[PATCH v9 9/9] selftests/livepatch: Add function test for provides/obsoletes

Live Patching
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From: Yafang Shao <laoar.shao@gmail.com>
To: jpoimboe@kernel.org, jikos@kernel.org, mbenes@suse.cz,
	pmladek@suse.com, joe.lawrence@redhat.com, song@kernel.org
Cc: live-patching@vger.kernel.org, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v9 9/9] selftests/livepatch: Add function test for provides/obsoletes
Date: Sun, 13 Sep 2026 10:42:28 +0800	[thread overview]
Message-ID: <20260913024228.72317-10-laoar.shao@gmail.com> (raw)
In-Reply-To: <20260913024228.72317-1-laoar.shao@gmail.com>

Livepatches with different provides ids must not modify the same
function, unless they share the same provides id or the second
livepatch obsoletes the first one.

Add test scenarios that verify this rule on the combination of
patched functions and provides ids.

These tests are skipped on kernels that still support the legacy
"replace" attribute.

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 .../livepatch/test-provides-obsoletes.sh      | 188 ++++++++++++++++++
 .../selftests/livepatch/test_modules/Makefile |   1 +
 .../test_modules/test_klp_meminfo_lp2.c       |   1 +
 3 files changed, 190 insertions(+)
 create mode 100644 tools/testing/selftests/livepatch/test_modules/test_klp_meminfo_lp2.c

diff --git a/tools/testing/selftests/livepatch/test-provides-obsoletes.sh b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
index f2d23914b7d3..4c635492b341 100755
--- a/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
+++ b/tools/testing/selftests/livepatch/test-provides-obsoletes.sh
@@ -5,6 +5,7 @@
 . $(dirname $0)/functions.sh
 
 MOD_MEMINFO=test_klp_meminfo_lp
+MOD_MEMINFO2=test_klp_meminfo_lp2
 MOD_CMDLINE=test_klp_cmdline_lp
 MOD_STATE=test_klp_state
 MOD_STATE2=test_klp_state2
@@ -452,4 +453,191 @@ $MOD_STATE: free_loglevel_state: freeing space for the stored console_loglevel
 livepatch: '$MOD_STATE': unpatching complete
 % rmmod $MOD_STATE"
 
