On Thu, May 12, 2022 at 7:31 AM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Wed, May 11, 2022 at 9:49 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> >
> > -/* sections that we do not want to do full section mismatch check on */
> > -static const char *const section_white_list[] =
> > -{
> > - ".comment*",
> > - ".debug*",
> > - ".cranges", /* sh64 */
> > - ".zdebug*", /* Compressed debug sections. */
> > - ".GCC.command.line", /* record-gcc-switches */
> > - ".mdebug*", /* alpha, score, mips etc. */
> > - ".pdr", /* alpha, score, mips etc. */
> > - ".stab*",
> > - ".note*",
> > - ".got*",
> > - ".toc*",
> > - ".xt.prop", /* xtensa */
> > - ".xt.lit", /* xtensa */
> > - ".arcextmap*", /* arc */
> > - ".gnu.linkonce.arcext*", /* arc : modules */
> > - ".cmem*", /* EZchip */
> > - ".fmt_slot*", /* EZchip */
> > - ".gnu.lto*",
> > - ".discard.*",
> > - NULL
> > -};
>
>
> > -/**
> > - * Whitelist to allow certain references to pass with no warning.
> > - *
> > - * Pattern 1:
> > - * If a module parameter is declared __initdata and permissions=0
> > - * then this is legal despite the warning generated.
> > - * We cannot see value of permissions here, so just ignore
> > - * this pattern.
> > - * The pattern is identified by:
> > - * tosec = .init.data
> > - * fromsec = .data*
> > - * atsym =__param*
> > - *
> > - * Pattern 1a:
> > - * module_param_call() ops can refer to __init set function if permissions=0
> > - * The pattern is identified by:
> > - * tosec = .init.text
> > - * fromsec = .data*
> > - * atsym = __param_ops_*
> > - *
> > - * Pattern 2:
> > - * Many drivers utilise a *driver container with references to
> > - * add, remove, probe functions etc.
> > - * the pattern is identified by:
> > - * tosec = init or exit section
> > - * fromsec = data section
> > - * atsym = *driver, *_template, *_sht, *_ops, *_probe,
> > - * *probe_one, *_console, *_timer
> > - *
> > - * Pattern 3:
> > - * Whitelist all references from .head.text to any init section
> > - *
> > - * Pattern 4:
> > - * Some symbols belong to init section but still it is ok to reference
> > - * these from non-init sections as these symbols don't have any memory
> > - * allocated for them and symbol address and value are same. So even
> > - * if init section is freed, its ok to reference those symbols.
> > - * For ex. symbols marking the init section boundaries.
> > - * This pattern is identified by
> > - * refsymname = __init_begin, _sinittext, _einittext
> > - *
> > - * Pattern 5:
> > - * GCC may optimize static inlines when fed constant arg(s) resulting
> > - * in functions like cpumask_empty() -- generating an associated symbol
> > - * cpumask_empty.constprop.3 that appears in the audit. If the const that
> > - * is passed in comes from __init, like say nmi_ipi_mask, we get a
> > - * meaningless section warning. May need to add isra symbols too...
> > - * This pattern is identified by
> > - * tosec = init section
> > - * fromsec = text section
> > - * refsymname = *.constprop.*
> > - *
> > - * Pattern 6:
> > - * Hide section mismatch warnings for ELF local symbols. The goal
> > - * is to eliminate false positive modpost warnings caused by
> > - * compiler-generated ELF local symbol names such as ".LANCHOR1".
> > - * Autogenerated symbol names bypass modpost's "Pattern 2"
> > - * whitelisting, which relies on pattern-matching against symbol
> > - * names to work. (One situation where gcc can autogenerate ELF
> > - * local symbols is when "-fsection-anchors" is used.)
> > - **/
>
> Losing the ability to git blame (from the top level) the above lines
> does cause me grief and mental anguish though. It's not gone, just
> buried a bit deeper.
According to 'man git-blame', -C option is needed
to follow the code move between files.
git blame -C scripts/mod/section-check.c
showed me the origin commit of each line.
> --
> Thanks,
> ~Nick Desaulniers
--
Best Regards
Masahiro Yamada
