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kernel: selinux: rules: Remove unnecessary RCU dereference in get_policydb()

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get_policydb() uses rcu_dereference() to read pointers to selinux_state.policy.
But in the SELinux implementation, these pointers are assigned once during
initialization and never changed with rcu_assign_pointer(), rendering the
rcu_dereference() call in get_policydb() completely useless. This just adds
unwanted overhead and implies concurrency pattern that is not even present in
the kernel.

Therefore, read the pointers directly since it's safe.

* selinux_state.ss needs more context.

Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
This commit is contained in:
Tashfin Shakeer Rhythm
2025-08-01 00:54:50 +06:00
committed by ShirkNeko
parent 8eb2c79471
commit 157df04c8b
1 changed files with 2 additions and 2 deletions
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4
kernel/selinux/rules.c
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@@ -24,10 +24,10 @@ static struct policydb *get_policydb(void)
// selinux_state does not exists before 4.19 // selinux_state does not exists before 4.19
#ifdef KSU_COMPAT_USE_SELINUX_STATE #ifdef KSU_COMPAT_USE_SELINUX_STATE
#ifdef SELINUX_POLICY_INSTEAD_SELINUX_SS #ifdef SELINUX_POLICY_INSTEAD_SELINUX_SS
struct selinux_policy *policy = rcu_dereference(selinux_state.policy); struct selinux_policy *policy = selinux_state.policy;
db = &policy->policydb; db = &policy->policydb;
#else #else
struct selinux_ss *ss = rcu_dereference(selinux_state.ss); struct selinux_ss *ss = selinux_state.ss;
db = &ss->policydb; db = &ss->policydb;
#endif #endif
#else #else