Add -K support to gprof(1), which enables dynamic symbol resolution from

the currently-running kernel (and supercedes an executable file argument
given).  With this change, properly-compiled KLD modules are now
able to be profiled.

Obtained from:	NAI Labs CBOSS project
Funded by:	DARPA

1 files changed, 64 insertions, 0 deletions

diff --git a/usr.bin/gprof/kernel.c b/usr.bin/gprof/kernel.c
new file mode 100644
index 0000000..c8df0d0
--- /dev/null
+++ b/usr.bin/gprof/kernel.c
@@ -0,0 +1,64 @@
+#ifndef lint
+static const char rcsid[] =
+  "$FreeBSD$";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/linker.h>
+#include <sys/sysctl.h>
+#include <sys/errno.h>
+
+#include <err.h>
+#include <stdlib.h>
+
+#include "gprof.h"
+
+/* Things which get -E excluded by default. */
+static char	*excludes[] = { ".mcount", "_mcleanup", NULL };
+
+int
+kernel_getnfile(const char *unused, char ***defaultEs)
+{
+	char *namelist;
+	size_t len;
+	char *name;
+
+	if (sysctlbyname("kern.function_list", NULL, &len, NULL, 0) == -1)
+		err(1, "sysctlbyname: function_list size");
+	for (;;) {
+		namelist = malloc(len);
+		if (namelist == NULL)
+			err(1, "malloc");
+		if (sysctlbyname("kern.function_list", namelist, &len, NULL,
+		   0) == 0)
+			break;
+		if (errno == ENOMEM)
+			free(namelist);
+		else
+			err(1, "sysctlbyname: function_list");
+	}
+	nname = 0;
+	for (name = namelist; *name != '\0'; name += strlen(name) + 1)
+		nname++;
+	/* Allocate memory for them, plus a terminating entry. */
+	if ((nl = (nltype *)calloc(nname + 1, sizeof(nltype))) == NULL)
+		errx(1, "Insufficient memory for symbol table");
+	npe = nl;
+	for (name = namelist; *name != '\0'; name += strlen(name) + 1) {
+		struct kld_sym_lookup ksl;
+
+		ksl.version = sizeof(ksl);
+		ksl.symname = name;
+		if (kldsym(0, KLDSYM_LOOKUP, &ksl))
+			err(1, "kldsym(%s)", name);
+		/* aflag not supported */
+		if (uflag && strchr(name, '.') != NULL)
+			continue;
+		npe->value = ksl.symvalue;
+		npe->name = name;
+		npe++;
+	}
+	npe->value = -1;
+
+	*defaultEs = excludes;
+}