On Tue, Oct 31, 2023 at 06:10:52PM -0300, Marcos Paulo de Souza wrote:

The modules are being moved from lib/livepatch to tools/testing/selftests/livepatch/test_modules.

This code moving will allow writing more complex tests, like for example an userspace C code that will call a livepatched kernel function.

The modules are now built as out-of-tree modules, but being part of the kernel source means they will be maintained.

Another advantage of the code moving is to be able to easily change, debug and rebuild the tests by running make on the selftests/livepatch directory, which is not currently possible since the modules on lib/livepatch are build and installed using the "modules" target.

The current approach also keeps the ability to execute the tests manually by executing the scripts inside selftests/livepatch directory, as it's currently supported. If the modules are modified, they needed to be rebuilt before running the scripts though.

The modules are built before running the selftests when using the kselftest invocations:

make kselftest TARGETS=livepatch or make -C tools/testing/selftests/livepatch run_tests

Quick question:

- We have been building with CONFIG_LIVEPATCH_TEST=m to generate the test modules at kernel build time

- Our packaging filters out the selftest scripts and supporting modules from the general kernel RPM package into their subpackages

- Tests are run as part of CKI or other manual tests by installing the pre-built packages from the previous step

After this patch, we would need to add something like the following to our kernel build, before packaging:

$ make KDIR=$(pwd) -C tools/testing/selftests/livepatch/ ^^^^

If this is the correct way to build the test modules for *this* tree and /lib/modules/$(shell uname -r)/build... it might be useful to document in the commit message as an alternative use case.

-- Joe

Having the modules being built as out-of-modules requires changing the currently used 'modprobe' by 'insmod' and adapt the test scripts that check for the kernel message buffer.

As there aren't any modules being built on lib/livepatch, remove the TEST_LIVEPATCH Kconfig and it's references.

Note: "make gen_tar" packages the pre-built binaries into the tarball. It means that it will store the test modules pre-built for the kernel running on the build host.

   Note that these modules need not binary compatible with
   the kernel built from the same sources. But the same
   is true for other packaged selftest binaries.

   The entire kernel sources are needed for rebuilding
   the selftests on another system.

Signed-off-by: Marcos Paulo de Souza mpdesouza@suse.com

arch/s390/configs/debug_defconfig | 1 - arch/s390/configs/defconfig | 1 - lib/Kconfig.debug | 22 ---------- lib/Makefile | 2 - lib/livepatch/Makefile | 14 ------ tools/testing/selftests/livepatch/Makefile | 1 + tools/testing/selftests/livepatch/README | 17 +++++--- tools/testing/selftests/livepatch/config | 1 - tools/testing/selftests/livepatch/functions.sh | 34 ++++++--------- .../testing/selftests/livepatch/test-callbacks.sh | 50 +++++++++++----------- tools/testing/selftests/livepatch/test-ftrace.sh | 6 +-- .../testing/selftests/livepatch/test-livepatch.sh | 10 ++--- .../selftests/livepatch/test-shadow-vars.sh | 2 +- tools/testing/selftests/livepatch/test-state.sh | 18 ++++---- tools/testing/selftests/livepatch/test-sysfs.sh | 6 +-- .../selftests/livepatch/test_modules/Makefile | 19 ++++++++ .../test_modules}/test_klp_atomic_replace.c | 0 .../test_modules}/test_klp_callbacks_busy.c | 0 .../test_modules}/test_klp_callbacks_demo.c | 0 .../test_modules}/test_klp_callbacks_demo2.c | 0 .../test_modules}/test_klp_callbacks_mod.c | 0 .../livepatch/test_modules}/test_klp_livepatch.c | 0 .../livepatch/test_modules}/test_klp_shadow_vars.c | 0 .../livepatch/test_modules}/test_klp_state.c | 0 .../livepatch/test_modules}/test_klp_state2.c | 0 .../livepatch/test_modules}/test_klp_state3.c | 0 26 files changed, 89 insertions(+), 115 deletions(-)

diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig index 438cd92e6080..9672b9f31710 100644 --- a/arch/s390/configs/debug_defconfig +++ b/arch/s390/configs/debug_defconfig @@ -885,4 +885,3 @@ CONFIG_ATOMIC64_SELFTEST=y CONFIG_STRING_SELFTEST=y CONFIG_TEST_BITOPS=m CONFIG_TEST_BPF=m -CONFIG_TEST_LIVEPATCH=m diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig index 1b8150e50f6a..a8a66264a72d 100644 --- a/arch/s390/configs/defconfig +++ b/arch/s390/configs/defconfig @@ -813,4 +813,3 @@ CONFIG_KPROBES_SANITY_TEST=m CONFIG_PERCPU_TEST=m CONFIG_ATOMIC64_SELFTEST=y CONFIG_TEST_BPF=m -CONFIG_TEST_LIVEPATCH=m diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index fa307f93fa2e..af67c5f5d031 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2862,28 +2862,6 @@ config TEST_MEMCAT_P If unsure, say N. -config TEST_LIVEPATCH

