Unwrapping early produces a much nicer log output.
Disallow recursive syscall, as per ARM and MIPS.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/syscall.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 4f6c01092b..87374014b1 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -10230,11 +10230,6 @@ static abi_long do_syscall1(void *cpu_env, unsigned
num, abi_long arg1,
switch(num) {
case TARGET_NR_vhangup:
return get_errno(vhangup());
-#ifdef TARGET_NR_syscall
- case TARGET_NR_syscall:
- return do_syscall(cpu_env, arg1 & 0xffff, arg2, arg3, arg4, arg5,
- arg6, arg7, arg8, 0);
-#endif
case TARGET_NR_wait4:
{
int status;
@@ -13171,6 +13166,32 @@ abi_long do_syscall(void *cpu_env, unsigned num,
abi_long arg1,
}
}
#endif
+#ifdef TARGET_NR_syscall
+ /* For the benefit of strace, unwrap NR_syscall now. */
+ if (num == TARGET_NR_syscall) {
+ num = arg1 & 0xffff;
+ if (num == TARGET_NR_syscall) {
+ /* Do not allow recursion. */
+ ret = -TARGET_ENOSYS;
+ trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4,
+ arg5, arg6, arg7, arg8);
+ if (unlikely(do_strace)) {
+ print_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
+ print_syscall_ret(num, ret);
+ }
+ trace_guest_user_syscall_ret(cpu, num, ret);
+ return ret;
+ }
+ arg1 = arg2;
+ arg2 = arg3;
+ arg3 = arg4;
+ arg4 = arg5;
+ arg5 = arg6;
+ arg6 = arg7;
+ arg7 = arg8;
+ arg8 = 0;
+ }
+#endif
trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4,
arg5, arg6, arg7, arg8);
--
2.17.1
