Re: [Qemu-devel] [PATCH 02/12 v9] linux-user: tilegx: Add target features support within qemu

[Peter Maydell <peter.maydell@linaro.org>]

On 10 April 2015 at 21:41, Chen Gang <xili_gchen_5257@hotmail.com> wrote:
> On 4/10/15 05:31, Peter Maydell wrote:
>> On 27 March 2015 at 10:49, Chen Gang <xili_gchen_5257@hotmail.com> wrote:
>>> +typedef struct target_sigaltstack {
>>> +    abi_ulong ss_sp;
>>> +    abi_ulong ss_size;
>>> +    abi_long ss_flags;
>>> +} target_stack_t;
>>
>> Where does this come from? It doesn't match the kernel's
>> generic-headers struct layout.
>>
>
> Oh, sorry, originally, I guess, I only copied it from microblaze, did
> not check kernel.

These structures are all user-guest-facing ABI, so they must
match the kernel's structures for your target architecture.

> I shall use generic-headers which tilegx will use (the result will like
> alpha has done):
>
> typedef struct target_sigaltstack {
>     abi_ulong ss_sp;
>     int32_t ss_flags;
>     int32_t dummy;
>     abi_ulong ss_size;
> } target_stack_t;

This doesn't match the kernel either.

http://lxr.free-electrons.com/source/include/uapi/asm-generic/signal.h#L111

You have a pointer, an int and a size_t, so you want
    abi_ulong ss_sp;
    abi_int ss_flags;
    abi_ulong ss_size;

like aarch64.

>
> [...]
>>> +
>>> +struct target_ipc_perm {
>>> +    abi_int __key;                      /* Key.  */
>>> +    abi_uint uid;                       /* Owner's user ID.  */
>>> +    abi_uint gid;                       /* Owner's group ID.  */
>>> +    abi_uint cuid;                      /* Creator's user ID.  */
>>> +    abi_uint cgid;                      /* Creator's group ID.  */
>>> +    abi_uint mode;                    /* Read/write permission.  */
>>> +    abi_ushort __seq;                   /* Sequence number.  */
>>> +    abi_ushort __pad2;
>>> +    abi_ulong __unused1;
>>> +    abi_ulong __unused2;
>>> +};
>>
>> Again, doesn't seem to match kernel?
>>
>
> For me, it matches kernel. mode is abi_uint (__kernel_mode_t is 32-bit).

I'm looking at
http://lxr.free-electrons.com/source/include/uapi/linux/ipc.h#L9
which doesn't have that padding and unused fields at the end.
However the ipc structs are pretty confusing so maybe that's
the wrong one -- which one are you looking at?

-- PMM