Linux Manuals session 2

s390_pci_mmio_write, s390_pci_mmio_read – transfer data to/from PCI MMIO memory page Synopsis#include <asm/unistd.h> int s390_pci_mmio_write(unsigned long mmio_addr, void *user_buffer, size_t length); int s390_pci_mmio_read(unsigned long mmio_addr, void *user_buffer, size_t length);DescriptionThe s390_pci_mmio_write() system call writes length bytes of data from the user-space buffer user_buffer to the PCI MMIO memory location specified by mmio_addr. The s390_pci_mmio_read() system call reads…

s390_pci_mmio_write, s390_pci_mmio_read – transfer data to/from PCI MMIO memory page Synopsis#include <asm/unistd.h> int s390_pci_mmio_write(unsigned long mmio_addr, void *user_buffer, size_t length); int s390_pci_mmio_read(unsigned long mmio_addr, void *user_buffer, size_t length);DescriptionThe s390_pci_mmio_write() system call writes length bytes of data from the user-space buffer user_buffer to the PCI MMIO memory location specified by mmio_addr. The s390_pci_mmio_read() system call reads…

s390_guarded_storage – operations with z/Architecture guarded storage facility Synopsis#include <asm/guarded_storage.h> int s390_guarded_storage(int command, struct gs_cb *gs_cb);DescriptionThe s390_guarded_storage() system call enables the use of the Guarded Storage Facility (a z/Architecture-specific feature) for user-space processes. The guarded storage facility is a hardware feature that allows marking up to 64 memory regions (as of z14) as guarded; reading…

rtas – Allows userspace to call RTAS (Run Time Abstraction Services) Synopsisint ppc_rtas (struct rtas_args *uargs); Descriptionppc_rtas enables userspace manipulation of the RunTime Abstraction Services (RTAS). RTAS provides for a portable method of access and setting system information. For example, you could gather information on various system sensors and set poweron values. RTAS is accessed via the /proc…

rt_sigqueueinfo, rt_tgsigqueueinfo – queue a signal and data Synopsisint rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *info); int rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, siginfo_t *info);Note: There are no glibc wrappers for these system calls; see NOTES. DescriptionThe rt_sigqueueinfo() and rt_tgsigqueueinfo() system calls are the low-level interfaces used to send a signal plus data to a process…

sigwaitinfo, sigtimedwait, rt_sigtimedwait – synchronously wait for queued signals Synopsis#include <signal.h> int sigwaitinfo(const sigset_t *set, siginfo_t *info); int sigtimedwait(const sigset_t *set, siginfo_t *info, const struct timespec *timeout);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigwaitinfo(), sigtimedwait(): _POSIX_C_SOURCE >= 199309L Descriptionsigwaitinfo() suspends execution of the calling thread until one of the signals in set is pending (If one…

sigsuspend, rt_sigsuspend – wait for a signal Synopsis#include <signal.h> int sigsuspend(const sigset_t *mask); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigsuspend(): _POSIX_C_SOURCE Descriptionsigsuspend() temporarily replaces the signal mask of the calling thread with the mask given by mask and then suspends the thread until delivery of a signal whose action is to invoke a…

sigreturn, rt_sigreturn – return from signal handler and cleanup stack frame Synopsisint sigreturn(…); DescriptionIf the Linux kernel determines that an unblocked signal is pending for a process, then, at the next transition back to user mode in that process (e.g., upon return from a system call or when the process is rescheduled onto the CPU),…

rt_sigqueueinfo, rt_tgsigqueueinfo – queue a signal and data Synopsisint rt_sigqueueinfo(pid_t tgid, int sig, siginfo_t *info); int rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, siginfo_t *info);Note: There are no glibc wrappers for these system calls; see NOTES. DescriptionThe rt_sigqueueinfo() and rt_tgsigqueueinfo() system calls are the low-level interfaces used to send a signal plus data to a process…

