Interface improvements

.gitignore

@@ -1,13 +1,9 @@
-kpatch-diff-gen/kpatch-diff-gen
 *.o
 *.o.cmd
 *.ko
 *.ko.cmd
 *.mod.c
 *.swp
-kmod/.tmp_versions/
-kmod/Module.symvers
-kmod/modules.order
-tools/add-patches-section
-tools/create-diff-object
-tools/link-vmlinux-syms
+kpatch-build/add-patches-section
+kpatch-build/create-diff-object
+kpatch-build/link-vmlinux-syms

README

@@ -12,6 +12,20 @@ scale-out, run on a single machine and are very downtime
 sensitive or require a heavyweight approval process and
 notification of workload users in the event of downtime.
 
+QUICK START
+
+NOTE: While kpatch is designed to work with any recent Linux
+kernel on any distribution, these quick start instructions
+currently only work on Fedora.
+
+First make a patch against the kernel tree, e.g. foo.patch.
+Then:
+
+    sudo kpatch-build/kpatch-build ~/foo.patch
+    insmod kpatch.ko kpatch-foo.ko
+
+Voila, your kernel is patched.
+
 LICENSE
 
 kpatch is under the GPLv2 license.
@@ -38,7 +52,7 @@ patches and environments is conducted.
 
 DEPENDENCIES
 
-kpatch tools require libelf library and development headers to be installed.
+kpatch-build tools require libelf library and development headers to be installed.
 See GOTCHAS below.
 
 GOTCHAS
@@ -54,11 +68,11 @@ git://git.fedorahosted.org/git/elfutils.git
 
 HOWTO
 
-An example script for automating the hotfix module generation is in
-scripts/kpatch-build.  The script is written for Fedora but should
+An example script for automating the patch module generation is
+kpatch-build/kpatch-build.  The script is written for Fedora but should
 be adaptable to other distributions with limited changes.
 
-The primary steps in the hotfix module generation process are:
+The primary steps in the patch module generation process are:
 - Building the unstripped vmlinux for the kernel
 - Patching the source tree
 - Rebuilding vmlinux and monitoring which objects are building rebuilt.
@@ -67,17 +81,17 @@ The primary steps in the hotfix module generation process are:
   resulting in the changed patched objects
 - Unpatch the source tree
 - Recompile each changed object with -ffunction-sections -fdata-sections
-  resulting in the changed base objects
-- Use tools/create-diff-object to analyze each base/patched object pair
+  resulting in the changed original objects
+- Use create-diff-object to analyze each original/patched object pair
   for patchability and generate an output object containing modified
   sections
 - Link all the output objects in a into a cumulative object
-- Use tools/add-patches-section to add the .patches section that the
+- Use add-patches-section to add the .patches section that the
   core kpatch module uses to determine the list of functions that need
   to be redirected using ftrace
-- Generate the hotfix kernel module
-- Use tools/link-vmlinux-syms to hardcode non-exported kernel symbols
-  into the symbol table of the hotfix kernel module
+- Generate the patch kernel module
+- Use link-vmlinux-syms to hardcode non-exported kernel symbols
+  into the symbol table of the patch kernel module
 
 DEMONSTRATION
 

kpatch-kmod/Makefile → kmod/core/Makefile

@@ -2,9 +2,9 @@ KPATCH_BUILD ?= /usr/lib/modules/$(shell uname -r)/build
 KPATCH_MAKE = $(MAKE) -C $(KPATCH_BUILD) M=$(PWD)
 
 obj-m := kpatch.o
-kpatch-y := base.o trampoline.o
+kpatch-y := core.o trampoline.o
 
