From cab12fd049380b1d0c3ac9f534407a8cc0ac4bba Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 4 May 2020 19:31:36 -0700 Subject: [PATCH] pstore: Convert "psinfo" locking to mutex Currently pstore can only have a single backend attached at a time, and it tracks the active backend via "psinfo", under a lock. The locking for this does not need to be a spinlock, and in order to avoid may_sleep() issues during future changes to pstore_unregister(), switch to a mutex instead. Link: https://lore.kernel.org/lkml/20200506152114.50375-4-keescook@chromium.org/ Signed-off-by: Kees Cook --- fs/pstore/platform.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 347b6c0..d0ce222 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -72,7 +72,7 @@ static DECLARE_WORK(pstore_work, pstore_dowork); * psinfo_lock just protects "psinfo" during * calls to pstore_register() */ -static DEFINE_SPINLOCK(psinfo_lock); +static DEFINE_MUTEX(psinfo_lock); struct pstore_info *psinfo; static char *backend; @@ -574,11 +574,11 @@ int pstore_register(struct pstore_info *psi) return -EINVAL; } - spin_lock(&psinfo_lock); + mutex_lock(&psinfo_lock); if (psinfo) { pr_warn("backend '%s' already loaded: ignoring '%s'\n", psinfo->name, psi->name); - spin_unlock(&psinfo_lock); + mutex_unlock(&psinfo_lock); return -EBUSY; } @@ -587,7 +587,7 @@ int pstore_register(struct pstore_info *psi) psinfo = psi; mutex_init(&psinfo->read_mutex); sema_init(&psinfo->buf_lock, 1); - spin_unlock(&psinfo_lock); + mutex_unlock(&psinfo_lock); if (psi->flags & PSTORE_FLAGS_DMESG) -- 2.7.4