Re: [PATCH-for-8.0 v3] target/arm: Fix non-TCG build failure by inlining pauth_ptr_mask()

[Peter Maydell]

On Thu, 30 Mar 2023 at 11:31, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Tue, 28 Mar 2023 at 22:25, Philippe Mathieu-Daudé <philmd@linaro.org> 
> wrote:
> >
> > aarch64_gdb_get_pauth_reg() -- although disabled since commit
> > 5787d17a42 ("target/arm: Don't advertise aarch64-pauth.xml to
> > gdb") is still compiled in. It calls pauth_ptr_mask() which is
> > located in target/arm/tcg/pauth_helper.c, a TCG specific helper.
> >
> > To avoid a linking error when TCG is not enabled:
> >
> >   Undefined symbols for architecture arm64:
> >     "_pauth_ptr_mask", referenced from:
> >         _aarch64_gdb_get_pauth_reg in target_arm_gdbstub64.c.o
> >   ld: symbol(s) not found for architecture arm64
> >   clang: error: linker command failed with exit code 1 (use -v to see 
> > invocation)
> >
> > - Inline pauth_ptr_mask() in aarch64_gdb_get_pauth_reg()
> >   (this is the single user),
> > - Rename pauth_ptr_mask_internal() as pauth_ptr_mask() and
> >   inline it in "internals.h",
> >
> > Fixes: e995d5cce4 ("target/arm: Implement gdbstub pauth extension")
> > Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> > Reviewed-by: Fabiano Rosas <farosas@suse.de>
> > Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > ---
> > Supersedes: <20230328133054.6553-1-philmd@linaro.org>
> >
> > Since v2:
> > - Rebased (patch #1 merged)
> > - Addressed rth's comments
> > - Added R-b tags
> > ---
> >  target/arm/internals.h        | 16 +++++++---------
> >  target/arm/gdbstub64.c        |  7 +++++--
> >  target/arm/tcg/pauth_helper.c | 18 +-----------------
> >  3 files changed, 13 insertions(+), 28 deletions(-)
> >
> > diff --git a/target/arm/internals.h b/target/arm/internals.h
> > index 673519a24a..71f4c6d8a2 100644
> > --- a/target/arm/internals.h
> > +++ b/target/arm/internals.h
> > @@ -1389,15 +1389,13 @@ int exception_target_el(CPUARMState *env);
> >  bool arm_singlestep_active(CPUARMState *env);
> >  bool arm_generate_debug_exceptions(CPUARMState *env);
> >
> > -/**
> > - * pauth_ptr_mask:
> > - * @env: cpu context
> > - * @ptr: selects between TTBR0 and TTBR1
> > - * @data: selects between TBI and TBID
> > - *
> > - * Return a mask of the bits of @ptr that contain the authentication code.
> > - */
> > -uint64_t pauth_ptr_mask(CPUARMState *env, uint64_t ptr, bool data);
> > +static inline uint64_t pauth_ptr_mask(ARMVAParameters param)
> > +{
> > +    int bot_pac_bit = 64 - param.tsz;
> > +    int top_pac_bit = 64 - 8 * param.tbi;
> > +
> > +    return MAKE_64BIT_MASK(bot_pac_bit, top_pac_bit - bot_pac_bit);
> > +}
>
> Any reason for deleting the doc comment ?

Applied to target-arm.next with a doc comment:

/**
 * pauth_ptr_mask:
 * @param: parameters defining the MMU setup
 *
 * Return a mask of the address bits that contain the authentication code,
 * given the MMU config defined by @param.
 */


-- PMM