+
+# - load two livepatches that modify the same function
+#   (meminfo_proc_show), both with provides=1. The second livepatch
+#   replaces the first one because of the same provides id, even
+#   though they share the patched function.
+# - verify that the first livepatch is gone from sysfs (replaced)
+#   and that the second one is enabled
+# - unload the replacing livepatch, then the replaced one
+
+start_test "same function, replaced by provides"
+
+load_lp $MOD_MEMINFO provides=1
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+
+load_lp $MOD_MEMINFO2 provides=1
+
+loop_until '[[ ! -e "$SYSFS_KLP_DIR/$MOD_MEMINFO" ]]' ||
+	die "failed to replace $MOD_MEMINFO"
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+
+check_sysfs_value "$MOD_MEMINFO2" "provides" "1"
+
+disable_lp $MOD_MEMINFO2
+unload_lp $MOD_MEMINFO2
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+
+unload_lp $MOD_MEMINFO
+
+check_result "% insmod test_modules/$MOD_MEMINFO.ko provides=1
+livepatch: enabling patch '$MOD_MEMINFO'
+livepatch: '$MOD_MEMINFO': initializing patching transition
+livepatch: '$MOD_MEMINFO': starting patching transition
+livepatch: '$MOD_MEMINFO': completing patching transition
+livepatch: '$MOD_MEMINFO': patching complete
+$MOD_MEMINFO: this has been live patched
+% insmod test_modules/$MOD_MEMINFO2.ko provides=1
+livepatch: enabling patch '$MOD_MEMINFO2'
+livepatch: '$MOD_MEMINFO2': initializing patching transition
+livepatch: '$MOD_MEMINFO2': starting patching transition
+livepatch: '$MOD_MEMINFO2': completing patching transition
+livepatch: '$MOD_MEMINFO2': patching complete
+$MOD_MEMINFO2: this has been live patched
+% echo 0 > $SYSFS_KLP_DIR/$MOD_MEMINFO2/enabled
+livepatch: '$MOD_MEMINFO2': initializing unpatching transition
+livepatch: '$MOD_MEMINFO2': starting unpatching transition
+livepatch: '$MOD_MEMINFO2': completing unpatching transition
+livepatch: '$MOD_MEMINFO2': unpatching complete
+% rmmod $MOD_MEMINFO2
+% rmmod $MOD_MEMINFO"
+
+
+# - load a livepatch that modifies meminfo_proc_show with provides=1,
+#   then try to load another livepatch that modifies the same
+#   function with a different provides id (provides=2).
+# - since the provides ids differ, the second livepatch would not
+#   replace the first one; the same function can not be handled by
+#   two different provides groups in parallel, so the load must fail.
+# - unload the first livepatch
+
+start_test "same function, can't be loaded in parallel"
+
+load_lp $MOD_MEMINFO provides=1
+load_failing_mod $MOD_MEMINFO2 provides=2
+
+disable_lp $MOD_MEMINFO
+unload_lp $MOD_MEMINFO
+
+check_result "% insmod test_modules/$MOD_MEMINFO.ko provides=1
+livepatch: enabling patch '$MOD_MEMINFO'
+livepatch: '$MOD_MEMINFO': initializing patching transition
+livepatch: '$MOD_MEMINFO': starting patching transition
+livepatch: '$MOD_MEMINFO': completing patching transition
+livepatch: '$MOD_MEMINFO': patching complete
+% insmod test_modules/$MOD_MEMINFO2.ko provides=2
+livepatch: Livepatch patch ($MOD_MEMINFO2) is not compatible with the already installed livepatches.
+insmod: ERROR: could not insert module test_modules/$MOD_MEMINFO2.ko: Invalid parameters
+% echo 0 > $SYSFS_KLP_DIR/$MOD_MEMINFO/enabled
+livepatch: '$MOD_MEMINFO': initializing unpatching transition
+livepatch: '$MOD_MEMINFO': starting unpatching transition
+livepatch: '$MOD_MEMINFO': completing unpatching transition
+livepatch: '$MOD_MEMINFO': unpatching complete
+% rmmod $MOD_MEMINFO"
+
+
+# - load a livepatch that modifies meminfo_proc_show with provides=1,
+#   then another livepatch with provides=1 that modifies a different
+#   function (cmdline_proc_show). The second one replaces the first
+#   one because of the same provides id.
+# - since the patched functions differ, the replacement does not need
+#   to restore the old function body; the transition only switches
+#   the ftrace nops, i.e. the atomic replace (nops) path.
+# - after the replacement /proc/meminfo is no longer patched, while
+#   /proc/cmdline is patched
+# - unload the replacing livepatch, then the replaced one
+
+start_test "different functions, atomic replace works (nops)"
+
+load_lp $MOD_MEMINFO provides=1
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+
+load_lp $MOD_CMDLINE provides=1
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+grep 'live patched' /proc/cmdline > /dev/kmsg
+
+disable_lp $MOD_CMDLINE
+unload_lp $MOD_CMDLINE
+unload_lp $MOD_MEMINFO
+
+check_result "% insmod test_modules/$MOD_MEMINFO.ko provides=1
+livepatch: enabling patch '$MOD_MEMINFO'
+livepatch: '$MOD_MEMINFO': initializing patching transition
+livepatch: '$MOD_MEMINFO': starting patching transition
+livepatch: '$MOD_MEMINFO': completing patching transition
+livepatch: '$MOD_MEMINFO': patching complete
+$MOD_MEMINFO: this has been live patched
+% insmod test_modules/$MOD_CMDLINE.ko provides=1
+livepatch: enabling patch '$MOD_CMDLINE'
+livepatch: '$MOD_CMDLINE': initializing patching transition
+livepatch: '$MOD_CMDLINE': starting patching transition
+livepatch: '$MOD_CMDLINE': completing patching transition
+livepatch: '$MOD_CMDLINE': patching complete
+$MOD_CMDLINE: this has been live patched
+% echo 0 > $SYSFS_KLP_DIR/$MOD_CMDLINE/enabled
+livepatch: '$MOD_CMDLINE': initializing unpatching transition
+livepatch: '$MOD_CMDLINE': starting unpatching transition
+livepatch: '$MOD_CMDLINE': completing unpatching transition
+livepatch: '$MOD_CMDLINE': unpatching complete
+% rmmod $MOD_CMDLINE
+% rmmod $MOD_MEMINFO"
+
+
+# - load two livepatches with different provides ids (1 and 2) that
+#   modify different functions (meminfo_proc_show and
+#   cmdline_proc_show). Neither of them replaces the other, so both
+#   livepatches must coexist.
+# - verify that both /proc/meminfo and /proc/cmdline are patched
+# - disable and unload both livepatches
+
+start_test "different functions, install in parallel"
+
+load_lp $MOD_MEMINFO provides=1
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+
+load_lp $MOD_CMDLINE provides=2
+
+grep 'live patched' /proc/meminfo > /dev/kmsg
+grep 'live patched' /proc/cmdline > /dev/kmsg
+
+disable_lp $MOD_MEMINFO
+unload_lp $MOD_MEMINFO
+disable_lp $MOD_CMDLINE
+unload_lp $MOD_CMDLINE
+
+check_result "% insmod test_modules/$MOD_MEMINFO.ko provides=1
+livepatch: enabling patch '$MOD_MEMINFO'
+livepatch: '$MOD_MEMINFO': initializing patching transition
+livepatch: '$MOD_MEMINFO': starting patching transition
+livepatch: '$MOD_MEMINFO': completing patching transition
+livepatch: '$MOD_MEMINFO': patching complete
+$MOD_MEMINFO: this has been live patched
+% insmod test_modules/$MOD_CMDLINE.ko provides=2
+livepatch: enabling patch '$MOD_CMDLINE'
+livepatch: '$MOD_CMDLINE': initializing patching transition
+livepatch: '$MOD_CMDLINE': starting patching transition
+livepatch: '$MOD_CMDLINE': completing patching transition
+livepatch: '$MOD_CMDLINE': patching complete
+$MOD_MEMINFO: this has been live patched
+$MOD_CMDLINE: this has been live patched
+% echo 0 > $SYSFS_KLP_DIR/$MOD_MEMINFO/enabled
+livepatch: '$MOD_MEMINFO': initializing unpatching transition
+livepatch: '$MOD_MEMINFO': starting unpatching transition
+livepatch: '$MOD_MEMINFO': completing unpatching transition
+livepatch: '$MOD_MEMINFO': unpatching complete
+% rmmod $MOD_MEMINFO
+% echo 0 > $SYSFS_KLP_DIR/$MOD_CMDLINE/enabled
+livepatch: '$MOD_CMDLINE': initializing unpatching transition
+livepatch: '$MOD_CMDLINE': starting unpatching transition
+livepatch: '$MOD_CMDLINE': completing unpatching transition
+livepatch: '$MOD_CMDLINE': unpatching complete
+% rmmod $MOD_CMDLINE"
+
 exit 0
diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile
index 732e0003930b..0c17754997d2 100644
--- a/tools/testing/selftests/livepatch/test_modules/Makefile
+++ b/tools/testing/selftests/livepatch/test_modules/Makefile
@@ -2,6 +2,7 @@ TESTMODS_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
 KDIR ?= /lib/modules/$(shell uname -r)/build
 
