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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2023-05-09 15:49:02 +0200 |
|---|---|---|
| committer | Luis Chamberlain <mcgrof@kernel.org> | 2023-05-24 07:23:18 +0200 |
| commit | cb0b50b813f6198b7d44ae8e169803440333577a (patch) | |
| tree | cdfef99608a1e25ec39c5e685ec42e9494c343bb /kernel/module | |
| parent | module: Fix use-after-free bug in read_file_mod_stats() (diff) | |
| download | linux-cb0b50b813f6198b7d44ae8e169803440333577a.tar.xz linux-cb0b50b813f6198b7d44ae8e169803440333577a.zip | |
module: Remove preempt_disable() from module reference counting.
The preempt_disable() section in module_put() was added in commit
e1783a240f491 ("module: Use this_cpu_xx to dynamically allocate counters")
while the per-CPU counter were switched to another API. The API requires
that during the RMW operation the CPU remained the same.
This counting API was later replaced with atomic_t in commit
2f35c41f58a97 ("module: Replace module_ref with atomic_t refcnt")
Since this atomic_t replacement there is no need to keep preemption
disabled while the reference counter is modified.
Remove preempt_disable() from module_put(), __module_get() and
try_module_get().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'kernel/module')
| -rw-r--r-- | kernel/module/main.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/kernel/module/main.c b/kernel/module/main.c index 044aa2c9e3cb..ea7d0c7f3e60 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -820,10 +820,8 @@ static struct module_attribute modinfo_refcnt = void __module_get(struct module *module) { if (module) { - preempt_disable(); atomic_inc(&module->refcnt); trace_module_get(module, _RET_IP_); - preempt_enable(); } } EXPORT_SYMBOL(__module_get); @@ -833,15 +831,12 @@ bool try_module_get(struct module *module) bool ret = true; if (module) { - preempt_disable(); /* Note: here, we can fail to get a reference */ if (likely(module_is_live(module) && atomic_inc_not_zero(&module->refcnt) != 0)) trace_module_get(module, _RET_IP_); else ret = false; - - preempt_enable(); } return ret; } @@ -852,11 +847,9 @@ void module_put(struct module *module) int ret; if (module) { - preempt_disable(); ret = atomic_dec_if_positive(&module->refcnt); WARN_ON(ret < 0); /* Failed to put refcount */ trace_module_put(module, _RET_IP_); - preempt_enable(); } } EXPORT_SYMBOL(module_put); |