- Linux-kselftest-mirror - lists.linaro.org

[PATCH] Resolve 'Unused Result' Warning from proc-empty-vm.c

by angquan yu

From: angquan yu <angquan21(a)gmail.com> In tools/testing/selftests/proc/proc-empty->because the return value of a write call was being ignored. This call was partof a conditional debugging block (if (0) { ... }), which meant it would neveractually execute. This patch removes the unused debug write call. This cleanup resolves the compi>warning about ignoring the result of write declared with the warn_unused_resultattribute. Removing this code also improves the clarity and maintainability of the function, as it eliminates a non-functional block of code. This is original warning: proc-empty-vm.c: In function ‘test_proc_pid_statm’ :proc-empty-vm.c:385:17: warning: ignoring return value of ‘write’ declared with>385 | write(1, buf, rv);| Signed-off-by: angquan yu <angquan21(a)gmail.com> --- tools/testing/selftests/proc/proc-empty-vm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c index 5e7020630..d231e61e4 100644 --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -383,8 +383,10 @@ static int test_proc_pid_statm(pid_t pid) assert(rv <= sizeof(buf)); if (0) { ssize_t written = write(1, buf, rv); + if (written == -1) { perror("write failed to /proc/${pid}"); + return EXIT_FAILURE; } } -- 2.39.2

2 years

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[PATCH AUTOSEL 6.1 14/25] selftests/bpf: fix bpf_loop_bench for new callback verification scheme

by Sasha Levin

From: Eduard Zingerman <eddyz87(a)gmail.com> [ Upstream commit f40bfd1679446b22d321e64a1fa98b7d07d2be08 ] This is a preparatory change. A follow-up patch "bpf: verify callbacks as if they are called unknown number of times" changes logic for callbacks handling. While previously callbacks were verified as a single function call, new scheme takes into account that callbacks could be executed unknown number of times. This has dire implications for bpf_loop_bench: SEC("fentry/" SYS_PREFIX "sys_getpgid") int benchmark(void *ctx) { for (int i = 0; i < 1000; i++) { bpf_loop(nr_loops, empty_callback, NULL, 0); __sync_add_and_fetch(&hits, nr_loops); } return 0; } W/o callbacks change verifier sees it as a 1000 calls to empty_callback(). However, with callbacks change things become exponential: - i=0: state exploring empty_callback is scheduled with i=0 (a); - i=1: state exploring empty_callback is scheduled with i=1; ... - i=999: state exploring empty_callback is scheduled with i=999; - state (a) is popped from stack; - i=1: state exploring empty_callback is scheduled with i=1; ... Avoid this issue by rewriting outer loop as bpf_loop(). Unfortunately, this adds a function call to a loop at runtime, which negatively affects performance: throughput latency before: 149.919 ± 0.168 M ops/s, 6.670 ns/op after : 137.040 ± 0.187 M ops/s, 7.297 ns/op Acked-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Eduard Zingerman <eddyz87(a)gmail.com> Link: https://lore.kernel.org/r/20231121020701.26440-4-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/bpf/progs/bpf_loop_bench.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/bpf_loop_bench.c b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c index 4ce76eb064c41..d461746fd3c1e 100644 --- a/tools/testing/selftests/bpf/progs/bpf_loop_bench.c +++ b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c @@ -15,13 +15,16 @@ static int empty_callback(__u32 index, void *data) return 0; } +static int outer_loop(__u32 index, void *data) +{ + bpf_loop(nr_loops, empty_callback, NULL, 0); + __sync_add_and_fetch(&hits, nr_loops); + return 0; +} + SEC("fentry/" SYS_PREFIX "sys_getpgid") int benchmark(void *ctx) { - for (int i = 0; i < 1000; i++) { - bpf_loop(nr_loops, empty_callback, NULL, 0); - - __sync_add_and_fetch(&hits, nr_loops); - } + bpf_loop(1000, outer_loop, NULL, 0); return 0; } -- 2.42.0

