ae97089d49
sd_j_e_u needs to keep a reference to an object while comparing it with possibly duplicate objects in other files. Because the size of mmap cache is limited, with enough files and object to compare to, at some point the object being compared would be munmapped, resulting in a segmentation fault. Fix this issue by turning keep_always into a reference count that can be increased and decreased. Other callers which set keep_always=true are unmodified: their references are never released but are ignored when the whole file is closed, which happens at some point. keep_always is increased in sd_j_e_u and later on released.
56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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#pragma once
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/***
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This file is part of systemd.
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Copyright 2012 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <inttypes.h>
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#include <stdbool.h>
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#include <sys/stat.h>
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typedef struct MMapCache MMapCache;
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MMapCache* mmap_cache_new(void);
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MMapCache* mmap_cache_ref(MMapCache *m);
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MMapCache* mmap_cache_unref(MMapCache *m);
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int mmap_cache_get(
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MMapCache *m,
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int fd,
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int prot,
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unsigned context,
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bool keep_always,
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uint64_t offset,
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size_t size,
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struct stat *st,
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void **ret);
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int mmap_cache_release(
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MMapCache *m,
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int fd,
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int prot,
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unsigned context,
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uint64_t offset,
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size_t size);
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void mmap_cache_close_fd(MMapCache *m, int fd);
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void mmap_cache_close_context(MMapCache *m, unsigned context);
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unsigned mmap_cache_get_hit(MMapCache *m);
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unsigned mmap_cache_get_missed(MMapCache *m);
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