linux-kernel - Re: [GIT PULL] Modules changes for v6.13-rc1

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Message-ID: <Z0fT4hC30NISjmi_@bombadil.infradead.org>
Date: Wed, 27 Nov 2024 18:22:26 -0800
From: Luis Chamberlain <mcgrof@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: samitolvanen@...gle.com, petr.pavlu@...e.com, da.gomez@...sung.com,
	linux-modules@...r.kernel.org, patches@...ts.linux.dev,
	linux-kernel@...r.kernel.org, masahiroy@...nel.org,
	mmaurer@...gle.com, arnd@...db.de, deller@....de, song@...nel.org
Subject: Re: [GIT PULL] Modules changes for v6.13-rc1

On Wed, Nov 27, 2024 at 03:56:48PM -0800, Linus Torvalds wrote:
> On Wed, 27 Nov 2024 at 15:26, Luis Chamberlain <mcgrof@...nel.org> wrote:
> >
> > On Wed, Nov 27, 2024 at 02:35:36PM -0800, Luis Chamberlain wrote:
> > > Sorry about that, I'm on it.
> >
> > OK here is a fix, goes double build tested and then run time tested.
> 
> No, you misunderstand.
> 
> I don't mind the tests being built. That's *good*.
> 
> I mind them being built *twice*. That means that there's some
> seriously broken lack of dependency logic.

Ah, gobble gobble, got it. That was also fixed in the patch but it I
also changed the default build to go fast, ok we'll revert back to the
older defaults (TEST_KALLSYMS_LARGE now) now and just make it clear the
double build was the issue being fixed.

>From f7da80262bd89a0d2c2c1a9e59f5a14b84e34f3f Mon Sep 17 00:00:00 2001
From: Luis Chamberlain <mcgrof@...nel.org>
Date: Wed, 27 Nov 2024 14:10:57 -0800
Subject: [PATCH v2] selftests: kallsyms: fix double build stupidity

Fix the stupid FORCE so that re-builds will only trigger
when really needed. While at it, document the sensible ranges
supported and fix the script to accept these alternatives.

Reported-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@...nel.org>
---
 lib/Kconfig.debug                     | 32 ++++++++++++++++++++++++++-
 lib/tests/module/Makefile             |  2 +-
 lib/tests/module/gen_test_kallsyms.sh |  9 ++++++--
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b5929721fc63..da8c35bfaeaf 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2986,9 +2986,39 @@ config TEST_KALLSYMS_D
 	tristate
 	depends on m
 
+choice
+	prompt "Kallsym test range"
+	default TEST_KALLSYMS_LARGE
+	help
+	  Selecting something other than "Fast" will enable tests which slow
+	  down the build and may crash your build.
+
+config TEST_KALLSYMS_FAST
+	bool "Fast builds"
+	help
+	  You won't really be testing kallsysms, so this just helps fast builds
+	  when allmodconfig is used..
+
+config TEST_KALLSYMS_LARGE
+	bool "Enable testing kallsyms with large exports"
+	help
+	  This will enable larger number of symbols. Only enable this if you
+	  are a modules developer. This will slow down your build considerbly.
+
+config TEST_KALLSYMS_MAX
+	bool "Known kallsysms limits"
+	help
+	  This will enable exports to the point we know we'll start crashing
+	  builds.
+
+endchoice
+
 config TEST_KALLSYMS_NUMSYMS
 	int "test kallsyms number of symbols"
-	default 100
+	range 2 10000
+	default 2 if TEST_KALLSYMS_FAST
+	default 100 if TEST_KALLSYMS_LARGE
+	default 10000 if TEST_KALLSYMS_MAX
 	help
 	  The number of symbols to create on TEST_KALLSYMS_A, only one of which
 	  module TEST_KALLSYMS_B will use. This also will be used
diff --git a/lib/tests/module/Makefile b/lib/tests/module/Makefile
index af5c27b996cb..5436386d7aa0 100644
--- a/lib/tests/module/Makefile
+++ b/lib/tests/module/Makefile
@@ -3,7 +3,7 @@ obj-$(CONFIG_TEST_KALLSYMS_B) += test_kallsyms_b.o
 obj-$(CONFIG_TEST_KALLSYMS_C) += test_kallsyms_c.o
 obj-$(CONFIG_TEST_KALLSYMS_D) += test_kallsyms_d.o
 
-$(obj)/%.c: FORCE
+$(obj)/%.c: $(srctree)/lib/tests/module/gen_test_kallsyms.sh $(KCONFIG_CONFIG)
 	@$(kecho) "  GEN     $@"
 	$(Q)$(srctree)/lib/tests/module/gen_test_kallsyms.sh $@\
 		$(CONFIG_TEST_KALLSYMS_NUMSYMS) \
diff --git a/lib/tests/module/gen_test_kallsyms.sh b/lib/tests/module/gen_test_kallsyms.sh
index 3f2c626350ad..561dcac0f359 100755
--- a/lib/tests/module/gen_test_kallsyms.sh
+++ b/lib/tests/module/gen_test_kallsyms.sh
@@ -7,6 +7,11 @@ NUM_SYMS=$2
 SCALE_FACTOR=$3
 TEST_TYPE=$(echo $TARGET | sed -e 's|lib/tests/module/test_kallsyms_||g')
 TEST_TYPE=$(echo $TEST_TYPE | sed -e 's|.c||g')
+FIRST_B_LOOKUP=1
+
+if [[ $NUM_SYMS -gt 2 ]]; then
+	FIRST_B_LOOKUP=$((NUM_SYMS/2))
+fi
 
 gen_template_module_header()
 {
@@ -52,10 +57,10 @@ ____END_MODULE
 
 gen_template_module_data_b()
 {
-	printf "\nextern int auto_test_a_%010d;\n\n" 28
+	printf "\nextern int auto_test_a_%010d;\n\n" $FIRST_B_LOOKUP
 	echo "static int auto_runtime_test(void)"
 	echo "{"
-	printf "\nreturn auto_test_a_%010d;\n" 28
+	printf "\nreturn auto_test_a_%010d;\n" $FIRST_B_LOOKUP
 	echo "}"
 }
 
-- 
2.45.2