_3;
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case 4: return ctor_4;
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case 5: return ctor_5;
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case 6: return ctor_6;
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case 7: return ctor_7;
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case 8: return ctor_8;
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case 9: return ctor_9;
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case 10: return ctor_10;
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case 11: return ctor_11;
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case 12: return ctor_12;
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case 13: return ctor_13;
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case 14: return ctor_14;
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case 15: return ctor_15;
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}
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return NULL;
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}
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struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
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EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */
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/*
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* Create a kmem_cache() for pagetables. This is not used for PTE
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* pages - they're linked to struct page, come from the normal free
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* pages pool and have a different entry size (see real_pte_t) to
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* everything else. Caches created by this function are used for all
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* the higher level pagetables, and for hugepage pagetables.
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*/
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void pgtable_cache_add(unsigned int shift)
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{
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char *name;
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unsigned long table_size = sizeof(void *) << shift;
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unsigned long align = table_size;
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/* When batching pgtable pointers for RCU freeing, we store
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* the index size in the low bits. Table alignment must be
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* big enough to fit it.
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*
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* Likewise, hugeapge pagetable pointers contain a (different)
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* shift value in the low bits. All tables must be aligned so
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* as to leave enough 0 bits in the address to contain it. */
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unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
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HUGEPD_SHIFT_MASK + 1);
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struct kmem_cache *new;
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/* It would be nice if this was a BUILD_BUG_ON(), but at the
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* moment, gcc doesn't seem to recognize is_power_of_2 as a
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* constant expression, so so much for that. */
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BUG_ON(!is_power_of_2(minalign));
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BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
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if (PGT_CACHE(shift))
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return; /* Already have a cache of this size */
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align = max_t(unsigned long, align, minalign);
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name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
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new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
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if (!new)
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panic("Could not allocate pgtable cache for order %d", shift);
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kfree(name);
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pgtable_cache[shift] = new;
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pr_debug("Allocated pgtable cache for order %d\n", shift);
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}
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EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */
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void pgtable_cache_init(void)
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{
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pgtable_cache_add(PGD_INDEX_SIZE);
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if (PMD_CACHE_INDEX)
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pgtable_cache_add(PMD_CACHE_INDEX);
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/*
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* In all current configs, when the PUD index exists it's the
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* same size as either the pgd or pmd index except with THP enabled
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* on book3s 64
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*/
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if (PUD_CACHE_INDEX)
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pgtable_cache_add(PUD_CACHE_INDEX);
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}
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