selftests/seccomp: add xtensa support

Xtensa syscall number can be obtained and changed through the
struct user_pt_regs. Syscall return value register is fixed relatively
to the current register window in the user_pt_regs, so it needs a bit of
special treatment.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 252140a525531463cc2872a2ec3d7500fe06f4e8..1b445c2e7fbe2dbef88ab5b01a858a4f014c6a74 100644 (file)
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -122,6 +122,8 @@ struct seccomp_data {
 #  define __NR_seccomp 358
 # elif defined(__s390__)
 #  define __NR_seccomp 348
+# elif defined(__xtensa__)
+#  define __NR_seccomp 337
 # else
 #  warning "seccomp syscall number unknown for this architecture"
 #  define __NR_seccomp 0xffff
@@ -1622,6 +1624,14 @@ TEST_F(TRACE_poke, getpid_runs_normally)
 # define SYSCALL_SYSCALL_NUM regs[4]
 # define SYSCALL_RET   regs[2]
 # define SYSCALL_NUM_RET_SHARE_REG
+#elif defined(__xtensa__)
+# define ARCH_REGS     struct user_pt_regs
+# define SYSCALL_NUM   syscall
+/*
+ * On xtensa syscall return value is in the register
+ * a2 of the current window which is not fixed.
+ */
+#define SYSCALL_RET(reg) a[(reg).windowbase * 4 + 2]
 #else
 # error "Do not know how to find your architecture's registers and syscalls"
 #endif
@@ -1693,7 +1703,8 @@ void change_syscall(struct __test_metadata *_metadata,
        EXPECT_EQ(0, ret) {}
 
 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
-       defined(__s390__) || defined(__hppa__) || defined(__riscv)
+       defined(__s390__) || defined(__hppa__) || defined(__riscv) || \
+       defined(__xtensa__)
        {
                regs.SYSCALL_NUM = syscall;
        }
@@ -1736,6 +1747,9 @@ void change_syscall(struct __test_metadata *_metadata,
        if (syscall == -1)
 #ifdef SYSCALL_NUM_RET_SHARE_REG
                TH_LOG("Can't modify syscall return on this architecture");
+
+#elif defined(__xtensa__)
+               regs.SYSCALL_RET(regs) = result;
 #else
                regs.SYSCALL_RET = result;
 #endif