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, 284 insertions, 0 deletions

diff --git a/include/net/mld.h b/include/net/mld.h
new file mode 100644
index 000000000..23255cc47
--- /dev/null
+++ b/include/net/mld.h
@@ -0,0 +1,284 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_MLD_H
+#define LINUX_MLD_H
+
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+
+/* MLDv1 Query/Report/Done */
+struct mld_msg {
+	struct icmp6hdr		mld_hdr;
+	struct in6_addr		mld_mca;
+};
+
+#define mld_type		mld_hdr.icmp6_type
+#define mld_code		mld_hdr.icmp6_code
+#define mld_cksum		mld_hdr.icmp6_cksum
+#define mld_maxdelay		mld_hdr.icmp6_maxdelay
+#define mld_reserved		mld_hdr.icmp6_dataun.un_data16[1]
+
+/* Multicast Listener Discovery version 2 headers */
+/* MLDv2 Report */
+struct mld2_grec {
+	__u8		grec_type;
+	__u8		grec_auxwords;
+	__be16		grec_nsrcs;
+	struct in6_addr	grec_mca;
+	struct in6_addr	grec_src[];
+};
+
+struct mld2_report {
+	struct icmp6hdr		mld2r_hdr;
+	struct mld2_grec	mld2r_grec[];
+};
+
+#define mld2r_type		mld2r_hdr.icmp6_type
+#define mld2r_resv1		mld2r_hdr.icmp6_code
+#define mld2r_cksum		mld2r_hdr.icmp6_cksum
+#define mld2r_resv2		mld2r_hdr.icmp6_dataun.un_data16[0]
+#define mld2r_ngrec		mld2r_hdr.icmp6_dataun.un_data16[1]
+
+/* MLDv2 Query */
+struct mld2_query {
+	struct icmp6hdr		mld2q_hdr;
+	struct in6_addr		mld2q_mca;
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u8			mld2q_qrv:3,
+				mld2q_suppress:1,
+				mld2q_resv2:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u8			mld2q_resv2:4,
+				mld2q_suppress:1,
+				mld2q_qrv:3;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+	__u8			mld2q_qqic;
+	__be16			mld2q_nsrcs;
+	struct in6_addr		mld2q_srcs[];
+};
+
+#define mld2q_type		mld2q_hdr.icmp6_type
+#define mld2q_code		mld2q_hdr.icmp6_code
+#define mld2q_cksum		mld2q_hdr.icmp6_cksum
+#define mld2q_mrc		mld2q_hdr.icmp6_maxdelay
+#define mld2q_resv1		mld2q_hdr.icmp6_dataun.un_data16[1]
+
+/* RFC3810, 5.1.3. Maximum Response Code:
+ *
+ * If Maximum Response Code >= 32768, Maximum Response Code represents a
+ * floating-point value as follows:
+ *
+ *  0 1 2 3 4 5 6 7 8 9 A B C D E F
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |1| exp |          mant         |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+#define MLDV2_MRC_EXP(value)	(((value) >> 12) & 0x0007)
+#define MLDV2_MRC_MAN(value)	((value) & 0x0fff)
+
+/* RFC3810, 5.1.9. QQIC (Querier's Query Interval Code):
+ *
+ * If QQIC >= 128, QQIC represents a floating-point value as follows:
+ *
+ *  0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+
+ * |1| exp | mant  |
+ * +-+-+-+-+-+-+-+-+
+ */
+#define MLDV2_QQIC_EXP(value)	(((value) >> 4) & 0x07)
+#define MLDV2_QQIC_MAN(value)	((value) & 0x0f)
+
+/* MLDv2 QQIC floating-point exponential field min threshold */
+#define MLD_QQIC_MIN_THRESHOLD	128
+/* MLDv2 QQIC FP max threshold (mant = 0xF, exp = 7) -> 31744 */
+#define MLD_QQIC_MAX_THRESHOLD	31744
+/* MLDv2 MRC floating-point exponential field min threshold */
+#define MLD_MRC_MIN_THRESHOLD	32768UL
+/* MLDv2 MRC FP max threshold (mant = 0xFFF, exp = 7) -> 8387584 */
+#define MLD_MRC_MAX_THRESHOLD	8387584
+#define MLDV1_MRD_MAX_COMPAT	(MLD_MRC_MIN_THRESHOLD - 1)
+
+#define MLD_MAX_QUEUE		8
+#define MLD_MAX_SKBS		32
+
+/* V2 exponential field encoding */
+
+/*
+ * Calculate Maximum Response Code from Maximum Response Delay
+ *
+ * MRC represents the 16-bit encoded form of Maximum Response Delay (MRD);
+ * once decoded, the resulting value is in milliseconds.
+ *
+ * RFC3810, 5.1.3. defines only the decoding formula:
+ *     Maximum Response Delay = (mant | 0x1000) << (exp + 3)
+ *
+ * but does NOT define the encoding procedure. To derive exponent:
+ *
+ * For the 16-bit MRC, the "hidden bit" (0x1000) is left shifted by 12 to
+ * sit above the 12-bit mantissa. The RFC then shifts this entire block
+ * left by (exp + 3) to reconstruct the value. So, 'hidden bit' is the
+ * MSB which is shifted by (12 + exp + 3).
+ *
+ * Total left shift of the hidden bit = 12 + (exp + 3) = exp + 15.
+ * This is the MSB at the 0-based bit position: (exp + 15).
+ * Since fls() is 1-based, fls(value) - 1 = exp + 15.
