D40283.1778050231.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
	@@ -22,6 +22,7 @@
	#include "kinst.h"

	#define KINST_PUSHL_RBP 0x55
	+#define KINST_POPL_RBP 0x5d
	#define KINST_STI 0xfb
	#define KINST_POPF 0x9d

	@@ -500,7 +501,8 @@
	dtrace_kinst_probedesc_t *pd;
	const char *func;
	int error, instrsize, n, off;
	- uint8_t instr, limit;
	+ uint8_t instr, limit, *tmp;
	+ bool push_found, pop_found;

	pd = opaque;
	func = symval->name;
	@@ -515,12 +517,21 @@
	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().
	+ * Refuse to instrument functions lacking the usual frame pointer
	+ * manipulations since they might correspond to exception handlers.
	*/
	- if (*instr != KINST_PUSHL_RBP)
	+ tmp = instr;
	+ push_found = pop_found = false;
	+ while (tmp < limit) {
	+ if (*tmp == KINST_PUSHL_RBP)
	+ push_found = true;
	+ else if (*tmp == KINST_POPL_RBP)
	+ pop_found = true;
	+ if (push_found && pop_found)
	+ break;
	+ tmp += dtrace_instr_size(tmp);
	+ }
	+ if (!push_found \|\| !pop_found)
	return (0);

	n = 0;