cvs commit: src/lib/libc/gen Makefile.inc posixshm.c shm_open.3 src/lib/libc/sys Makefile.inc shm_open.2 src/sys/compat/freebsd32 syscalls.master src/sys/conf files src/sys/kern kern_descrip.c syscalls.master uipc_shm.c src/sys/security/mac mac_framework.h ...

[John Baldwin]

jhb         2008-01-08 21:58:16 UTC

  FreeBSD src repository

  Modified files:
    lib/libc/gen         Makefile.inc 
    lib/libc/sys         Makefile.inc shm_open.2 
    sys/compat/freebsd32 syscalls.master 
    sys/conf             files 
    sys/kern             kern_descrip.c syscalls.master 
    sys/security/mac     mac_framework.h mac_policy.h 
    sys/security/mac_stub mac_stub.c 
    sys/security/mac_test mac_test.c 
    sys/sys              fcntl.h file.h mman.h 
    sys/vm               vm_mmap.c 
  Added files:
    sys/kern             uipc_shm.c 
    sys/security/mac     mac_posix_shm.c 
  Removed files:
    lib/libc/gen         posixshm.c shm_open.3 
  Log:
  Add a new file descriptor type for IPC shared memory objects and use it to
  implement shm_open(2) and shm_unlink(2) in the kernel:
  - Each shared memory file descriptor is associated with a swap-backed vm
    object which provides the backing store.  Each descriptor starts off with
    a size of zero, but the size can be altered via ftruncate(2).  The shared
    memory file descriptors also support fstat(2).  read(2), write(2),
    ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
    memory file descriptors.
  - shm_open(2) and shm_unlink(2) are now implemented as system calls that
    manage shared memory file descriptors.  The virtual namespace that maps
    pathnames to shared memory file descriptors is implemented as a hash
    table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
    of the pathname.
  - As an extension, the constant 'SHM_ANON' may be specified in place of the
    path argument to shm_open(2).  In this case, an unnamed shared memory
    file descriptor will be created similar to the IPC_PRIVATE key for
    shmget(2).  Note that the shared memory object can still be shared among
    processes by sharing the file descriptor via fork(2) or sendmsg(2), but
    it is unnamed.  This effectively serves to implement the getmemfd() idea
    bandied about the lists several times over the years.
  - The backing store for shared memory file descriptors are garbage
    collected when they are not referenced by any open file descriptors or
    the shm_open(2) virtual namespace.
  
  Submitted by:   dillon, peter (previous versions)
  Submitted by:   rwatson (I based this on his version)
  Reviewed by:    alc (suggested converting getmemfd() to shm_open())
  
  Revision  Changes    Path
  1.129     +2 -3      src/lib/libc/gen/Makefile.inc
  1.5       +0 -72     src/lib/libc/gen/posixshm.c (dead)
  1.13      +0 -192    src/lib/libc/gen/shm_open.3 (dead)
  1.128     +2 -1      src/lib/libc/sys/Makefile.inc
  1.13      +158 -68   src/lib/libc/sys/shm_open.2
  1.94      +3 -0      src/sys/compat/freebsd32/syscalls.master
  1.1262    +2 -0      src/sys/conf/files
  1.318     +2 -0      src/sys/kern/kern_descrip.c
  1.235     +3 -0      src/sys/kern/syscalls.master
  1.1       +608 -0    src/sys/kern/uipc_shm.c (new)
  1.96      +13 -0     src/sys/security/mac/mac_framework.h
  1.106     +28 -0     src/sys/security/mac/mac_policy.h
  1.1       +146 -0    src/sys/security/mac/mac_posix_shm.c (new)
  1.80      +56 -0     src/sys/security/mac_stub/mac_stub.c
  1.94      +96 -0     src/sys/security/mac_test/mac_test.c
  1.17      +12 -7     src/sys/sys/fcntl.h
  1.76      +1 -0      src/sys/sys/file.h
  1.41      +32 -1     src/sys/sys/mman.h
  1.216     +53 -3     src/sys/vm/vm_mmap.c