2 years

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[RFC PATCH v2 0/2] Add test to verify probe of devices from discoverable busses

by Nícolas F. R. A. Prado

Hi, v1 [1] was discussed during Plumbers [2], where a lot of feedback was given. I hope to justify the changes in v2 and address the feedback here. One feedback from Shuah was that keeping per-platform files with the USB/PCI devices to test as part of the kselftest tree wasn't maintainable. One proposed alternative was to generate a list of probed devices on a known-good kernel and use that as a reference. However you need someone to look at that generated reference to be able to say it is a good one, and you need to save it to ensure it will be reproducible later anyway, so that wouldn't actually solve the problem. It is a matter of hand-crafting vs generating the test definitions, but they will need to be vouched by someone and stored somewhere in both cases. So for this v2, in patch 2 I just have a sample test definition, and the per-platform test definitions would be added to a separate repository. The other feedback received was that the BIOS might reconfigure the PCI topology (at least on x86), meaning that relying on a sequence of device and function numbers (eg 1d.0/02.0/0.0) as a stable description of a device on the platform is not possible. I couldn't verify whether this is really the case (if you have any more insight into this, please let me know), but with that in mind, here in v2 I have taken a different approach. Here I'm using the device's properties which are used for driver matching (the same that show on modalias) to identify a device in a stable way. This approach has some drawbacks compared to the one on v1. For one it doesn't uniquely identify a device, so if there are multiple of the same device on a platform they have to be checked as a group. Also the test definition isn't as human-readable. I'm adding in CC the people I recognized at the Plumbers session that were interested in this work. Feel free to add anyone missing. Thanks, Nícolas [1] https://lore.kernel.org/all/20231024211818.365844-1-nfraprado@collabora.com [2] https://www.youtube.com/watch?v=oE73eVSyFXQ&t=9377s Original cover letter: This is part of an effort to improve detection of regressions impacting device probe on all platforms. The recently merged DT kselftest [3] detects probe issues for all devices described statically in the DT. That leaves out devices discovered at run-time from discoverable busses. This is where this test comes in. All of the devices that are connected through discoverable busses (ie USB and PCI), and which are internal and therefore always present, can be described in a per-platform file so they can be checked for. The test will check that the device has been instantiated and bound to a driver. Patch 1 introduces the test. Patch 2 adds the test definitions for the google,spherion machine (Acer Chromebook 514) as an example. This is the sample output from the test running on Spherion: TAP version 13 Using board file: boards/google,spherion 1..3 ok 1 usb.camera ok 2 usb.bluetooth ok 3 pci.wifi Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 [3] https://lore.kernel.org/all/20230828211424.2964562-1-nfraprado@collabora.co… Changes in v2: - Changed approach of encoding stable device reference in test file from HW topology to device match fields (the ones from modalias) - Better documented test format Nícolas F. R. A. Prado (2): kselftest: Add test to verify probe of devices from discoverable busses kselftest: devices: Add sample board file for google,spherion tools/testing/selftests/Makefile | 1 + tools/testing/selftests/devices/.gitignore | 1 + tools/testing/selftests/devices/Makefile | 8 + .../selftests/devices/boards/google,spherion | 12 ++ .../devices/test_discoverable_devices.sh | 160 ++++++++++++++++++ 5 files changed, 182 insertions(+) create mode 100644 tools/testing/selftests/devices/.gitignore create mode 100644 tools/testing/selftests/devices/Makefile create mode 100644 tools/testing/selftests/devices/boards/google,spherion create mode 100755 tools/testing/selftests/devices/test_discoverable_devices.sh -- 2.42.1

2 years

4
10
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[PATCH AUTOSEL 6.6 17/40] selftests/bpf: fix bpf_loop_bench for new callback verification scheme

