> 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.
