[GIT pull] locking fixes for 4.20

From: Thomas Gleixner
Date: Sun Nov 11 2018 - 03:11:12 EST


Linus,

please pull the latest locking-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking-urgent-for-linus


A single fix for a build fail with CONFIG_PROFILE_ALL_BRANCHES=y in the
qspinlock code.

Thanks,

tglx

------------------>
Peter Zijlstra (1):
x86/qspinlock: Fix compile error


arch/x86/include/asm/qspinlock.h | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index 87623c6b13db..bd5ac6cc37db 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -13,12 +13,15 @@
#define queued_fetch_set_pending_acquire queued_fetch_set_pending_acquire
static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
{
- u32 val = 0;
-
- if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
- "I", _Q_PENDING_OFFSET))
- val |= _Q_PENDING_VAL;
+ u32 val;

+ /*
+ * We can't use GEN_BINARY_RMWcc() inside an if() stmt because asm goto
+ * and CONFIG_PROFILE_ALL_BRANCHES=y results in a label inside a
+ * statement expression, which GCC doesn't like.
+ */
+ val = GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
+ "I", _Q_PENDING_OFFSET) * _Q_PENDING_VAL;
val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;

return val;