Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 321 insertions, 0 deletions

diff --git a/include/net/erspan.h b/include/net/erspan.h
new file mode 100644
index 000000000..c6209e7b6
--- /dev/null
+++ b/include/net/erspan.h
@@ -0,0 +1,321 @@
+#ifndef __LINUX_ERSPAN_H
+#define __LINUX_ERSPAN_H
+
+/*
+ * GRE header for ERSPAN type I encapsulation (4 octets [34:37])
+ *      0                   1                   2                   3
+ *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |0|0|0|0|0|00000|000000000|00000|    Protocol Type for ERSPAN   |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *  The Type I ERSPAN frame format is based on the barebones IP + GRE
+ *  encapsulation (as described above) on top of the raw mirrored frame.
+ *  There is no extra ERSPAN header.
+ *
+ *
+ * GRE header for ERSPAN type II and II encapsulation (8 octets [34:41])
+ *       0                   1                   2                   3
+ *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |0|0|0|1|0|00000|000000000|00000|    Protocol Type for ERSPAN   |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |      Sequence Number (increments per packet per session)      |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *  Note that in the above GRE header [RFC1701] out of the C, R, K, S,
+ *  s, Recur, Flags, Version fields only S (bit 03) is set to 1. The
+ *  other fields are set to zero, so only a sequence number follows.
+ *
+ *  ERSPAN Version 1 (Type II) header (8 octets [42:49])
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |  Ver  |          VLAN         | COS | En|T|    Session ID     |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |      Reserved         |                  Index                |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *
+ *  ERSPAN Version 2 (Type III) header (12 octets [42:49])
+ *  0                   1                   2                   3
+ *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |  Ver  |          VLAN         | COS |BSO|T|     Session ID    |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                          Timestamp                            |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |             SGT               |P|    FT   |   Hw ID   |D|Gra|O|
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *      Platform Specific SubHeader (8 octets, optional)
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |  Platf ID |               Platform Specific Info              |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |                  Platform Specific Info                       |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB
+ */
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/skbuff.h>
+#include <uapi/linux/erspan.h>
+
+#define ERSPAN_VERSION	0x1	/* ERSPAN type II */
+#define VER_MASK	0xf000
+#define VLAN_MASK	0x0fff
+#define COS_MASK	0xe000
+#define EN_MASK		0x1800
+#define T_MASK		0x0400
+#define ID_MASK		0x03ff
+#define INDEX_MASK	0xfffff
+
+#define ERSPAN_VERSION2	0x2	/* ERSPAN type III*/
+#define BSO_MASK	EN_MASK
+#define SGT_MASK	0xffff0000
+#define P_MASK		0x8000
+#define FT_MASK		0x7c00
+#define HWID_MASK	0x03f0
+#define DIR_MASK	0x0008
+#define GRA_MASK	0x0006
+#define O_MASK		0x0001
+
+#define HWID_OFFSET    4
+#define DIR_OFFSET     3
+
+enum erspan_encap_type {
+	ERSPAN_ENCAP_NOVLAN = 0x0,	/* originally without VLAN tag */
+	ERSPAN_ENCAP_ISL = 0x1,		/* originally ISL encapsulated */
+	ERSPAN_ENCAP_8021Q = 0x2,	/* originally 802.1Q encapsulated */
+	ERSPAN_ENCAP_INFRAME = 0x3,	/* VLAN tag preserved in frame */
+};
+
+#define ERSPAN_V1_MDSIZE	4
+#define ERSPAN_V2_MDSIZE	8
+
+struct erspan_base_hdr {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8	vlan_upper:4,
+		ver:4;
+	__u8	vlan:8;
+	__u8	session_id_upper:2,
+		t:1,
+		en:2,
+		cos:3;
+	__u8	session_id:8;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u8	ver: 4,
+		vlan_upper:4;
+	__u8	vlan:8;
+	__u8	cos:3,
+		en:2,
+		t:1,
+		session_id_upper:2;
+	__u8	session_id:8;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+};
+
+static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
+{
+	ershdr->session_id = id & 0xff;
+	ershdr->session_id_upper = (id >> 8) & 0x3;
+}
+
+static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
+{
+	return (ershdr->session_id_upper << 8) + ershdr->session_id;
+}
+
+static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
+{
+	ershdr->vlan = vlan & 0xff;
+	ershdr->vlan_upper = (vlan >> 8) & 0xf;
+}
+
+static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
+{
+	return (ershdr->vlan_upper << 8) + ershdr->vlan;
+}
+
+static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
+{
+	md2->hwid = hwid & 0xf;
+	md2->hwid_upper = (hwid >> 4) & 0x3;
+}
+
+static inline u8 get_hwid(const struct erspan_md2 *md2)
+{
+	return (md2->hwid_upper << 4) + md2->hwid;
+}
+
+static inline int erspan_hdr_len(int version)
+{
+	if (version == 0)
+		return 0;
+
+	return sizeof(struct erspan_base_hdr) +
+	       (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE);
+}
+
+static inline u8 tos_to_cos(u8 tos)
+{
+	u8 dscp, cos;
+
+	dscp = tos >> 2;
+	cos = dscp >> 3;
+	return cos;
+}
+
+static inline void erspan_build_header(struct sk_buff *skb,
+				u32 id, u32 index,
+				bool truncate, bool is_ipv4)
+{
+	struct ethhdr *eth = (struct ethhdr *)skb->data;
+	enum erspan_encap_type enc_type;
+	struct erspan_base_hdr *ershdr;
+	struct qtag_prefix {
+		__be16 eth_type;
+		__be16 tci;
+	} *qp;
+	u16 vlan_tci = 0;
+	u8 tos;
+	__be32 *idx;
+
+	tos = is_ipv4 ? ip_hdr(skb)->tos :
+			(ipv6_hdr(skb)->priority << 4) +
+			(ipv6_hdr(skb)->flow_lbl[0] >> 4);
+
+	enc_type = ERSPAN_ENCAP_NOVLAN;
+
+	/* If mirrored packet has vlan tag, extract tci and
+	 * preserve vlan header in the mirrored frame.
