Re: [PATCH v6 0/3] x86_64: aarch64: Set call number just before syscall

[Joe Simmons-Talbott <josimmon@redhat.com>]

Is there anything further I need to do to get this patchset reviewed?

Thanks,
Joe
On Mon, Apr 24, 2023 at 11:03:50AM -0400, Joe Simmons-Talbott wrote:
> To make binary call tree analysis easier place the syscall number into
> the register just before the syscall is made.  Only do this if the
> syscall number is a constant integer.
> 
> Compiler optimizations can place quite a few instructions between the
> setting of the syscall number and the syscall instruction.  During call
> tree analysis the number of instructions between the two can lead to
> more difficulty for both tools and humans in properly identifying the
> syscall number.  Having the syscall number set in the prior instruction
> to the syscall instruction makes this task easier and less error prone.
> Being able to reliably identify syscalls made by a given API will make
> it easier to understand and verify the safety and security of glibc.
> 
> Tested on x86_64 and aarch64.
> 
> Chnages to v5:
>   * aarch64: Remove '\n\t' from asm.
>   * x86_64: Remove unused macros.
> 
> Changes to v4:
>   * aarch64: Move generated comment.  Remove unused macros from earlier
>   version.
> 
>   * Added patch
>     - nptl: Convert indirect syscall numbers to compile time numeric
>       values.
> 
> Changes to v3:
>   * x86_64: Combine two inline asms into one.
>     - Suggested by "H.J. Lu" <hjl.tools@gmail.com>
> 
> Changes to v2:
>   * Add a more detailed commit message.
>   
> Changes to v1:
>   * aarch64: Combine two inline asms into one.  Avoid loading name twice.
> 
> Joe Simmons-Talbott (3):
>   x86_64: Set the syscall register right before doing the syscall.
>   aarch64: Set the syscall register right before doing the syscall.
>   nptl: Use direct syscall numbers in setxid
> 
>  nptl/nptl_setxid.c                       | 136 ++++++++++++++++++++++-
>  sysdeps/unix/sysv/linux/aarch64/sysdep.h |  29 +++--
>  sysdeps/unix/sysv/linux/x86_64/sysdep.h  |  24 ++--
>  3 files changed, 164 insertions(+), 25 deletions(-)
> 
> -- 
> 2.39.2
>