VDSO
Encyclopedia
VDSOs are a way to export kernel space routines to user space
applications, using standard mechanisms for linking and loading (i.e. standard ELF
format).
It helps to reduce the calling overhead on simple kernel routines, and also can work as a way to select the best system call
method on some architectures.
An advantage over other methods is that such exported routines can provide proper DWARF
debugging information.
Implementation generally implies hooks in the dynamic linker to find the VDSOs.
User space
A conventional computer operating system usually segregates virtual memory into kernel space and user space. Kernel space is strictly reserved for running the kernel, kernel extensions, and most device drivers...
applications, using standard mechanisms for linking and loading (i.e. standard ELF
ELF
ELF may be:Science* Electron localization function, a concept in quantum mechanics* Extremely low frequency, the band of radio frequencies from 3 to 30 HertzLinguistics...
format).
It helps to reduce the calling overhead on simple kernel routines, and also can work as a way to select the best system call
System call
In computing, a system call is how a program requests a service from an operating system's kernel. This may include hardware related services , creating and executing new processes, and communicating with integral kernel services...
method on some architectures.
An advantage over other methods is that such exported routines can provide proper DWARF
DWARF
DWARF is a widely used, standardized debugging data format. DWARF was originally designed along with Executable and Linkable Format , although it is independent of object file formats...
debugging information.
Implementation generally implies hooks in the dynamic linker to find the VDSOs.