Implement COUNTER_* ioctl decoding

Introduced by Linux commit v5.16-rc1~119^2~29^2~10.

* bundled/linux/include/uapi/linux/counter.h: New file.
* bundled/Makefile.am (EXTRA_DIST): Add it.
* src/counter_ioctl.c: New file.
* src/Makefile.am (libstrace_a_SOURCES): Add it.
* src/defs.h (DECL_IOCTL(counter)): New declaration.
* src/ioctl.c (ioctl_decode) <case '>'>: Call counter_ioctl.
* src/xlat/counter_ioctl_component_types.in: New file.
* src/xlat/counter_ioctl_event_types.in: Likewise.
* src/xlat/counter_ioctl_scopes.in: Likewise.
* tests/ioctl_counter-Xabbrev.c: Likewise.
* tests/ioctl_counter-Xraw.c: Likewise.
* tests/ioctl_counter-Xverbose.c: Likewise.
* tests/ioctl_counter.c: Likewise.
* tests/.gitignore: Add ioctl_counter, ioctl_counter-Xabbrev,
ioctl_counter-Xraw, and ioctl_counter-Xverbose.
* tests/pure_executables.list: Likewise.
* tests/gen_tests.in (ioctl_counter, ioctl_counter-Xabbrev,
ioctl_counter-Xraw, ioctl_counter-Xverbose): New tests.
* NEWS: Mention it.

