25abe0db92
RISC-V Kfence implementation used to rely on the fact the linear mapping
was backed by at most PMD hugepages, which is not true anymore since
commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear
mapping").
Instead of splitting PUD/P4D/PGD mappings afterwards, directly map the
kfence pool region using PTE mappings by allocating this region before
setup_vm_final().
Reported-by: syzbot+a74d57bddabbedd75135@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a74d57bddabbedd75135
Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230606130444.25090-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
31 lines
611 B
C
31 lines
611 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_RISCV_KFENCE_H
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#define _ASM_RISCV_KFENCE_H
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#include <linux/kfence.h>
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#include <linux/pfn.h>
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#include <asm-generic/pgalloc.h>
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#include <asm/pgtable.h>
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static inline bool arch_kfence_init_pool(void)
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{
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return true;
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}
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static inline bool kfence_protect_page(unsigned long addr, bool protect)
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{
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pte_t *pte = virt_to_kpte(addr);
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if (protect)
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set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
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else
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set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
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flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
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return true;
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}
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#endif /* _ASM_RISCV_KFENCE_H */
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