-kpatch.ko: base.c trampoline.S
+kpatch.ko: core.c trampoline.S
 	$(KPATCH_MAKE) kpatch.ko
 
 all: kpatch.ko

kpatch-kmod/base.c → kmod/core/core.c

@@ -1,17 +1,15 @@
 /*
- * kpatch-kmod/base.c
- *
  * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
  * Copyright (C) 2013 Josh Poimboeuf <jpoimboe@redhat.com>
  *
  * Contains the code for the core kpatch module.  This module reads
- * information from the hotfix modules, find new patched functions,
+ * information from the patch modules, find new patched functions,
  * and register those functions in the ftrace handlers the redirects
  * the old function call to the new function code.
  *
- * Each hotfix can contain one or more patched functions.  This information
- * is contained in the .patches section of the hotfix module.  For each
- * function patched by the module we must:
+ * Each patch module can contain one or more patched functions.  This
+ * information is contained in the .patches section of the patch module.  For
+ * each function patched by the module we must:
  * - Call stop_machine
  * - Ensure that no execution thread is currently in the function to be
  *   patched (or has the function in the call stack)

kpatch-kmod/kpatch.h → kmod/core/kpatch.h

@@ -4,7 +4,7 @@
  * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
  * Copyright (C) 2013 Josh Poimboeuf <jpoimboe@redhat.com>
  *
- * Contains the API for the core kpatch module used by the hotfix modules
+ * Contains the API for the core kpatch module used by the patch modules
  */
 
 #ifndef _KPATCH_H_

kmod/patch/Makefile

@@ -0,0 +1,20 @@
+KPATCH_NAME ?= patch
+KPATCH_BUILD ?= /lib/modules/$(shell uname -r)/build
+KPATCH_MAKE = $(MAKE) -C $(KPATCH_BUILD) M=$(PWD)
+ccflags-y += -I$(KPATCH_BASEDIR)
+
+obj-m += kpatch-$(KPATCH_NAME).o
+
+kpatch-$(KPATCH_NAME)-objs += kpatch-patch-hook.o kpatch.lds output.o
+
+all: kpatch-$(KPATCH_NAME).ko
+
+kpatch-$(KPATCH_NAME).ko:
+	$(KPATCH_MAKE) kpatch-$(KPATCH_NAME).ko
+
+kpatch-patch-hook.o: kpatch-patch-hook.c
+	$(KPATCH_MAKE) kpatch-patch-hook.o
+
+clean:
+	$(RM) -Rf .*.o.cmd .*.ko.cmd .tmp_versions *.o *.ko *.mod.c \
+	Module.symvers

kpatch-files/kpatch-patch-hook.c → kmod/patch/kpatch-patch-hook.c

@@ -2,7 +2,7 @@
 
 #include <linux/module.h>
 #include <linux/printk.h>
-#include "../kpatch-kmod/kpatch.h"
+#include "kpatch.h"
 
 extern char __kpatch_patches, __kpatch_patches_end;
 

tools/Makefile → kpatch-build/Makefile

@@ -1,3 +1,5 @@
+CFLAGS=-I../kmod/core
+
 all: create-diff-object add-patches-section link-vmlinux-syms
 
 create-diff-object: create-diff-object.c

tools/add-patches-section.c → kpatch-build/add-patches-section.c

@@ -26,7 +26,7 @@
 #include <gelf.h>
 #include <unistd.h>
 
-#include "../kpatch-kmod/kpatch.h"
+#include "kpatch.h"
 
 #define ERROR(format, ...) \
 	error(1, 0, "%s: %d: " format, __FUNCTION__, __LINE__, ##__VA_ARGS__)

tools/create-diff-object.c → kpatch-build/create-diff-object.c

@@ -39,7 +39,7 @@
 #include <error.h>
 #include <gelf.h>
 
-#include "../kpatch-kmod/kpatch.h"
+#include "kpatch.h"
 
