Skip to main content

How System Calls Are Implemented on i386 Architecture?

Native Linux programs use int 0x80 whilst binaries from foreign flavours of UNIX (Solaris, UnixWare 7 etc.) use the lcall7 mechanism. The name 'lcall7' is historically misleading because it also covers lcall27 (e.g. Solaris/x86), but the handler function is called lcall7_func.
When the system boots, the function arch/i386/kernel/traps.c:trap_init() is called which sets up the IDT so that vector 0x80 (of type 15, dpl 3) points to the address of system_call entry from arch/i386/kernel/entry.S.read more.

Comments

Post a Comment

Popular posts from this blog

Fixing Unix/Linux/POSIX Filenames

Traditionally, Unix/Linux/POSIX filenames can be almost any sequence of bytes, and their meaning is unassigned. The only real rules are that "/" is always the directory separator, and that filenames can't contain byte 0 (because this is the terminator). Although this is flexible, this creates many unnecessary problems. In particular, this lack of limitations makes it unnecessarily difficult to write correct programs (enabling many security flaws), makes it impossible to consistently and accurately display filenames, causes portability problems, and confuses users. more ....
Post a Comment
Read more

How To Set Up A Cisco Lab On Linux

After a quick search I found the wonderful Dynamips project that goes beyond what other simulators do by running actual Cisco IOS images, as well as the PEMU project which allows for running of Cisco PIX images. To integrate the various pieces of software... more .
Post a Comment
Read more

Installing Samba on a Unix System.

you know what Samba can do for you and your users, it's time to get your own network set up. Let's start with the installation of Samba itself on a Unix system. When dancing the samba, one learns by taking small steps. It's just the same when installing Samba; we need to teach it step by step. This chapter will help you to start off on the right foot. read more
Post a Comment
Read more