ci, docs, patches: skip some files for 5.15.y

ci/2_pull_source.sh

@@ -14,3 +14,4 @@ cd $MCDC_HOME/linux
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0001-llvm-cov-add-Clang-s-Source-based-Code-Coverage-supp.patch
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0002-kbuild-llvm-cov-disable-instrumentation-in-odd-or-se.patch
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0003-llvm-cov-add-Clang-s-MC-DC-support.patch
+git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0004-kbuild-llvm-cov-disable-instrumentation-in-odd-or-se.patch

docs/measure-kernel-mcdc.md

@@ -74,6 +74,7 @@ cd $MCDC_HOME/linux
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0001-llvm-cov-add-Clang-s-Source-based-Code-Coverage-supp.patch
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0002-kbuild-llvm-cov-disable-instrumentation-in-odd-or-se.patch
 git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0003-llvm-cov-add-Clang-s-MC-DC-support.patch
+git apply $MCDC_HOME/linux-mcdc/patches/v0.6/0004-kbuild-llvm-cov-disable-instrumentation-in-odd-or-se.patch
 ```
 
 ## 3. Get LLVM

patches/v0.6/0004-kbuild-llvm-cov-disable-instrumentation-in-odd-or-se.patch

@@ -0,0 +1,85 @@
+From 0f3be98299c1331dd6a8d1fb0ad7bf94f18f2ebe Mon Sep 17 00:00:00 2001
+From: Wentao Zhang <[email protected]>
+Date: Thu, 18 Jul 2024 13:12:23 -0500
+Subject: [RFC PATCH 4/4] kbuild, llvm-cov: disable instrumentation in odd or
+ sensitive code
+
+Skip some extra files in kernel 5.15.y that are problematic with LLVM 19
+MC/DC instrumentation.
+
+Signed-off-by: Wentao Zhang <[email protected]>
+---
+ arch/x86/kernel/cpu/mtrr/Makefile         | 3 +++
+ drivers/base/power/Makefile               | 3 +++
+ drivers/gpu/drm/i915/Makefile             | 3 +++
+ drivers/net/ethernet/intel/e1000/Makefile | 2 ++
+ net/ipv4/Makefile                         | 2 ++
+ 5 files changed, 13 insertions(+)
+
+diff --git a/arch/x86/kernel/cpu/mtrr/Makefile b/arch/x86/kernel/cpu/mtrr/Makefile
+index cc4f9f1cb..443a5bf03 100644
+--- a/arch/x86/kernel/cpu/mtrr/Makefile
++++ b/arch/x86/kernel/cpu/mtrr/Makefile
+@@ -1,4 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0-only
++
++LLVM_COV_PROFILE_generic.o := n
++
+ obj-y		:= mtrr.o if.o generic.o cleanup.o
+ obj-$(CONFIG_X86_32) += amd.o cyrix.o centaur.o
+
+diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile
+index 8fdd0073e..ac1f2f4f6 100644
+--- a/drivers/base/power/Makefile
++++ b/drivers/base/power/Makefile
+@@ -1,4 +1,7 @@
+ # SPDX-License-Identifier: GPL-2.0
++
++LLVM_COV_PROFILE_main.o := n
++
+ obj-$(CONFIG_PM)	+= sysfs.o generic_ops.o common.o qos.o runtime.o wakeirq.o
+ obj-$(CONFIG_PM_SLEEP)	+= main.o wakeup.o wakeup_stats.o
+ obj-$(CONFIG_PM_TRACE_RTC)	+= trace.o
+diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
+index 9d371be7d..b24919604 100644
+--- a/drivers/gpu/drm/i915/Makefile
++++ b/drivers/gpu/drm/i915/Makefile
+@@ -12,6 +12,9 @@
+ # Note the danger in using -Wall -Wextra is that when CI updates gcc we
+ # will most likely get a sudden build breakage... Hopefully we will fix
+ # new warnings before CI updates!
++
++LLVM_COV_PROFILE_intel_bios.o := n
++
+ subdir-ccflags-y := -Wall -Wextra
+ subdir-ccflags-y += $(call cc-disable-warning, unused-parameter)
+ subdir-ccflags-y += $(call cc-disable-warning, type-limits)
+diff --git a/drivers/net/ethernet/intel/e1000/Makefile b/drivers/net/ethernet/intel/e1000/Makefile
+index 314c52d44..a3c4caa6c 100644
+--- a/drivers/net/ethernet/intel/e1000/Makefile
++++ b/drivers/net/ethernet/intel/e1000/Makefile
+@@ -5,6 +5,8 @@
+ # Makefile for the Intel(R) PRO/1000 ethernet driver
+ #
+
++LLVM_COV_PROFILE_e1000_main.o := n
++
+ obj-$(CONFIG_E1000) += e1000.o
+
+ e1000-objs := e1000_main.o e1000_hw.o e1000_ethtool.o e1000_param.o
+diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
+index bbdd9c44f..779dcf156 100644
+--- a/net/ipv4/Makefile
++++ b/net/ipv4/Makefile
+@@ -3,6 +3,8 @@
+ # Makefile for the Linux TCP/IP (INET) layer.
+ #
+
++LLVM_COV_PROFILE_ipconfig.o := n
++
+ obj-y     := route.o inetpeer.o protocol.o \
+ 	     ip_input.o ip_fragment.o ip_forward.o ip_options.o \
+ 	     ip_output.o ip_sockglue.o inet_hashtables.o \
+-- 
+2.34.1
+

patches/v0.6/README.md

@@ -0,0 +1,2 @@
+Note: patch 0004 is only needed for 5.15.y but not mainline. We won't include it
+in our patch 1.0.