 #define ERROR(format, ...) \
 	error(1, 0, "%s: %d: " format, __FUNCTION__, __LINE__, ##__VA_ARGS__)

scripts/kpatch-build → kpatch-build/kpatch-build

@@ -1,4 +1,4 @@
-#/bin/bash
+#!/bin/bash
 
 # kpatch build script for Fedora
 
@@ -24,25 +24,29 @@
 
 BASE=$PWD
 LOGFILE=$PWD/kpatch-build.log
-KPATCHPATH=/usr/local/share/kpatch
+TOOLSDIR=$BASE/kpatch-build
 ARCHVERSION=$(uname -r)
 DISTROVERSION=${ARCHVERSION%*.*}
 CPUS=$(grep -c ^processor /proc/cpuinfo)
 LOCALVERSION=$(uname -r)
 LOCALVERSION=-${LOCALVERSION##*-}
+KSRCDIR=~/.kpatch/$ARCHVERSION
+KSRCDIR_DIR=$(dirname $KSRCDIR)
+KSRCDIR_CACHE=$KSRCDIR.tgz
 
 cleanup() {
-	rm -Rf kernel-$DISTROVERSION.src.rpm rpmbuild $LOGFILE $TEMPDIR > /dev/null 2>/dev/null
+	rm -Rf $KSRCDIR kernel-$DISTROVERSION.src.rpm $LOGFILE $TEMPDIR > /dev/null 2>/dev/null
 }
 
 die() {
 	echo "kpatch encountered an error"
+	echo "check kpatch-build.log"
 	exit 1
 }
 
 if [ $# -ne 1 ]
 then
-	echo "kpatch patchfile"
+	echo "usage: $0 PATCH"
 	exit 2
 fi
 
@@ -53,34 +57,56 @@ then
 	exit 3
 fi
 
-cleanup
+PATCHNAME=`basename $PATCHFILE`
+if [[ $PATCHNAME =~ \.patch ]] || [[ $PATCHNAME =~ \.diff ]]
+then
+	PATCHNAME=${PATCHNAME%.*}
+fi
 
-echo "Verifying required development tools"
-yum install rpmdevtools yum-utils || die
+cleanup
 
-echo "Downloading kernel source for $ARCHVERSION"
-yumdownloader --source kernel-$ARCHVERSION || die
+echo "Building tools"
+make -C $TOOLSDIR >> $LOGFILE 2>&1 || die
 
-echo "Verifying build dependencies for kernel package"
-yum-builddep kernel-$DISTROVERSION.src.rpm || die
+TEMPDIR=`mktemp -d` || die
 
-echo "Unpacking kernel source"
-rpmdev-setuptree >> $LOGFILE 2>&1 || die
-rpm -Uvh kernel-$DISTROVERSION.src.rpm >> $LOGFILE 2>&1 || die
-cd ~/rpmbuild/SPECS || die
-rpmbuild -bp --target=$(uname -m) kernel.spec >> $LOGFILE 2>&1 || die
-cd ~/rpmbuild/BUILD/kernel-* || die
-cd linux-$ARCHVERSION || die
-BUILD=$PWD
-echo $LOCALVERSION > localversion
+if [ -f "$KSRCDIR_CACHE" ]
+then
+	echo "Using cache at $KSRCDIR_CACHE"
+	rm -rf $KSRCDIR
+	tar xzf $KSRCDIR_CACHE -C $KSRCDIR_DIR || die
+	cd $KSRCDIR || die
+else
+	echo "Verifying required development tools"
+	yum install rpmdevtools yum-utils || die
+
+	echo "Downloading kernel source for $ARCHVERSION"
+	yumdownloader --source kernel-$ARCHVERSION || die
+
+	echo "Verifying build dependencies for kernel package"
+	yum-builddep kernel-$DISTROVERSION.src.rpm || die
+
+	echo "Unpacking kernel source"
+	rpmdev-setuptree >> $LOGFILE 2>&1 || die
+	rpm -Uvh kernel-$DISTROVERSION.src.rpm >> $LOGFILE 2>&1 || die
+	rpmbuild -bp --target=$(uname -m) ~/rpmbuild/SPECS/kernel.spec >> $LOGFILE 2>&1 || die
+	rm -rf $KSRCDIR
+	mkdir -p $KSRCDIR_DIR
+	mv ~/rpmbuild/BUILD/kernel-*/linux-$ARCHVERSION $KSRCDIR >> $LOGFILE 2>&1 || die
+
+	echo "Building original kernel"
+	cd $KSRCDIR
+	echo $LOCALVERSION > localversion
+	make -j$CPUS vmlinux >> $LOGFILE 2>&1 || die
+
+	echo "Creating cache"
+	tar czf $KSRCDIR_CACHE -C $KSRCDIR_DIR $ARCHVERSION
+fi
 
