Unverified Commit 4cb699d0 authored Jul 10, 2020 by Vincent Chen Committed by Palmer Dabbelt Jul 20, 2020

riscv: kasan: use local_tlb_flush_all() to avoid uninitialized __sbi_rfence



It fails to boot the v5.8-rc4 kernel with CONFIG_KASAN because kasan_init
and kasan_early_init use uninitialized __sbi_rfence as executing the
tlb_flush_all(). Actually, at this moment, only the CPU which is
responsible for the system initialization enables the MMU. Other CPUs are
parking at the .Lsecondary_start. Hence the tlb_flush_all() is able to be
replaced by local_tlb_flush_all() to avoid using uninitialized
__sbi_rfence.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

parent ba47d845

arch/riscv/mm/kasan_init.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -44,7 +44,7 @@ asmlinkage void __init kasan_early_init(void)
		(__pa(((uintptr_t) kasan_early_shadow_pmd))),
		__pgprot(_PAGE_TABLE)));

		flush_tlb_all();
		local_flush_tlb_all();
		}

		static void __init populate(void start, void end)
		@@ -79,7 +79,7 @@ static void __init populate(void start, void end)
		pfn_pgd(PFN_DOWN(__pa(&pmd[offset])),
		__pgprot(_PAGE_TABLE)));

		flush_tlb_all();
		local_flush_tlb_all();
		memset(start, 0, end - start);
		}

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