Re: [PATCH V5 09/21] riscv: compat: Add basic compat data type implementation

Guo Ren
2022-02-23T08:54:47Z

On Wed, Feb 23, 2022 at 9:42 AM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> On Tue, 01 Feb 2022 07:05:33 PST (-0800), guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Implement riscv asm/compat.h for struct compat_xxx,
> > is_compat_task, compat_user_regset, regset convert.
> >
> > The rv64 compat.h has inherited most of the structs
> > from the generic one.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Palmer Dabbelt <palmer@dabbelt.com>
> > ---
> > arch/riscv/include/asm/compat.h | 129 +++++++++++++++++++++++++++
> > arch/riscv/include/asm/thread_info.h | 1 +
> > 2 files changed, 130 insertions(+)
> > create mode 100644 arch/riscv/include/asm/compat.h
> >
> > diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
> > new file mode 100644
> > index 000000000000..2ac955b51148
> > --- /dev/null
> > +++ b/arch/riscv/include/asm/compat.h
> > @@ -0,0 +1,129 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_COMPAT_H
> > +#define __ASM_COMPAT_H
> > +
> > +#define COMPAT_UTS_MACHINE "riscv\0\0"
> > +
> > +/*
> > + * Architecture specific compatibility types
> > + */
> > +#include <linux/types.h>
> > +#include <linux/sched.h>
> > +#include <linux/sched/task_stack.h>
> > +#include <asm-generic/compat.h>
> > +
> > +static inline int is_compat_task(void)
> > +{
> > + return test_thread_flag(TIF_32BIT);
> > +}
> > +
> > +struct compat_user_regs_struct {
> > + compat_ulong_t pc;
> > + compat_ulong_t ra;
> > + compat_ulong_t sp;
> > + compat_ulong_t gp;
> > + compat_ulong_t tp;
> > + compat_ulong_t t0;
> > + compat_ulong_t t1;
> > + compat_ulong_t t2;
> > + compat_ulong_t s0;
> > + compat_ulong_t s1;
> > + compat_ulong_t a0;
> > + compat_ulong_t a1;
> > + compat_ulong_t a2;
> > + compat_ulong_t a3;
> > + compat_ulong_t a4;
> > + compat_ulong_t a5;
> > + compat_ulong_t a6;
> > + compat_ulong_t a7;
> > + compat_ulong_t s2;
> > + compat_ulong_t s3;
> > + compat_ulong_t s4;
> > + compat_ulong_t s5;
> > + compat_ulong_t s6;
> > + compat_ulong_t s7;
> > + compat_ulong_t s8;
> > + compat_ulong_t s9;
> > + compat_ulong_t s10;
> > + compat_ulong_t s11;
> > + compat_ulong_t t3;
> > + compat_ulong_t t4;
> > + compat_ulong_t t5;
> > + compat_ulong_t t6;
> > +};
> > +
> > +static inline void regs_to_cregs(struct compat_user_regs_struct *cregs,
> > + struct pt_regs *regs)
> > +{
> > + cregs->pc = (compat_ulong_t) regs->epc;
> > + cregs->ra = (compat_ulong_t) regs->ra;
> > + cregs->sp = (compat_ulong_t) regs->sp;
> > + cregs->gp = (compat_ulong_t) regs->gp;
> > + cregs->tp = (compat_ulong_t) regs->tp;
> > + cregs->t0 = (compat_ulong_t) regs->t0;
> > + cregs->t1 = (compat_ulong_t) regs->t1;
> > + cregs->t2 = (compat_ulong_t) regs->t2;
> > + cregs->s0 = (compat_ulong_t) regs->s0;
> > + cregs->s1 = (compat_ulong_t) regs->s1;
> > + cregs->a0 = (compat_ulong_t) regs->a0;
> > + cregs->a1 = (compat_ulong_t) regs->a1;
> > + cregs->a2 = (compat_ulong_t) regs->a2;
> > + cregs->a3 = (compat_ulong_t) regs->a3;
> > + cregs->a4 = (compat_ulong_t) regs->a4;
