diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-livepatch | 8 | ||||
| -rw-r--r-- | kernel/livepatch/core.c | 20 | ||||
| -rw-r--r-- | kernel/livepatch/transition.c | 18 | ||||
| -rw-r--r-- | tools/testing/selftests/livepatch/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/livepatch/functions.sh | 36 | ||||
| -rwxr-xr-x | tools/testing/selftests/livepatch/test-sysfs.sh | 86 |
6 files changed, 166 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-livepatch b/Documentation/ABI/testing/sysfs-kernel-livepatch index bea7bd5a1d5f..a5df9b4910dc 100644 --- a/Documentation/ABI/testing/sysfs-kernel-livepatch +++ b/Documentation/ABI/testing/sysfs-kernel-livepatch @@ -55,6 +55,14 @@ Description: The object directory contains subdirectories for each function that is patched within the object. +What: /sys/kernel/livepatch/<patch>/<object>/patched +Date: August 2022 +KernelVersion: 6.1.0 +Contact: live-patching@vger.kernel.org +Description: + An attribute which indicates whether the object is currently + patched. + What: /sys/kernel/livepatch/<patch>/<object>/<function,sympos> Date: Nov 2014 KernelVersion: 3.19.0 diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index ec06ce59d728..9ada0bc5247b 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -325,6 +325,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, * /sys/kernel/livepatch/<patch>/transition * /sys/kernel/livepatch/<patch>/force * /sys/kernel/livepatch/<patch>/<object> + * /sys/kernel/livepatch/<patch>/<object>/patched * /sys/kernel/livepatch/<patch>/<object>/<function,sympos> */ static int __klp_disable_patch(struct klp_patch *patch); @@ -431,6 +432,22 @@ static struct attribute *klp_patch_attrs[] = { }; ATTRIBUTE_GROUPS(klp_patch); +static ssize_t patched_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct klp_object *obj; + + obj = container_of(kobj, struct klp_object, kobj); + return sysfs_emit(buf, "%d\n", obj->patched); +} + +static struct kobj_attribute patched_kobj_attr = __ATTR_RO(patched); +static struct attribute *klp_object_attrs[] = { + &patched_kobj_attr.attr, + NULL, +}; +ATTRIBUTE_GROUPS(klp_object); + static void klp_free_object_dynamic(struct klp_object *obj) { kfree(obj->name); @@ -576,6 +593,7 @@ static void klp_kobj_release_object(struct kobject *kobj) static struct kobj_type klp_ktype_object = { .release = klp_kobj_release_object, .sysfs_ops = &kobj_sysfs_ops, + .default_groups = klp_object_groups, }; static void klp_kobj_release_func(struct kobject *kobj) @@ -1171,7 +1189,7 @@ int klp_module_coming(struct module *mod) return -EINVAL; if (!strcmp(mod->name, "vmlinux")) { - pr_err("vmlinux.ko: invalid module name"); + pr_err("vmlinux.ko: invalid module name\n"); return -EINVAL; } diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 5d03a2ad1066..30187b1d8275 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -610,9 +610,23 @@ void klp_reverse_transition(void) /* Called from copy_process() during fork */ void klp_copy_process(struct task_struct *child) { - child->patch_state = current->patch_state; - /* TIF_PATCH_PENDING gets copied in setup_thread_stack() */ + /* + * The parent process may have gone through a KLP transition since + * the thread flag was copied in setup_thread_stack earlier. Bring + * the task flag up to date with the parent here. + * + * The operation is serialized against all klp_*_transition() + * operations by the tasklist_lock. The only exception is + * klp_update_patch_state(current), but we cannot race with + * that because we are current. + */ + if (test_tsk_thread_flag(current, TIF_PATCH_PENDING)) + set_tsk_thread_flag(child, TIF_PATCH_PENDING); + else + clear_tsk_thread_flag(child, TIF_PATCH_PENDING); + + child->patch_state = current->patch_state; } /* diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index 1acc9e1fa3fb..02fadc9d55e0 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -6,7 +6,8 @@ TEST_PROGS := \ test-callbacks.sh \ test-shadow-vars.sh \ test-state.sh \ - test-ftrace.sh + test-ftrace.sh \ + test-sysfs.sh TEST_FILES := settings diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index 9230b869371d..c8416c54b463 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -6,6 +6,7 @@ MAX_RETRIES=600 RETRY_INTERVAL=".1" # seconds +KLP_SYSFS_DIR="/sys/kernel/livepatch" # Kselftest framework requirement - SKIP code is 4 ksft_skip=4 @@ -86,7 +87,7 @@ function set_ftrace_enabled() { if [[ "$result" != "$1" ]] ; then if [[ $can_fail -eq 1 ]] ; then - echo "livepatch: $err" > /dev/kmsg + echo "livepatch: $err" | sed 's#/proc/sys/kernel/#kernel.