by Sasha Levin

From: Eduard Zingerman <eddyz87(a)gmail.com> [ Upstream commit f40bfd1679446b22d321e64a1fa98b7d07d2be08 ] This is a preparatory change. A follow-up patch "bpf: verify callbacks as if they are called unknown number of times" changes logic for callbacks handling. While previously callbacks were verified as a single function call, new scheme takes into account that callbacks could be executed unknown number of times. This has dire implications for bpf_loop_bench: SEC("fentry/" SYS_PREFIX "sys_getpgid") int benchmark(void *ctx) { for (int i = 0; i < 1000; i++) { bpf_loop(nr_loops, empty_callback, NULL, 0); __sync_add_and_fetch(&hits, nr_loops); } return 0; } W/o callbacks change verifier sees it as a 1000 calls to empty_callback(). However, with callbacks change things become exponential: - i=0: state exploring empty_callback is scheduled with i=0 (a); - i=1: state exploring empty_callback is scheduled with i=1; ... - i=999: state exploring empty_callback is scheduled with i=999; - state (a) is popped from stack; - i=1: state exploring empty_callback is scheduled with i=1; ... Avoid this issue by rewriting outer loop as bpf_loop(). Unfortunately, this adds a function call to a loop at runtime, which negatively affects performance: throughput latency before: 149.919 ± 0.168 M ops/s, 6.670 ns/op after : 137.040 ± 0.187 M ops/s, 7.297 ns/op Acked-by: Andrii Nakryiko <andrii(a)kernel.org> Signed-off-by: Eduard Zingerman <eddyz87(a)gmail.com> Link: https://lore.kernel.org/r/20231121020701.26440-4-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/bpf/progs/bpf_loop_bench.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/bpf_loop_bench.c b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c index 4ce76eb064c41..d461746fd3c1e 100644 --- a/tools/testing/selftests/bpf/progs/bpf_loop_bench.c +++ b/tools/testing/selftests/bpf/progs/bpf_loop_bench.c @@ -15,13 +15,16 @@ static int empty_callback(__u32 index, void *data) return 0; } +static int outer_loop(__u32 index, void *data) +{ + bpf_loop(nr_loops, empty_callback, NULL, 0); + __sync_add_and_fetch(&hits, nr_loops); + return 0; +} + SEC("fentry/" SYS_PREFIX "sys_getpgid") int benchmark(void *ctx) { - for (int i = 0; i < 1000; i++) { - bpf_loop(nr_loops, empty_callback, NULL, 0); - - __sync_add_and_fetch(&hits, nr_loops); - } + bpf_loop(1000, outer_loop, NULL, 0); return 0; } -- 2.42.0

2 years

1
0
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[PATCH] Fix Format String Warning in breakpoint_test

by angquan yu

From: angquan yu <angquan21(a)gmail.com> This commit resolves a compiler warning regardingthe use of non-literal format strings in breakpoint_test.c. The functions `ksft_test_result_pass` and `ksft_test_result_fail` were previously called with a variable `msg` directly, which could potentially lead to format string vulnerabilities. Changes made: - Modified the calls to `ksft_test_result_pass` and `ksft_test_result_fail` by adding a "%s" format specifier. This explicitly declares `msg` as a string argument, adhering to safer coding practices and resolving the compiler warning. This change does not affect the functional behavior of the code but ensures better code safety and compliance with recommended C programming standards. The previous warning is "breakpoint_test.c:287:17: warning: format not a string literal and no format arguments [-Wformat-security] 287 | ksft_test_result_pass(msg); | ^~~~~~~~~~~~~~~~~~~~~ breakpoint_test.c:289:17: warning: format not a string literal and no format arguments [-Wformat-security] 289 | ksft_test_result_fail(msg); | " Signed-off-by: angquan yu <angquan21(a)gmail.com> --- tools/testing/selftests/breakpoints/breakpoint_test.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/breakpoints/breakpoint_test.c b/tools/testing/selftests/breakpoints/breakpoint_test.c index 3266cc929..d46962a24 100644 --- a/tools/testing/selftests/breakpoints/breakpoint_test.c +++ b/tools/testing/selftests/breakpoints/breakpoint_test.c @@ -284,9 +284,9 @@ static void check_success(const char *msg) nr_tests++; if (ret) - ksft_test_result_pass(msg); + ksft_test_result_pass("%s", msg); else - ksft_test_result_fail(msg); + ksft_test_result_fail("%s", msg); } static void launch_instruction_breakpoints(char *buf, int local, int global) -- 2.39.2

