Re: [PATCH bpf-next v2 2/2] selftests/bpf: Add trampolines multi-level pointer params test coverage
From: bot+bpf-ci@kernel.org
Date: 2026-02-17 22:48:00
Also in:
bpf, linux-kselftest, lkml
quoted hunk ↗ jump to hunk
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 178c4738e63b..19c82ae9bfe6 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c
[ ... ]
+static void *create_bad_kaddr(void)
+{
+ /*
+ * Try to get an address that passes kernel range checks but causes
+ * a page fault handler invocation if accessed from a BPF program.
+ */
+#if defined(CONFIG_ARCH_HAS_SET_MEMORY) && defined(CONFIG_X86)The first branch requires both CONFIG_ARCH_HAS_SET_MEMORY and CONFIG_X86. The second branch requires CONFIG_ARCH_HAS_SET_DIRECT_MAP. PowerPC selects ARCH_HAS_SET_MEMORY (arch/powerpc/Kconfig) but not ARCH_HAS_SET_DIRECT_MAP, so neither branch compiles in and the function always returns NULL on that architecture.
+ void *addr = vmalloc(PAGE_SIZE);
+
+ if (!addr)
+ return NULL;
+ /* Make it non-present - any access will fault */
+ if (set_memory_np((unsigned long)addr, 1)) {
+ vfree(addr);
+ return NULL;
+ }
+ return addr;
+#elif defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)[ ... ]
+#endif + return NULL; +}
[ ... ]
+static void free_bad_kaddr(void *addr)
+{
+ if (!addr)
+ return;
+
+ /*
+ * Free an invalid test address created by get_invalid_address().
+ * Restores the page to present state before freeing.
+ */The comment references get_invalid_address() but the function that creates the address is create_bad_kaddr().
+#if defined(CONFIG_ARCH_HAS_SET_MEMORY) && defined(CONFIG_X86)
[ ... ]
+#endif +}
[ ... ]
+ } else if (!strcmp(attach_name, "bpf_fentry_test13_pptr")) {
+ kaddr = create_bad_kaddr();
+ WARN_ON(!kaddr);Since create_bad_kaddr() returns NULL on PowerPC (which supports BPF trampolines via HAVE_DYNAMIC_FTRACE_WITH_ARGS), would this WARN_ON fire every time the bpf_fentry_test13_pptr test runs on that architecture?
+ CONSUME(bpf_fentry_test13_pptr(kaddr)); + CONSUME(bpf_fentry_test13_pptr((void **)19)); + CONSUME(bpf_fentry_test13_pptr(ERR_PTR(-ENOMEM))); + break;
[ ... ] --- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md CI run summary: https://github.com/kernel-patches/bpf/actions/runs/22118172993 AI-authorship-score: low AI-authorship-explanation: Stale comment referencing a renamed function and an architecture coverage gap with WARN_ON are characteristic of human-authored code that underwent refactoring. issues-found: 2 issue-severity-score: medium issue-severity-explanation: WARN_ON(!kaddr) fires unconditionally on PowerPC where create_bad_kaddr() always returns NULL, producing kernel warnings on every test run and potential panics with panic_on_warn.