[PATCH v1 5/9] selftests/powerpc/dexcr: Add DEXCR prctl interface test
Benjamin Gray
bgray at linux.ibm.com
Wed Apr 17 21:23:21 AEST 2024
Some basic tests of the prctl interface of the DEXCR.
Signed-off-by: Benjamin Gray <bgray at linux.ibm.com>
---
.../selftests/powerpc/dexcr/.gitignore | 1 +
.../testing/selftests/powerpc/dexcr/Makefile | 4 +-
tools/testing/selftests/powerpc/dexcr/dexcr.c | 40 ++++
tools/testing/selftests/powerpc/dexcr/dexcr.h | 10 +
.../selftests/powerpc/dexcr/dexcr_test.c | 213 ++++++++++++++++++
5 files changed, 267 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/powerpc/dexcr/dexcr_test.c
diff --git a/tools/testing/selftests/powerpc/dexcr/.gitignore b/tools/testing/selftests/powerpc/dexcr/.gitignore
index b82f45dd46b9..5d526613cd26 100644
--- a/tools/testing/selftests/powerpc/dexcr/.gitignore
+++ b/tools/testing/selftests/powerpc/dexcr/.gitignore
@@ -1,2 +1,3 @@
+dexcr_test
hashchk_test
lsdexcr
diff --git a/tools/testing/selftests/powerpc/dexcr/Makefile b/tools/testing/selftests/powerpc/dexcr/Makefile
index 829ad075b4a4..076943193c07 100644
--- a/tools/testing/selftests/powerpc/dexcr/Makefile
+++ b/tools/testing/selftests/powerpc/dexcr/Makefile
@@ -1,8 +1,10 @@
-TEST_GEN_PROGS := hashchk_test
+TEST_GEN_PROGS := dexcr_test hashchk_test
TEST_GEN_FILES := lsdexcr
include ../../lib.mk
+CFLAGS += $(KHDR_INCLUDES)
+
$(OUTPUT)/hashchk_test: CFLAGS += -fno-pie -no-pie $(call cc-option,-mno-rop-protect)
$(TEST_GEN_PROGS): ../harness.c ../utils.c ./dexcr.c
diff --git a/tools/testing/selftests/powerpc/dexcr/dexcr.c b/tools/testing/selftests/powerpc/dexcr/dexcr.c
index 65ec5347de98..468fd0dc9912 100644
--- a/tools/testing/selftests/powerpc/dexcr/dexcr.c
+++ b/tools/testing/selftests/powerpc/dexcr/dexcr.c
@@ -3,6 +3,7 @@
#include <errno.h>
#include <setjmp.h>
#include <signal.h>
+#include <sys/prctl.h>
#include <sys/types.h>
#include <sys/wait.h>
@@ -43,6 +44,45 @@ bool dexcr_exists(void)
return exists;
}
+unsigned int pr_which_to_aspect(unsigned long which)
+{
+ switch (which) {
+ case PR_PPC_DEXCR_SBHE:
+ return DEXCR_PR_SBHE;
+ case PR_PPC_DEXCR_IBRTPD:
+ return DEXCR_PR_IBRTPD;
+ case PR_PPC_DEXCR_SRAPD:
+ return DEXCR_PR_SRAPD;
+ case PR_PPC_DEXCR_NPHIE:
+ return DEXCR_PR_NPHIE;
+ default:
+ FAIL_IF_EXIT_MSG(true, "unknown PR aspect");
+ }
+}
+
+int pr_get_dexcr(unsigned long which)
+{
+ return prctl(PR_PPC_GET_DEXCR, which, 0UL, 0UL, 0UL);
+}
+
+int pr_set_dexcr(unsigned long which, unsigned long ctrl)
+{
+ return prctl(PR_PPC_SET_DEXCR, which, ctrl, 0UL, 0UL);
+}
+
+bool pr_dexcr_aspect_supported(unsigned long which)
+{
+ if (pr_get_dexcr(which) == -1)
+ return errno == ENODEV;
+
+ return true;
+}
+
+bool pr_dexcr_aspect_editable(unsigned long which)
+{
+ return pr_get_dexcr(which) & PR_PPC_DEXCR_CTRL_EDITABLE;
+}
+
/*
* Just test if a bad hashchk triggers a signal, without checking
* for support or if the NPHIE aspect is enabled.
