From e45b4843ab10e7521e7d564159d1b399af0448f5 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sun, 10 Aug 2014 20:50:30 -0700 Subject: [PATCH] seccomp: Replace BUG(!spin_is_locked()) with assert_spin_lock Current upstream kernel hangs with mips and powerpc targets in uniprocessor mode if SECCOMP is configured. Bisect points to commit dbd952127d11 ("seccomp: introduce writer locking"). Turns out that code such as BUG_ON(!spin_is_locked(&list_lock)); can not be used in uniprocessor mode because spin_is_locked() always returns false in this configuration, and that assert_spin_locked() exists for that very purpose and must be used instead. Fixes: dbd952127d11 ("seccomp: introduce writer locking") Cc: Kees Cook Signed-off-by: Guenter Roeck Signed-off-by: Kees Cook Git-commit: 9ac860041db860a59bfd6ac82b31d6b6f76ebb52 Git-repo: https://android.googlesource.com/kernel/common.git Signed-off-by: Ian Maund --- kernel/fork.c | 2 +- kernel/seccomp.c | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index ee1cff7dec24..b1d0b618c3e5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1125,7 +1125,7 @@ static void copy_seccomp(struct task_struct *p) * needed because this new task is not yet running and cannot * be racing exec. */ - BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + assert_spin_locked(¤t->sighand->siglock); /* Ref-count the new filter user, and assign it. */ get_seccomp_filter(current); diff --git a/kernel/seccomp.c b/kernel/seccomp.c index ebdaaf427de2..1fbb1a2bc459 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -229,7 +229,7 @@ static u32 seccomp_run_filters(int syscall) static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode) { - BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + assert_spin_locked(¤t->sighand->siglock); if (current->seccomp.mode && current->seccomp.mode != seccomp_mode) return false; @@ -240,7 +240,7 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode) static inline void seccomp_assign_mode(struct task_struct *task, unsigned long seccomp_mode) { - BUG_ON(!spin_is_locked(&task->sighand->siglock)); + assert_spin_locked(&task->sighand->siglock); task->seccomp.mode = seccomp_mode; /* @@ -279,7 +279,7 @@ static inline pid_t seccomp_can_sync_threads(void) struct task_struct *thread, *caller; BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); - BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + assert_spin_locked(¤t->sighand->siglock); /* Validate all threads being eligible for synchronization. */ caller = current; @@ -320,7 +320,7 @@ static inline void seccomp_sync_threads(void) struct task_struct *thread, *caller; BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); - BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + assert_spin_locked(¤t->sighand->siglock); /* Synchronize all threads. */ caller = current; @@ -466,7 +466,7 @@ static long seccomp_attach_filter(unsigned int flags, unsigned long total_insns; struct seccomp_filter *walker; - BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + assert_spin_locked(¤t->sighand->siglock); /* Validate resulting filter length. */ total_insns = filter->len;