On Mon, Mar 10, 2025 at 11:42 PM Deepak Gupta <debug@rivosinc.com> wrote:
>
> This patch implements creating shadow stack pte (on riscv). Creating
> shadow stack PTE on riscv means that clearing RWX and then setting W=1.
>
> Signed-off-by: Deepak Gupta <debug@rivosinc.com>
> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> ---
> arch/riscv/include/asm/pgtable.h | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 8c528cd7347a..ede43185ffdf 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -421,6 +421,11 @@ static inline pte_t pte_mkwrite_novma(pte_t pte)
> return __pte(pte_val(pte) | _PAGE_WRITE);
> }
>
> +static inline pte_t pte_mkwrite_shstk(pte_t pte)
> +{
> + return __pte((pte_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
> +}
> +
> /* static inline pte_t pte_mkexec(pte_t pte) */
>
> static inline pte_t pte_mkdirty(pte_t pte)
> @@ -749,6 +754,11 @@ static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
> return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)));
> }
>
> +static inline pmd_t pmd_mkwrite_shstk(pmd_t pte)
> +{
> + return __pmd((pmd_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
> +}
> +
> static inline pmd_t pmd_wrprotect(pmd_t pmd)
> {
> return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
>
LGTM.
Reviewed-by: Zong Li <zong.li@sifive.com>
> --
> 2.34.1
>
>
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