Re: [PATCH 5/8] scripts/kallsyms: move compiler-generated symbol patterns to mksysmap

[Nick Desaulniers]

On Wed, Mar 8, 2023 at 3:53 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
>
> scripts/kallsyms.c maintains compiler-generated symbols, but we end up
> with something similar in scripts/mksysmap to avoid the "Inconsistent
> kallsyms data" error. For example, commit c17a2538704f ("mksysmap: Fix
> the mismatch of 'L0' symbols in System.map").
>
> They were separately maintained prior to commit 94ff2f63d6a3 ("kbuild:
> reuse mksysmap output for kallsyms").
>
> Now that scripts/kallsyms.c parses the output of scripts/mksysmap,
> it makes more sense to collect all the ignored patterns to mksysmap.

Cool, thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
>  scripts/kallsyms.c | 59 ----------------------------------------------
>  scripts/mksysmap   | 43 +++++++++++++++++++++++++++++++++
>  2 files changed, 43 insertions(+), 59 deletions(-)
>
> diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
> index e572fda6fe42..97d514c0fc8f 100644
> --- a/scripts/kallsyms.c
> +++ b/scripts/kallsyms.c
> @@ -102,65 +102,6 @@ static char *sym_name(const struct sym_entry *s)
>
>  static bool is_ignored_symbol(const char *name, char type)
>  {
> -       /* Symbol names that exactly match to the following are ignored.*/
> -       static const char * const ignored_symbols[] = {
> -               "_SDA_BASE_",           /* ppc */
> -               "_SDA2_BASE_",          /* ppc */
> -               NULL
> -       };
> -
> -       /* Symbol names that begin with the following are ignored.*/
> -       static const char * const ignored_prefixes[] = {
> -               "__efistub_",           /* arm64 EFI stub namespace */
> -               "__kvm_nvhe_$",         /* arm64 local symbols in non-VHE KVM namespace */
> -               "__kvm_nvhe_.L",        /* arm64 local symbols in non-VHE KVM namespace */
> -               "__AArch64ADRPThunk_",  /* arm64 lld */
> -               "__ARMV5PILongThunk_",  /* arm lld */
> -               "__ARMV7PILongThunk_",
> -               "__ThumbV7PILongThunk_",
> -               "__LA25Thunk_",         /* mips lld */
> -               "__microLA25Thunk_",
> -               "__kcfi_typeid_",       /* CFI type identifiers */
> -               NULL
> -       };
> -
> -       /* Symbol names that end with the following are ignored.*/
> -       static const char * const ignored_suffixes[] = {
> -               "_from_arm",            /* arm */
> -               "_from_thumb",          /* arm */
> -               "_veneer",              /* arm */
> -               NULL
> -       };
> -
> -       /* Symbol names that contain the following are ignored.*/
> -       static const char * const ignored_matches[] = {
> -               ".long_branch.",        /* ppc stub */
> -               ".plt_branch.",         /* ppc stub */
> -               NULL
> -       };
> -
> -       const char * const *p;
> -
> -       for (p = ignored_symbols; *p; p++)
> -               if (!strcmp(name, *p))
> -                       return true;
> -
> -       for (p = ignored_prefixes; *p; p++)
> -               if (!strncmp(name, *p, strlen(*p)))
> -                       return true;
> -
> -       for (p = ignored_suffixes; *p; p++) {
> -               int l = strlen(name) - strlen(*p);
> -
> -               if (l >= 0 && !strcmp(name + l, *p))
> -                       return true;
> -       }
> -
> -       for (p = ignored_matches; *p; p++) {
> -               if (strstr(name, *p))
> -                       return true;
> -       }
> -
>         if (type == 'u' || type == 'n')
>                 return true;
>
> diff --git a/scripts/mksysmap b/scripts/mksysmap
> index 1efd61ee0bac..d8ad6ff69320 100755
> --- a/scripts/mksysmap
> +++ b/scripts/mksysmap
> @@ -36,6 +36,28 @@ ${NM} -n ${1} | sed >${2} -e "
>  # local labels, .LBB, .Ltmpxxx, .L__unnamed_xx, .LASANPC, etc.
>  / \.L/d
>
> +# arm64 EFI stub namespace
> +/ __efistub_/d
> +
> +# arm64 local symbols in non-VHE KVM namespace
> +/ __kvm_nvhe_\$/d
> +/ __kvm_nvhe_\.L/d
> +
> +# arm64 lld
> +/ __AArch64ADRPThunk_/d
> +
> +# arm lld
> +/ __ARMV5PILongThunk_/d
> +/ __ARMV7PILongThunk_/d
> +/ __ThumbV7PILongThunk_/d
> +
> +# mips lld
> +/ __LA25Thunk_/d
> +/ __microLA25Thunk_/d
> +
> +# CFI type identifiers
> +/ __kcfi_typeid_/d
> +
>  # CRC from modversions
>  / __crc_/d
>
> @@ -45,6 +67,15 @@ ${NM} -n ${1} | sed >${2} -e "
>  # EXPORT_SYMBOL (namespace)
>  / __kstrtabns_/d
>
> +# ---------------------------------------------------------------------------
> +# Ignored suffixes
> +#  (do not forget '$' after each pattern)
> +
> +# arm
> +/_from_arm$/d
> +/_from_thumb$/d
> +/_veneer$/d
> +
>  # ---------------------------------------------------------------------------
>  # Ignored symbols (exact match)
>  #  (do not forget a space before and '$' after each pattern)
> @@ -52,6 +83,18 @@ ${NM} -n ${1} | sed >${2} -e "
>  # for LoongArch?
>  / L0$/d
>
> +# ppc
> +/ _SDA_BASE_$/d
> +/ _SDA2_BASE_$/d
> +
> +# ---------------------------------------------------------------------------
> +# Ignored patterns
> +#  (symbols that contain the pattern are ignored)
> +
> +# ppc stub
> +/\.long_branch\./d
> +/\.plt_branch\./d
> +
>  # ---------------------------------------------------------------------------
>  # Ignored kallsyms symbols
>  #
> --
> 2.34.1
>


-- 
Thanks,
~Nick Desaulniers