sigprocmask, rt_sigprocmask – examine and change blocked signals Synopsis#include <signal.h> /* Prototype for the glibc wrapper function */ int sigprocmask(int how, const sigset_t *set, sigset_t *oldset); /* Prototype for the underlying system call */ int rt_sigprocmask(int how, const kernel_sigset_t *set, kernel_sigset_t *oldset, size_t sigsetsize); /* Prototype for the legacy system call (deprecated) */ int sigprocmask(int…

sigpending, rt_sigpending – examine pending signals Synopsis#include <signal.h> int sigpending(sigset_t *set); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigpending(): _POSIX_C_SOURCE Descriptionsigpending() returns the set of signals that are pending for delivery to the calling thread (i.e., the signals which have been raised while blocked). The mask of pending signals is returned in set. Return…

sigaction, rt_sigaction – examine and change a signal action Synopsis#include <signal.h> int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact);Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigaction(): _POSIX_C_SOURCE siginfo_t: _POSIX_C_SOURCE >= 199309L DescriptionThe sigaction() system call is used to change the action taken by a process on receipt of a specific signal. (See…

rmdir – delete a directory Synopsis#include <unistd.h> int rmdir(const char *pathname); Descriptionrmdir() deletes a directory, which must be empty. Return ValueOn success, zero is returned. On error, -1 is returned, and errno is set appropriately. ErrorsEACCES Write access to the directory containing pathname was not allowed, or one of the directories in the path prefix…

restart_syscall – restart a system call after interruption by a stop signal Synopsislong restart_syscall(void); Note: There is no glibc wrapper for this system call; see NOTES. DescriptionThe restart_syscall() system call is used to restart certain system calls after a process that was stopped by a signal (e.g., SIGSTOP or SIGTSTP) is later resumed after receiving…

request_key – request a key from the kernel’s key management facility Synopsis#include <sys/types.h> #include <keyutils.h> key_serial_t request_key(const char *type, const char *description, const char *callout_info, key_serial_t dest_keyring);No glibc wrapper is provided for this system call; see NOTES. Descriptionrequest_key() attempts to find a key of the given type with a description (name) that matches the specified…

rename, renameat, renameat2 – change the name or location of a file Synopsis#include <stdio.h> int rename(const char *oldpath, const char *newpath); #include <fcntl.h> /* Definition of AT_* constants */ #include <stdio.h> int renameat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath); int renameat2(int olddirfd, const char *oldpath, int newdirfd, const char *newpath, unsigned int…

rename, renameat, renameat2 – change the name or location of a file Synopsis#include <stdio.h> int rename(const char *oldpath, const char *newpath); #include <fcntl.h> /* Definition of AT_* constants */ #include <stdio.h> int renameat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath); int renameat2(int olddirfd, const char *oldpath, int newdirfd, const char *newpath, unsigned int…

rename, renameat, renameat2 – change the name or location of a file Synopsis#include <stdio.h> int rename(const char *oldpath, const char *newpath); #include <fcntl.h> /* Definition of AT_* constants */ #include <stdio.h> int renameat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath); int renameat2(int olddirfd, const char *oldpath, int newdirfd, const char *newpath, unsigned int…

removexattr, lremovexattr, fremovexattr – remove an extended attribute Synopsis#include <sys/types.h> #include <sys/xattr.h> int removexattr(const char *path, const char *name); int lremovexattr(const char *path, const char *name); int fremovexattr(int fd, const char *name);DescriptionExtended attributes are name:value pairs associated with inodes (files, directories, symbolic links, etc.). They are extensions to the normal attributes which are associated with all inodes in the system…

remap_file_pages – create a nonlinear file mapping Synopsis#define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/mman.h> int remap_file_pages(void *addr, size_t size, int prot, size_t pgoff, int flags);DescriptionNote: this system call was marked as deprecated starting with Linux 3.16. In Linux 4.0, the implementation was replaced by a slower in-kernel emulation. Those few applications that use this…