Regressions that cause a device to no longer be probed by a driver can
have a big impact on the platform's functionality, and despite being
relatively common there isn't currently any generic test to detect them.
As an example, bootrr [1] does test for device probe, but it requires
defining the expected probed devices for each platform.
Given that the Devicetree already provides a static description of
devices on the system, it is a good basis for building such a test on
top.
This series introduces a test to catch regressions that prevent devices
from probing.
Patch 1 introduces a script to parse the kernel source using Coccinelle
and extract all compatibles that can be matched by a Devicetree node to
a driver. Patch 2 adds a kselftest that walks over the Devicetree nodes
on the current platform and compares the compatibles to the ones on the
list, and on an ignore list, to point out devices that failed to be
probed.
A compatible list is needed because not all compatibles that can show up
in a Devicetree node can be used to match to a driver, for example the
code for that compatible might use "OF_DECLARE" type macros and avoid
the driver framework, or the node might be controlled by a driver that
was bound to a different node.
An ignore list is needed for the few cases where it's common for a
driver to match a device but not probe, like for the "simple-mfd"
compatible, where the driver only probes if that compatible is the
node's first compatible.
Even though there's already scripts/dtc/dt-extract-compatibles that does
a similar job, it didn't seem to find all compatibles, returning ~3k,
while Coccinelle found ~11k. Besides that, Coccinelle actually parses
the C files, so it should be a more robust solution than relying on
regexes.
The reason for parsing the kernel source instead of relying on
information exposed by the kernel at runtime (say, looking at modaliases
or introducing some other mechanism), is to be able to catch issues
where a config was renamed or a driver moved across configs, and the
.config used by the kernel not updated accordingly. We need to parse the
source to find all compatibles present in the kernel independent of the
current config being run.
Feedback is very much welcome.
Thanks,
Nícolas
[1] https://github.com/kernelci/bootrr
Nícolas F. R. A. Prado (2):
scripts/dtc: Add script to extract matchable DT compatibles
kselftest: Add Devicetree unprobed devices test
scripts/dtc/extract-matchable-dt-compatibles | 33 +++++++++++
scripts/dtc/matchable_dt_compatibles.cocci | 58 +++++++++++++++++++
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/dt/.gitignore | 1 +
tools/testing/selftests/dt/Makefile | 17 ++++++
.../selftests/dt/compatible_ignore_list | 3 +
.../selftests/dt/test_unprobed_devices.sh | 58 +++++++++++++++++++
7 files changed, 171 insertions(+)
create mode 100755 scripts/dtc/extract-matchable-dt-compatibles
create mode 100644 scripts/dtc/matchable_dt_compatibles.cocci
create mode 100644 tools/testing/selftests/dt/.gitignore
create mode 100644 tools/testing/selftests/dt/Makefile
create mode 100644 tools/testing/selftests/dt/compatible_ignore_list
create mode 100755 tools/testing/selftests/dt/test_unprobed_devices.sh
--
2.41.0
When naively running all kselftests on some systems, it was observed
that the landlock selftest is quite picky and reports failures, even
though the system is fine.
Those two patches relax some tests to make them pass on older kernels:
- The landlock ABI version is only "3" in recent kernels, so patch 1/2
relaxes the test to accept other numbers.
- Older kernels or some defconfig based kernels might not implement
the landlock syscall at all. Patch 2/2 catches this.
I couldn't find an easy way to not check for the syscall availability in
*every* test in base_test.c, short of not using TEST_HARNESS_MAIN at all.
If someone has a better idea, I am all ears, especially as this approach
will get quite annoying in fs_base.c.
Cheers,
Andre
Andre Przywara (2):
selftests: landlock: allow other ABI versions
selftests: landlock: skip all tests without landlock syscall
tools/testing/selftests/landlock/base_test.c | 29 +++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
--
2.25.1
While building selftests landlock following warnings / errors noticed on the
Linux next with clang-17 toolchain.
Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org>
Build errors:
------------
timens/timerfd
timerfd.c:64:7: error: absolute value function 'abs' given an argument
of type 'long long' but has parameter of type 'int' which may cause
truncation of value [-Werror,-Wabsolute-value]
64 | if (abs(elapsed - 3600) > 60) {
| ^
timerfd.c:64:7: note: use function 'llabs' instead
64 | if (abs(elapsed - 3600) > 60) {
| ^~~
| llabs
1 error generated.
make[4]: Leaving directory 'selftests/timens'
Links:
- https://storage.tuxsuite.com/public/linaro/lkft/builds/2U69ue7AaypfY7eRU4UU…
Steps to reproduce:
tuxmake --runtime podman --target-arch arm64 --toolchain clang-17
--kconfig https://storage.tuxsuite.com/public/linaro/lkft/builds/2U69ue7AaypfY7eRU4UU…
LLVM=1 LLVM_IAS=1 dtbs dtbs-legacy headers kernel kselftest modules
--
Linaro LKFT
https://lkft.linaro.org
Adds a check to verify if the rtc device file is valid or not
and prints a useful error message if the file is not accessible.
