diff options
| -rw-r--r-- | internal/generate/codegen_test.go | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/internal/generate/codegen_test.go b/internal/generate/codegen_test.go index cc5ad7c..13c5270 100644 --- a/internal/generate/codegen_test.go +++ b/internal/generate/codegen_test.go @@ -302,6 +302,42 @@ func TestGenerateMemHandlerMadvise(t *testing.T) { requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") } +// TestGenerateMemHandlerMincore locks in the BPF handler wiring for mincore(2): +// int mincore(void addr[.length], size_t length, unsigned char *vec). +// The queried address range is args[0]/args[1] (addr/length). args[2] is `vec`, +// a *userspace output pointer* where the kernel writes one byte per page telling +// whether that page is resident — it is NOT a flags value. mincore therefore has +// neither a flags argument nor a second length, so both ev->flags and ev->length2 +// must stay zero. This guards against the historical mistake of blindly mapping +// args[2] onto ev->flags (as flags-bearing siblings like madvise/mlock2/mseal do); +// doing so here would surface a meaningless userspace pointer as a flags field. +// mincore returns int 0 on success / -1 on error, captured generically via +// ev->ret as UNCLASSIFIED like every other KindMem exit. +func TestGenerateMemHandlerMincore(t *testing.T) { + output := GenerateTracepointsC(mustParseAll(t, syntheticPair("mincore"))) + + requireContains(t, output, `SEC("tracepoint/syscalls/sys_enter_mincore")`) + requireContains(t, output, "struct mem_event *ev") + requireContains(t, output, "ev->event_type = ENTER_MEM_EVENT;") + requireContains(t, output, "ev->addr = (__u64)ctx->args[0];") + requireContains(t, output, "ev->length = (__u64)ctx->args[1];") + requireContains(t, output, "ev->length2 = 0;") + requireContains(t, output, "ev->flags = 0;") + // args[2] is the userspace `vec` output pointer, not flags. It must never be + // wired into ev->flags (nor ev->length2). + if strings.Contains(output, "ev->flags = (__u64)ctx->args[2];") { + t.Error("mincore handler must keep flags zero; args[2] is the vec output pointer, not a flags value") + } + if strings.Contains(output, "ev->length2 = (__u64)ctx->args") { + t.Error("mincore handler must keep length2 zero; it has no second length argument") + } + // The exit handler returns the int status generically (0 on success, -1 on + // error), not via a byte-count classification. + requireContains(t, output, `SEC("tracepoint/syscalls/sys_exit_mincore")`) + requireContains(t, output, "ev->ret = ctx->ret;") + requireContains(t, output, "ev->ret_type = UNCLASSIFIED;") +} + func TestGenerateMemHandlerPkeyMprotect(t *testing.T) { output := GenerateTracepointsC(mustParseAll(t, syntheticPair("pkey_mprotect"))) |