Re: [PATCH] hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from uapi header

[Thomas Huth]

On 29/11/2023 04.42, Brian Cain wrote:
> > -----Original Message-----
> > From: Thomas Huth <thuth@xxxxxxxxxx>
> > Sent: Thursday, October 26, 2023 6:31 AM
> > To: Arnd Bergmann <arnd@xxxxxxxx>; linux-hexagon@xxxxxxxxxxxxxxx; Brian
> > Cain <bcain@xxxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; Oleg Nesterov <oleg@xxxxxxxxxx>
> > Subject: [PATCH] hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from
> > uapi header
> >
> > WARNING: This email originated from outside of Qualcomm. Please be wary of
> > any links or attachments, and do not enable macros.
> >
> > uapi headers should not expose CONFIG switches since they are not
> > available in userspace. Fix it in arch/hexagon/include/uapi/asm/user.h
> > by always defining the cs0 and cs1 entries instead of pad values.
> >
> > Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
> > ---
> >   Based-on: <20231025073802.117625-1-thuth@xxxxxxxxxx>
> >
> >   Compile tested only (with CONFIG_HEXAGON_ARCH_VERSION set to 2
> >   and with CONFIG_HEXAGON_ARCH_VERSION set to 4)
> >
> >   arch/hexagon/include/uapi/asm/user.h | 7 +------
> >   arch/hexagon/kernel/ptrace.c         | 7 +++++--
> >   scripts/headers_install.sh           | 1 -
> >   3 files changed, 6 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/hexagon/include/uapi/asm/user.h
> > b/arch/hexagon/include/uapi/asm/user.h
> > index 7327ec59b22f..abae6a4b5813 100644
> > --- a/arch/hexagon/include/uapi/asm/user.h
> > +++ b/arch/hexagon/include/uapi/asm/user.h
> > @@ -56,15 +56,10 @@ struct user_regs_struct {
> >          unsigned long pc;
> >          unsigned long cause;
> >          unsigned long badva;
> > -#if CONFIG_HEXAGON_ARCH_VERSION < 4
> > -       unsigned long pad1;  /* pad out to 48 words total */
> > -       unsigned long pad2;  /* pad out to 48 words total */
> > -       unsigned long pad3;  /* pad out to 48 words total */
> > -#else
> > +       /* cs0 and cs1 are only available with HEXAGON_ARCH_VERSION >= 4 */
> >          unsigned long cs0;
> >          unsigned long cs1;
> >          unsigned long pad1;  /* pad out to 48 words total */
> > -#endif
> >   };
> >
> >   #endif
> > diff --git a/arch/hexagon/kernel/ptrace.c b/arch/hexagon/kernel/ptrace.c
> > index 125f19995b76..905b06790ab7 100644
> > --- a/arch/hexagon/kernel/ptrace.c
> > +++ b/arch/hexagon/kernel/ptrace.c
> > @@ -74,7 +74,7 @@ static int genregs_set(struct task_struct *target,
> >                     unsigned int pos, unsigned int count,
> >                     const void *kbuf, const void __user *ubuf)
> >   {
> > -       int ret;
> > +       int ret, ignore_offset;
> >          unsigned long bucket;
> >          struct pt_regs *regs = task_pt_regs(target);
> >
> > @@ -111,12 +111,15 @@ static int genregs_set(struct task_struct *target,
> >   #if CONFIG_HEXAGON_ARCH_VERSION >=4
> >          INEXT(&regs->cs0, cs0);
> >          INEXT(&regs->cs1, cs1);
> > +       ignore_offset = offsetof(struct user_regs_struct, pad1);
> > +#else
> > +       ignore_offset = offsetof(struct user_regs_struct, cs0);
> >   #endif
> >
> >          /* Ignore the rest, if needed */
> >          if (!ret)
> >                  user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
> > -                       offsetof(struct user_regs_struct, pad1), -1);
> > +                                         ignore_offset, -1);
> >          else
> >                  return ret;
> >
> > diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
> > index c3064ac31003..f7d9b114de8f 100755
> > --- a/scripts/headers_install.sh
> > +++ b/scripts/headers_install.sh
> > @@ -74,7 +74,6 @@
> > arch/arc/include/uapi/asm/page.h:CONFIG_ARC_PAGE_SIZE_16K
> >   arch/arc/include/uapi/asm/page.h:CONFIG_ARC_PAGE_SIZE_4K
> >   arch/arc/include/uapi/asm/swab.h:CONFIG_ARC_HAS_SWAPE
> >   arch/arm/include/uapi/asm/ptrace.h:CONFIG_CPU_ENDIAN_BE8
> > -arch/hexagon/include/uapi/asm/user.h:CONFIG_HEXAGON_ARCH_VERSION
> >   arch/m68k/include/uapi/asm/ptrace.h:CONFIG_COLDFIRE
> >   arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_NO
> >   arch/nios2/include/uapi/asm/swab.h:CONFIG_NIOS2_CI_SWAB_SUPPORT
> > --
> > 2.41.0
>
> Acked-by: Brian Cain <bcain@xxxxxxxxxxx>

Thanks!

Arnd, could you maybe take this patch through your "generic include/asm 
header files" tree?

 Thomas