10 docs tagged with "syscalls"

"We do not break user space" is usually quoted as a slogan. Treated as an engineering constraint it is

A syscall has no calling convention of its own. It borrows one — the same general-purpose registers a

There is a rule that sounds like bureaucracy and is not: the kernel may never dereference a user

End to end in the QEMU lab: define it, wire the table, rebuild, boot, call it, and watch it in

There is a layer most C programmers forget is there. Almost nobody calls the kernel directly — they

Some of what happens between the SYSCALL instruction and dosyscall64 is done by the CPU, because

Behind a grand-sounding interface is a mundane mechanism: the syscall number is an index, that index

Some "system calls" are not system calls. clock_gettime is called millions of times a second by

Watching a syscall and changing what it does are completely different mechanisms with completely

A system call is not a function call into the kernel. It is a deliberate, hardware-mediated