arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 331 insertions, 0 deletions

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
new file mode 100644
index 000000000..485d55b66
--- /dev/null
+++ b/include/net/mptcp.h
@@ -0,0 +1,331 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Multipath TCP
+ *
+ * Copyright (c) 2017 - 2019, Intel Corporation.
+ */
+
+#ifndef __NET_MPTCP_H
+#define __NET_MPTCP_H
+
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/types.h>
+
+struct mptcp_info;
+struct mptcp_sock;
+struct mptcp_pm_addr_entry;
+struct seq_file;
+
+/* MPTCP sk_buff extension data */
+struct mptcp_ext {
+	u64		data_seq;
+	u32		subflow_seq;
+	u16		data_len;
+	__sum16		csum;
+
+	struct_group(flags,
+		u8	use_map:1,
+			dsn64:1,
+			data_fin:1,
+			use_ack:1,
+			ack64:1,
+			mpc_map:1,
+			frozen:1,
+			reset_transient:1;
+		u8	reset_reason:4,
+			csum_reqd:1,
+			infinite_map:1;
+	); /* end of flags group */
+};
+
+#define MPTCPOPT_HMAC_LEN	20
+#define MPTCP_RM_IDS_MAX	8
+
+struct mptcp_rm_list {
+	u8 ids[MPTCP_RM_IDS_MAX];
+	u8 nr;
+};
+
+struct mptcp_addr_info {
+	u8			id;
+	sa_family_t		family;
+	__be16			port;
+	union {
+		struct in_addr	addr;
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+		struct in6_addr	addr6;
+#endif
+	};
+};
+
+struct mptcp_out_options {
+#if IS_ENABLED(CONFIG_MPTCP)
+	u16 suboptions;
+	struct mptcp_rm_list rm_list;
+	u8 join_id;
+	u8 backup;
+	u8 reset_reason:4,
+	   reset_transient:1,
+	   csum_reqd:1,
+	   allow_join_id0:1,
+	   drop_ts:1;
+	union {
+		struct {
+			u64 sndr_key;
+			u64 rcvr_key;
+			u64 data_seq;
+			u32 subflow_seq;
+			u16 data_len;
+			__sum16 csum;
+		};
+		struct {
+			struct mptcp_addr_info addr;
+			u64 ahmac;
+		};
+		struct {
+			struct mptcp_ext ext_copy;
+			u64 fail_seq;
+		};
+		struct {
+			u32 nonce;
+			u32 token;
+			u64 thmac;
+			u8 hmac[MPTCPOPT_HMAC_LEN];
+		};
+	};
+#endif
+};
+
+#define MPTCP_SCHED_NAME_MAX	16
+#define MPTCP_SCHED_MAX		128
+#define MPTCP_SCHED_BUF_MAX	(MPTCP_SCHED_NAME_MAX * MPTCP_SCHED_MAX)
+
+struct mptcp_sched_ops {
+	int (*get_send)(struct mptcp_sock *msk);
+	int (*get_retrans)(struct mptcp_sock *msk);
+
+	char			name[MPTCP_SCHED_NAME_MAX];
+	struct module		*owner;
+	struct list_head	list;
+
+	void (*init)(struct mptcp_sock *msk);
+	void (*release)(struct mptcp_sock *msk);
+} ____cacheline_aligned_in_smp;
+
+#define MPTCP_PM_NAME_MAX	16
+#define MPTCP_PM_MAX		128
+#define MPTCP_PM_BUF_MAX	(MPTCP_PM_NAME_MAX * MPTCP_PM_MAX)
+
+struct mptcp_pm_ops {
+	char			name[MPTCP_PM_NAME_MAX];
+	struct module		*owner;
+	struct list_head	list;
+
+	void (*init)(struct mptcp_sock *msk);
+	void (*release)(struct mptcp_sock *msk);
+} ____cacheline_aligned_in_smp;
+
+#ifdef CONFIG_MPTCP
+void mptcp_init(void);
+
+static inline bool sk_is_mptcp(const struct sock *sk)
+{
+	return tcp_sk(sk)->is_mptcp;
+}
+
+static inline bool rsk_is_mptcp(const struct request_sock *req)
+{
+	return tcp_rsk(req)->is_mptcp;
+}
+
+static inline bool rsk_drop_req(const struct request_sock *req)
+{
+	return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
+}
+
+void mptcp_space(const struct sock *ssk, int *space, int *full_space);
+bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
+		       unsigned int *size, struct mptcp_out_options *opts);
+bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
+			  struct mptcp_out_options *opts);
+int mptcp_established_options(struct sock *sk, struct sk_buff *skb,
+			      unsigned int remaining, bool has_ts,
+			      struct mptcp_out_options *opts);
+bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
+
+void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
+			 struct mptcp_out_options *opts);
+
+void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);
+
+/* move the skb extension owership, with the assumption that 'to' is
+ * newly allocated
+ */
+static inline void mptcp_skb_ext_move(struct sk_buff *to,
+				      struct sk_buff *from)
+{
+	if (!skb_ext_exist(from, SKB_EXT_MPTCP))
+		return;
+
+	if (WARN_ON_ONCE(to->active_extensions))
+		skb_ext_put(to);
+
