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2024-10-08selftests: vDSO: Explicitly include sched.hYu Liao
The previous commit introduced the use of CLONE_NEWTIME without including <sched.h> which contains its definition. Add an explicit include of <sched.h> to ensure that CLONE_NEWTIME is correctly defined before it is used. Fixes: 2aec90036dcd ("selftests: vDSO: ensure vgetrandom works in a time namespace") Signed-off-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-10-08selftests: vDSO: improve getrandom and chacha error messagesJason A. Donenfeld
Improve the error and skip condition messages to let the developer know precisely where a test has failed. Also make better use of the ksft api for this. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-10-08selftests: vDSO: unconditionally build getrandom testJason A. Donenfeld
Rather than building on supported archs, build on all archs, and then use the presence of the symbol in the vDSO to either skip the test or move forward with it. Note that this means that this test no longer checks whether the symbol was correctly added to the kernel. But hopefully this will be clear enough to developers and we'll cross our fingers that symbols aren't removed by accident and not caught after this change. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-10-01selftests: vDSO: align getrandom states to cache lineJason A. Donenfeld
This prevents false sharing, which makes a large difference on machines with several NUMA nodes, such as on a dual socket Intel(R) Xeon(R) Gold 6338 CPU @ 2.00GHz, where the "bench-multi" test goes from 2.7s down to 1.9s. While this is just test code, it also forms the basis of how folks will wind up implementing this in libraries, so we should implement this simple cache alignment improvement here. Suggested-by: Florian Weimer <fweimer@redhat.com> Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-09-13selftests: vDSO: ensure vgetrandom works in a time namespaceJason A. Donenfeld
After verifying that vDSO getrandom does work, which ensures that the RNG is initialized, test to see if it also works inside of a time namespace. This is important to test, because the vvar pages get swizzled around there. If the arch code isn't careful, the RNG will appear uninitialized inside of a time namespace. Because broken code makes the RNG appear uninitialized, test that everything works by issuing a call to vgetrandom from a fork in a time namespace, and use ptrace to ensure that the actual syscall getrandom doesn't get called. If it doesn't get called, then the test succeeds. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-30selftests: vDSO: quash clang omitted parameter warning in getrandom testJason A. Donenfeld
When building with clang, there's this warning: vdso_test_getrandom.c:145:40: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 145 | static void *test_vdso_getrandom(void *) | ^ vdso_test_getrandom.c:155:40: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 155 | static void *test_libc_getrandom(void *) | ^ vdso_test_getrandom.c:165:43: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 165 | static void *test_syscall_getrandom(void *) Add the named ctx parameter to quash it. Reported-by: Mark Brown <broonie@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-30selftests: vDSO: fix the way vDSO functions are called for powerpcChristophe Leroy
vdso_test_correctness test fails on powerpc: ~ # ./vdso_test_correctness ... [RUN] Testing clock_gettime for clock CLOCK_REALTIME_ALARM (8)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 [RUN] Testing clock_gettime for clock CLOCK_BOOTTIME_ALARM (9)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 [RUN] Testing clock_gettime for clock CLOCK_SGI_CYCLE (10)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 ... [RUN] Testing clock_gettime for clock invalid (-1)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 [RUN] Testing clock_gettime for clock invalid (-2147483648)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 [RUN] Testing clock_gettime for clock invalid (2147483647)... [FAIL] No such clock, but __vdso_clock_gettime returned 22 On powerpc, a call to a VDSO function is not an ordinary C function call. Unlike several architectures which returns a negative error code in case of an error, powerpc sets CR[SO] and returns the error code as a positive value. Define and use a macro called VDSO_CALL() which takes a pointer to the function to call, the number of arguments and the arguments. Also update ABI vdso documentation to reflect this subtlety. Provide a specific version of VDSO_CALL() for powerpc that negates the error code on return when CR[SO] is set. Fixes: c7e5789b24d3 ("kselftest: Move test_vdso to the vDSO test suite") Fixes: 2e9a97256616 ("selftests: vdso: Add a selftest for vDSO getcpu()") Fixes: 693f5ca08ca0 ("kselftest: Extend vDSO selftest") Fixes: b2f1c3db2887 ("kselftest: Extend vdso correctness test to clock_gettime64") Fixes: 4920a2590e91 ("selftests/vDSO: add tests for vgetrandom") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-30selftests: vDSO: skip getrandom test if architecture is unsupportedJason A. Donenfeld
If the getrandom test compiles for an arch, don't exit fatally if the actual cpu it's running on is unsupported. Suggested-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-30selftests: vDSO: look for arch-specific function name in getrandom testChristophe Leroy
Don't hard-code x86 specific names. Rather, use vdso_config definitions to find the correct function matching the architecture. Add random VDSO function names in names[][]. Remove the #ifdef CONFIG_VDSO32, as having the name there all the time is harmless and guaranties a steady index for following strings. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [Jason: add [6] to variable declaration rather than each usage site.] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-30selftests: vDSO: simplify getrandom thread local storage and structsJason A. Donenfeld
Rather than using pthread_get/set_specific, just use gcc's __thread annotation, which is noticeably faster and makes the code more obvious. Also, just have one simplified struct called vgrnd, instead of trying to split things up semantically. Those divisions were useful when this code was split across several commit *messages*, but doesn't make as much sense within a single file. This should make the code more clear and provide a better example for implementers. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-07-19selftests/vDSO: add tests for vgetrandomJason A. Donenfeld
This adds two tests for vgetrandom. The first one, vdso_test_chacha, simply checks that the assembly implementation of chacha20 matches that of libsodium, a basic sanity check that should catch most errors. The second, vdso_test_getrandom, is a full "libc-like" implementation of the userspace side of vgetrandom() support. It's meant to be used also as example code for libcs that might be integrating this. Cc: linux-kselftest@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>