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0042090548
Make use of the newly introduced arch_validate_flags() hook to sanity-check the PROT_MTE request passed to mmap() and mprotect(). If the mapping does not support MTE, these syscalls will return -EINVAL. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
88 lines
2.5 KiB
C
88 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_MMAN_H__
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#define __ASM_MMAN_H__
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <uapi/asm/mman.h>
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static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
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unsigned long pkey __always_unused)
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{
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unsigned long ret = 0;
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if (system_supports_bti() && (prot & PROT_BTI))
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ret |= VM_ARM64_BTI;
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if (system_supports_mte() && (prot & PROT_MTE))
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ret |= VM_MTE;
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return ret;
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}
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#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
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static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)
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{
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/*
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* Only allow MTE on anonymous mappings as these are guaranteed to be
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* backed by tags-capable memory. The vm_flags may be overridden by a
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* filesystem supporting MTE (RAM-based).
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*/
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if (system_supports_mte() && (flags & MAP_ANONYMOUS))
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return VM_MTE_ALLOWED;
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return 0;
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}
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#define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags)
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static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
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{
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pteval_t prot = 0;
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if (vm_flags & VM_ARM64_BTI)
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prot |= PTE_GP;
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/*
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* There are two conditions required for returning a Normal Tagged
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* memory type: (1) the user requested it via PROT_MTE passed to
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* mmap() or mprotect() and (2) the corresponding vma supports MTE. We
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* register (1) as VM_MTE in the vma->vm_flags and (2) as
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* VM_MTE_ALLOWED. Note that the latter can only be set during the
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* mmap() call since mprotect() does not accept MAP_* flags.
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* Checking for VM_MTE only is sufficient since arch_validate_flags()
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* does not permit (VM_MTE & !VM_MTE_ALLOWED).
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*/
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if (vm_flags & VM_MTE)
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prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED);
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return __pgprot(prot);
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}
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#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
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static inline bool arch_validate_prot(unsigned long prot,
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unsigned long addr __always_unused)
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{
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unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
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if (system_supports_bti())
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supported |= PROT_BTI;
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if (system_supports_mte())
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supported |= PROT_MTE;
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return (prot & ~supported) == 0;
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}
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#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
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static inline bool arch_validate_flags(unsigned long vm_flags)
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{
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if (!system_supports_mte())
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return true;
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/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
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return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
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}
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#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
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#endif /* ! __ASM_MMAN_H__ */
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