Module solana_rbpf::syscalls

This module implements some built-in syscalls that can be called from within an eBPF program.

These syscalls may originate from several places:

• Some of them mimic the syscalls available in the Linux kernel.
• Some of them were proposed as example syscalls in uBPF and they were adapted here.
• Other syscalls may be specific to rbpf.

The prototype for syscalls is always the same: five u64 as arguments, and a u64 as a return value. Hence some syscalls have unused arguments, or return a 0 value in all cases, in order to respect this convention.

Structs

• SyscallGatherBytes
  The idea is to assemble five bytes into a single u64. For compatibility with the syscalls API, each argument must be a u64.
• SyscallMemFrob
  Same as void *memfrob(void *s, size_t n); in string.h in C. See the GNU manual page (in section 3) for memfrob. The memory is directly modified, and the syscall returns 0 in all cases. Arguments 3 to 5 are unused.
• SyscallStrCmp
  C-like strcmp, return 0 if the strings are equal, and a non-null value otherwise.
• SyscallString
  Prints a NULL-terminated UTF-8 string.
• SyscallTracePrintf
  Prints its last three arguments to standard output. The first two arguments are unused. Returns the number of bytes written.
• SyscallU64
  Prints the five arguments formated as u64 in decimal.