diff --git a/tools/testing/selftests/powerpc/dexcr/dexcr.h b/tools/testing/selftests/powerpc/dexcr/dexcr.h
index f55cbbc8643b..a6aa7eac11da 100644
--- a/tools/testing/selftests/powerpc/dexcr/dexcr.h
+++ b/tools/testing/selftests/powerpc/dexcr/dexcr.h
@@ -28,6 +28,16 @@
bool dexcr_exists(void);
+bool pr_dexcr_aspect_supported(unsigned long which);
+
+bool pr_dexcr_aspect_editable(unsigned long which);
+
+int pr_get_dexcr(unsigned long pr_aspect);
+
+int pr_set_dexcr(unsigned long pr_aspect, unsigned long ctrl);
+
+unsigned int pr_which_to_aspect(unsigned long which);
+
bool hashchk_triggers(void);
enum dexcr_source {
diff --git a/tools/testing/selftests/powerpc/dexcr/dexcr_test.c b/tools/testing/selftests/powerpc/dexcr/dexcr_test.c
new file mode 100644
index 000000000000..4662c823a4f1
--- /dev/null
+++ b/tools/testing/selftests/powerpc/dexcr/dexcr_test.c
@@ -0,0 +1,213 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <unistd.h>
+
+#include "dexcr.h"
+#include "utils.h"
+
+/*
+ * Helper function for testing the behaviour of a newly exec-ed process
+ */
+static int dexcr_prctl_onexec_test_child(unsigned long which, const char *status)
+{
+ unsigned long dexcr = mfspr(SPRN_DEXCR_RO);
+ unsigned long aspect = pr_which_to_aspect(which);
+ int ctrl = pr_get_dexcr(which);
+
+ if (!strcmp(status, "set")) {
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET),
+ "setting aspect across exec not applied");
+
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET_ONEXEC),
+ "setting aspect across exec not inherited");
+
+ FAIL_IF_EXIT_MSG(!(aspect & dexcr), "setting aspect across exec did not take effect");
+ } else if (!strcmp(status, "clear")) {
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR),
+ "clearing aspect across exec not applied");
+
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC),
+ "clearing aspect across exec not inherited");
+
+ FAIL_IF_EXIT_MSG(aspect & dexcr, "clearing aspect across exec did not take effect");
+ } else {
+ FAIL_IF_EXIT_MSG(true, "unknown expected status");
+ }
+
+ return 0;
+}
+
+/*
+ * Test that the given prctl value can be manipulated freely
+ */
+static int dexcr_prctl_aspect_test(unsigned long which)
+{
+ unsigned long aspect = pr_which_to_aspect(which);
+ pid_t pid;
+ int ctrl;
+ int err;
+ int errno_save;
+
+ SKIP_IF_MSG(!dexcr_exists(), "DEXCR not supported");
+ SKIP_IF_MSG(!pr_dexcr_aspect_supported(which), "DEXCR aspect not supported");
+ SKIP_IF_MSG(!pr_dexcr_aspect_editable(which), "DEXCR aspect not editable with prctl");
+
+ /* We reject invalid combinations of arguments */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET | PR_PPC_DEXCR_CTRL_CLEAR);
+ errno_save = errno;
+ FAIL_IF_MSG(err != -1, "simultaneous set and clear should be rejected");
+ FAIL_IF_MSG(errno_save != EINVAL, "simultaneous set and clear should be rejected with EINVAL");
+
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET_ONEXEC | PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC);
+ errno_save = errno;
+ FAIL_IF_MSG(err != -1, "simultaneous set and clear on exec should be rejected");
+ FAIL_IF_MSG(errno_save != EINVAL, "simultaneous set and clear on exec should be rejected with EINVAL");
+
+ /* We set the aspect */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_SET failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET), "config value not PR_PPC_DEXCR_CTRL_SET");
+ FAIL_IF_MSG(ctrl & PR_PPC_DEXCR_CTRL_CLEAR, "config value unexpected clear flag");
+ FAIL_IF_MSG(!(aspect & mfspr(SPRN_DEXCR_RO)), "setting aspect did not take effect");
+
+ /* We clear the aspect */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_CLEAR);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_CLEAR failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR), "config value not PR_PPC_DEXCR_CTRL_CLEAR");
+ FAIL_IF_MSG(ctrl & PR_PPC_DEXCR_CTRL_SET, "config value unexpected set flag");
+ FAIL_IF_MSG(aspect & mfspr(SPRN_DEXCR_RO), "clearing aspect did not take effect");
+
+ /* We make it set on exec (doesn't change our current value) */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET_ONEXEC);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_SET_ONEXEC failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR), "process aspect should still be cleared");
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET_ONEXEC), "config value not PR_PPC_DEXCR_CTRL_SET_ONEXEC");
