selftests: Add tests for PR_SYS_DISPATCH_INCLUSIVE_ON

Add tests for PR_SYS_DISPATCH_INCLUSIVE_ON correct/incorrect args,
and a test that ensures that the specified range is respected
by both PR_SYS_DISPATCH_EXCLUSIVE_ON and PR_SYS_DISPATCH_INCLUSIVE_ON.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/8df4b50b176b073550bab5b3f3faff752c5f8e17.1747839857.git.dvyukov@google.com

diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
index 48cf01aeec3e77322eba04e3e4b4085b10d19150..2eb2c06303f2aa08e098192b1c3f29220fdc778d 100644 (file)
--- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c
+++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c
@@ -10,6 +10,8 @@
 #include <sys/sysinfo.h>
 #include <sys/syscall.h>
 #include <signal.h>
+#include <stdbool.h>
+#include <stdlib.h>
 
 #include <asm/unistd.h>
 #include "../kselftest_harness.h"
@@ -17,11 +19,15 @@
 #ifndef PR_SET_SYSCALL_USER_DISPATCH
 # define PR_SET_SYSCALL_USER_DISPATCH  59
 # define PR_SYS_DISPATCH_OFF   0
-# define PR_SYS_DISPATCH_ON    1
 # define SYSCALL_DISPATCH_FILTER_ALLOW 0
 # define SYSCALL_DISPATCH_FILTER_BLOCK 1
 #endif
 
+#ifndef PR_SYS_DISPATCH_EXCLUSIVE_ON
+# define PR_SYS_DISPATCH_EXCLUSIVE_ON  1
+# define PR_SYS_DISPATCH_INCLUSIVE_ON  2
+#endif
+
 #ifndef SYS_USER_DISPATCH
 # define SYS_USER_DISPATCH     2
 #endif
@@ -65,7 +71,7 @@ TEST_SIGNAL(dispatch_trigger_sigsys, SIGSYS)
        ret = sysinfo(&info);
        ASSERT_EQ(0, ret);
 
-       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 0, 0, &sel);
+       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, 0, &sel);
        ASSERT_EQ(0, ret) {
                TH_LOG("Kernel does not support CONFIG_SYSCALL_USER_DISPATCH");
        }
@@ -118,8 +124,8 @@ TEST(bad_prctl_param)
        /* Valid parameter */
        prctl_valid(_metadata, op, 0x0, 0x0, 0x0);
 
-       /* PR_SYS_DISPATCH_ON */
-       op = PR_SYS_DISPATCH_ON;
+       /* PR_SYS_DISPATCH_EXCLUSIVE_ON */
+       op = PR_SYS_DISPATCH_EXCLUSIVE_ON;
 
        /* Dispatcher region is bad (offset > 0 && len == 0) */
        prctl_invalid(_metadata, op, 0x1, 0x0, &sel, EINVAL);
@@ -131,12 +137,24 @@ TEST(bad_prctl_param)
        /*
         * Dispatcher range overflows unsigned long
         */
-       prctl_invalid(_metadata, PR_SYS_DISPATCH_ON, 1, -1L, &sel, EINVAL);
+       prctl_invalid(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, 1, -1L, &sel, EINVAL);
 
        /*
         * Allowed range overflows usigned long
         */
-       prctl_invalid(_metadata, PR_SYS_DISPATCH_ON, -1L, 0x1, &sel, EINVAL);
+       prctl_invalid(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, -1L, 0x1, &sel, EINVAL);
+
+       /* 0 len should fail for PR_SYS_DISPATCH_INCLUSIVE_ON */
+       prctl_invalid(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, 1, 0, 0, EINVAL);
+
+       /* Range wrap-around should fail */
+       prctl_invalid(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, -1L, 2, 0, EINVAL);
+
+       /* Normal range shouldn't fail */
+       prctl_valid(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, 2, 3, 0);
+
+       /* Invalid selector */
+       prctl_invalid(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, 2, 3, (void *) -1, EFAULT);
 }
 
 /*
@@ -147,11 +165,13 @@ char glob_sel;
 int nr_syscalls_emulated;
 int si_code;
 int si_errno;
+unsigned long syscall_addr;
 
 static void handle_sigsys(int sig, siginfo_t *info, void *ucontext)
 {
        si_code = info->si_code;
        si_errno = info->si_errno;
+       syscall_addr = (unsigned long)info->si_call_addr;
 
        if (info->si_syscall == MAGIC_SYSCALL_1)
                nr_syscalls_emulated++;
@@ -174,31 +194,34 @@ static void handle_sigsys(int sig, siginfo_t *info, void *ucontext)
 #endif
 }
 