2 years

1
0
0 0

[PATCH] cgroup/cpuset: Expose cpuset.cpus.isolated

by Waiman Long

The root-only cpuset.cpus.isolated control file shows the current set of isolated CPUs in isolated partitions. This control file is currently exposed only with the cgroup_debug boot command line option which also adds the ".__DEBUG__." prefix. This is actually a useful control file if users want to find out which CPUs are currently in an isolated state by the cpuset controller. Remove CFTYPE_DEBUG flag for this control file and make it available by default without any prefix. The test_cpuset_prs.sh test script and the cgroup-v2.rst documentation file are also updated accordingly. Minor code change is also made in test_cpuset_prs.sh to avoid false test failure when running on debug kernel. Signed-off-by: Waiman Long <longman(a)redhat.com> --- Documentation/admin-guide/cgroup-v2.rst | 7 ++++ kernel/cgroup/cpuset.c | 2 +- .../selftests/cgroup/test_cpuset_prs.sh | 32 +++++++++++-------- 3 files changed, 26 insertions(+), 15 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index cf5651a11df8..30f6ff2eba47 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2316,6 +2316,13 @@ Cpuset Interface Files treated to have an implicit value of "cpuset.cpus" in the formation of local partition. + cpuset.cpus.isolated + A read-only and root cgroup only multiple values file. + + This file shows the set of all isolated CPUs used in existing + isolated partitions. It will be empty if no isolated partition + is created. + cpuset.cpus.partition A read-write single value file which exists on non-root cpuset-enabled cgroups. This flag is owned by the parent cgroup diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 1bad4007ff4b..2a16df86c55c 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3974,7 +3974,7 @@ static struct cftype dfl_files[] = { .name = "cpus.isolated", .seq_show = cpuset_common_seq_show, .private = FILE_ISOLATED_CPULIST, - .flags = CFTYPE_ONLY_ON_ROOT | CFTYPE_DEBUG, + .flags = CFTYPE_ONLY_ON_ROOT, }, { } /* terminate */ diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index 7b7c4c2b6d85..b5eb1be2248c 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -508,7 +508,7 @@ dump_states() XECPUS=$DIR/cpuset.cpus.exclusive.effective PRS=$DIR/cpuset.cpus.partition PCPUS=$DIR/.__DEBUG__.cpuset.cpus.subpartitions - ISCPUS=$DIR/.__DEBUG__.cpuset.cpus.isolated + ISCPUS=$DIR/cpuset.cpus.isolated [[ -e $CPUS ]] && echo "$CPUS: $(cat $CPUS)" [[ -e $XCPUS ]] && echo "$XCPUS: $(cat $XCPUS)" [[ -e $ECPUS ]] && echo "$ECPUS: $(cat $ECPUS)" @@ -593,17 +593,17 @@ check_cgroup_states() # # Get isolated (including offline) CPUs by looking at -# /sys/kernel/debug/sched/domains and *cpuset.cpus.isolated control file, +# /sys/kernel/debug/sched/domains and cpuset.cpus.isolated control file, # if available, and compare that with the expected value. # # Note that isolated CPUs from the sched/domains context include offline # CPUs as well as CPUs in non-isolated 1-CPU partition. Those CPUs may -# not be included in the *cpuset.cpus.isolated control file which contains +# not be included in the cpuset.cpus.isolated control file which contains # only CPUs in isolated partitions. # # $1 - expected isolated cpu list(s) <isolcpus1>{,<isolcpus2>} # <isolcpus1> - expected sched/domains value -# <isolcpus2> - *cpuset.cpus.isolated value = <isolcpus1> if not defined +# <isolcpus2> - cpuset.cpus.isolated value = <isolcpus1> if not defined # check_isolcpus() { @@ -611,7 +611,7 @@ check_isolcpus() ISOLCPUS= LASTISOLCPU= SCHED_DOMAINS=/sys/kernel/debug/sched/domains - ISCPUS=${CGROUP2}/.__DEBUG__.cpuset.cpus.isolated + ISCPUS=${CGROUP2}/cpuset.cpus.isolated if [[ $EXPECT_VAL = . ]] then EXPECT_VAL= @@ -692,14 +692,18 @@ test_fail() null_isolcpus_check() { [[ $VERBOSE -gt 0 ]] || return 0 - pause 0.02 - check_isolcpus "." - if [[ $? -ne 0 ]] - then - echo "Unexpected isolated CPUs: $ISOLCPUS" - dump_states - exit 1 - fi + # Retry a few times before printing error + RETRY=0 + while [[ $RETRY -lt 5 ]] + do + pause 0.01 + check_isolcpus "." + [[ $? -eq 0 ]] && return 0 + ((RETRY++)) + done + echo "Unexpected isolated CPUs: $ISOLCPUS" + dump_states + exit 1 } # @@ -776,7 +780,7 @@ run_state_test() # NEWLIST=$(cat cpuset.cpus.effective) RETRY=0 - while [[ $NEWLIST != $CPULIST && $RETRY -lt 5 ]] + while [[ $NEWLIST != $CPULIST && $RETRY -lt 8 ]] do # Wait a bit longer & recheck a few times pause 0.01 -- 2.39.3

