Re: [PATCH v2 2/3] x86: move / split usercopy.c to / into arch-specific library

[Jan Beulich <jbeulich@xxxxxxxx>]

On 08.12.2025 22:48, Grygorii Strashko wrote:
> 
> 
> On 08.12.25 14:05, Jan Beulich wrote:
>> The file wasn't correctly named for our purposes anyway. Split it into its
>> "guest" and "unsafe" parts, thus allowing the latter to not be linked in
>> at all (for presently having no caller). The building of the "guest" part
>> can then (later) become conditional upon PV=y.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>> ---
>>   xen/arch/x86/Makefile                         |  4 ----
>>   xen/arch/x86/lib/Makefile                     |  2 ++
>>   xen/arch/x86/{usercopy.c => lib/copy-guest.c} | 12 +---------
>>   xen/arch/x86/lib/copy-unsafe.c                | 22 +++++++++++++++++++
>>   4 files changed, 25 insertions(+), 15 deletions(-)
>>   rename xen/arch/x86/{usercopy.c => lib/copy-guest.c} (94%)
>>   create mode 100644 xen/arch/x86/lib/copy-unsafe.c
>>
>> diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
>> index 61e2293a467e..dfb258d7ac1c 100644
>> --- a/xen/arch/x86/Makefile
>> +++ b/xen/arch/x86/Makefile
>> @@ -72,7 +72,6 @@ obj-y += time.o
>>   obj-y += traps-setup.o
>>   obj-y += traps.o
>>   obj-$(CONFIG_INTEL) += tsx.o
>> -obj-y += usercopy.o
>>   obj-y += x86_emulate.o
>>   obj-$(CONFIG_TBOOT) += tboot.o
>>   obj-y += hpet.o
>> @@ -93,9 +92,6 @@ hostprogs-y += efi/mkreloc
>>   
>>   $(obj)/efi/mkreloc: HOSTCFLAGS += -I$(srctree)/include
>>   
>> -# Allows usercopy.c to include itself
>> -$(obj)/usercopy.o: CFLAGS-y += -iquote .
>> -
>>   ifneq ($(CONFIG_HVM),y)
>>   $(obj)/x86_emulate.o: CFLAGS-y += -Wno-unused-label
>>   endif
>> diff --git a/xen/arch/x86/lib/Makefile b/xen/arch/x86/lib/Makefile
>> index ddf7e19bdc1d..8fe2dfd88553 100644
>> --- a/xen/arch/x86/lib/Makefile
>> +++ b/xen/arch/x86/lib/Makefile
>> @@ -1 +1,3 @@
>> +lib-y += copy-guest.o
>> +lib-y += copy-unsafe.o
>>   lib-y += generic-hweightl.o
>> diff --git a/xen/arch/x86/usercopy.c b/xen/arch/x86/lib/copy-guest.c
>> similarity index 94%
>> rename from xen/arch/x86/usercopy.c
>> rename to xen/arch/x86/lib/copy-guest.c
>> index a24b52cc66c1..25eeb35427e2 100644
>> --- a/xen/arch/x86/usercopy.c
>> +++ b/xen/arch/x86/lib/copy-guest.c
>> @@ -1,4 +1,4 @@
>> -/*
>> +/*
>>    * User address space access functions.
>>    *
>>    * Copyright 1997 Andi Kleen <ak@xxxxxx>
>> @@ -6,8 +6,6 @@
>>    * Copyright 2002 Andi Kleen <ak@xxxxxxx>
>>    */
>>   
>> -#include <xen/lib.h>
>> -#include <xen/sched.h>
> 
> This will not build :(
> 
>    CC      arch/x86/lib/copy-guest.o
> In file included from ././include/xen/config.h:27,
>                   from <command-line>:
> arch/x86/lib/copy-guest.c: In function ‘copy_to_guest_pv’:
> ./arch/x86/include/asm/config.h:270:32: error: invalid use of undefined type 
> ‘struct vcpu’
>    270 |     (ARG_XLAT_VIRT_START + ((v)->vcpu_id << ARG_XLAT_VA_SHIFT))
> 

Hmm, yes. It does build here, but of course I have many other patches in
place. The issue looks to be that for me access_ok() isn't a macro anymore,
but a function.

Thanks for pointing out,
Jan