df323337e5
The get_buffers() macro may provide one or two buffers to the caller. Those buffers are pre-allocated on init for each CPU. By default it allocates 2* 2 * MAX_PATH * POSSIBLE_CPU which equals 64KiB on a system with 4 CPUs or 1MiB with 64 CPUs and so on. Replace the per-CPU buffers with a common memory pool which is shared across all CPUs. The pool grows on demand and never shrinks. The pool starts with two (UP) or four (SMP) elements. By using this pool it is possible to request a buffer and keeping preemption enabled which avoids the hack in profile_transition(). It has been pointed out by Tetsuo Handa that GFP_KERNEL allocations for small amount of memory do not fail. In order not to have an endless retry, __GFP_RETRY_MAYFAIL is passed (so the memory allocation is not repeated until success) and retried once hoping that in the meantime a buffer has been returned to the pool. Since now NULL is possible all allocation paths check the buffer pointer and return -ENOMEM on failure. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: John Johansen <john.johansen@canonical.com>
36 lines
1.0 KiB
C
36 lines
1.0 KiB
C
/*
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* AppArmor security module
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*
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* This file contains AppArmor basic path manipulation function definitions.
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*
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* Copyright (C) 1998-2008 Novell/SUSE
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* Copyright 2009-2010 Canonical Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#ifndef __AA_PATH_H
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#define __AA_PATH_H
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enum path_flags {
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PATH_IS_DIR = 0x1, /* path is a directory */
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PATH_CONNECT_PATH = 0x4, /* connect disconnected paths to / */
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PATH_CHROOT_REL = 0x8, /* do path lookup relative to chroot */
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PATH_CHROOT_NSCONNECT = 0x10, /* connect paths that are at ns root */
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PATH_DELEGATE_DELETED = 0x08000, /* delegate deleted files */
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PATH_MEDIATE_DELETED = 0x10000, /* mediate deleted paths */
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};
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int aa_path_name(const struct path *path, int flags, char *buffer,
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const char **name, const char **info,
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const char *disconnected);
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char *aa_get_buffer(void);
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void aa_put_buffer(char *buf);
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#endif /* __AA_PATH_H */
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