2 years

2
2
0 0

[PATCH ipsec-next v2 0/6] Add bpf_xdp_get_xfrm_state() kfunc

by Daniel Xu

This patchset adds two kfunc helpers, bpf_xdp_get_xfrm_state() and bpf_xdp_xfrm_state_release() that wrap xfrm_state_lookup() and xfrm_state_put(). The intent is to support software RSS (via XDP) for the ongoing/upcoming ipsec pcpu work [0]. Recent experiments performed on (hopefully) reproducible AWS testbeds indicate that single tunnel pcpu ipsec can reach line rate on 100G ENA nics. Note this patchset only tests/shows generic xfrm_state access. The "secret sauce" (if you can really even call it that) involves accessing a soon-to-be-upstreamed pcpu_num field in xfrm_state. Early example is available here [1]. [0]: https://datatracker.ietf.org/doc/draft-ietf-ipsecme-multi-sa-performance/03/ [1]: https://github.com/danobi/xdp-tools/blob/e89a1c617aba3b50d990f779357d6ce286… Changes from v1: * Move xfrm tunnel tests to test_progs * Fix writing to opts->error when opts is invalid * Use __bpf_kfunc_start_defs() * Remove unused vxlanhdr definition * Add and use BPF_CORE_WRITE_BITFIELD() macro * Make series bisect clean Changes from RFCv2: * Rebased to ipsec-next * Fix netns leak Changes from RFCv1: * Add Antony's commit tags * Add KF_ACQUIRE and KF_RELEASE semantics Daniel Xu (6): bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc bpf: xfrm: Add bpf_xdp_xfrm_state_release() kfunc libbpf: Add BPF_CORE_WRITE_BITFIELD() macro bpf: selftests: test_tunnel: Use vmlinux.h declarations bpf: selftests: Move xfrm tunnel test to test_progs bpf: xfrm: Add selftest for bpf_xdp_get_xfrm_state() include/net/xfrm.h | 9 + net/xfrm/Makefile | 1 + net/xfrm/xfrm_policy.c | 2 + net/xfrm/xfrm_state_bpf.c | 128 +++++++++++++++ tools/lib/bpf/bpf_core_read.h | 36 ++++ .../selftests/bpf/prog_tests/test_tunnel.c | 155 ++++++++++++++++++ .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../selftests/bpf/progs/test_tunnel_kern.c | 138 +++++++++------- tools/testing/selftests/bpf/test_tunnel.sh | 92 ----------- 9 files changed, 412 insertions(+), 150 deletions(-) create mode 100644 net/xfrm/xfrm_state_bpf.c -- 2.42.1

2 years

1
3
0 0

[PATCH ipsec-next v1 0/7] Add bpf_xdp_get_xfrm_state() kfunc

by Daniel Xu

This patchset adds two kfunc helpers, bpf_xdp_get_xfrm_state() and bpf_xdp_xfrm_state_release() that wrap xfrm_state_lookup() and xfrm_state_put(). The intent is to support software RSS (via XDP) for the ongoing/upcoming ipsec pcpu work [0]. Recent experiments performed on (hopefully) reproducible AWS testbeds indicate that single tunnel pcpu ipsec can reach line rate on 100G ENA nics. Note this patchset only tests/shows generic xfrm_state access. The "secret sauce" (if you can really even call it that) involves accessing a soon-to-be-upstreamed pcpu_num field in xfrm_state. Early example is available here [1]. [0]: https://datatracker.ietf.org/doc/draft-ietf-ipsecme-multi-sa-performance/03/ [1]: https://github.com/danobi/xdp-tools/blob/e89a1c617aba3b50d990f779357d6ce286… Changes from RFCv2: * Rebased to ipsec-next * Fix netns leak Changes from RFCv1: * Add Antony's commit tags * Add KF_ACQUIRE and KF_RELEASE semantics Daniel Xu (7): bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc bpf: xfrm: Add bpf_xdp_xfrm_state_release() kfunc bpf: selftests: test_tunnel: Use ping -6 over ping6 bpf: selftests: test_tunnel: Mount bpffs if necessary bpf: selftests: test_tunnel: Use vmlinux.h declarations bpf: selftests: test_tunnel: Disable CO-RE relocations bpf: xfrm: Add selftest for bpf_xdp_get_xfrm_state() include/net/xfrm.h | 9 ++ net/xfrm/Makefile | 1 + net/xfrm/xfrm_policy.c | 2 + net/xfrm/xfrm_state_bpf.c | 127 ++++++++++++++++++ .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../selftests/bpf/progs/test_tunnel_kern.c | 98 ++++++++------ tools/testing/selftests/bpf/test_tunnel.sh | 43 ++++-- 7 files changed, 227 insertions(+), 54 deletions(-) create mode 100644 net/xfrm/xfrm_state_bpf.c -- 2.42.1