+ *
+ * Therefore:
+ *     exp  = fls(value) - 16
+ *     mant = (value >> (exp + 3)) & 0x0FFF
+ *
+ * Final encoding formula:
+ *     0x8000 | (exp << 12) | mant
+ *
+ * Example (value = 1311744):
+ *  0               1               2               3
+ *  0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0| 1311744
+ * |                      ^-^--------mant---------^ ^...(exp+3)...^| exp=5
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Encoded:
+ *   0x8000 | (5 << 12) | 0x404 = 0xD404
+ */
+static inline u16 mldv2_mrc(unsigned long mrd)
+{
+	u16 mc_man, mc_exp;
+
+	/* MRC < 32768 is literal */
+	if (mrd < MLD_MRC_MIN_THRESHOLD)
+		return mrd;
+
+	/* Saturate at max representable (mant = 0xFFF, exp = 7) -> 8387584 */
+	if (mrd >= MLD_MRC_MAX_THRESHOLD)
+		return 0xFFFF;
+
+	mc_exp = fls(mrd) - 16;
+	mc_man = (mrd >> (mc_exp + 3)) & 0x0FFF;
+
+	return 0x8000 | (mc_exp << 12) | mc_man;
+}
+
+/*
+ * Calculate Querier's Query Interval Code from Querier's Query Interval
+ *
+ * QQIC represents the 8-bit encoded form of Querier's Query Interval (QQI);
+ * once decoded, the resulting value is in seconds.
+ *
+ * RFC3810, 5.1.9. defines only the decoding formula:
+ *     QQI = (mant | 0x10) << (exp + 3)
+ *
+ * but does NOT define the encoding procedure. To derive exponent:
+ *
+ * For any value of mantissa and exponent, the decoding formula indicates
+ * that the "hidden bit" (0x10) is shifted 4 bits left to sit above the
+ * 4-bit mantissa. The RFC again shifts this entire block left by (exp + 3)
+ * to reconstruct the value. So, 'hidden bit' is the MSB which is shifted
+ * by (4 + exp + 3).
+ *
+ * Total left shift of the 'hidden bit' = 4 + (exp + 3) = exp + 7.
+ * This is the MSB at the 0-based bit position: (exp + 7).
+ * Since fls() is 1-based, fls(value) - 1 = exp + 7.
+ *
+ * Therefore:
+ *     exp  = fls(value) - 8
+ *     mant = (value >> (exp + 3)) & 0x0F
+ *
+ * Final encoding formula:
+ *     0x80 | (exp << 4) | mant
+ *
+ * Example (value = 3200):
+ *  0               1
+ *  0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |0 0 0 0 1 1 0 0 1 0 0 0 0 0 0 0| (value = 3200)
+ * |        ^-^-mant^ ^..(exp+3)..^| exp = 4, mant = 9
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Encoded:
+ *   0x80 | (4 << 4) | 9 = 0xC9
+ */
+static inline u8 mldv2_qqic(unsigned long value)
+{
+	u8 mc_man, mc_exp;
+
+	/* QQIC < 128 is literal */
+	if (value < MLD_QQIC_MIN_THRESHOLD)
+		return value;
+
+	/* Saturate at max representable (mant = 0xF, exp = 7) -> 31744 */
+	if (value >= MLD_QQIC_MAX_THRESHOLD)
+		return 0xFF;
+
+	mc_exp  = fls(value) - 8;
+	mc_man = (value >> (mc_exp + 3)) & 0x0F;
+
+	return 0x80 | (mc_exp << 4) | mc_man;
+}
+
+/* V2 exponential field decoding */
+
+/* Calculate Maximum Response Delay from Maximum Response Code
+ *
+ * RFC3810, relevant sections:
+ *  - 5.1.3. Maximum Response Code defines the decoding formula:
+ *      0 1 2 3 4 5 6 7 8 9 A B C D E F
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *     |1| exp |          mant         |
+ *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *    Maximum Response Delay = (mant | 0x1000) << (exp+3)
+ *  - 9.3. Query Response Interval
+ *
+ * After decode, MRC represents the Maximum Response Delay (MRD) in
+ * units of milliseconds.
+ */
+static inline unsigned long mldv2_mrd(const struct mld2_query *mlh2)
+{
+	unsigned long mc_mrc = ntohs(mlh2->mld2q_mrc);
+
+	if (mc_mrc < MLD_MRC_MIN_THRESHOLD) {
+		return mc_mrc;
+	} else {
+		unsigned long mc_man, mc_exp;
+
+		mc_exp = MLDV2_MRC_EXP(mc_mrc);
+		mc_man = MLDV2_MRC_MAN(mc_mrc);
+
+		return (mc_man | 0x1000) << (mc_exp + 3);
+	}
+}
+
+/* Calculate Querier's Query Interval from Querier's Query Interval Code
+ *
+ * RFC3810, relevant sections:
+ *  - 5.1.9. QQIC (Querier's Query Interval Code) defines the decoding formula:
+ *      0 1 2 3 4 5 6 7
+ *     +-+-+-+-+-+-+-+-+
+ *     |1| exp | mant  |
+ *     +-+-+-+-+-+-+-+-+
+ *    QQI = (mant | 0x10) << (exp + 3)
+ *  - 9.2. Query Interval
+ *  - 9.12. Older Version Querier Present Timeout
+ *    (the [Query Interval] in the last Query received)
+ *
+ * After decode, QQIC represents the Querier's Query Interval in units
+ * of seconds.
+ */
+static inline unsigned long mldv2_qqi(const struct mld2_query *mlh2)
+{
+	unsigned long qqic = mlh2->mld2q_qqic;
+
+	if (qqic < MLD_QQIC_MIN_THRESHOLD) {
+		return qqic;
+	} else {
+		unsigned long mc_man, mc_exp;
+
+		mc_exp = MLDV2_QQIC_EXP(qqic);
+		mc_man = MLDV2_QQIC_MAN(qqic);
+
+		return (mc_man | 0x10) << (mc_exp + 3);
+	}
+}
+
+#endif