On Tue, May 10, 2022 at 2:51 AM Nick Desaulniers
[off-list ref] wrote:

 On Sun, May 8, 2022 at 12:10 PM Masahiro Yamada [off-list ref] wrote:

quoted

diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h
index 07a36a874dca..51ce72ce80fa 100644
--- a/include/asm-generic/export.h
+++ b/include/asm-generic/export.h

@@ -2,6 +2,14 @@
 #ifndef __ASM_GENERIC_EXPORT_H
 #define __ASM_GENERIC_EXPORT_H

+/*
+ * This comment block is used by fixdep. Please do not remove.

I don't know much about fixdep. How does that work, if you could summarize?

You can find detailed explanation in scripts/basic/fixdep.c


In short, it works like this:

fixdep parses every source (including headers).
If it finds "CONFIG_MODVERSIONS", it adds a dependency
on $(wildcard include/config/MODVERSIONS)
to the .cmd files.

If CONFIG_MODVERSIONS is toggled in Kconfig,
it touches include/config/MODVERSIONS.    [1]

In the next run of Make, all the sources depending on
CONFIG_MODVERSIONS will be re-compiled because the
timestamp of include/config/MODVERSIONS is up-to-date.


[1]: https://github.com/torvalds/linux/blob/v5.17/scripts/kconfig/confdata.c#L141

quoted

+ *
+ * When CONFIG_MODVERSIONS is changed from n to y, all source files having
+ * EXPORT_SYMBOL variants must be re-compiled because genksyms is run as a
+ * side effect of the .o build rule.
+ */
+
 #ifndef KSYM_FUNC
 #define KSYM_FUNC(x) x
 #endif

@@ -12,9 +20,6 @@
 #else
 #define KSYM_ALIGN 4
 #endif
-#ifndef KCRC_ALIGN
-#define KCRC_ALIGN 4
-#endif

The #ifndef is there because arch/m68k/include/asm/export.h:1 defines
KCRC_ALIGN. You should delete that, too.

Nice catch! I will clean it up too.

quoted

diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index 4827c5abe5b7..6e6933ae7911 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c

@@ -33,7 +33,7 @@ char *cur_filename;
 int in_source_file;

 static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
-          flag_preserve, flag_warnings, flag_rel_crcs;
+          flag_preserve, flag_warnings;

 static int errors;
 static int nsyms;

@@ -681,10 +681,7 @@ void export_symbol(const char *name)
                        fputs(">\n", debugfile);

                /* Used as a linker script. */

^ Does this comment still apply?

No.  From this commit going forward,
the genksyms output will not be used as a linker script.

08/14 will delete this comment anyway, but
it is possible to remove it in this commit.

quoted

-               printf(!flag_rel_crcs ? "__crc_%s = 0x%08lx;\n" :
-                      "SECTIONS { .rodata : ALIGN(4) { "
-                      "__crc_%s = .; LONG(0x%08lx); } }\n",
-                      name, crc);
+               printf("__crc_%s = 0x%08lx;\n", name, crc);
        }
 }

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index eceb3ee7ec06..6aee2401f3ad 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh

@@ -88,11 +88,6 @@ modpost_link()
                gen_initcalls
                lds="-T .tmp_initcalls.lds"

-               if is_enabled CONFIG_MODVERSIONS; then
-                       gen_symversions

^ this is the only caller of gen_symversions, right? Then
gen_symversions can be cleaned up, too?

We can keep it in this commit.

The follow-up cleaning is done in 07/14.

To avoid too big commit,
I separated the build flow change and
trivial cleanups.

quoted

-                       lds="${lds} -T .tmp_symversions.lds"
-               fi
-
                # This might take a while, so indicate that we're doing
                # an LTO link
                info LTO ${1}

@@ -183,6 +178,10 @@ vmlinux_link()
                libs="${KBUILD_VMLINUX_LIBS}"
        fi

+       if is_enabled CONFIG_MODULES; then
+               objs="${objs} .vmlinux.export.o"
+       fi
+
        if [ "${SRCARCH}" = "um" ]; then
                wl=-Wl,
                ld="${CC}"

@@ -312,6 +311,7 @@ cleanup()
        rm -f vmlinux.o
        rm -f .vmlinux.d
        rm -f .vmlinux.objs
+       rm -f .vmlinux.export.c

Probably can drop the `rm -f .tmp_symversions.lds` here, too?

It will be cleaned up by 07/14.

--
Thanks,
~Nick Desaulniers

--
Best Regards
Masahiro Yamada