From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/perf/tests/demangle-java-test.c | 49 +++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 tools/perf/tests/demangle-java-test.c (limited to 'tools/perf/tests/demangle-java-test.c') diff --git a/tools/perf/tests/demangle-java-test.c b/tools/perf/tests/demangle-java-test.c new file mode 100644 index 000000000..0fb3e5a4a --- /dev/null +++ b/tools/perf/tests/demangle-java-test.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "debug.h" +#include "symbol.h" +#include "tests.h" + +static int test__demangle_java(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + int ret = TEST_OK; + char *buf = NULL; + size_t i; + + struct { + const char *mangled, *demangled; + } test_cases[] = { + { "Ljava/lang/StringLatin1;equals([B[B)Z", + "java.lang.StringLatin1.equals(byte[], byte[])" }, + { "Ljava/util/zip/ZipUtils;CENSIZ([BI)J", + "java.util.zip.ZipUtils.CENSIZ(byte[], int)" }, + { "Ljava/util/regex/Pattern$BmpCharProperty;match(Ljava/util/regex/Matcher;ILjava/lang/CharSequence;)Z", + "java.util.regex.Pattern$BmpCharProperty.match(java.util.regex.Matcher, int, java.lang.CharSequence)" }, + { "Ljava/lang/AbstractStringBuilder;appendChars(Ljava/lang/String;II)V", + "java.lang.AbstractStringBuilder.appendChars(java.lang.String, int, int)" }, + { "Ljava/lang/Object;()V", + "java.lang.Object()" }, + }; + + for (i = 0; i < ARRAY_SIZE(test_cases); i++) { + buf = dso__demangle_sym(/*dso=*/NULL, /*kmodule=*/0, test_cases[i].mangled); + if (!buf) { + pr_debug("FAILED to demangle: \"%s\"\n \"%s\"\n", test_cases[i].mangled, + test_cases[i].demangled); + continue; + } + if (strcmp(buf, test_cases[i].demangled)) { + pr_debug("FAILED: %s: %s != %s\n", test_cases[i].mangled, + buf, test_cases[i].demangled); + ret = TEST_FAIL; + } + free(buf); + } + + return ret; +} + +DEFINE_SUITE("Demangle Java", demangle_java); -- cgit v1.3.1