diff options
Diffstat (limited to 'debian/patches-rt/0013-net-Use-nested-BH-locking-for-bpf_scratchpad.patch')
| -rw-r--r-- | debian/patches-rt/0013-net-Use-nested-BH-locking-for-bpf_scratchpad.patch | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/debian/patches-rt/0013-net-Use-nested-BH-locking-for-bpf_scratchpad.patch b/debian/patches-rt/0013-net-Use-nested-BH-locking-for-bpf_scratchpad.patch new file mode 100644 index 0000000000..9132b002e6 --- /dev/null +++ b/debian/patches-rt/0013-net-Use-nested-BH-locking-for-bpf_scratchpad.patch @@ -0,0 +1,70 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Thu, 26 Oct 2023 15:17:32 +0200 +Subject: [PATCH 13/15] net: Use nested-BH locking for bpf_scratchpad. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.10/older/patches-6.10.2-rt14.tar.xz + +bpf_scratchpad is a per-CPU variable and relies on disabled BH for its +locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT +this data structure requires explicit locking. + +Add a local_lock_t to the data structure and use local_lock_nested_bh() +for locking. This change adds only lockdep coverage and does not alter +the functional behaviour for !PREEMPT_RT. + +Cc: Alexei Starovoitov <ast@kernel.org> +Cc: Andrii Nakryiko <andrii@kernel.org> +Cc: Hao Luo <haoluo@google.com> +Cc: Jiri Olsa <jolsa@kernel.org> +Cc: John Fastabend <john.fastabend@gmail.com> +Cc: KP Singh <kpsingh@kernel.org> +Cc: Martin KaFai Lau <martin.lau@linux.dev> +Cc: Song Liu <song@kernel.org> +Cc: Stanislav Fomichev <sdf@google.com> +Cc: Yonghong Song <yonghong.song@linux.dev> +Cc: bpf@vger.kernel.org +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + net/core/filter.c | 11 +++++++++-- + 1 file changed, 9 insertions(+), 2 deletions(-) + +--- a/net/core/filter.c ++++ b/net/core/filter.c +@@ -1658,9 +1658,12 @@ struct bpf_scratchpad { + __be32 diff[MAX_BPF_STACK / sizeof(__be32)]; + u8 buff[MAX_BPF_STACK]; + }; ++ local_lock_t bh_lock; + }; + +-static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp); ++static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp) = { ++ .bh_lock = INIT_LOCAL_LOCK(bh_lock), ++}; + + static inline int __bpf_try_make_writable(struct sk_buff *skb, + unsigned int write_len) +@@ -2021,6 +2024,7 @@ BPF_CALL_5(bpf_csum_diff, __be32 *, from + struct bpf_scratchpad *sp = this_cpu_ptr(&bpf_sp); + u32 diff_size = from_size + to_size; + int i, j = 0; ++ __wsum ret; + + /* This is quite flexible, some examples: + * +@@ -2034,12 +2038,15 @@ BPF_CALL_5(bpf_csum_diff, __be32 *, from + diff_size > sizeof(sp->diff))) + return -EINVAL; + ++ local_lock_nested_bh(&bpf_sp.bh_lock); + for (i = 0; i < from_size / sizeof(__be32); i++, j++) + sp->diff[j] = ~from[i]; + for (i = 0; i < to_size / sizeof(__be32); i++, j++) + sp->diff[j] = to[i]; + +- return csum_partial(sp->diff, diff_size, seed); ++ ret = csum_partial(sp->diff, diff_size, seed); ++ local_unlock_nested_bh(&bpf_sp.bh_lock); ++ return ret; + } + + static const struct bpf_func_proto bpf_csum_diff_proto = { |