2 years

5
27
0 0

[RFC] drm/tests: annotate intentional stack trace in drm_test_rect_calc_hscale()

by Dan Carpenter

We have started printing more and more intentional stack traces. Whether it's testing KASAN is able to detect use after frees or it's part of a kunit test. These stack traces can be problematic. They suddenly show up as a new failure. Now the test team has to contact the developers. A bunch of people have to investigate the bug. We finally decide that it's intentional so now the test team has to update their filter scripts to mark it as intentional. These filters are ad-hoc because there is no standard format for warnings. A better way would be to mark it as intentional from the start. Here, I have marked the beginning and the end of the trace. It's more tricky for things like lkdtm_FORTIFY_MEM_MEMBER() where the flow doesn't reach the end of the function. I guess I would print a different warning for stack traces that can't have a "Intentional warning finished\n" message at the end. I haven't actually tested this patch... Daniel, do you have a list of intentional stack traces we could annotate? Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> --- drivers/gpu/drm/tests/drm_rect_test.c | 2 ++ include/kunit/test.h | 3 +++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c index 76332cd2ead8..367738254493 100644 --- a/drivers/gpu/drm/tests/drm_rect_test.c +++ b/drivers/gpu/drm/tests/drm_rect_test.c @@ -409,8 +409,10 @@ static void drm_test_rect_calc_hscale(struct kunit *test) const struct drm_rect_scale_case *params = test->param_value; int scaling_factor; + START_INTENTIONAL_WARNING(); scaling_factor = drm_rect_calc_hscale(&params->src, &params->dst, params->min_range, params->max_range); + END_INTENTIONAL_WARNING(); KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor); } diff --git a/include/kunit/test.h b/include/kunit/test.h index 20ed9f9275c9..1f01d4c81055 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -337,6 +337,9 @@ void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites); void kunit_exec_run_tests(struct kunit_suite_set *suite_set, bool builtin); void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr); +#define START_INTENTIONAL_WARNING() pr_info("Triggering a stack trace\n") +#define END_INTENTIONAL_WARNING() pr_info("Intentional warning finished\n") + #if IS_BUILTIN(CONFIG_KUNIT) int kunit_run_all_tests(void); #else -- 2.42.0