 obj-m += test_klp_meminfo_lp.o \
+	test_klp_meminfo_lp2.o \
 	test_klp_callbacks_busy.o \
 	test_klp_callbacks_demo.o \
 	test_klp_callbacks_demo2.o \
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_meminfo_lp2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_meminfo_lp2.c
new file mode 100644
index 000000000000..c82827207f10
--- /dev/null
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_meminfo_lp2.c
@@ -0,0 +1 @@
+#include "test_klp_meminfo_lp.c"
-- 
2.52.0

     prev parent reply	other threads:[~2026-09-13  2:43 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-13  2:42 [PATCH v9 0/9] livepatch: Add support for scoped atomic replace Yafang Shao
2026-09-13  2:42 ` [PATCH v9 1/9] selftests/livepatch: Clarify test module file names Yafang Shao
2026-09-13  2:42 ` [PATCH v9 2/9] selftests/livepatch: Adapt atomic replace tests to provides/obsoletes Yafang Shao
2026-09-13  2:42 ` [PATCH v9 3/9] livepatch: Make klp_find_func() non static Yafang Shao
2026-09-13  2:42 ` [PATCH v9 4/9] livepatch: Call klp_init_patch_early() earlier Yafang Shao
2026-09-13  2:55   ` sashiko-bot
2026-09-13  2:57     ` Yafang Shao
2026-09-13  2:42 ` [PATCH v9 5/9] livepatch: Implement provides and obsoletes for scoped atomic replace Yafang Shao
2026-09-13  2:42 ` [PATCH v9 6/9] livepatch: Deprecate stack_order Yafang Shao
2026-09-13  2:48   ` sashiko-bot
2026-09-13  2:55     ` Yafang Shao
2026-09-13  2:42 ` [PATCH v9 7/9] selftests/livepatch: Add provides/obsoletes test scenarios Yafang Shao
2026-09-13  2:42 ` [PATCH v9 8/9] selftests/livepatch: Add state test for provides/obsoletes Yafang Shao
2026-09-13  2:42 ` Yafang Shao [this message]

find likely ancestor, descendant, or conflicting patches for this message:
( dfblob:f2d23914b7d dfblob:4c635492b34 dfblob:732e0003930
dfblob:0c17754997d dfblob:c82827207f1 )
 OR (
bs:"[PATCH v9 9/9] selftests/livepatch: Add function test for provides/obsoletes" )
	(help)

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