Description of problem: Unlike some/most other archs, x86-64 has real syscalls for the SysV IPC operations. This means the special #ifdef LINUX code in the various sys_* functions must be avoided for x86-64. Version-Release number of selected component (if applicable): strace-4.5.12-1.x86_64 How reproducible: always Steps to Reproduce: 1.strace any code using msgsnd, msgrcv, ... 2. 3. Actual results: [pid 19816] msgsnd(98304, {6549608, umovestr: Input/output error 0x8}, 140737484181616, 0x4 /* MSG_??? */) = 0 Expected results: [pid 24526] msgsnd(262149, {1, "\0\0\0\0"}, 4, 0) = 0 Additional info: Attached patch should fix it. There are also some syscall number bugs. 2005-07-31 Ulrich Drepper <drepper> * linux/x86_64/syscallent.h: Fix syscall parameter count for msgrcv and msgctl. * ipc.c: Don't use LINUX specific code in sys_msgctl, sys_msgsnd, sys_msgrcv, sys_semop, sys_shmctl, sys_shmat, sys_shmdt. Add appropriate non-demux code to sys_semtimedop.
Created attachment 117330 [details] Remove special linux demux handling for x86-64
Created attachment 117546 [details] strace-4.5.13-drepper-x86_64-ipc.patch Rediffed for strace-4.5.13.
Your patch breaks it for 32-bit inferiors. I've put in changes upstream that should do the trick.
Fixed in fc4 update and in fc5.