Signed-off-by: Atul Kumar Pant <atulpant.linux(a)gmail.com>
---
changes since v4:
Updated the commit message.
changes since v3:
Added Linux-kselftest and Linux-kernel mailing lists.
changes since v2:
Changed error message when rtc file does not exist.
changes since v1:
Removed check for uid=0
If rtc file is invalid, then exit the test.
tools/testing/selftests/rtc/rtctest.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/rtc/rtctest.c b/tools/testing/selftests/rtc/rtctest.c
index 63ce02d1d5cc..630fef735c7e 100644
--- a/tools/testing/selftests/rtc/rtctest.c
+++ b/tools/testing/selftests/rtc/rtctest.c
@@ -17,6 +17,7 @@
#include <unistd.h>
#include "../kselftest_harness.h"
+#include "../kselftest.h"
#define NUM_UIE 3
#define ALARM_DELTA 3
@@ -419,6 +420,8 @@ __constructor_order_last(void)
int main(int argc, char **argv)
{
+ int ret = -1;
+
switch (argc) {
case 2:
rtc_file = argv[1];
@@ -430,5 +433,11 @@ int main(int argc, char **argv)
return 1;
}
- return test_harness_run(argc, argv);
+ // Run the test if rtc_file is valid
+ if (access(rtc_file, F_OK) == 0)
+ ret = test_harness_run(argc, argv);
+ else
+ ksft_exit_fail_msg("[ERROR]: Cannot access rtc file %s - Exiting\n", rtc_file);
+
+ return ret;
}
--
2.25.1
From: Rong Tao <rongtao(a)cestc.cn>
Static ksyms often have problems because the number of symbols exceeds the
MAX_SYMS limit. Like changing the MAX_SYMS from 300000 to 400000 in
commit e76a014334a6("selftests/bpf: Bump and validate MAX_SYMS") solves
the problem somewhat, but it's not the perfect way.
This commit uses dynamic memory allocation, which completely solves the
problem caused by the limitation of the number of kallsyms.
Acked-by: Stanislav Fomichev <sdf(a)google.com>
Signed-off-by: Rong Tao <rongtao(a)cestc.cn>
---
v4: Make sure most cases we don't need the realloc() path to begin with,
and check strdup() return value.
v3: https://lore.kernel.org/lkml/tencent_50B4B2622FE7546A5FF9464310650C008509@q…
Do not use structs and judge ksyms__add_symbol function return value.
v2: https://lore.kernel.org/lkml/tencent_B655EE5E5D463110D70CD2846AB3262EED09@q…
Do the usual len/capacity scheme here to amortize the cost of realloc, and
don't free symbols.
v1: https://lore.kernel.org/lkml/tencent_AB461510B10CD484E0B2F62E3754165F2909@q…
---
tools/testing/selftests/bpf/trace_helpers.c | 46 ++++++++++++++++-----
1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index f83d9f65c65b..a1461508925e 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -18,10 +18,35 @@
#define TRACEFS_PIPE "/sys/kernel/tracing/trace_pipe"
#define DEBUGFS_PIPE "/sys/kernel/debug/tracing/trace_pipe"
-#define MAX_SYMS 400000
-static struct ksym syms[MAX_SYMS];
+static struct ksym *syms;
+static int sym_cap;
static int sym_cnt;
+static int ksyms__add_symbol(const char *name, unsigned long addr)
+{
+ void *tmp;
+ unsigned int new_cap;
+
+ if (sym_cnt + 1 > sym_cap) {
+ new_cap = sym_cap * 4 / 3;
+ tmp = realloc(syms, sizeof(struct ksym) * new_cap);
+ if (!tmp)
+ return -ENOMEM;
+ syms = tmp;
+ sym_cap = new_cap;
+ }
+
+ tmp = strdup(name);
+ if (!tmp)
+ return -ENOMEM;
+ syms[sym_cnt].addr = addr;
+ syms[sym_cnt].name = tmp;
+
+ sym_cnt++;
+
+ return 0;
+}
+
static int ksym_cmp(const void *p1, const void *p2)
{
return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
@@ -33,9 +58,14 @@ int load_kallsyms_refresh(void)
char func[256], buf[256];
char symbol;
void *addr;
- int i = 0;
+ int ret;
+ /* Make sure most cases we don't need the realloc() path to begin with */
+ sym_cap = 400000;
sym_cnt = 0;
+ syms = malloc(sizeof(struct ksym) * sym_cap);
+ if (!syms)
+ return -ENOMEM;
f = fopen("/proc/kallsyms", "r");
if (!f)
@@ -46,15 +76,11 @@ int load_kallsyms_refresh(void)
break;
if (!addr)
continue;
- if (i >= MAX_SYMS)
- return -EFBIG;
-
- syms[i].addr = (long) addr;
- syms[i].name = strdup(func);
- i++;
+ ret = ksyms__add_symbol(func, (unsigned long)addr);
+ if (ret)
+ return ret;
}
fclose(f);
- sym_cnt = i;
qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
return 0;
}
--
2.39.3