• tristate "Test livepatching"
• default n
• depends on DYNAMIC_DEBUG
• depends on LIVEPATCH
• depends on m
• help

•  Test kernel livepatching features for correctness.  The tests will
  

•  load test modules that will be livepatched in various scenarios.
  

•  To run all the livepatching tests:
  

•  make -C tools/testing/selftests TARGETS=livepatch run_tests
  

•  Alternatively, individual tests may be invoked:
  

•  tools/testing/selftests/livepatch/test-callbacks.sh
  

•  tools/testing/selftests/livepatch/test-livepatch.sh
  

•  tools/testing/selftests/livepatch/test-shadow-vars.sh
  

•  If unsure, say N.
  

config TEST_OBJAGG tristate "Perform selftest on object aggreration manager" default n diff --git a/lib/Makefile b/lib/Makefile index 740109b6e2c8..b96b280787ca 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -132,8 +132,6 @@ endif obj-$(CONFIG_TEST_FPU) += test_fpu.o CFLAGS_test_fpu.o += $(FPU_CFLAGS) -obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/

# Some KUnit files (hooks.o) need to be built-in even when KUnit is a module, # so we can't just use obj-$(CONFIG_KUNIT). ifdef CONFIG_KUNIT diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile deleted file mode 100644 index dcc912b3478f..000000000000 --- a/lib/livepatch/Makefile +++ /dev/null @@ -1,14 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -# -# Makefile for livepatch test code.

-obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \

• 		test_klp_callbacks_demo.o \
  

• 		test_klp_callbacks_demo2.o \
  

• 		test_klp_callbacks_busy.o \
  

• 		test_klp_callbacks_mod.o \
  

• 		test_klp_livepatch.o \
  

• 		test_klp_shadow_vars.o \
  

• 		test_klp_state.o \
  

• 		test_klp_state2.o \
  

• 		test_klp_state3.o
  

diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index 02fadc9d55e0..119e2bbebe5d 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +TEST_GEN_MODS_DIR := test_modules TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ test-livepatch.sh \ diff --git a/tools/testing/selftests/livepatch/README b/tools/testing/selftests/livepatch/README index 0942dd5826f8..c5eb3cb67b66 100644 --- a/tools/testing/selftests/livepatch/README +++ b/tools/testing/selftests/livepatch/README @@ -13,23 +13,26 @@ the message buffer for only the duration of each individual test.) Config

---

-Set these config options and their prerequisites:

-CONFIG_LIVEPATCH=y -CONFIG_TEST_LIVEPATCH=m +Set CONFIG_LIVEPATCH=y option and it's prerequisites. Running the tests

---

-Test kernel modules are built as part of lib/ (make modules) and need to -be installed (make modules_install) as the test scripts will modprobe -them. +Test kernel modules are built before running the livepatch selftests. The +modules are located under test_modules directory, and are built as out-of-tree +modules. This is specially useful since the same sources can be built and +tested on systems with different kABI, ensuring they the tests are backwards +compatible. The modules will be loaded by the test scripts using insmod. To run the livepatch selftests, from the top of the kernel source tree: % make -C tools/testing/selftests TARGETS=livepatch run_tests +or

• % make kselftest TARGETS=livepatch

Adding tests

---

diff --git a/tools/testing/selftests/livepatch/config b/tools/testing/selftests/livepatch/config index ad23100cb27c..e88bf518a23a 100644 --- a/tools/testing/selftests/livepatch/config +++ b/tools/testing/selftests/livepatch/config @@ -1,3 +1,2 @@ CONFIG_LIVEPATCH=y CONFIG_DYNAMIC_DEBUG=y -CONFIG_TEST_LIVEPATCH=m diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index c8416c54b463..e60cf09491a6 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -127,16 +127,14 @@ function loop_until() { done } -function assert_mod() {

• local mod="$1"
• modprobe --dry-run "$mod" &>/dev/null

-}

function is_livepatch_mod() { local mod="$1"

• if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then

• if [[ ! -f "test_modules/$mod.ko" ]]; then

• die "Can't find \"test_modules/$mod.ko\", try \"make\""
  

