On Fri, 29 Mar 2019 20:12:21 +0300
"Dmitry V. Levin" <[email protected]> wrote:
> RISC-V syscall arguments are located in orig_a0,a1..a5 fields
> of struct pt_regs.
>
> Due to an off-by-one bug and a bug in pointer arithmetic
> syscall_get_arguments() was reading s3..s7 fields instead of a1..a5.
> Likewise, syscall_set_arguments() was writing s3..s7 fields
> instead of a1..a5.
Should I add this to my series? And then rebase on top of it?
-- Steve
>
> Fixes: e2c0cdfba7f69 ("RISC-V: User-facing API")
> Cc: Steven Rostedt <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Kees Cook <[email protected]>
> Cc: Andy Lutomirski <[email protected]>
> Cc: Will Drewry <[email protected]>
> Cc: [email protected]
> Cc: [email protected] # v4.15+
> Signed-off-by: Dmitry V. Levin <[email protected]>
> ---
> arch/riscv/include/asm/syscall.h | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/include/asm/syscall.h
> b/arch/riscv/include/asm/syscall.h
> index bba3da6ef157..6ea9e1804233 100644
> --- a/arch/riscv/include/asm/syscall.h
> +++ b/arch/riscv/include/asm/syscall.h
> @@ -79,10 +79,11 @@ static inline void syscall_get_arguments(struct
> task_struct *task,
> if (i == 0) {
> args[0] = regs->orig_a0;
> args++;
> - i++;
> n--;
> + } else {
> + i--;
> }
> - memcpy(args, ®s->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
> + memcpy(args, ®s->a1 + i, n * sizeof(args[0]));
> }
>
> static inline void syscall_set_arguments(struct task_struct *task,
> @@ -94,10 +95,11 @@ static inline void syscall_set_arguments(struct
> task_struct *task,
> if (i == 0) {
> regs->orig_a0 = args[0];
> args++;
> - i++;
> n--;
> - }
> - memcpy(®s->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
> + } else {
> + i--;
> + }
> + memcpy(®s->a1 + i, args, n * sizeof(regs->a1));
> }
>
> static inline int syscall_get_arch(void)