-TEST(dispatch_and_return)
+int setup_sigsys_handler(void)
 {
-       long ret;
        struct sigaction act;
        sigset_t mask;
 
-       glob_sel = 0;
-       nr_syscalls_emulated = 0;
-       si_code = 0;
-       si_errno = 0;
-
        memset(&act, 0, sizeof(act));
        sigemptyset(&mask);
-
        act.sa_sigaction = handle_sigsys;
        act.sa_flags = SA_SIGINFO;
        act.sa_mask = mask;
+       return sigaction(SIGSYS, &act, NULL);
+}
 
-       ret = sigaction(SIGSYS, &act, NULL);
-       ASSERT_EQ(0, ret);
+TEST(dispatch_and_return)
+{
+       long ret;
+
+       glob_sel = 0;
+       nr_syscalls_emulated = 0;
+       si_code = 0;
+       si_errno = 0;
+
+       ASSERT_EQ(0, setup_sigsys_handler());
 
        /* Make sure selector is good prior to prctl. */
        SYSCALL_DISPATCH_OFF(glob_sel);
 
-       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 0, 0, &glob_sel);
+       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, 0, &glob_sel);
        ASSERT_EQ(0, ret) {
                TH_LOG("Kernel does not support CONFIG_SYSCALL_USER_DISPATCH");
        }
@@ -254,7 +277,7 @@ TEST_SIGNAL(bad_selector, SIGSYS)
        /* Make sure selector is good prior to prctl. */
        SYSCALL_DISPATCH_OFF(glob_sel);
 
-       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 0, 0, &glob_sel);
+       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, 0, &glob_sel);
        ASSERT_EQ(0, ret) {
                TH_LOG("Kernel does not support CONFIG_SYSCALL_USER_DISPATCH");
        }
@@ -278,7 +301,7 @@ TEST(disable_dispatch)
        struct sysinfo info;
        char sel = 0;
 
-       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 0, 0, &sel);
+       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, 0, &sel);
        ASSERT_EQ(0, ret) {
                TH_LOG("Kernel does not support CONFIG_SYSCALL_USER_DISPATCH");
        }
@@ -310,7 +333,7 @@ TEST(direct_dispatch_range)
         * Instead of calculating libc addresses; allow the entire
         * memory map and lock the selector.
         */
-       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 0, -1L, &sel);
+       ret = prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, -1L, &sel);
        ASSERT_EQ(0, ret) {
                TH_LOG("Kernel does not support CONFIG_SYSCALL_USER_DISPATCH");
        }
@@ -323,4 +346,35 @@ TEST(direct_dispatch_range)
        }
 }
 
+static void test_range(struct __test_metadata *_metadata,
+                      unsigned long op, unsigned long off,
+                      unsigned long size, bool dispatch)
+{
+       nr_syscalls_emulated = 0;
+       SYSCALL_DISPATCH_OFF(glob_sel);
+       EXPECT_EQ(0, prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, &glob_sel));
+       SYSCALL_DISPATCH_ON(glob_sel);
+       if (dispatch) {
+               EXPECT_EQ(syscall(MAGIC_SYSCALL_1), MAGIC_SYSCALL_1);
+               EXPECT_EQ(nr_syscalls_emulated, 1);
+       } else {
+               EXPECT_EQ(syscall(MAGIC_SYSCALL_1), -1);
+               EXPECT_EQ(nr_syscalls_emulated, 0);
+       }
+}
+
+TEST(dispatch_range)
+{
+       ASSERT_EQ(0, setup_sigsys_handler());
+       test_range(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, 0, 0, true);
+       test_range(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, syscall_addr, 1, false);
+       test_range(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, syscall_addr-100, 200, false);
+       test_range(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, syscall_addr+1, 100, true);
+       test_range(_metadata, PR_SYS_DISPATCH_EXCLUSIVE_ON, syscall_addr-100, 100, true);
+       test_range(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, syscall_addr, 1, true);
+       test_range(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, syscall_addr-1, 1, false);
+       test_range(_metadata, PR_SYS_DISPATCH_INCLUSIVE_ON, syscall_addr+1, 1, false);
+       SYSCALL_DISPATCH_OFF(glob_sel);
+}
+
 TEST_HARNESS_MAIN