Xtensa returns 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 <[email protected]>
---
tools/testing/selftests/seccomp/seccomp_bpf.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 252140a52553..1b445c2e7fbe 100644
--- 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
--
2.20.1