diff options
Diffstat (limited to 'debian/patches-rt/0257-apparmor-use-a-locallock-instead-preempt_disable.patch')
| -rw-r--r-- | debian/patches-rt/0257-apparmor-use-a-locallock-instead-preempt_disable.patch | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/debian/patches-rt/0257-apparmor-use-a-locallock-instead-preempt_disable.patch b/debian/patches-rt/0257-apparmor-use-a-locallock-instead-preempt_disable.patch new file mode 100644 index 000000000..c00ea5391 --- /dev/null +++ b/debian/patches-rt/0257-apparmor-use-a-locallock-instead-preempt_disable.patch @@ -0,0 +1,85 @@ +From bc99d234e02c1f42a9a71a2aca38406d1902582b Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Wed, 11 Oct 2017 17:43:49 +0200 +Subject: [PATCH 257/347] apparmor: use a locallock instead preempt_disable() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +get_buffers() disables preemption which acts as a lock for the per-CPU +variable. Since we can't disable preemption here on RT, a local_lock is +lock is used in order to remain on the same CPU and not to have more +than one user within the critical section. + +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + security/apparmor/include/path.h | 19 ++++++++++++++++--- + security/apparmor/lsm.c | 2 +- + 2 files changed, 17 insertions(+), 4 deletions(-) + +diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h +index b6380c5f0097..12abfddb19c9 100644 +--- a/security/apparmor/include/path.h ++++ b/security/apparmor/include/path.h +@@ -40,8 +40,10 @@ struct aa_buffers { + + #include <linux/percpu.h> + #include <linux/preempt.h> ++#include <linux/locallock.h> + + DECLARE_PER_CPU(struct aa_buffers, aa_buffers); ++DECLARE_LOCAL_IRQ_LOCK(aa_buffers_lock); + + #define ASSIGN(FN, A, X, N) ((X) = FN(A, N)) + #define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/ +@@ -51,7 +53,17 @@ DECLARE_PER_CPU(struct aa_buffers, aa_buffers); + + #define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++) + +-#ifdef CONFIG_DEBUG_PREEMPT ++#ifdef CONFIG_PREEMPT_RT_BASE ++static inline void AA_BUG_PREEMPT_ENABLED(const char *s) ++{ ++ struct local_irq_lock *lv; ++ ++ lv = this_cpu_ptr(&aa_buffers_lock); ++ WARN_ONCE(lv->owner != current, ++ "__get_buffer without aa_buffers_lock\n"); ++} ++ ++#elif defined(CONFIG_DEBUG_PREEMPT) + #define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X) + #else + #define AA_BUG_PREEMPT_ENABLED(X) /* nop */ +@@ -67,14 +79,15 @@ DECLARE_PER_CPU(struct aa_buffers, aa_buffers); + + #define get_buffers(X...) \ + do { \ +- struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers); \ ++ struct aa_buffers *__cpu_var; \ ++ __cpu_var = get_locked_ptr(aa_buffers_lock, &aa_buffers); \ + __get_buffers(__cpu_var, X); \ + } while (0) + + #define put_buffers(X, Y...) \ + do { \ + __put_buffers(X, Y); \ +- put_cpu_ptr(&aa_buffers); \ ++ put_locked_ptr(aa_buffers_lock, &aa_buffers); \ + } while (0) + + #endif /* __AA_PATH_H */ +diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c +index 898752b818dc..690c8fccd0a0 100644 +--- a/security/apparmor/lsm.c ++++ b/security/apparmor/lsm.c +@@ -45,7 +45,7 @@ + int apparmor_initialized; + + DEFINE_PER_CPU(struct aa_buffers, aa_buffers); +- ++DEFINE_LOCAL_IRQ_LOCK(aa_buffers_lock); + + /* + * LSM hook functions +-- +2.36.1 + |