EVOLUTION-MANAGER

Edit File: atomic.stp

// 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 *)(uintptr_t)STAP_ARG_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); STAP_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 *)(uintptr_t)STAP_ARG_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); STAP_RETVALUE = atomic_long_read(a); CATCH_DEREF_FAULT(); #endif %}