Re: [Qemu-devel] [PATCH v4 2/4] linux-user: Set PAGE_TARGET_1 for TARGET_PROT_BTI

[Richard Henderson]

On 4/30/19 3:40 AM, Peter Maydell wrote:
> On Mon, 29 Apr 2019 at 21:13, Richard Henderson
> <address@hidden> wrote:
>>
>> On 4/29/19 9:21 AM, Peter Maydell wrote:
>>> This looks ok code-wise, but we'd need to hide it behind
>>> a defaults-to-off x-something property if we wanted to
>>> commit it before the kernel ABI is fixed.
>>
>> I'm not intending to change the user-level abi, only the
>> internal abi within qemu, for handling of the elf notes.
> 
> You're changing target_mmap(), which is used by the
> guest mmap syscall, though, right?

Yes, but it's also used by elfload.c to map the executable.

> I think that we shouldn't allow guest binaries written
> to the ad-hoc TARGET_PROT_BTI ABI to work without an
> explicit x-something command line argument to QEMU...

The guest binary is not written to an ad-hoc abi.

It is written to the finalized ELF note abi, which
I am trying to implement with a *private* QEMU abi.


r~