Re: [PATCH 22/23] Add set_mcontext function for ARM AArch64 in bsd-user

[Richard Henderson <richard.henderson@linaro.org>]

On 6/23/24 08:54, Warner Losh wrote:
> 
> 
> On Tue, Jun 18, 2024 at 4:51 PM Richard Henderson <richard.henderson@linaro.org 
> <mailto:richard.henderson@linaro.org>> wrote:
> 
>     On 6/17/24 11:58, Ajeet Singh wrote:
>      > From: Stacey Son <sson@FreeBSD.org>
>      >
>      > The function copies register values from the provided target_mcontext_t
>      > structure to the CPUARMState registers
>      >
>      > Signed-off-by: Stacey Son <sson@FreeBSD.org>
>      > Signed-off-by: Ajeet Singh <itachis@FreeBSD.org>
>      > ---
>      >   bsd-user/aarch64/signal.c | 22 ++++++++++++++++++++++
>      >   1 file changed, 22 insertions(+)
>      >
>      > diff --git a/bsd-user/aarch64/signal.c b/bsd-user/aarch64/signal.c
>      > index 43c886e603..13faac8ce6 100644
>      > --- a/bsd-user/aarch64/signal.c
>      > +++ b/bsd-user/aarch64/signal.c
>      > @@ -95,3 +95,25 @@ abi_long setup_sigframe_arch(CPUARMState *env, abi_ulong frame_addr,
>      >       return 0;
>      >   }
>      >
>      > +/*
>      > + * Compare to set_mcontext() in arm64/arm64/machdep.c
>      > + * Assumes that the memory is locked if frame points to user memory.
>      > + */
>      > +abi_long set_mcontext(CPUARMState *regs, target_mcontext_t *mcp, int srflag)
>      > +{
>      > +    int err = 0, i;
>      > +    const uint64_t *gr = mcp->mc_gpregs.gp_x;
>      > +
>      > +    for (i = 0; i < 30; i++) {
>      > +        regs->xregs[i] = tswap64(gr[i]);
>      > +    }
>      > +
>      > +    regs->xregs[TARGET_REG_SP] = tswap64(mcp->mc_gpregs.gp_sp);
>      > +    regs->xregs[TARGET_REG_LR] = tswap64(mcp->mc_gpregs.gp_lr);
>      > +    regs->pc = mcp->mc_gpregs.gp_elr;
> 
>     tswap.
> 
> 
> So "regs->pc = tswap64(mcp->mc_gpregs.gp_elr)"  then?

Yes.

> 
>      > +    pstate_write(regs, mcp->mc_gpregs.gp_spsr);
>      > +
>      > +    /* XXX FP? */
> 
>     Similarly, see target_restore_fpsimd_record.
> 
> 
> Since neither this, nor the get_mcontext is written for FP on upstream yet, can we do 
> those as a followup commit?

Yes.


r~