git: f9d36fa86cdd - stable/13 - tests: Test that SIGSYS is not delivered if kern.signosys knob is off

[Dmitry Chagin]

The branch stable/13 has been updated by dchagin:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=f9d36fa86cdd458c00c74b8a211d049a560af322

commit f9d36fa86cdd458c00c74b8a211d049a560af322
Author:     Dmitry Chagin <dcha...@freebsd.org>
AuthorDate: 2023-10-03 07:38:02 +0000
Commit:     Dmitry Chagin <dcha...@freebsd.org>
CommitDate: 2023-10-10 05:15:57 +0000

    tests: Test that SIGSYS is not delivered if kern.signosys knob is off
    
    Reviewed by:            markj
    Differential Revision:  https://reviews.freebsd.org/D41979
    MFC after:              1 week
    
    (cherry picked from commit b67c0ba4613861f8245ce835081311aef1c19bae)
---
 tests/sys/kern/Makefile |   1 +
 tests/sys/kern/sigsys.c | 101 +++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 88 insertions(+), 14 deletions(-)

diff --git a/tests/sys/kern/Makefile b/tests/sys/kern/Makefile
index ec2bbd742956..16faeeb40421 100644
--- a/tests/sys/kern/Makefile
+++ b/tests/sys/kern/Makefile
@@ -41,6 +41,7 @@ ATF_TESTS_C+= unix_socketpair_test
 ATF_TESTS_C+=  waitpid_nohang
 ATF_TESTS_C+=  pdeathsig
 ATF_TESTS_C+=  sigsys
+TEST_METADATA.sigsys+= is_exclusive="true"
 
 ATF_TESTS_SH+= coredump_phnum_test
 ATF_TESTS_SH+= sonewconn_overflow
diff --git a/tests/sys/kern/sigsys.c b/tests/sys/kern/sigsys.c
index 75e3816fc158..8554a646ebc6 100644
--- a/tests/sys/kern/sigsys.c
+++ b/tests/sys/kern/sigsys.c
@@ -7,31 +7,29 @@
  * under sponsorship from the FreeBSD Foundation.
  */
 
+#include <sys/param.h>
 #include <sys/syscall.h>
+#include <sys/sysctl.h>
 
 #include <atf-c.h>
 #include <errno.h>
 #include <signal.h>
 #include <stdatomic.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 static sig_atomic_t sigsys_cnt;
 
+#define        SAVEDVALUE      "savedsignosys"
+
 static void
 sigsys_handler(int signo, siginfo_t *si, void *ucp)
 {
        sigsys_cnt++;
 }
 
-ATF_TC(sigsys_test);
-
-ATF_TC_HEAD(sigsys_test, tc)
-{
-       atf_tc_set_md_var(tc, "descr",
-           "Testing delivery of SIGSYS on invalid syscalls");
-}
-
-ATF_TC_BODY(sigsys_test, tc)
+static void
+sigsys_test(int knob)
 {
        struct sigaction sa;
 
@@ -43,27 +41,102 @@ ATF_TC_BODY(sigsys_test, tc)
        ATF_REQUIRE(syscall(273) == -1);        /* reserved */
        ATF_CHECK_ERRNO(ENOSYS, true);
        atomic_signal_fence(memory_order_seq_cst);
-       ATF_CHECK_EQ(1, sigsys_cnt);
+       ATF_CHECK_EQ(1 * knob, sigsys_cnt * knob);
 
        ATF_REQUIRE(syscall(440) == -1);        /* SYS_kse_switchin */
        ATF_CHECK_ERRNO(ENOSYS, true);
        atomic_signal_fence(memory_order_seq_cst);
-       ATF_CHECK_EQ(2, sigsys_cnt);
+       ATF_CHECK_EQ(2 * knob, sigsys_cnt * knob);
 
        /* Hope this is enough for say next two months */
        ATF_REQUIRE(syscall(3000000) == -1);
        ATF_CHECK_ERRNO(ENOSYS, true);
        atomic_signal_fence(memory_order_seq_cst);
-       ATF_CHECK_EQ(3, sigsys_cnt);
+       ATF_CHECK_EQ(3 * knob, sigsys_cnt * knob);
 
        ATF_REQUIRE(syscall(SYS_afs3_syscall) == -1);
        ATF_CHECK_ERRNO(ENOSYS, true);
        atomic_signal_fence(memory_order_seq_cst);
-       ATF_CHECK_EQ(4, sigsys_cnt);
+       ATF_CHECK_EQ(4 * knob, sigsys_cnt * knob);
+}
+
+static void
+sysctlset(const char *name, int val)
+{
+       size_t oldlen;
+       int oldval;
+       char buf[80];
+
+       ATF_REQUIRE(sysctlbyname(name, &oldval, &oldlen, NULL, 0) == 0);
+
+       /* Store old %name in a symlink for cleanup */
+       snprintf(buf, sizeof(buf), "%d", oldval);
+       ATF_REQUIRE(symlink(buf, SAVEDVALUE) == 0);
+
+       ATF_REQUIRE(sysctlbyname(name, NULL, NULL, &val, sizeof(val)) == 0);
+}
+
+static void
+sysctlcleanup(const char *name)
+{
+       size_t oldlen;
+       int n, oldval;
+       char buf[80];
+
+       if ((n = readlink(SAVEDVALUE, buf, sizeof(buf))) > 0) {
+               buf[MIN((size_t)n, sizeof(buf) - 1)] = '\0';
+               if (sscanf(buf, "%d", &oldval) == 1) {
+                       oldlen = sizeof(oldval);
+                       (void)sysctlbyname(name, NULL, 0,
+                           &oldval, oldlen);
+               }
+       }
+       (void)unlink(SAVEDVALUE);
+}
+
+ATF_TC_WITH_CLEANUP(sigsys_test_on);
+ATF_TC_HEAD(sigsys_test_on, tc)
+{
+       atf_tc_set_md_var(tc, "require.user", "root");
+       atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
+       atf_tc_set_md_var(tc, "descr",
+           "Testing delivery of SIGSYS on invalid syscalls");
+}
+
+ATF_TC_BODY(sigsys_test_on, tc)
+{
+       sysctlset("kern.signosys", 1);
+       sigsys_test(1);
+}
+
+ATF_TC_CLEANUP(sigsys_test_on, tc)
+{
+       sysctlcleanup("kern.signosys");
+}
+
+ATF_TC_WITH_CLEANUP(sigsys_test_off);
+ATF_TC_HEAD(sigsys_test_off, tc)
+{
+       atf_tc_set_md_var(tc, "require.user", "root");
+       atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
+       atf_tc_set_md_var(tc, "descr",
+           "Testing SIGSYS silence on invalid syscalls");
+}
+
+ATF_TC_BODY(sigsys_test_off, tc)
+{
+       sysctlset("kern.signosys", 0);
+       sigsys_test(0);
+}
+
+ATF_TC_CLEANUP(sigsys_test_off, tc)
+{
+       sysctlcleanup("kern.signosys");
 }
 
 ATF_TP_ADD_TCS(tp)
 {
-       ATF_TP_ADD_TC(tp, sigsys_test);
+       ATF_TP_ADD_TC(tp, sigsys_test_on);
+       ATF_TP_ADD_TC(tp, sigsys_test_off);
        return (atf_no_error());
 }