[DTrace-devel] [PATCH 7/7] tests: filter-out spurious references to bpf module symbols from kallmodsyms

[eugene.loh at oracle.com]

From: David Mc Lean <david.mclean at oracle.com>

We see references to symbols assigned to a "bpf" module in
/proc/kallmodsyms.  We filter these references out in a few tests and in
libdtrace/dt_module.c.

The tests which were failing before the changes here include:
test/unittest/aggs/tst.aggmod_full.sh
test/unittest/aggs/tst.aggmod_full2.sh
test/unittest/consumer/tst.merge_ranges_bug25767469.c
test/unittest/consumer/tst.symbols.c

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
Signed-off-by: David Mc Lean <david.mclean at oracle.com>
Reviewed-by: Kris Van Hees <kris.van.hees at oracle.com>
---
 libdtrace/dt_module.c                  | 3 +++
 test/unittest/aggs/tst.aggmod_full.sh  | 1 +
 test/unittest/aggs/tst.aggmod_full2.sh | 4 ++++
 test/unittest/consumer/tst.symbols.c   | 2 ++
 4 files changed, 10 insertions(+)

diff --git a/libdtrace/dt_module.c b/libdtrace/dt_module.c
index 8e50a315..8af3695d 100644
--- a/libdtrace/dt_module.c
+++ b/libdtrace/dt_module.c
@@ -1123,6 +1123,9 @@ dt_modsym_update(dtrace_hdl_t *dtp, const char *line, int flag)
 	     || (sym_type == 'w') || (sym_type == 'W');
 	mod_name[strlen(mod_name)-1] = '\0';	/* chop trailing ] */
 
+	if (strcmp(mod_name, "bpf") == 0)
+		return 0;
+
 	/*
 	 * Symbols of "absolute" type are typically defined per CPU.
 	 * Their "addresses" here are very low and are actually offsets.
diff --git a/test/unittest/aggs/tst.aggmod_full.sh b/test/unittest/aggs/tst.aggmod_full.sh
index 22b6f670..b876d736 100755
--- a/test/unittest/aggs/tst.aggmod_full.sh
+++ b/test/unittest/aggs/tst.aggmod_full.sh
@@ -86,6 +86,7 @@ NF == 4 && $4 == "__init_scratch_begin" {
 NF == 4 {$5 = "[vmlinux]"};
 $3 == "a" {$2 = 0};
 $3 == "A" {$2 = 0};
+$5 == "[bpf]" {$2 = 0};
 $2 != 0 { print $1 >> $5 }
 ' /proc/kallmodsyms
 
diff --git a/test/unittest/aggs/tst.aggmod_full2.sh b/test/unittest/aggs/tst.aggmod_full2.sh
index 0472facc..e2716a09 100755
--- a/test/unittest/aggs/tst.aggmod_full2.sh
+++ b/test/unittest/aggs/tst.aggmod_full2.sh
@@ -43,6 +43,7 @@ cat > test.c << EOF
 #include <string.h>
 #include <unistd.h>
 #include <linux/limits.h>
+#include <time.h>
 #include "prov.h"
 
 /*
@@ -92,6 +93,9 @@ int main(int argc, char **argv) {
 		if (size == 0)
 			continue;
 
+		if (strcmp(modname, "bpf]") == 0)
+			continue;
+
 		/* trim the trailing ']' and print modname to stdout */
 		modname[strlen(modname)-1] = '\0';
 		printf("%s\n", modname);
diff --git a/test/unittest/consumer/tst.symbols.c b/test/unittest/consumer/tst.symbols.c
index 24d16d1f..66f044a3 100644
--- a/test/unittest/consumer/tst.symbols.c
+++ b/test/unittest/consumer/tst.symbols.c
@@ -107,6 +107,8 @@ int read_symbols() {
 			continue;
 		}
 #undef KERNEL_FLAG_INIT_SCRATCH
+		if (strcmp(modname, "bpf]") == 0)
+			continue;
 
 		/*
 		 * In libdtrace/dt_module.c function dt_modsym_update(),
-- 
2.18.4