• fi
• if [[ $(modinfo "test_modules/$mod.ko" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then return 0 fi

@@ -146,9 +144,9 @@ function is_livepatch_mod() { function __load_mod() { local mod="$1"; shift

• local msg="% modprobe $mod $*"

• local msg="% insmod test_modules/$mod.ko $*" log "${msg%% }"

• ret=$(modprobe "$mod" "$@" 2>&1)

• ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1) if [[ "$ret" != "" ]]; then die "$ret" fi

@@ -161,13 +159,10 @@ function __load_mod() { # load_mod(modname, params) - load a kernel module # modname - module name to load -# params - module parameters to pass to modprobe +# params - module parameters to pass to insmod function load_mod() { local mod="$1"; shift

• assert_mod "$mod" ||

• skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
  

• is_livepatch_mod "$mod" && die "use load_lp() to load the livepatch module $mod"

@@ -177,13 +172,10 @@ function load_mod() { # load_lp_nowait(modname, params) - load a kernel module with a livepatch # but do not wait on until the transition finishes # modname - module name to load -# params - module parameters to pass to modprobe +# params - module parameters to pass to insmod function load_lp_nowait() { local mod="$1"; shift

• assert_mod "$mod" ||

• skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
  

• is_livepatch_mod "$mod" || die "module $mod is not a livepatch"

@@ -196,7 +188,7 @@ function load_lp_nowait() { # load_lp(modname, params) - load a kernel module with a livepatch # modname - module name to load -# params - module parameters to pass to modprobe +# params - module parameters to pass to insmod function load_lp() { local mod="$1"; shift @@ -209,13 +201,13 @@ function load_lp() { # load_failing_mod(modname, params) - load a kernel module, expect to fail # modname - module name to load -# params - module parameters to pass to modprobe +# params - module parameters to pass to insmod function load_failing_mod() { local mod="$1"; shift

• local msg="% modprobe $mod $*"

• local msg="% insmod test_modules/$mod.ko $*" log "${msg%% }"

• ret=$(modprobe "$mod" "$@" 2>&1)

• ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1) if [[ "$ret" == "" ]]; then die "$mod unexpectedly loaded" fi

diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh index 90b26dbb2626..32b150e25b10 100755 --- a/tools/testing/selftests/livepatch/test-callbacks.sh +++ b/tools/testing/selftests/livepatch/test-callbacks.sh @@ -34,9 +34,9 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET -check_result "% modprobe $MOD_TARGET +check_result "% insmod test_modules/$MOD_TARGET.ko $MOD_TARGET: ${MOD_TARGET}_init -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -81,7 +81,7 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -89,7 +89,7 @@ livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_TARGET +% insmod test_modules/$MOD_TARGET.ko livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET' $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init $MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init @@ -129,9 +129,9 @@ unload_mod $MOD_TARGET disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_TARGET +check_result "% insmod test_modules/$MOD_TARGET.ko $MOD_TARGET: ${MOD_TARGET}_init -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -177,7 +177,7 @@ unload_mod $MOD_TARGET disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -185,7 +185,7 @@ livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_TARGET +% insmod test_modules/$MOD_TARGET.ko livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET' $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init $MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init @@ -219,7 +219,7 @@ load_lp $MOD_LIVEPATCH disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -254,9 +254,9 @@ load_mod $MOD_TARGET load_failing_mod $MOD_LIVEPATCH pre_patch_ret=-19 unload_mod $MOD_TARGET -check_result "% modprobe $MOD_TARGET +check_result "% insmod test_modules/$MOD_TARGET.ko $MOD_TARGET: ${MOD_TARGET}_init -% modprobe $MOD_LIVEPATCH pre_patch_ret=-19 +% insmod test_modules/$MOD_LIVEPATCH.ko pre_patch_ret=-19 livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition test_klp_callbacks_demo: pre_patch_callback: vmlinux @@ -265,7 +265,7 @@ livepatch: failed to enable patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch livepatch: '$MOD_LIVEPATCH': completing unpatching transition livepatch: '$MOD_LIVEPATCH': unpatching complete -modprobe: ERROR: could not insert '$MOD_LIVEPATCH': No such device +insmod: ERROR: could not insert module test_modules/$MOD_LIVEPATCH.ko: No such device % rmmod $MOD_TARGET $MOD_TARGET: ${MOD_TARGET}_exit" @@ -295,7 +295,7 @@ load_failing_mod $MOD_TARGET disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -304,12 +304,12 @@ livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux livepatch: '$MOD_LIVEPATCH': patching complete % echo -19 > /sys/module/$MOD_LIVEPATCH/parameters/pre_patch_ret -% modprobe $MOD_TARGET +% insmod test_modules/$MOD_TARGET.ko livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET' $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init livepatch: pre-patch callback failed for object '$MOD_TARGET' livepatch: patch '$MOD_LIVEPATCH' failed for module '$MOD_TARGET', refusing to load module '$MOD_TARGET' -modprobe: ERROR: could not insert '$MOD_TARGET': No such device +insmod: ERROR: could not insert module test_modules/$MOD_TARGET.ko: No such device % echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled livepatch: '$MOD_LIVEPATCH': initializing unpatching transition $MOD_LIVEPATCH: pre_unpatch_callback: vmlinux @@ -340,11 +340,11 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET_BUSY -check_result "% modprobe $MOD_TARGET_BUSY block_transition=N +check_result "% insmod test_modules/$MOD_TARGET_BUSY.ko block_transition=N $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init $MOD_TARGET_BUSY: busymod_work_func enter $MOD_TARGET_BUSY: busymod_work_func exit -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -354,7 +354,7 @@ livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux $MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_TARGET +% insmod test_modules/$MOD_TARGET.ko livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET' $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init $MOD_LIVEPATCH: post_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init @@ -421,16 +421,16 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH unload_mod $MOD_TARGET_BUSY -check_result "% modprobe $MOD_TARGET_BUSY block_transition=Y +check_result "% insmod test_modules/$MOD_TARGET_BUSY.ko block_transition=Y $MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_init $MOD_TARGET_BUSY: busymod_work_func enter -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET_BUSY -> [MODULE_STATE_LIVE] Normal state livepatch: '$MOD_LIVEPATCH': starting patching transition -% modprobe $MOD_TARGET +% insmod test_modules/$MOD_TARGET.ko livepatch: applying patch '$MOD_LIVEPATCH' to loading module '$MOD_TARGET' $MOD_LIVEPATCH: pre_patch_callback: $MOD_TARGET -> [MODULE_STATE_COMING] Full formed, running module_init $MOD_TARGET: ${MOD_TARGET}_init @@ -467,7 +467,7 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -475,7 +475,7 @@ livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_LIVEPATCH2 +% insmod test_modules/$MOD_LIVEPATCH2.ko livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux @@ -523,7 +523,7 @@ disable_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -531,7 +531,7 @@ livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_LIVEPATCH2 replace=1 +% insmod test_modules/$MOD_LIVEPATCH2.ko replace=1 livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh index 825540a5194d..730218bce99c 100755 --- a/tools/testing/selftests/livepatch/test-ftrace.sh +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -35,7 +35,7 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH check_result "livepatch: kernel.ftrace_enabled = 0 -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: failed to register ftrace handler for function 'cmdline_proc_show' (-16) @@ -44,9 +44,9 @@ livepatch: failed to enable patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch livepatch: '$MOD_LIVEPATCH': completing unpatching transition livepatch: '$MOD_LIVEPATCH': unpatching complete -modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Device or resource busy +insmod: ERROR: could not insert module test_modules/$MOD_LIVEPATCH.ko: Device or resource busy livepatch: kernel.ftrace_enabled = 1 -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: '$MOD_LIVEPATCH': starting patching transition diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh index 5fe79ac34be1..e3455a6b1158 100755 --- a/tools/testing/selftests/livepatch/test-livepatch.sh +++ b/tools/testing/selftests/livepatch/test-livepatch.sh @@ -31,7 +31,7 @@ if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] die "livepatch kselftest(s) failed" fi -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: '$MOD_LIVEPATCH': starting patching transition @@ -75,14 +75,14 @@ unload_lp $MOD_LIVEPATCH grep 'live patched' /proc/cmdline > /dev/kmsg grep 'live patched' /proc/meminfo > /dev/kmsg -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition livepatch: '$MOD_LIVEPATCH': patching complete $MOD_LIVEPATCH: this has been live patched -% modprobe $MOD_REPLACE replace=0 +% insmod test_modules/$MOD_REPLACE.ko replace=0 livepatch: enabling patch '$MOD_REPLACE' livepatch: '$MOD_REPLACE': initializing patching transition livepatch: '$MOD_REPLACE': starting patching transition @@ -135,14 +135,14 @@ unload_lp $MOD_REPLACE grep 'live patched' /proc/cmdline > /dev/kmsg grep 'live patched' /proc/meminfo > /dev/kmsg -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: '$MOD_LIVEPATCH': starting patching transition livepatch: '$MOD_LIVEPATCH': completing patching transition livepatch: '$MOD_LIVEPATCH': patching complete $MOD_LIVEPATCH: this has been live patched -% modprobe $MOD_REPLACE replace=1 +% insmod test_modules/$MOD_REPLACE.ko replace=1 livepatch: enabling patch '$MOD_REPLACE' livepatch: '$MOD_REPLACE': initializing patching transition livepatch: '$MOD_REPLACE': starting patching transition diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh index e04cb354f56b..1218c155bffe 100755 --- a/tools/testing/selftests/livepatch/test-shadow-vars.sh +++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh @@ -16,7 +16,7 @@ start_test "basic shadow variable API" load_mod $MOD_TEST unload_mod $MOD_TEST -check_result "% modprobe $MOD_TEST +check_result "% insmod test_modules/$MOD_TEST.ko $MOD_TEST: klp_shadow_get(obj=PTR1, id=0x1234) = PTR0 $MOD_TEST: got expected NULL result $MOD_TEST: shadow_ctor: PTR3 -> PTR2 diff --git a/tools/testing/selftests/livepatch/test-state.sh b/tools/testing/selftests/livepatch/test-state.sh index 38656721c958..10a52ac06185 100755 --- a/tools/testing/selftests/livepatch/test-state.sh +++ b/tools/testing/selftests/livepatch/test-state.sh @@ -19,7 +19,7 @@ load_lp $MOD_LIVEPATCH disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -51,7 +51,7 @@ unload_lp $MOD_LIVEPATCH disable_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH2 -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition $MOD_LIVEPATCH: pre_patch_callback: vmlinux @@ -61,7 +61,7 @@ livepatch: '$MOD_LIVEPATCH': completing patching transition $MOD_LIVEPATCH: post_patch_callback: vmlinux $MOD_LIVEPATCH: fix_console_loglevel: fixing console_loglevel livepatch: '$MOD_LIVEPATCH': patching complete -% modprobe $MOD_LIVEPATCH2 +% insmod test_modules/$MOD_LIVEPATCH2.ko livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux @@ -96,7 +96,7 @@ disable_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH3 -check_result "% modprobe $MOD_LIVEPATCH2 +check_result "% insmod test_modules/$MOD_LIVEPATCH2.ko livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux @@ -106,7 +106,7 @@ livepatch: '$MOD_LIVEPATCH2': completing patching transition $MOD_LIVEPATCH2: post_patch_callback: vmlinux $MOD_LIVEPATCH2: fix_console_loglevel: fixing console_loglevel livepatch: '$MOD_LIVEPATCH2': patching complete -% modprobe $MOD_LIVEPATCH3 +% insmod test_modules/$MOD_LIVEPATCH3.ko livepatch: enabling patch '$MOD_LIVEPATCH3' livepatch: '$MOD_LIVEPATCH3': initializing patching transition $MOD_LIVEPATCH3: pre_patch_callback: vmlinux @@ -117,7 +117,7 @@ $MOD_LIVEPATCH3: post_patch_callback: vmlinux $MOD_LIVEPATCH3: fix_console_loglevel: taking over the console_loglevel change livepatch: '$MOD_LIVEPATCH3': patching complete % rmmod $MOD_LIVEPATCH2 -% modprobe $MOD_LIVEPATCH2 +% insmod test_modules/$MOD_LIVEPATCH2.ko livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux @@ -149,7 +149,7 @@ load_failing_mod $MOD_LIVEPATCH disable_lp $MOD_LIVEPATCH2 unload_lp $MOD_LIVEPATCH2 -check_result "% modprobe $MOD_LIVEPATCH2 +check_result "% insmod test_modules/$MOD_LIVEPATCH2.ko livepatch: enabling patch '$MOD_LIVEPATCH2' livepatch: '$MOD_LIVEPATCH2': initializing patching transition $MOD_LIVEPATCH2: pre_patch_callback: vmlinux @@ -159,9 +159,9 @@ livepatch: '$MOD_LIVEPATCH2': completing patching transition $MOD_LIVEPATCH2: post_patch_callback: vmlinux $MOD_LIVEPATCH2: fix_console_loglevel: fixing console_loglevel livepatch: '$MOD_LIVEPATCH2': patching complete -% modprobe $MOD_LIVEPATCH +% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: Livepatch patch ($MOD_LIVEPATCH) is not compatible with the already installed livepatches. -modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Invalid argument +insmod: ERROR: could not insert module test_modules/$MOD_LIVEPATCH.ko: Invalid parameters % echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH2/enabled livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition $MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux diff --git a/tools/testing/selftests/livepatch/test-sysfs.sh b/tools/testing/selftests/livepatch/test-sysfs.sh index 7f76f280189a..6c646afa7395 100755 --- a/tools/testing/selftests/livepatch/test-sysfs.sh +++ b/tools/testing/selftests/livepatch/test-sysfs.sh @@ -27,7 +27,7 @@ disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe $MOD_LIVEPATCH +check_result "% insmod test_modules/$MOD_LIVEPATCH.ko livepatch: enabling patch '$MOD_LIVEPATCH' livepatch: '$MOD_LIVEPATCH': initializing patching transition livepatch: '$MOD_LIVEPATCH': starting patching transition @@ -56,7 +56,7 @@ check_sysfs_value "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0" disable_lp $MOD_LIVEPATCH unload_lp $MOD_LIVEPATCH -check_result "% modprobe test_klp_callbacks_demo +check_result "% insmod test_modules/test_klp_callbacks_demo.ko livepatch: enabling patch 'test_klp_callbacks_demo' livepatch: 'test_klp_callbacks_demo': initializing patching transition test_klp_callbacks_demo: pre_patch_callback: vmlinux @@ -64,7 +64,7 @@ livepatch: 'test_klp_callbacks_demo': starting patching transition livepatch: 'test_klp_callbacks_demo': completing patching transition test_klp_callbacks_demo: post_patch_callback: vmlinux livepatch: 'test_klp_callbacks_demo': patching complete -% modprobe test_klp_callbacks_mod +% insmod test_modules/test_klp_callbacks_mod.ko livepatch: applying patch 'test_klp_callbacks_demo' to loading module 'test_klp_callbacks_mod' test_klp_callbacks_demo: pre_patch_callback: test_klp_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init test_klp_callbacks_demo: post_patch_callback: test_klp_callbacks_mod -> [MODULE_STATE_COMING] Full formed, running module_init diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile new file mode 100644 index 000000000000..6f7c2103d27d --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/Makefile @@ -0,0 +1,19 @@ +TESTMODS_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST))))) +KDIR ?= /lib/modules/$(shell uname -r)/build

