Re: PTRACE_SYSCALL analysis

2013-11-28 Thread Mike Frysinger
On Thursday 28 November 2013 11:59:19 Piotr Szerman wrote: > Hello. I'm writing to ask how strace is able to distinguish a syscall entry > from a syscall exit with ptrace(PTRACE_SYSCALL...)? On x86_64, it seems > you can rely on the -ENOSYS value in RAX. However, for some reason I can't > pick up a

PTRACE_SYSCALL analysis

2013-11-28 Thread Piotr Szerman
Hello. I'm writing to ask how strace is able to distinguish a syscall entry from a syscall exit with ptrace(PTRACE_SYSCALL...)? On x86_64, it seems you can rely on the -ENOSYS value in RAX. However, for some reason I can't pick up an analogous coherent pattern on ARM. I'd be deeply indebted for