diff options
| author | Christoph Hellwig <hch@lst.de> | 2021-02-02 13:13:25 +0100 |
|---|---|---|
| committer | Jessica Yu <jeyu@kernel.org> | 2021-02-08 12:21:40 +0100 |
| commit | a006050575745ca2be25118b90f1c37f454ac542 (patch) | |
| tree | 443ebee9efd98b83825c939c1a8879613ac32561 | |
| parent | 089049f6c9956c5cf1fc89fe10229c76e99f4bef (diff) | |
| download | linux-a006050575745ca2be25118b90f1c37f454ac542.tar.bz2 | |
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>
| -rw-r--r-- | include/linux/module.h | 2 | ||||
| -rw-r--r-- | kernel/livepatch/core.c | 5 | ||||
| -rw-r--r-- | kernel/module.c | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 4 |
4 files changed, 6 insertions, 6 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 7a0bcb5b1ffc..a64aa84d1b18 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -586,7 +586,7 @@ static inline bool within_module(unsigned long addr, const struct module *mod) return within_module_init(addr, mod) || within_module_core(addr, mod); } -/* Search for module by name: must hold module_mutex. */ +/* Search for module by name: must be in a RCU-sched critical section. */ struct module *find_module(const char *name); struct symsearch { diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index f76fdb925532..262cd9b003b9 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -19,6 +19,7 @@ #include <linux/moduleloader.h> #include <linux/completion.h> #include <linux/memory.h> +#include <linux/rcupdate.h> #include <asm/cacheflush.h> #include "core.h" #include "patch.h" @@ -57,7 +58,7 @@ static void klp_find_object_module(struct klp_object *obj) if (!klp_is_module(obj)) return; - mutex_lock(&module_mutex); + rcu_read_lock_sched(); /* * We do not want to block removal of patched modules and therefore * we do not take a reference here. The patches are removed by @@ -74,7 +75,7 @@ static void klp_find_object_module(struct klp_object *obj) if (mod && mod->klp_alive) obj->mod = mod; - mutex_unlock(&module_mutex); + rcu_read_unlock_sched(); } static bool klp_initialized(void) diff --git a/kernel/module.c b/kernel/module.c index 8fb16e704b89..63cc03393a07 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -668,7 +668,6 @@ static struct module *find_module_all(const char *name, size_t len, struct module *find_module(const char *name) { - module_assert_mutex(); return find_module_all(name, strlen(name), false); } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index e6fba1798771..3137992baa5e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -124,9 +124,9 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) if (!p) return true; *p = '\0'; - mutex_lock(&module_mutex); + rcu_read_lock_sched(); ret = !!find_module(tk->symbol); - mutex_unlock(&module_mutex); + rcu_read_unlock_sched(); *p = ':'; return ret; |