144 lines
3.5 KiB
C
144 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2002 Richard Henderson
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* Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
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* Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
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* Copyright (C) 2024 Mike Rapoport IBM.
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*/
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/execmem.h>
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#include <linux/moduleloader.h>
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static struct execmem_info *execmem_info __ro_after_init;
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static struct execmem_info default_execmem_info __ro_after_init;
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static void *__execmem_alloc(struct execmem_range *range, size_t size)
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{
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bool kasan = range->flags & EXECMEM_KASAN_SHADOW;
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unsigned long vm_flags = VM_FLUSH_RESET_PERMS;
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gfp_t gfp_flags = GFP_KERNEL | __GFP_NOWARN;
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unsigned long start = range->start;
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unsigned long end = range->end;
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unsigned int align = range->alignment;
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pgprot_t pgprot = range->pgprot;
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void *p;
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if (kasan)
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vm_flags |= VM_DEFER_KMEMLEAK;
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p = __vmalloc_node_range(size, align, start, end, gfp_flags,
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pgprot, vm_flags, NUMA_NO_NODE,
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__builtin_return_address(0));
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if (!p && range->fallback_start) {
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start = range->fallback_start;
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end = range->fallback_end;
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p = __vmalloc_node_range(size, align, start, end, gfp_flags,
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pgprot, vm_flags, NUMA_NO_NODE,
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__builtin_return_address(0));
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}
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if (!p) {
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pr_warn_ratelimited("execmem: unable to allocate memory\n");
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return NULL;
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}
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if (kasan && (kasan_alloc_module_shadow(p, size, GFP_KERNEL) < 0)) {
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vfree(p);
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return NULL;
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}
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return kasan_reset_tag(p);
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}
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void *execmem_alloc(enum execmem_type type, size_t size)
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{
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struct execmem_range *range = &execmem_info->ranges[type];
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return __execmem_alloc(range, size);
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}
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void execmem_free(void *ptr)
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{
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/*
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* This memory may be RO, and freeing RO memory in an interrupt is not
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* supported by vmalloc.
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*/
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WARN_ON(in_interrupt());
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vfree(ptr);
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}
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static bool execmem_validate(struct execmem_info *info)
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{
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struct execmem_range *r = &info->ranges[EXECMEM_DEFAULT];
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if (!r->alignment || !r->start || !r->end || !pgprot_val(r->pgprot)) {
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pr_crit("Invalid parameters for execmem allocator, module loading will fail");
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return false;
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}
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return true;
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}
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static void execmem_init_missing(struct execmem_info *info)
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{
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struct execmem_range *default_range = &info->ranges[EXECMEM_DEFAULT];
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for (int i = EXECMEM_DEFAULT + 1; i < EXECMEM_TYPE_MAX; i++) {
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struct execmem_range *r = &info->ranges[i];
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if (!r->start) {
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if (i == EXECMEM_MODULE_DATA)
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r->pgprot = PAGE_KERNEL;
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else
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r->pgprot = default_range->pgprot;
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r->alignment = default_range->alignment;
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r->start = default_range->start;
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r->end = default_range->end;
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r->flags = default_range->flags;
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r->fallback_start = default_range->fallback_start;
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r->fallback_end = default_range->fallback_end;
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}
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}
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}
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struct execmem_info * __weak execmem_arch_setup(void)
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{
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return NULL;
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}
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static void __init __execmem_init(void)
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{
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struct execmem_info *info = execmem_arch_setup();
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if (!info) {
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info = execmem_info = &default_execmem_info;
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info->ranges[EXECMEM_DEFAULT].start = VMALLOC_START;
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info->ranges[EXECMEM_DEFAULT].end = VMALLOC_END;
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info->ranges[EXECMEM_DEFAULT].pgprot = PAGE_KERNEL_EXEC;
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info->ranges[EXECMEM_DEFAULT].alignment = 1;
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}
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if (!execmem_validate(info))
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return;
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execmem_init_missing(info);
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execmem_info = info;
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}
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#ifdef CONFIG_ARCH_WANTS_EXECMEM_LATE
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static int __init execmem_late_init(void)
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{
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__execmem_init();
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return 0;
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}
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core_initcall(execmem_late_init);
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#else
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void __init execmem_init(void)
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{
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__execmem_init();
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}
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#endif
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