+	 */
+	if (eth->h_proto == htons(ETH_P_8021Q)) {
+		qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
+		vlan_tci = ntohs(qp->tci);
+		enc_type = ERSPAN_ENCAP_INFRAME;
+	}
+
+	skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
+	ershdr = (struct erspan_base_hdr *)skb->data;
+	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
+
+	/* Build base header */
+	ershdr->ver = ERSPAN_VERSION;
+	ershdr->cos = tos_to_cos(tos);
+	ershdr->en = enc_type;
+	ershdr->t = truncate;
+	set_vlan(ershdr, vlan_tci);
+	set_session_id(ershdr, id);
+
+	/* Build metadata */
+	idx = (__be32 *)(ershdr + 1);
+	*idx = htonl(index & INDEX_MASK);
+}
+
+/* ERSPAN GRA: timestamp granularity
+ *   00b --> granularity = 100 microseconds
+ *   01b --> granularity = 100 nanoseconds
+ *   10b --> granularity = IEEE 1588
+ * Here we only support 100 microseconds.
+ */
+static inline __be32 erspan_get_timestamp(void)
+{
+	u64 h_usecs;
+	ktime_t kt;
+
+	kt = ktime_get_real();
+	h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC);
+
+	/* ERSPAN base header only has 32-bit,
+	 * so it wraps around 4 days.
+	 */
+	return htonl((u32)h_usecs);
+}
+
+/* ERSPAN BSO (Bad/Short/Oversized), see RFC1757
+ *   00b --> Good frame with no error, or unknown integrity
+ *   01b --> Payload is a Short Frame
+ *   10b --> Payload is an Oversized Frame
+ *   11b --> Payload is a Bad Frame with CRC or Alignment Error
+ */
+enum erspan_bso {
+	BSO_NOERROR = 0x0,
+	BSO_SHORT = 0x1,
+	BSO_OVERSIZED = 0x2,
+	BSO_BAD = 0x3,
+};
+
+static inline u8 erspan_detect_bso(struct sk_buff *skb)
+{
+	/* BSO_BAD is not handled because the frame CRC
+	 * or alignment error information is in FCS.
+	 */
+	if (skb->len < ETH_ZLEN)
+		return BSO_SHORT;
+
+	if (skb->len > ETH_FRAME_LEN)
+		return BSO_OVERSIZED;
+
+	return BSO_NOERROR;
+}
+
+static inline void erspan_build_header_v2(struct sk_buff *skb,
+					  u32 id, u8 direction, u16 hwid,
+					  bool truncate, bool is_ipv4)
+{
+	struct ethhdr *eth = (struct ethhdr *)skb->data;
+	struct erspan_base_hdr *ershdr;
+	struct erspan_md2 *md2;
+	struct qtag_prefix {
+		__be16 eth_type;
+		__be16 tci;
+	} *qp;
+	u16 vlan_tci = 0;
+	u8 gra = 0; /* 100 usec */
+	u8 bso = 0; /* Bad/Short/Oversized */
+	u8 sgt = 0;
+	u8 tos;
+
+	tos = is_ipv4 ? ip_hdr(skb)->tos :
+			(ipv6_hdr(skb)->priority << 4) +
+			(ipv6_hdr(skb)->flow_lbl[0] >> 4);
+
+	/* Unlike v1, v2 does not have En field,
+	 * so only extract vlan tci field.
+	 */
+	if (eth->h_proto == htons(ETH_P_8021Q)) {
+		qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
+		vlan_tci = ntohs(qp->tci);
+	}
+
+	bso = erspan_detect_bso(skb);
+	skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
+	ershdr = (struct erspan_base_hdr *)skb->data;
+	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
+
+	/* Build base header */
+	ershdr->ver = ERSPAN_VERSION2;
+	ershdr->cos = tos_to_cos(tos);
+	ershdr->en = bso;
+	ershdr->t = truncate;
+	set_vlan(ershdr, vlan_tci);
+	set_session_id(ershdr, id);
+
+	/* Build metadata */
+	md2 = (struct erspan_md2 *)(ershdr + 1);
+	md2->timestamp = erspan_get_timestamp();
+	md2->sgt = htons(sgt);
+	md2->p = 1;
+	md2->ft = 0;
+	md2->dir = direction;
+	md2->gra = gra;
+	md2->o = 0;
+	set_hwid(md2, hwid);
+}
+
+#endif