+obj-m += test_klp_atomic_replace.o \

• test_klp_callbacks_busy.o \
• test_klp_callbacks_demo.o \
• test_klp_callbacks_demo2.o \
• test_klp_callbacks_mod.o \
• test_klp_livepatch.o \
• test_klp_state.o \
• test_klp_state2.o \
• test_klp_state3.o \
• test_klp_shadow_vars.o

+modules:

• $(Q)$(MAKE) -C $(KDIR) modules KBUILD_EXTMOD=$(TESTMODS_DIR)

+clean:

• $(Q)$(MAKE) -C $(KDIR) clean KBUILD_EXTMOD=$(TESTMODS_DIR)

diff --git a/lib/livepatch/test_klp_atomic_replace.c b/tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c similarity index 100% rename from lib/livepatch/test_klp_atomic_replace.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c diff --git a/lib/livepatch/test_klp_callbacks_busy.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_busy.c similarity index 100% rename from lib/livepatch/test_klp_callbacks_busy.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_busy.c diff --git a/lib/livepatch/test_klp_callbacks_demo.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c similarity index 100% rename from lib/livepatch/test_klp_callbacks_demo.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c diff --git a/lib/livepatch/test_klp_callbacks_demo2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c similarity index 100% rename from lib/livepatch/test_klp_callbacks_demo2.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c diff --git a/lib/livepatch/test_klp_callbacks_mod.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_mod.c similarity index 100% rename from lib/livepatch/test_klp_callbacks_mod.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_mod.c diff --git a/lib/livepatch/test_klp_livepatch.c b/tools/testing/selftests/livepatch/test_modules/test_klp_livepatch.c similarity index 100% rename from lib/livepatch/test_klp_livepatch.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_livepatch.c diff --git a/lib/livepatch/test_klp_shadow_vars.c b/tools/testing/selftests/livepatch/test_modules/test_klp_shadow_vars.c similarity index 100% rename from lib/livepatch/test_klp_shadow_vars.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_shadow_vars.c diff --git a/lib/livepatch/test_klp_state.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state.c similarity index 100% rename from lib/livepatch/test_klp_state.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_state.c diff --git a/lib/livepatch/test_klp_state2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c similarity index 100% rename from lib/livepatch/test_klp_state2.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_state2.c diff --git a/lib/livepatch/test_klp_state3.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state3.c similarity index 100% rename from lib/livepatch/test_klp_state3.c rename to tools/testing/selftests/livepatch/test_modules/test_klp_state3.c

-- 2.42.0

On Thu, Nov 30, 2023 at 04:24:26PM -0700, Shuah Khan wrote:

On 10/31/23 15:10, Marcos Paulo de Souza wrote:

...

