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223b5e57d0
Extend execmem parameters to accommodate more complex overrides of module_alloc() by architectures. This includes specification of a fallback range required by arm, arm64 and powerpc, EXECMEM_MODULE_DATA type required by powerpc, support for allocation of KASAN shadow required by s390 and x86 and support for late initialization of execmem required by arm64. The core implementation of execmem_alloc() takes care of suppressing warnings when the initial allocation fails but there is a fallback range defined. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Song Liu <song@kernel.org> Tested-by: Liviu Dudau <liviu@dudau.co.uk> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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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