Re: [PATCH 1/2] x86/tools/relocs: Fix non-POSIX regexp

[Masahiro Yamada]

On Thu, Jul 8, 2021 at 5:57 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
>
> Trying to run a cross-compiled x86 relocs tool on a BSD based
> HOSTCC leads to errors like
>
>   VOFFSET arch/x86/boot/compressed/../voffset.h - due to: vmlinux
>   CC      arch/x86/boot/compressed/misc.o - due to: arch/x86/boot/compressed/../voffset.h
>   OBJCOPY arch/x86/boot/compressed/vmlinux.bin - due to: vmlinux
>   RELOCS  arch/x86/boot/compressed/vmlinux.relocs - due to: vmlinux
> empty (sub)expressionarch/x86/boot/compressed/Makefile:118: recipe for target 'arch/x86/boot/compressed/vmlinux.relocs' failed
> make[3]: *** [arch/x86/boot/compressed/vmlinux.relocs] Error 1
>
> It turns out that relocs.c uses patterns like
>
>         "something(|_end)"
>
> This is not valid syntax or gives undefined results according
> to POSIX 9.5.3 ERE Grammar
>
>         https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html
>
> It seems to be silently accepted by the Linux regexp() implementation
> while a BSD host complains.
>
> Such patterns can be replaced by a transformation like
>
>         "(|p1|p2)" -> "(p1|p2)?"
>
> Fixes: fd952815307f ("x86-32, relocs: Whitelist more symbols for ld bug workaround")
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> ---



Applied to linux-kbuild/fixes.
Thanks.





>  arch/x86/tools/relocs.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
> index 04c5a44b96827..9ba700dc47de4 100644
> --- a/arch/x86/tools/relocs.c
> +++ b/arch/x86/tools/relocs.c
> @@ -57,12 +57,12 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
>         [S_REL] =
>         "^(__init_(begin|end)|"
>         "__x86_cpu_dev_(start|end)|"
> -       "(__parainstructions|__alt_instructions)(|_end)|"
> -       "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
> +       "(__parainstructions|__alt_instructions)(_end)?|"
> +       "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|"
>         "__(start|end)_pci_.*|"
>         "__(start|end)_builtin_fw|"
> -       "__(start|stop)___ksymtab(|_gpl)|"
> -       "__(start|stop)___kcrctab(|_gpl)|"
> +       "__(start|stop)___ksymtab(_gpl)?|"
> +       "__(start|stop)___kcrctab(_gpl)?|"
>         "__(start|stop)___param|"
>         "__(start|stop)___modver|"
>         "__(start|stop)___bug_table|"
> --
> 2.31.1
>


-- 
Best Regards
Masahiro Yamada