> > + cregs->a5 = (compat_ulong_t) regs->a5;
> > + cregs->a6 = (compat_ulong_t) regs->a6;
> > + cregs->a7 = (compat_ulong_t) regs->a7;
> > + cregs->s2 = (compat_ulong_t) regs->s2;
> > + cregs->s3 = (compat_ulong_t) regs->s3;
> > + cregs->s4 = (compat_ulong_t) regs->s4;
> > + cregs->s5 = (compat_ulong_t) regs->s5;
> > + cregs->s6 = (compat_ulong_t) regs->s6;
> > + cregs->s7 = (compat_ulong_t) regs->s7;
> > + cregs->s8 = (compat_ulong_t) regs->s8;
> > + cregs->s9 = (compat_ulong_t) regs->s9;
> > + cregs->s10 = (compat_ulong_t) regs->s10;
> > + cregs->s11 = (compat_ulong_t) regs->s11;
> > + cregs->t3 = (compat_ulong_t) regs->t3;
> > + cregs->t4 = (compat_ulong_t) regs->t4;
> > + cregs->t5 = (compat_ulong_t) regs->t5;
> > + cregs->t6 = (compat_ulong_t) regs->t6;
> > +};
> > +
> > +static inline void cregs_to_regs(struct compat_user_regs_struct *cregs,
> > + struct pt_regs *regs)
> > +{
> > + regs->epc = (unsigned long) cregs->pc;
> > + regs->ra = (unsigned long) cregs->ra;
> > + regs->sp = (unsigned long) cregs->sp;
> > + regs->gp = (unsigned long) cregs->gp;
> > + regs->tp = (unsigned long) cregs->tp;
> > + regs->t0 = (unsigned long) cregs->t0;
> > + regs->t1 = (unsigned long) cregs->t1;
> > + regs->t2 = (unsigned long) cregs->t2;
> > + regs->s0 = (unsigned long) cregs->s0;
> > + regs->s1 = (unsigned long) cregs->s1;
> > + regs->a0 = (unsigned long) cregs->a0;
> > + regs->a1 = (unsigned long) cregs->a1;
> > + regs->a2 = (unsigned long) cregs->a2;
> > + regs->a3 = (unsigned long) cregs->a3;
> > + regs->a4 = (unsigned long) cregs->a4;
> > + regs->a5 = (unsigned long) cregs->a5;
> > + regs->a6 = (unsigned long) cregs->a6;
> > + regs->a7 = (unsigned long) cregs->a7;
> > + regs->s2 = (unsigned long) cregs->s2;
> > + regs->s3 = (unsigned long) cregs->s3;
> > + regs->s4 = (unsigned long) cregs->s4;
> > + regs->s5 = (unsigned long) cregs->s5;
> > + regs->s6 = (unsigned long) cregs->s6;
> > + regs->s7 = (unsigned long) cregs->s7;
> > + regs->s8 = (unsigned long) cregs->s8;
> > + regs->s9 = (unsigned long) cregs->s9;
> > + regs->s10 = (unsigned long) cregs->s10;
> > + regs->s11 = (unsigned long) cregs->s11;
> > + regs->t3 = (unsigned long) cregs->t3;
> > + regs->t4 = (unsigned long) cregs->t4;
> > + regs->t5 = (unsigned long) cregs->t5;
> > + regs->t6 = (unsigned long) cregs->t6;
> > +};
> > +
> > +#endif /* __ASM_COMPAT_H */
> > diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
> > index 60da0dcacf14..9392e35c689d 100644
> > --- a/arch/riscv/include/asm/thread_info.h
> > +++ b/arch/riscv/include/asm/thread_info.h
> > @@ -91,6 +91,7 @@ struct thread_info {
> > #define TIF_SECCOMP 8 /* syscall secure computing */
> > #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
> > #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
> > +#define TIF_32BIT 11 /* 32bit process */
>
> Presumably that's just meant for 32-bit processes on rv64? Probably
> best to have the comment say that explicitly.
/* compat-mode 32bit process */

>
> > #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
> > #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)

--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/