| Message ID | 20240403234054.2020347-12-debug@rivosinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv control-flow integrity for usermode | expand |
On 04/04/2024 01:34, Deepak Gupta 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> > --- > arch/riscv/include/asm/pgtable.h | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 4d5983bc6766..6362407f1e83 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -408,6 +408,12 @@ 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) > +{ > + /* shadow stack on risc-v is XWR = 010. Clear everything and only set _PAGE_WRITE */ Nit: Not sure the comment is necessary > + 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) > @@ -693,6 +699,12 @@ 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) > +{ > + /* shadow stack on risc-v is XWR = 010. Clear everything and only set _PAGE_WRITE */ > + 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))); Otherwise: Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks, Alex
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 4d5983bc6766..6362407f1e83 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -408,6 +408,12 @@ 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) +{ + /* shadow stack on risc-v is XWR = 010. Clear everything and only set _PAGE_WRITE */ + 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) @@ -693,6 +699,12 @@ 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) +{ + /* shadow stack on risc-v is XWR = 010. Clear everything and only set _PAGE_WRITE */ + 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)));
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> --- arch/riscv/include/asm/pgtable.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)