On Thu, Jun 27, 2024 at 11:02:46AM +0800, [email protected] wrote: > From: Quan Zhou <[email protected]> > > Expose orig_a0 to userspace to ensure that users can modify > the actual value of `a0` in the traced process through the > ptrace(PTRACE_SETREGSET, ...) path. > > The addition of orig_a0 also requires the following adjustments: > 1) Adjust the position of orig_a0 in pt_regs to ensure correct copying. > 2) MAX_REG_OFFSET should match the new bottom of pt_regs. > > Suggested-by: Charlie Jenkins <[email protected]> > Signed-off-by: Quan Zhou <[email protected]> > --- > arch/riscv/include/asm/ptrace.h | 7 ++++--- > arch/riscv/include/uapi/asm/ptrace.h | 2 ++ > 2 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h > index b5b0adcc85c1..380cf54c1f3d 100644 > --- a/arch/riscv/include/asm/ptrace.h > +++ b/arch/riscv/include/asm/ptrace.h > @@ -12,6 +12,7 @@ > > #ifndef __ASSEMBLY__ > > +/* MAX_REG_OFFSET should match the bottom of pt_regs */ > struct pt_regs { > unsigned long epc; > unsigned long ra; > @@ -45,12 +46,12 @@ struct pt_regs { > unsigned long t4; > unsigned long t5; > unsigned long t6; > + /* a0 value before the syscall */ > + unsigned long orig_a0; > /* Supervisor/Machine CSRs */ > unsigned long status; > unsigned long badaddr; > unsigned long cause; > - /* a0 value before the syscall */ > - unsigned long orig_a0; > }; > > #define PTRACE_SYSEMU 0x1f > @@ -64,7 +65,7 @@ struct pt_regs { > > #define user_mode(regs) (((regs)->status & SR_PP) == 0) > > -#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0) > +#define MAX_REG_OFFSET offsetof(struct pt_regs, cause) > > /* Helpers for working with the instruction pointer */ > static inline unsigned long instruction_pointer(struct pt_regs *regs) > diff --git a/arch/riscv/include/uapi/asm/ptrace.h > b/arch/riscv/include/uapi/asm/ptrace.h > index a38268b19c3d..3e37f80cb3e8 100644 > --- a/arch/riscv/include/uapi/asm/ptrace.h > +++ b/arch/riscv/include/uapi/asm/ptrace.h > @@ -54,6 +54,8 @@ struct user_regs_struct { > unsigned long t4; > unsigned long t5; > unsigned long t6; > + /* a0 value before the syscall */ > + unsigned long orig_a0; > }; > > struct __riscv_f_ext_state { > -- > 2.34.1 >
Thank you! Reviewed-by: Charlie Jenkins <[email protected]>
