How can we implement the system call using sysenter/syscall directly in x86 Linux? Can anybody provide help? It would be even better if you can also show the code for amd64 platform.
I know in x86, we can use
__asm__(
" movl $1, %eax \n"" movl $0, %ebx \n"" call *%gs:0x10 \n"
);
to route to sysenter indirectly.
But how can we code using sysenter/syscall directly to issue a system call?
I find some material http://damocles.blogbus.com/tag/sysenter/ . But still find it difficult to figure out.
