Re: linux-next: Tree for Oct 31 (vboxguest)

[Randy Dunlap]

On 10/31/18 2:41 PM, Arnd Bergmann wrote:
> On 10/31/18, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>> On 10/30/18 8:59 PM, Stephen Rothwell wrote:
>>> Hi all,
>>>
>>> Please do not add any v4.21/v5.1 code to your linux-next included trees
>>> until after the merge window closes.
>>>
>>> Changes since 20181030:
>>>
>>
>>
>> on i386:
>>
>> ld: drivers/virt/vboxguest/vboxguest_core.o: in function
>> `vbg_ioctl_hgcm_call':
>> vboxguest_core.c:(.text+0x212b): undefined reference to `vbg_hgcm_call32'
>>
>>
>> Full randconfig file is attached.
>>
>> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> 
> I ran into the same thing, and lots of others like it; they all go back to
> the -Og compiler option introduced in commit 94c7dfd01652 ("kernel
> hacking: support building kernel with -Og optimization level").
> 
> 
> I have patches for most of these, but I'd prefer if we could leave
> that patch out of 4.20 for now, and have it in linux-next for merging
> into the next merge window, to give us more time to fix up all the
> regressions. This particular instance is fixed by the patch below.
> 
> Other symptoms caused by the change are tons of 'section mismatch'
> warnings for functions that are no longer automatically inlined, and
> sprintf format string overflow warnings when gcc fails to propagate
> an upper bound on an integer argument that is printed into a fixed
> length string.

Yeah, I saw lots of those but haven't tried to diagnose them yet,
so thanks for the info.

> 
>      Arnd
> ---
> From 8172e650c6797b9cc64c6f7b1c9e5433156290cc Mon Sep 17 00:00:00 2001
> From: Arnd Bergmann <arnd@xxxxxxxx>
> Date: Wed, 31 Oct 2018 16:24:35 +0100
> Subject: [PATCH] vbox: fix link error with 'gcc -Og'
> 
> With the new CONFIG_CC_OPTIMIZE_FOR_DEBUGGING option, we get a link
> error in the vboxguest driver, when that fails to optimize out the
> call to the compat handler:
> 
> drivers/virt/vboxguest/vboxguest_core.o: In function `vbg_ioctl_hgcm_call':
> vboxguest_core.c:(.text+0x1f6e): undefined reference to `vbg_hgcm_call32'
> 
> Another compile-time check documents better what we want and avoids
> the error.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> 
> diff --git a/drivers/virt/vboxguest/vboxguest_core.c
> b/drivers/virt/vboxguest/vboxguest_core.c
> index 3093655c7b92..1475ed5ffcde 100644
> --- a/drivers/virt/vboxguest/vboxguest_core.c
> +++ b/drivers/virt/vboxguest/vboxguest_core.c
> @@ -1312,7 +1312,7 @@ static int vbg_ioctl_hgcm_call(struct vbg_dev *gdev,
>  		return -EINVAL;
>  	}
> 
> -	if (f32bit)
> +	if (IS_ENABLED(CONFIG_COMPAT) && f32bit)
>  		ret = vbg_hgcm_call32(gdev, client_id,
>  				      call->function, call->timeout_ms,
>  				      VBG_IOCTL_HGCM_CALL_PARMS32(call),
> 

I have that same patch on my machine.  :)
You can added my Acked-by or Tested-by if you want to.

thanks,
-- 
~Randy