2 years

4
5
0 0

[PATCH v2 1/3] kunit: Add a macro to wrap a deferred action function

by David Gow

KUnit's deferred action API accepts a void(*)(void *) function pointer which is called when the test is exited. However, we very frequently want to use existing functions which accept a single pointer, but which may not be of type void*. While this is probably dodgy enough to be on the wrong side of the C standard, it's been often used for similar callbacks, and gcc's -Wcast-function-type seems to ignore cases where the only difference is the type of the argument, assuming it's compatible (i.e., they're both pointers to data). However, clang 16 has introduced -Wcast-function-type-strict, which no longer permits any deviation in function pointer type. This seems to be because it'd break CFI, which validates the type of function calls. This rather ruins our attempts to cast functions to defer them, and leaves us with a few options. The one we've chosen is to implement a macro which will generate a wrapper function which accepts a void*, and casts the argument to the appropriate type. For example, if you were trying to wrap: void foo_close(struct foo *handle); you could use: KUNIT_DEFINE_ACTION_WRAPPER(kunit_action_foo_close, foo_close, struct foo *); This would create a new kunit_action_foo_close() function, of type kunit_action_t, which could be passed into kunit_add_action() and similar functions. In addition to defining this macro, update KUnit and its tests to use it. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reviewed-by: Nathan Chancellor <nathan(a)kernel.org> Tested-by: Nathan Chancellor <nathan(a)kernel.org> Acked-by: Daniel Vetter <daniel(a)ffwll.ch> Reviewed-by: Maxime Ripard <mripard(a)kernel.org> Signed-off-by: David Gow <davidgow(a)google.com> --- Thanks everyone for testing v1 of this: this update only changes documentation. Changes since v1: https://lore.kernel.org/linux-kselftest/20231110200830.1832556-1-davidgow@g… - Update the usage.rst documentation (Thanks, Nathan) - Add a better doc comment for KUNIT_DEFINE_ACTION_WRAPPER() --- Documentation/dev-tools/kunit/usage.rst | 10 +++++++--- include/kunit/resource.h | 21 +++++++++++++++++++++ lib/kunit/kunit-test.c | 5 +---- lib/kunit/test.c | 6 ++++-- 4 files changed, 33 insertions(+), 9 deletions(-) diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst index c27e1646ecd9..9db12e91668e 100644 --- a/Documentation/dev-tools/kunit/usage.rst +++ b/Documentation/dev-tools/kunit/usage.rst @@ -651,12 +651,16 @@ For example: } Note that, for functions like device_unregister which only accept a single -pointer-sized argument, it's possible to directly cast that function to -a ``kunit_action_t`` rather than writing a wrapper function, for example: +pointer-sized argument, it's possible to automatically generate a wrapper +with the ``KUNIT_DEFINE_ACTION_WRAPPER()`` macro, for example: .. code-block:: C - kunit_add_action(test, (kunit_action_t *)&device_unregister, &dev); + KUNIT_DEFINE_ACTION_WRAPPER(device_unregister, device_unregister_wrapper, struct device *); + kunit_add_action(test, &device_unregister_wrapper, &dev); + +You should do this in preference to manually casting to the ``kunit_action_t`` type, +as casting function pointers will break Control Flow Integrity (CFI). ``kunit_add_action`` can fail if, for example, the system is out of memory. You can use ``kunit_add_action_or_reset`` instead which runs the action diff --git a/include/kunit/resource.h b/include/kunit/resource.h index c7383e90f5c9..4ad69a2642a5 100644 --- a/include/kunit/resource.h +++ b/include/kunit/resource.h @@ -390,6 +390,27 @@ void kunit_remove_resource(struct kunit *test, struct kunit_resource *res); /* A 'deferred action' function to be used with kunit_add_action. */ typedef void (kunit_action_t)(void *); +/** + * KUNIT_DEFINE_ACTION_WRAPPER() - Wrap a function for use as a deferred action. + * + * @wrapper: The name of the new wrapper function define. + * @orig: The original function to wrap. + * @arg_type: The type of the argument accepted by @orig. + * + * Defines a wrapper for a function which accepts a single, pointer-sized + * argument. This wrapper can then be passed to kunit_add_action() and + * similar. This should be used in preference to casting a function + * directly to kunit_action_t, as casting function pointers will break + * control flow integrity (CFI), leading to crashes. + */ +#define KUNIT_DEFINE_ACTION_WRAPPER(wrapper, orig, arg_type) \ + static void wrapper(void *in) \ + { \ + arg_type arg = (arg_type)in; \ + orig(arg); \ + } + + /** * kunit_add_action() - Call a function when the test ends. * @test: Test case to associate the action with. diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index 99d2a3a528e1..3e9c5192d095 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -538,10 +538,7 @@ static struct kunit_suite kunit_resource_test_suite = { #if IS_BUILTIN(CONFIG_KUNIT_TEST) /* This avoids a cast warning if kfree() is passed direct to kunit_add_action(). */ -static void kfree_wrapper(void *p) -{ - kfree(p); -} +KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *); static void kunit_log_test(struct kunit *test) { diff --git a/lib/kunit/test.c b/lib/kunit/test.c index f2eb71f1a66c..0308865194bb 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -772,6 +772,8 @@ static struct notifier_block kunit_mod_nb = { }; #endif +KUNIT_DEFINE_ACTION_WRAPPER(kfree_action_wrapper, kfree, const void *) + void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp) { void *data; @@ -781,7 +783,7 @@ void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp) if (!data) return NULL; - if (kunit_add_action_or_reset(test, (kunit_action_t *)kfree, data) != 0) + if (kunit_add_action_or_reset(test, kfree_action_wrapper, data) != 0) return NULL; return data; @@ -793,7 +795,7 @@ void kunit_kfree(struct kunit *test, const void *ptr) if (!ptr) return; - kunit_release_action(test, (kunit_action_t *)kfree, (void *)ptr); + kunit_release_action(test, kfree_action_wrapper, (void *)ptr); } EXPORT_SYMBOL_GPL(kunit_kfree); -- 2.43.0.rc1.413.gea7ed67945-goog

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