Re: [PATCH v2 14/30] bsd-user/arm/target_arch_thread.h: Routines to create and switch to a thread

[Richard Henderson]

On 11/2/21 6:52 PM, Warner Losh wrote:
> +    /*
> +     * Thumb mode is encoded by the low bit in the entry point (since ARM can't
> +     * execute at odd addresses). When it's set, set the Thumb bit (T) in the
> +     * CPSR.
> +     */
> +    if (entry & 0x1) {
> +        cpsr_write(env, cpsr_read(env) | CPSR_T, CPSR_T, CPSRWriteByInstr);
> +    }

This should be

  cpsr_write(env, (entry & 1) * CPSR_T, CPSR_T, CPSRWriteByInstr);

because you need to clear T for arm mode as well.

> +    /* FIXME - what to for failure of get_user()? */
> +    get_user_ual(regs->ARM_r2, stack + 8); /* envp */
> +    get_user_ual(regs->ARM_r1, stack + 4); /* envp */

Surely these values are present in image_info anyway?


r~