|ARCH_PRCTL(2)||Linux Programmer's Manual||ARCH_PRCTL(2)|
NAMEarch_prctl - set architecture-specific thread state
int arch_prctl(int code , unsigned long addr );
int arch_prctl(int code , unsigned long * addr );
DESCRIPTIONThe arch_prctl() function sets architecture-specific process or thread state. code selects a subfunction and passes argument addr to it; addr is interpreted as either an unsigned long for the "set" operations, or as an unsigned long *, for the "get" operations.
Subfunctions for x86-64 are:
- Set the 64-bit base for the FS register to addr.
- Return the 64-bit base value for the FS register of the current thread in the unsigned long pointed to by addr.
- Set the 64-bit base for the GS register to addr.
- Return the 64-bit base value for the GS register of the current thread in the unsigned long pointed to by addr.
RETURN VALUEOn success, arch_prctl() returns 0; on error, -1 is returned, and errno is set to indicate the error.
- addr points to an unmapped address or is outside the process address space.
- code is not a valid subcommand.
- addr is outside the process address space.
CONFORMING TOarch_prctl() is a Linux/x86-64 extension and should not be used in programs intended to be portable.
NOTESarch_prctl() is supported only on Linux/x86-64 for 64-bit programs currently.
SEE ALSOmmap(2), modify_ldt(2), prctl(2), set_thread_area(2)
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.