Add a simple klp-convert livepatch selftest that exercises various symbol homonym sympos scenarios. Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx> --- lib/livepatch/Makefile | 10 ++ lib/livepatch/test_klp_convert1.c | 106 ++++++++++++++++++ lib/livepatch/test_klp_convert2.c | 103 +++++++++++++++++ lib/livepatch/test_klp_convert_mod_a.c | 25 +++++ lib/livepatch/test_klp_convert_mod_b.c | 13 +++ .../selftests/livepatch/test-livepatch.sh | 64 +++++++++++ 6 files changed, 321 insertions(+) create mode 100644 lib/livepatch/test_klp_convert1.c create mode 100644 lib/livepatch/test_klp_convert2.c create mode 100644 lib/livepatch/test_klp_convert_mod_a.c create mode 100644 lib/livepatch/test_klp_convert_mod_b.c diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile index 513d200b7942..b19253c72d72 100644 --- a/lib/livepatch/Makefile +++ b/lib/livepatch/Makefile @@ -5,6 +5,8 @@ LIVEPATCH_test_klp_atomic_replace := y LIVEPATCH_test_klp_callbacks_demo := y LIVEPATCH_test_klp_callbacks_demo2 := y +LIVEPATCH_test_klp_convert1 := y +LIVEPATCH_test_klp_convert2 := y LIVEPATCH_test_klp_livepatch := y obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \ @@ -12,9 +14,17 @@ obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \ test_klp_callbacks_demo2.o \ test_klp_callbacks_busy.o \ test_klp_callbacks_mod.o \ + test_klp_convert1.o \ + test_klp_convert2.o \ + test_klp_convert_mod.o \ test_klp_livepatch.o \ test_klp_shadow_vars.o +test_klp_convert_mod-y := \ + test_klp_convert_mod_a.o \ + test_klp_convert_mod_b.o + # Target modules to be livepatched require CC_FLAGS_FTRACE CFLAGS_test_klp_callbacks_busy.o += $(CC_FLAGS_FTRACE) CFLAGS_test_klp_callbacks_mod.o += $(CC_FLAGS_FTRACE) +CFLAGS_test_klp_convert_mod.o += $(CC_FLAGS_FTRACE) diff --git a/lib/livepatch/test_klp_convert1.c b/lib/livepatch/test_klp_convert1.c new file mode 100644 index 000000000000..a359f69a8fdc --- /dev/null +++ b/lib/livepatch/test_klp_convert1.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2019 Joe Lawrence <joe.lawrence@xxxxxxxxxx> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/livepatch.h> + +/* klp-convert symbols - vmlinux */ +extern char *saved_command_line; +/* klp-convert symbols - test_klp_convert_mod.ko */ +extern char driver_name[]; +extern char homonym_string[]; +extern const char *get_homonym_string(void); +extern const char *get_driver_name(void); + +void print_saved_command_line(void) +{ + pr_info("saved_command_line, 0: %s\n", saved_command_line); +} + +void print_driver_name(void) +{ + pr_info("driver_name, 0: %s\n", driver_name); + pr_info("get_driver_name(), 0: %s\n", get_driver_name()); +} + +void print_homonym_string(void) +{ + pr_info("homonym_string, 1: %s\n", homonym_string); + pr_info("get_homonym_string(), 1: %s\n", get_homonym_string()); +} + +/* + * saved_command_line is a unique symbol, so the sympos annotation is + * optional. Provide to test that sympos=0 works correctly. + */ +KLP_MODULE_RELOC(vmlinux) vmlinux_relocs[] = { + KLP_SYMPOS(saved_command_line, 0) +}; + +/* + * driver_name symbols can be found in vmlinux (multiple) and also + * test_klp_convert_mod, therefore the annotation is required to + * clarify that we want the one from test_klp_convert_mod. + * + * test_klp_convert_mod contains multiple homonym_string and + * get_homonym_string symbols, test resolving the first set here and + * the others in test_klp_convert2.c + * + * get_driver_name is a uniquely named symbol, test that sympos=0 + * work correctly. + */ +KLP_MODULE_RELOC(test_klp_convert_mod) test_klp_convert_mod_relocs_a[] = { + KLP_SYMPOS(driver_name, 0), + KLP_SYMPOS(homonym_string, 1), + KLP_SYMPOS(get_homonym_string, 1), + KLP_SYMPOS(get_driver_name, 0), +}; + +static struct klp_func funcs[] = { + { + }, { } +}; + +static struct klp_object objs[] = { + { + /* name being NULL means vmlinux */ + .funcs = funcs, + }, + { + .name = "test_klp_convert_mod", + .funcs = funcs, + }, { } +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int test_klp_convert_init(void) +{ + int ret; + + ret = klp_enable_patch(&patch); + if (ret) + return ret; + + print_saved_command_line(); + print_driver_name(); + print_homonym_string(); + + return 0; +} + +static void test_klp_convert_exit(void) +{ +} + +module_init(test_klp_convert_init); +module_exit(test_klp_convert_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joe Lawrence <joe.lawrence@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Livepatch test: klp-convert1"); diff --git a/lib/livepatch/test_klp_convert2.c b/lib/livepatch/test_klp_convert2.c new file mode 100644 index 000000000000..7be9b2184fe1 --- /dev/null +++ b/lib/livepatch/test_klp_convert2.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2019 Joe Lawrence <joe.lawrence@xxxxxxxxxx> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/livepatch.h> + +/* klp-convert symbols - vmlinux */ +extern char *saved_command_line; +/* klp-convert symbols - test_klp_convert_mod.ko */ +extern char driver_name[]; +extern char homonym_string[]; +extern const char *get_homonym_string(void); +extern const char *get_driver_name(void); + +void print_saved_command_line(void) +{ + pr_info("saved_command_line (auto): %s\n", saved_command_line); +} + +void print_driver_name(void) +{ + pr_info("driver_name, 0: %s\n", driver_name); + pr_info("get_driver_name(), (auto): %s\n", get_driver_name()); +} + +void print_homonym_string(void) +{ + pr_info("homonym_string, 2: %s\n", homonym_string); + pr_info("get_homonym_string(), 2: %s\n", get_homonym_string()); +} + +/* + * saved_command_line is a uniquely named symbol, so the sympos + * annotation is optional. Skip it and test that klp-convert can + * resolve the symbol on its own. + */ + +/* + * driver_name symbols can be found in vmlinux (multiple) and also + * test_klp_convert_mod, therefore the annotation is required to + * clarify that we want the one from test_klp_convert_mod. + * + * test_klp_convert_mod contains multiple homonym_string symbols, + * test_klp_convert1.c resolved to the first one, resolve to the + * second one here. + * + * get_driver_name is a uniquely named symbol, test klp-convert can + * resolve it automatically. + */ +KLP_MODULE_RELOC(test_klp_convert_mod) test_klp_convert_mod_relocs_a[] = { + KLP_SYMPOS(driver_name, 0), + KLP_SYMPOS(homonym_string, 2), + KLP_SYMPOS(get_homonym_string, 2), +}; + +static struct klp_func funcs[] = { + { + }, { } +}; + +static struct klp_object objs[] = { + { + /* name being NULL means vmlinux */ + .funcs = funcs, + }, + { + .name = "test_klp_convert_mod", + .funcs = funcs, + }, { } +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int test_klp_convert_init(void) +{ + int ret; + + ret = klp_enable_patch(&patch); + if (ret) + return ret; + + print_saved_command_line(); + print_driver_name(); + print_homonym_string(); + + return 0; +} + +static void test_klp_convert_exit(void) +{ +} + +module_init(test_klp_convert_init); +module_exit(test_klp_convert_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joe Lawrence <joe.lawrence@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Livepatch test: klp-convert2"); diff --git a/lib/livepatch/test_klp_convert_mod_a.c b/lib/livepatch/test_klp_convert_mod_a.c new file mode 100644 index 000000000000..b2db9942fbd2 --- /dev/null +++ b/lib/livepatch/test_klp_convert_mod_a.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2019 Joe Lawrence <joe.lawrence@xxxxxxxxxx> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> + +/* Unique symbols that don't need sympos annotation */ +static const char driver_name[] = KBUILD_MODNAME; +__used static const char *get_driver_name(void) +{ + return driver_name; +} + +/* Common symbol names that need sympos */ +static const char homonym_string[] = "homonym string A"; +__used static const char *get_homonym_string(void) +{ + return homonym_string; +} + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joe Lawrence <joe.lawrence@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Livepatch test: klp-convert module"); diff --git a/lib/livepatch/test_klp_convert_mod_b.c b/lib/livepatch/test_klp_convert_mod_b.c new file mode 100644 index 000000000000..a3d529ff5f1f --- /dev/null +++ b/lib/livepatch/test_klp_convert_mod_b.