Hi Guo Ren, it seems the values of __NR_rt_sigreturn and __NR_getppid are swapped between csky qemu-user and the kernel. In qemu-user [0, 1]: (With context to show the disconuity) #define TARGET_NR_rt_sigqueueinfo 138 --> #define TARGET_NR_rt_sigreturn 173 #define TARGET_NR_setpriority 140 #define TARGET_NR_getpid 172 --> #define TARGET_NR_getppid 139 #define TARGET_NR_getuid 174 The mainline kernel however uses the generic syscall numbers: #define __NR_rt_sigreturn 139 #define __NR_getppid 173 Is this intentional? If so, what am I supposed to do about it? While we are here: Is there a known bug about upstream gcc 14.2.0 (and earlier) loosing track of registers, especially r4, during optimizations? It seems to me that this register gets overwritten sometimes before it is meant to be used. Thanks, Thomas [0] https://raw.githubusercontent.com/XUANTIE-RV/qemu/refs/heads/xuantie-qemu-6.1.0/linux-user/csky/syscall_nr.h [1] https://raw.githubusercontent.com/XUANTIE-RV/qemu/refs/heads/xuantie-qemu-8.0/linux-user/csky/syscall_nr.h