#' > /dev/kmsg return fi @@ -308,3 +309,36 @@ function check_result { cleanup_dmesg_file } + +# check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs +# path permissions +# modname - livepatch module creating the sysfs interface +# rel_path - relative path of the sysfs interface +# expected_rights - expected access rights +function check_sysfs_rights() { + local mod="$1"; shift + local rel_path="$1"; shift + local expected_rights="$1"; shift + + local path="$KLP_SYSFS_DIR/$mod/$rel_path" + local rights=$(/bin/stat --format '%A' "$path") + if test "$rights" != "$expected_rights" ; then + die "Unexpected access rights of $path: $expected_rights vs. $rights" + fi +} + +# check_sysfs_value(modname, rel_path, expected_value) - check sysfs value +# modname - livepatch module creating the sysfs interface +# rel_path - relative path of the sysfs interface +# expected_value - expected value read from the file +function check_sysfs_value() { + local mod="$1"; shift + local rel_path="$1"; shift + local expected_value="$1"; shift + + local path="$KLP_SYSFS_DIR/$mod/$rel_path" + local value=`cat $path` + if test "$value" != "$expected_value" ; then + die "Unexpected value in $path: $expected_value vs. $value" + fi +} diff --git a/tools/testing/selftests/livepatch/test-sysfs.sh b/tools/testing/selftests/livepatch/test-sysfs.sh new file mode 100755 index 000000000000..7f76f280189a --- /dev/null +++ b/tools/testing/selftests/livepatch/test-sysfs.sh @@ -0,0 +1,86 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2022 Song Liu <song@kernel.org> + +. $(dirname $0)/functions.sh + +MOD_LIVEPATCH=test_klp_livepatch + +setup_config + +# - load a livepatch and verifies the sysfs entries work as expected + +start_test "sysfs test" + +load_lp $MOD_LIVEPATCH + +check_sysfs_rights "$MOD_LIVEPATCH" "" "drwxr-xr-x" +check_sysfs_rights "$MOD_LIVEPATCH" "enabled" "-rw-r--r--" +check_sysfs_value "$MOD_LIVEPATCH" "enabled" "1" +check_sysfs_rights "$MOD_LIVEPATCH" "force" "--w-------" +check_sysfs_rights "$MOD_LIVEPATCH" "transition" "-r--r--r--" +check_sysfs_value "$MOD_LIVEPATCH" "transition" "0" +check_sysfs_rights "$MOD_LIVEPATCH" "vmlinux/patched" "-r--r--r--" +check_sysfs_value "$MOD_LIVEPATCH" "vmlinux/patched" "1" + +disable_lp $MOD_LIVEPATCH + +unload_lp $MOD_LIVEPATCH + +check_result "% modprobe $MOD_LIVEPATCH +livepatch: enabling patch '$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 +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled +livepatch: '$MOD_LIVEPATCH': initializing unpatching transition +livepatch: '$MOD_LIVEPATCH': starting unpatching transition +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +% rmmod $MOD_LIVEPATCH" + +start_test "sysfs test object/patched" + +MOD_LIVEPATCH=test_klp_callbacks_demo +MOD_TARGET=test_klp_callbacks_mod +load_lp $MOD_LIVEPATCH + +# check the "patch" file changes as target module loads/unloads +check_sysfs_value "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0" +load_mod $MOD_TARGET +check_sysfs_value "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "1" +unload_mod $MOD_TARGET +check_sysfs_value "$MOD_LIVEPATCH" "$MOD_TARGET/patched" "0" + +disable_lp $MOD_LIVEPATCH +unload_lp $MOD_LIVEPATCH + +check_result "% modprobe test_klp_callbacks_demo +livepatch: enabling patch 'test_klp_callbacks_demo' +livepatch: 'test_klp_callbacks_demo': initializing patching transition +test_klp_callbacks_demo: pre_patch_callback: vmlinux +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 +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 +test_klp_callbacks_mod: test_klp_callbacks_mod_init +% rmmod test_klp_callbacks_mod +test_klp_callbacks_mod: test_klp_callbacks_mod_exit +test_klp_callbacks_demo: pre_unpatch_callback: test_klp_callbacks_mod -> [MODULE_STATE_GOING] Going away +livepatch: reverting patch 'test_klp_callbacks_demo' on unloading module 'test_klp_callbacks_mod' +test_klp_callbacks_demo: post_unpatch_callback: test_klp_callbacks_mod -> [MODULE_STATE_GOING] Going away +% echo 0 > /sys/kernel/livepatch/test_klp_callbacks_demo/enabled +livepatch: 'test_klp_callbacks_demo': initializing unpatching transition +test_klp_callbacks_demo: pre_unpatch_callback: vmlinux +livepatch: 'test_klp_callbacks_demo': starting unpatching transition +livepatch: 'test_klp_callbacks_demo': completing unpatching transition +test_klp_callbacks_demo: post_unpatch_callback: vmlinux +livepatch: 'test_klp_callbacks_demo': unpatching complete +% rmmod test_klp_callbacks_demo" + +exit 0 |