The test proves that a syscall can be livepatched. It is interesting because syscalls are called a tricky way. Also the process gets livepatched either when sleeping in the userspace or when entering or leaving the kernel space.

The livepatch is a bit tricky:

1. The syscall function name is architecture specific. Also ARCH_HAS_SYSCALL_WRAPPER must be taken in account.

2. The syscall must stay working the same way for other processes on the system. It is solved by decrementing a counter only for PIDs of the test processes. It means that the test processes has to call the livepatched syscall at least once.

The test creates one userspace process per online cpu. The processes are calling getpid in a busy loop. The intention is to create random locations when the livepatch gets enabled. Nothing is guarantted. The magic is in the randomness.

Signed-off-by: Marcos Paulo de Souza mpdesouza@suse.com

tools/testing/selftests/livepatch/Makefile | 4 +- tools/testing/selftests/livepatch/test-syscall.sh | 53 ++++++++++ .../selftests/livepatch/test_klp-call_getpid.c | 44 ++++++++ .../selftests/livepatch/test_modules/Makefile | 3 +- .../livepatch/test_modules/test_klp_syscall.c | 116 +++++++++++++++++++++ 5 files changed, 218 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index 119e2bbebe5d..35418a4790be 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +TEST_GEN_FILES := test_klp-call_getpid TEST_GEN_MODS_DIR := test_modules TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ @@ -8,7 +9,8 @@ TEST_PROGS := \ test-shadow-vars.sh \ test-state.sh \ test-ftrace.sh \

• test-sysfs.sh

• test-sysfs.sh \
• test-syscall.sh TEST_FILES := settings

diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh new file mode 100755 index 000000000000..b76a881d4013 --- /dev/null +++ b/tools/testing/selftests/livepatch/test-syscall.sh @@ -0,0 +1,53 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2023 SUSE +# Author: Marcos Paulo de Souza mpdesouza@suse.com

+. $(dirname $0)/functions.sh

+MOD_SYSCALL=test_klp_syscall

+setup_config

+# - Start _NRPROC processes calling getpid and load a livepatch to patch the +# getpid syscall. Check if all the processes transitioned to the livepatched +# state.

+start_test "patch getpid syscall while being heavily hammered"

+for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do

• ./test_klp-call_getpid &
• pids[$i]="$!"

+done

+pid_list=$(echo ${pids[@]} | tr ' ' ',') +load_lp $MOD_SYSCALL klp_pids=$pid_list

+# wait for all tasks to transition to patched state +loop_until 'grep -q '^0$' /sys/kernel/test_klp_syscall/npids'

+pending_pids=$(cat /sys/kernel/test_klp_syscall/npids) +log "$MOD_SYSCALL: Remaining not livepatched processes: $pending_pids"

+for pid in ${pids[@]}; do

• kill $pid || true

+done

+disable_lp $MOD_SYSCALL +unload_lp $MOD_SYSCALL

+check_result "% insmod test_modules/$MOD_SYSCALL.ko klp_pids=$pid_list +livepatch: enabling patch '$MOD_SYSCALL' +livepatch: '$MOD_SYSCALL': initializing patching transition +livepatch: '$MOD_SYSCALL': starting patching transition +livepatch: '$MOD_SYSCALL': completing patching transition +livepatch: '$MOD_SYSCALL': patching complete +$MOD_SYSCALL: Remaining not livepatched processes: 0 +% echo 0 > /sys/kernel/livepatch/$MOD_SYSCALL/enabled +livepatch: '$MOD_SYSCALL': initializing unpatching transition +livepatch: '$MOD_SYSCALL': starting unpatching transition +livepatch: '$MOD_SYSCALL': completing unpatching transition +livepatch: '$MOD_SYSCALL': unpatching complete +% rmmod $MOD_SYSCALL"

+exit 0 diff --git a/tools/testing/selftests/livepatch/test_klp-call_getpid.c b/tools/testing/selftests/livepatch/test_klp-call_getpid.c new file mode 100644 index 000000000000..ce321a2d7308 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_klp-call_getpid.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (C) 2023 SUSE
• • Authors: Libor Pechacek lpechacek@suse.cz

• •      Marcos Paulo de Souza <mpdesouza@suse.com>
    

• */

+#include <stdio.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <signal.h>

+static int stop; +static int sig_int;

+void hup_handler(int signum) +{

• stop = 1;

