Patch "bpf: Factor out bpf_spin_lock into helpers." has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    bpf: Factor out bpf_spin_lock into helpers.

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bpf-factor-out-bpf_spin_lock-into-helpers.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 2c6156064b0a73d8d4123f43fa28ba10e8bfd922
Author: Alexei Starovoitov <ast@xxxxxxxxxx>
Date:   Wed Jul 14 17:54:08 2021 -0700

    bpf: Factor out bpf_spin_lock into helpers.
    
    [ Upstream commit c1b3fed319d32a721d4b9c17afaeb430444ff773 ]
    
    Move ____bpf_spin_lock/unlock into helpers to make it more clear
    that quadruple underscore bpf_spin_lock/unlock are irqsave/restore variants.
    
    Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Acked-by: Martin KaFai Lau <kafai@xxxxxx>
    Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
    Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20210715005417.78572-3-alexei.starovoitov@xxxxxxxxx
    Stable-dep-of: 178c54666f9c ("bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctly")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a77d2814cac5d..4ba3dc621a345 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -262,13 +262,18 @@ static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
 
 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
 
-notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
 	__bpf_spin_lock(lock);
 	__this_cpu_write(irqsave_flags, flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+	__bpf_spin_lock_irqsave(lock);
 	return 0;
 }
 
@@ -279,13 +284,18 @@ const struct bpf_func_proto bpf_spin_lock_proto = {
 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
 };
 
-notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
 {
 	unsigned long flags;
 
 	flags = __this_cpu_read(irqsave_flags);
 	__bpf_spin_unlock(lock);
 	local_irq_restore(flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+	__bpf_spin_unlock_irqrestore(lock);
 	return 0;
 }
 
@@ -306,9 +316,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
 	else
 		lock = dst + map->spin_lock_off;
 	preempt_disable();
-	____bpf_spin_lock(lock);
+	__bpf_spin_lock_irqsave(lock);
 	copy_map_value(map, dst, src);
-	____bpf_spin_unlock(lock);
+	__bpf_spin_unlock_irqrestore(lock);
 	preempt_enable();
 }