/usr/share/systemtap/tapset/atomic.stp is in systemtap-common 1.7-1+deb7u1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | // Atomic functions.
// Copyright (C) 2010 Red Hat Inc.
//
// This file is part of systemtap, and is free software. You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.
/**
* sfunction atomic_read - Retrieves an atomic variable from kernel memory
*
* @addr: pointer to atomic variable
*
* Safely perform the read of an atomic variable.
*/
function atomic_read:long(addr:long)
%{ /* pure */
atomic_t *a = (atomic_t *)(long)THIS->addr;
/* We call deref() here to ensure the memory is valid to read.
* Note the result is thrown away, then we use the "real"
* atomic read function now that we know the address is safe. */
(void)kderef(sizeof(*a), a);
THIS->__retvalue = atomic_read(a);
CATCH_DEREF_FAULT();
%}
/**
* sfunction atomic_long_read - Retrieves an atomic long variable from kernel memory
*
* @addr: pointer to atomic long variable
*
* Safely perform the read of an atomic long variable. This will be a
* NOP on kernels that do not have ATOMIC_LONG_INIT set on the kernel config.
*/
function atomic_long_read:long(addr:long)
%{ /* pure */
#ifdef ATOMIC_LONG_INIT
atomic_long_t *a = (atomic_long_t *)(long)THIS->addr;
/* We call deref() here to ensure the memory is valid to read.
* Note the result is thrown away, then we use the "real"
* atomic read function now that we know the address is safe. */
(void)kderef(sizeof(*a), a);
THIS->__retvalue = atomic_long_read(a);
CATCH_DEREF_FAULT();
#endif
%}
|