+}

+void int_handler(int signum) +{

• stop = 1;
• sig_int = 1;

+}

+int main(int argc, char *argv[]) +{

• long count = 0;
• signal(SIGHUP, &hup_handler);
• signal(SIGINT, &int_handler);
• while (!stop) {

• (void)syscall(SYS_getpid);
  

• count++;
  

• }
• if (sig_int)

• printf("%ld iterations done\n", count);
  

• return 0;

+} diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile index 6f7c2103d27d..f5e880269bff 100644 --- a/tools/testing/selftests/livepatch/test_modules/Makefile +++ b/tools/testing/selftests/livepatch/test_modules/Makefile @@ -10,7 +10,8 @@ obj-m += test_klp_atomic_replace.o \ test_klp_state.o \ test_klp_state2.o \ test_klp_state3.o \

• test_klp_shadow_vars.o

• test_klp_shadow_vars.o \
• test_klp_syscall.o modules: $(Q)$(MAKE) -C $(KDIR) modules KBUILD_EXTMOD=$(TESTMODS_DIR)

diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c new file mode 100644 index 000000000000..619496cc3481 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (C) 2017-2023 SUSE
• • Authors: Libor Pechacek lpechacek@suse.cz

• •      Nicolai Stange <nstange@suse.de>
    

• •      Marcos Paulo de Souza <mpdesouza@suse.com>
    

• */

+#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/livepatch.h>

+#if defined(__x86_64__) +#define FN_PREFIX __x64_ +#elif defined(__s390x__) +#define FN_PREFIX __s390x_ +#elif defined(__aarch64__) +#define FN_PREFIX __arm64_ +#else +/* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER */ +#define FN_PREFIX +#endif

+/* Protects klp_pids */ +static DEFINE_MUTEX(kpid_mutex);

+static unsigned int npids, npids_pending; +static int klp_pids[NR_CPUS]; +module_param_array(klp_pids, int, &npids_pending, 0); +MODULE_PARM_DESC(klp_pids, "Array of pids to be transitioned to livepatched state.");

+static ssize_t npids_show(struct kobject *kobj, struct kobj_attribute *attr,

• 	  char *buf)
  

+{

• return sprintf(buf, "%u\n", npids_pending);

+}

+static struct kobj_attribute klp_attr = __ATTR_RO(npids); +static struct kobject *klp_kobj;

+asmlinkage long lp_sys_getpid(void) +{

• int i;
• mutex_lock(&kpid_mutex);
• if (npids_pending > 0) {

• for (i = 0; i < npids; i++) {
  

• 	if (current->pid == klp_pids[i]) {
  

• 		klp_pids[i] = 0;
  

• 		npids_pending--;
  

• 		break;
  

• 	}
  

• }
  

• }
• mutex_unlock(&kpid_mutex);
• return task_tgid_vnr(current);

+}

+static struct klp_func vmlinux_funcs[] = {

• {

• .old_name = __stringify(FN_PREFIX) "sys_getpid",
  

• .new_func = lp_sys_getpid,
  

• }, {}

+};

+static struct klp_object objs[] = {

• {

• /* name being NULL means vmlinux */
  

• .funcs = vmlinux_funcs,
  

• }, {}

+};

+static struct klp_patch patch = {

• .mod = THIS_MODULE,
• .objs = objs,

+};

+static int livepatch_init(void) +{

• int ret;
• klp_kobj = kobject_create_and_add("test_klp_syscall", kernel_kobj);
• if (!klp_kobj)

• return -ENOMEM;
  

• ret = sysfs_create_file(klp_kobj, &klp_attr.attr);
• if (ret) {

• kobject_put(klp_kobj);
  

• return ret;
  

• }
• /*

• * Save the number pids to transition to livepatched state before the
  

• * number of pending pids is decremented.
  

• */
  

• npids = npids_pending;
• return klp_enable_patch(&patch);

+}

+static void livepatch_exit(void) +{

• kobject_put(klp_kobj);

+}

+module_init(livepatch_init); +module_exit(livepatch_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); +MODULE_AUTHOR("Libor Pechacek lpechacek@suse.cz"); +MODULE_AUTHOR("Nicolai Stange nstange@suse.de"); +MODULE_AUTHOR("Marcos Paulo de Souza mpdesouza@suse.com"); +MODULE_DESCRIPTION("Livepatch test: syscall transition");

Missing module name? Is there a reason to not name this module?

Can you please elaborate? This new module use the same MODULE_ macros used by the current livepatch selftests. What do you mean by module name?

Thanks in advance, Marcos

thanks, -- Shuah