+ FAIL_IF_MSG(ctrl & PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC, "config value unexpected clear on exec flag");
+ FAIL_IF_MSG(aspect & mfspr(SPRN_DEXCR_RO), "scheduling aspect to set on exec should not change it now");
+
+ /* We make it clear on exec (doesn't change our current value) */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR), "process aspect config should still be cleared");
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC), "config value not PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC");
+ FAIL_IF_MSG(ctrl & PR_PPC_DEXCR_CTRL_SET_ONEXEC, "config value unexpected set on exec flag");
+ FAIL_IF_MSG(aspect & mfspr(SPRN_DEXCR_RO), "process aspect should still be cleared");
+
+ /* We allow setting the current and on-exec value in a single call */
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET | PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_SET | PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET), "config value not PR_PPC_DEXCR_CTRL_SET");
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC), "config value not PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC");
+ FAIL_IF_MSG(!(aspect & mfspr(SPRN_DEXCR_RO)), "process aspect should be set");
+
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_CLEAR | PR_PPC_DEXCR_CTRL_SET_ONEXEC);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_CLEAR | PR_PPC_DEXCR_CTRL_SET_ONEXEC failed");
+
+ ctrl = pr_get_dexcr(which);
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR), "config value not PR_PPC_DEXCR_CTRL_CLEAR");
+ FAIL_IF_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET_ONEXEC), "config value not PR_PPC_DEXCR_CTRL_SET_ONEXEC");
+ FAIL_IF_MSG(aspect & mfspr(SPRN_DEXCR_RO), "process aspect should be clear");
+
+ /* Verify the onexec value is applied across exec */
+ pid = fork();
+ if (!pid) {
+ char which_str[32] = {};
+ char *args[] = { "dexcr_prctl_onexec_test_child", which_str, "set", NULL };
+ unsigned int ctrl = pr_get_dexcr(which);
+
+ sprintf(which_str, "%lu", which);
+
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_SET_ONEXEC),
+ "setting aspect on exec not copied across fork");
+
+ FAIL_IF_EXIT_MSG(mfspr(SPRN_DEXCR_RO) & aspect,
+ "setting aspect on exec wrongly applied to fork");
+
+ execve("/proc/self/exe", args, NULL);
+ _exit(errno);
+ }
+ await_child_success(pid);
+
+ err = pr_set_dexcr(which, PR_PPC_DEXCR_CTRL_SET | PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC);
+ FAIL_IF_MSG(err, "PR_PPC_DEXCR_CTRL_SET | PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC failed");
+
+ pid = fork();
+ if (!pid) {
+ char which_str[32] = {};
+ char *args[] = { "dexcr_prctl_onexec_test_child", which_str, "clear", NULL };
+ unsigned int ctrl = pr_get_dexcr(which);
+
+ sprintf(which_str, "%lu", which);
+
+ FAIL_IF_EXIT_MSG(!(ctrl & PR_PPC_DEXCR_CTRL_CLEAR_ONEXEC),
+ "clearing aspect on exec not copied across fork");
+
+ FAIL_IF_EXIT_MSG(!(mfspr(SPRN_DEXCR_RO) & aspect),
+ "clearing aspect on exec wrongly applied to fork");
+
+ execve("/proc/self/exe", args, NULL);
+ _exit(errno);
+ }
+ await_child_success(pid);
+
+ return 0;
+}
+
+static int dexcr_prctl_ibrtpd_test(void)
+{
+ return dexcr_prctl_aspect_test(PR_PPC_DEXCR_IBRTPD);
+}
+
+static int dexcr_prctl_srapd_test(void)
+{
+ return dexcr_prctl_aspect_test(PR_PPC_DEXCR_SRAPD);
+}
+
+static int dexcr_prctl_nphie_test(void)
+{
+ return dexcr_prctl_aspect_test(PR_PPC_DEXCR_NPHIE);
+}
+
+int main(int argc, char *argv[])
+{
+ int err = 0;
+
+ /*
+ * Some tests require checking what happens across exec, so we may be
+ * invoked as the child of a particular test
+ */
+ if (argc > 1) {
+ if (argc == 3 && !strcmp(argv[0], "dexcr_prctl_onexec_test_child")) {
+ unsigned long which;
+
+ err = parse_ulong(argv[1], strlen(argv[1]), &which, 10);
+ FAIL_IF_MSG(err, "failed to parse which value for child");
+
+ return dexcr_prctl_onexec_test_child(which, argv[2]);
+ }
+
+ FAIL_IF_MSG(true, "unknown test case");
+ }
+
+ /*
+ * Otherwise we are the main test invocation and run the full suite
+ */
+ err |= test_harness(dexcr_prctl_ibrtpd_test, "dexcr_prctl_ibrtpd");
+ err |= test_harness(dexcr_prctl_srapd_test, "dexcr_prctl_srapd");
+ err |= test_harness(dexcr_prctl_nphie_test, "dexcr_prctl_nphie");
+
+ return err;
+}
--
2.44.0
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