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2019 Joe Lawrence <joe.lawrence@xxxxxxxxxx> + +/* + * A second compilation unit to provide another set of similarly named + * symbols, forcing a livepatch to use sympos annotations. + */ + +static char homonym_string[] = "homonym string B"; +__used static char *get_homonym_string(void) +{ + return homonym_string; +} diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh index f05268aea859..9c3745e8ba1d 100755 --- a/tools/testing/selftests/livepatch/test-livepatch.sh +++ b/tools/testing/selftests/livepatch/test-livepatch.sh @@ -6,6 +6,9 @@ MOD_LIVEPATCH=test_klp_livepatch MOD_REPLACE=test_klp_atomic_replace +MOD_KLP_CONVERT_MOD=test_klp_convert_mod +MOD_KLP_CONVERT1=test_klp_convert1 +MOD_KLP_CONVERT2=test_klp_convert2 set_dynamic_debug @@ -165,4 +168,65 @@ livepatch: '$MOD_REPLACE': unpatching complete % rmmod $MOD_REPLACE" +# TEST: klp-convert symbols +# - load a livepatch that modifies the output from /proc/cmdline +# including a reference to vmlinux-local symbol that klp-convert +# will process +# - verify correct behavior +# - unload the livepatch and make sure the patch was removed + +echo -n "TEST: klp-convert symbols ... " +dmesg -C + +saved_cmdline=$(cat /proc/cmdline) + +load_mod $MOD_KLP_CONVERT_MOD + +load_lp $MOD_KLP_CONVERT1 +disable_lp $MOD_KLP_CONVERT1 +unload_lp $MOD_KLP_CONVERT1 + +load_lp $MOD_KLP_CONVERT2 +disable_lp $MOD_KLP_CONVERT2 +unload_lp $MOD_KLP_CONVERT2 + +unload_mod $MOD_KLP_CONVERT_MOD + +check_result "% modprobe $MOD_KLP_CONVERT_MOD +% modprobe $MOD_KLP_CONVERT1 +livepatch: enabling patch '$MOD_KLP_CONVERT1' +livepatch: '$MOD_KLP_CONVERT1': initializing patching transition +livepatch: '$MOD_KLP_CONVERT1': starting patching transition +$MOD_KLP_CONVERT1: saved_command_line, 0: $saved_cmdline +$MOD_KLP_CONVERT1: driver_name, 0: $MOD_KLP_CONVERT_MOD +$MOD_KLP_CONVERT1: get_driver_name(), 0: $MOD_KLP_CONVERT_MOD +$MOD_KLP_CONVERT1: homonym_string, 1: homonym string A +$MOD_KLP_CONVERT1: get_homonym_string(), 1: homonym string A +livepatch: '$MOD_KLP_CONVERT1': completing patching transition +livepatch: '$MOD_KLP_CONVERT1': patching complete +% echo 0 > /sys/kernel/livepatch/$MOD_KLP_CONVERT1/enabled +livepatch: '$MOD_KLP_CONVERT1': initializing unpatching transition +livepatch: '$MOD_KLP_CONVERT1': starting unpatching transition +livepatch: '$MOD_KLP_CONVERT1': completing unpatching transition +livepatch: '$MOD_KLP_CONVERT1': unpatching complete +% rmmod $MOD_KLP_CONVERT1 +% modprobe $MOD_KLP_CONVERT2 +livepatch: enabling patch '$MOD_KLP_CONVERT2' +livepatch: '$MOD_KLP_CONVERT2': initializing patching transition +livepatch: '$MOD_KLP_CONVERT2': starting patching transition +$MOD_KLP_CONVERT2: saved_command_line (auto): $saved_cmdline +$MOD_KLP_CONVERT2: driver_name, 0: $MOD_KLP_CONVERT_MOD +$MOD_KLP_CONVERT2: get_driver_name(), (auto): $MOD_KLP_CONVERT_MOD +$MOD_KLP_CONVERT2: homonym_string, 2: homonym string B +$MOD_KLP_CONVERT2: get_homonym_string(), 2: homonym string B +livepatch: '$MOD_KLP_CONVERT2': completing patching transition +livepatch: '$MOD_KLP_CONVERT2': patching complete +% echo 0 > /sys/kernel/livepatch/$MOD_KLP_CONVERT2/enabled +livepatch: '$MOD_KLP_CONVERT2': initializing unpatching transition +livepatch: '$MOD_KLP_CONVERT2': starting unpatching transition +livepatch: '$MOD_KLP_CONVERT2': completing unpatching transition +livepatch: '$MOD_KLP_CONVERT2': unpatching complete +% rmmod $MOD_KLP_CONVERT2 +% rmmod $MOD_KLP_CONVERT_MOD" + exit 0 -- 2.20.1