Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
module: use RCU to synchronize find_module
Allow for a RCU-sched critical section around find_module, following
the lower level find_module_all helper, and switch the two callers
outside of module.c to use such a RCU-sched critical section instead
of module_mutex.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
authored by
Christoph Hellwig
and committed by
Jessica Yu
a0060505
089049f6
+6
-6
+1
-1
include/linux/module.h
+1
-1
include/linux/module.h
···
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return within_module_init(addr, mod) || within_module_core(addr, mod);
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}
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-
/* Search for module by name: must hold module_mutex. */
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+
/* Search for module by name: must be in a RCU-sched critical section. */
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struct module *find_module(const char *name);
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struct symsearch {
+3
-2
kernel/livepatch/core.c
+3
-2
kernel/livepatch/core.c
···
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#include <linux/moduleloader.h>
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#include <linux/completion.h>
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#include <linux/memory.h>
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#include <linux/rcupdate.h>
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#include <asm/cacheflush.h>
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#include "core.h"
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#include "patch.h"
···
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if (!klp_is_module(obj))
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return;
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-
mutex_lock(&module_mutex);
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rcu_read_lock_sched();
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/*
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* We do not want to block removal of patched modules and therefore
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* we do not take a reference here. The patches are removed by
···
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if (mod && mod->klp_alive)
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obj->mod = mod;
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-
mutex_unlock(&module_mutex);
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rcu_read_unlock_sched();
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}
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static bool klp_initialized(void)
-1
kernel/module.c
-1
kernel/module.c
+2
-2
kernel/trace/trace_kprobe.c
+2
-2
kernel/trace/trace_kprobe.c