D39166.diff
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	diff --git a/sys/cddl/dev/kinst/amd64/kinst_isa.c b/sys/cddl/dev/kinst/amd64/kinst_isa.c
	--- a/sys/cddl/dev/kinst/amd64/kinst_isa.c
	+++ b/sys/cddl/dev/kinst/amd64/kinst_isa.c
	@@ -500,6 +500,29 @@
	return (0);
	}

	+
	+/*
	+ * Instead of ignoring functions that do not `push %rbp` in their first
	+ * instruction right away, we check if there's a `push %rbp` anywhere in the
	+ * function. Functions that do not push the frame pointer might correspond to
	+ * exception handlers with which we should not meddle.
	+ *
	+ * FIXME: This does however exclude functions which can be safely traced, such
	+ * as cpu_switch() and leaf functions compiled without
	+ * `-mno-omit-leaf-frame-pointer`.
	+ */
	+static bool
	+kinst_can_trace_func(uint8_t instr, uint8_t limit)
	+{
	+ uint8_t *p;
	+
	+ for (p = instr; p < limit; p += dtrace_instr_size(p))
	+ if (*p == KINST_PUSHL_RBP)
	+ return (true);
	+
	+ return (false);
	+}
	+
	int
	kinst_make_probe(linker_file_t lf, int symindx, linker_symval_t *symval,
	void *opaque)
	@@ -520,13 +543,7 @@
	if (instr >= limit)
	return (0);

	- /*
	- * Ignore functions not beginning with the usual function prologue.
	- * These might correspond to exception handlers with which we should not
	- * meddle. This does however exclude functions which can be safely
	- * traced, such as cpu_switch().
	- */
	- if (*instr != KINST_PUSHL_RBP)
	+ if (!kinst_can_trace_func(instr, limit))
	return (0);

	n = 0;