-echo "Building the base kernel"
-make -j$CPUS vmlinux >> $LOGFILE 2>&1 || die
-TEMPDIR=`mktemp -d` || die
-cp -R $KPATCHPATH/* $TEMPDIR || die
+cp -R $BASE/kmod/patch/* $BASE/kmod/core $TEMPDIR || die
 cp vmlinux $TEMPDIR || die
 
-echo "Building the patched kernel"
+echo "Building patched kernel"
 patch -p1 < $PATCHFILE >> $LOGFILE 2>&1
 make -j$CPUS vmlinux > $TEMPDIR/patched_build.log 2>&1 || die
 
@@ -103,34 +129,36 @@ do
 
 done
 patch -R -p1 < $PATCHFILE >> $LOGFILE 2>&1
-mkdir $TEMPDIR/base
+mkdir $TEMPDIR/orig
 for i in $(cat $TEMPDIR/changed_objs)
 do
 	rm -f $i
 	KCFLAGS="-ffunction-sections -fdata-sections" make $i >> $LOGFILE 2>&1 || die
 	strip -d $i
-	cp -f $i $TEMPDIR/base/
+	cp -f $i $TEMPDIR/orig/
 done
 
 echo "Extracting new and modified ELF sections"
 cd $TEMPDIR
 mkdir output
-for i in base/* 
+for i in orig/* 
 do
 	FILE=`basename $i`
-	./tools/create-diff-object base/$FILE patched/$FILE output/$FILE >> $LOGFILE 2>&1
+	$TOOLSDIR/create-diff-object orig/$FILE patched/$FILE output/$FILE >> $LOGFILE 2>&1 || die
 done
 
-echo "Building hotfix module"
+echo "Building core module: kpatch.ko"
+cd core
+KPATCH_BUILD=$KSRCDIR make >> $LOGFILE 2>&1 || die
+cd ..
+
+echo "Building patch module: kpatch-$PATCHNAME.ko"
 ld -r -o output.o output/* >> $LOGFILE 2>&1 || die
-./tools/add-patches-section output.o vmlinux >> $LOGFILE 2>&1 || die
-KPATCH_BUILD=$BUILD make >> $LOGFILE 2>&1 || die
-strip -d kpatch-patch.ko >> $LOGFILE 2>&1 || die
-./tools/link-vmlinux-syms kpatch-patch.ko vmlinux >> $LOGFILE 2>&1 || die
-
-echo "Patch generation complete"
-cp -f $TEMPDIR/kpatch-patch.ko $BASE
-echo "Cleaning up"
-cleanup
-echo "Done"
+$TOOLSDIR/add-patches-section output.o vmlinux >> $LOGFILE 2>&1 || die
+KPATCH_BASEDIR=$TEMPDIR/core KPATCH_BUILD=$KSRCDIR KPATCH_NAME=$PATCHNAME make >> $LOGFILE 2>&1 || die
+strip -d kpatch-$PATCHNAME.ko >> $LOGFILE 2>&1 || die
+$TOOLSDIR/link-vmlinux-syms kpatch-$PATCHNAME.ko vmlinux >> $LOGFILE 2>&1 || die
 
+echo "SUCCESS"
+cp -f $TEMPDIR/kpatch-$PATCHNAME.ko $TEMPDIR/core/kpatch.ko $BASE
+cleanup

tools/link-vmlinux-syms.c → kpatch-build/link-vmlinux-syms.c

@@ -23,7 +23,7 @@
 #include <gelf.h>
 #include <unistd.h>
 
-#include "../kpatch-kmod/kpatch.h"
+#include "kpatch.h"
 
 #define ERROR(format, ...) \
 	error(1, 0, "%s: %d: " format, __FUNCTION__, __LINE__, ##__VA_ARGS__)