+	to->active_extensions = from->active_extensions;
+	to->extensions = from->extensions;
+	from->active_extensions = 0;
+}
+
+static inline void mptcp_skb_ext_copy(struct sk_buff *to,
+				      struct sk_buff *from)
+{
+	struct mptcp_ext *from_ext;
+
+	from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
+	if (!from_ext)
+		return;
+
+	from_ext->frozen = 1;
+	skb_ext_copy(to, from);
+}
+
+static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
+				     const struct mptcp_ext *from_ext)
+{
+	/* MPTCP always clears the ext when adding it to the skb, so
+	 * holes do not bother us here
+	 */
+	return !from_ext ||
+	       (to_ext && from_ext &&
+	        !memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
+}
+
+/* check if skbs can be collapsed.
+ * MPTCP collapse is allowed if neither @to or @from carry an mptcp data
+ * mapping, or if the extension of @to is the same as @from.
+ * Collapsing is not possible if @to lacks an extension, but @from carries one.
+ */
+static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
+					  const struct sk_buff *from)
+{
+	return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
+				 skb_ext_find(from, SKB_EXT_MPTCP));
+}
+
+void mptcp_seq_show(struct seq_file *seq);
+int mptcp_subflow_init_cookie_req(struct request_sock *req,
+				  const struct sock *sk_listener,
+				  struct sk_buff *skb);
+struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
+					       struct sock *sk_listener,
+					       bool attach_listener);
+
+__be32 mptcp_get_reset_option(const struct sk_buff *skb);
+
+static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
+{
+	if (skb_ext_exist(skb, SKB_EXT_MPTCP))
+		return mptcp_get_reset_option(skb);
+
+	return htonl(0u);
+}
+
+void mptcp_active_detect_blackhole(struct sock *sk, bool expired);
+#else
+
+static inline void mptcp_init(void)
+{
+}
+
+static inline bool sk_is_mptcp(const struct sock *sk)
+{
+	return false;
+}
+
+static inline bool rsk_is_mptcp(const struct request_sock *req)
+{
+	return false;
+}
+
+static inline bool rsk_drop_req(const struct request_sock *req)
+{
+	return false;
+}
+
+static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
+				     unsigned int *size,
+				     struct mptcp_out_options *opts)
+{
+	return false;
+}
+
+static inline bool mptcp_synack_options(const struct request_sock *req,
+					unsigned int *size,
+					struct mptcp_out_options *opts)
+{
+	return false;
+}
+
+static inline bool mptcp_incoming_options(struct sock *sk,
+					  struct sk_buff *skb)
+{
+	return true;
+}
+
+static inline void mptcp_skb_ext_move(struct sk_buff *to,
+				      const struct sk_buff *from)
+{
+}
+
+static inline void mptcp_skb_ext_copy(struct sk_buff *to,
+				      struct sk_buff *from)
+{
+}
+
+static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
+					  const struct sk_buff *from)
+{
+	return true;
+}
+
+static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
+static inline void mptcp_seq_show(struct seq_file *seq) { }
+
+static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
+						const struct sock *sk_listener,
+						struct sk_buff *skb)
+{
+	return 0; /* TCP fallback */
+}
+
+static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
+							     struct sock *sk_listener,
+							     bool attach_listener)
+{
+	return NULL;
+}
+
+static inline __be32 mptcp_reset_option(const struct sk_buff *skb)  { return htonl(0u); }
+
+static inline void mptcp_active_detect_blackhole(struct sock *sk, bool expired) { }
+#endif /* CONFIG_MPTCP */
+
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+int mptcpv6_init(void);
+void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
+#elif IS_ENABLED(CONFIG_IPV6)
+static inline int mptcpv6_init(void) { return 0; }
+static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
+#endif
+
+#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
+struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
+#else
+static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
+#endif
+
+#if !IS_ENABLED(CONFIG_MPTCP)
+struct mptcp_sock { };
+#endif
+
+#endif /* __NET_MPTCP_H */