17 files changed, 408 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 7a55a37fd..fdc68bcd8 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * Added --tips option to print strace tips, tricks, and tweaks
     at the end of the tracing session.
   * Enhanced decoding of bpf and io_uring_register syscalls.
+  * Implemented decoding of COUNTER_* ioctl commands.
   * Updated lists of BPF_*, BR_*, BTRFS_*, IFA_*, IFLA_*, IORING_*, KEY_*,
     KVM_*, MADV_*, and UFFD_* constants.
   * Updated lists of ioctl commands from Linux 5.18.
diff --git a/bundled/Makefile.am b/bundled/Makefile.am
index e2c6c382e..58be2a7b5 100644
--- a/bundled/Makefile.am
+++ b/bundled/Makefile.am
@@ -28,6 +28,7 @@ EXTRA_DIST = \
 	linux/include/uapi/linux/btrfs_tree.h \
 	linux/include/uapi/linux/close_range.h \
 	linux/include/uapi/linux/const.h \
+	linux/include/uapi/linux/counter.h \
 	linux/include/uapi/linux/cryptouser.h \
 	linux/include/uapi/linux/dcbnl.h \
 	linux/include/uapi/linux/dm-ioctl.h \
diff --git a/bundled/linux/include/uapi/linux/counter.h b/bundled/linux/include/uapi/linux/counter.h
new file mode 100644
index 000000000..22036fc09
--- /dev/null
+++ b/bundled/linux/include/uapi/linux/counter.h
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Userspace ABI for Counter character devices
+ * Copyright (C) 2020 William Breathitt Gray
+ */
+#ifndef _COUNTER_H_
+#define _COUNTER_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/* Component type definitions */
+enum counter_component_type {
+	COUNTER_COMPONENT_NONE,
+	COUNTER_COMPONENT_SIGNAL,
+	COUNTER_COMPONENT_COUNT,
+	COUNTER_COMPONENT_FUNCTION,
+	COUNTER_COMPONENT_SYNAPSE_ACTION,
+	COUNTER_COMPONENT_EXTENSION,
+};
+
+/* Component scope definitions */
+enum counter_scope {
+	COUNTER_SCOPE_DEVICE,
+	COUNTER_SCOPE_SIGNAL,
+	COUNTER_SCOPE_COUNT,
+};
+
+/**
+ * struct counter_component - Counter component identification
+ * @type: component type (one of enum counter_component_type)
+ * @scope: component scope (one of enum counter_scope)
+ * @parent: parent ID (matching the ID suffix of the respective parent sysfs
+ *          path as described by the ABI documentation file
+ *          Documentation/ABI/testing/sysfs-bus-counter)
+ * @id: component ID (matching the ID provided by the respective *_component_id
+ *      sysfs attribute of the desired component)
+ *
+ * For example, if the Count 2 ceiling extension of Counter device 4 is desired,
+ * set type equal to COUNTER_COMPONENT_EXTENSION, scope equal to
+ * COUNTER_COUNT_SCOPE, parent equal to 2, and id equal to the value provided by
+ * the respective /sys/bus/counter/devices/counter4/count2/ceiling_component_id
+ * sysfs attribute.
+ */
+struct counter_component {
+	__u8 type;
+	__u8 scope;
+	__u8 parent;
+	__u8 id;
+};
+
+/* Event type definitions */
+enum counter_event_type {
+	/* Count value increased past ceiling */
+	COUNTER_EVENT_OVERFLOW,
+	/* Count value decreased past floor */
+	COUNTER_EVENT_UNDERFLOW,
+	/* Count value increased past ceiling, or decreased past floor */
+	COUNTER_EVENT_OVERFLOW_UNDERFLOW,
+	/* Count value reached threshold */
+	COUNTER_EVENT_THRESHOLD,
+	/* Index signal detected */
+	COUNTER_EVENT_INDEX,
+	/* State of counter is changed */
+	COUNTER_EVENT_CHANGE_OF_STATE,
+};
+
+/**
+ * struct counter_watch - Counter component watch configuration
+ * @component: component to watch when event triggers
+ * @event: event that triggers (one of enum counter_event_type)
+ * @channel: event channel (typically 0 unless the device supports concurrent
+ *	     events of the same type)
+ */
+struct counter_watch {
+	struct counter_component component;
+	__u8 event;
+	__u8 channel;
+};
+
+/*
+ * Queues a Counter watch for the specified event.
+ *
+ * The queued watches will not be applied until COUNTER_ENABLE_EVENTS_IOCTL is
+ * called.
+ */
+#define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x00, struct counter_watch)
+/*
+ * Enables monitoring the events specified by the Counter watches that were
+ * queued by COUNTER_ADD_WATCH_IOCTL.
+ *
+ * If events are already enabled, the new set of watches replaces the old one.
+ * Calling this ioctl also has the effect of clearing the queue of watches added
+ * by COUNTER_ADD_WATCH_IOCTL.
+ */
+#define COUNTER_ENABLE_EVENTS_IOCTL _IO(0x3E, 0x01)
+/*
+ * Stops monitoring the previously enabled events.
+ */
+#define COUNTER_DISABLE_EVENTS_IOCTL _IO(0x3E, 0x02)
+
+/**
+ * struct counter_event - Counter event data
+ * @timestamp: best estimate of time of event occurrence, in nanoseconds
+ * @value: component value
+ * @watch: component watch configuration
+ * @status: return status (system error number)
+ */
+struct counter_event {
+	__aligned_u64 timestamp;
+	__aligned_u64 value;
+	struct counter_watch watch;
+	__u8 status;
+};
+
+/* Count direction values */
+enum counter_count_direction {
+	COUNTER_COUNT_DIRECTION_FORWARD,
+	COUNTER_COUNT_DIRECTION_BACKWARD,
+};
+
+/* Count mode values */
+enum counter_count_mode {
+	COUNTER_COUNT_MODE_NORMAL,
+	COUNTER_COUNT_MODE_RANGE_LIMIT,
+	COUNTER_COUNT_MODE_NON_RECYCLE,
+	COUNTER_COUNT_MODE_MODULO_N,
+};
+
+/* Count function values */
+enum counter_function {
+	COUNTER_FUNCTION_INCREASE,
+	COUNTER_FUNCTION_DECREASE,
+	COUNTER_FUNCTION_PULSE_DIRECTION,
+	COUNTER_FUNCTION_QUADRATURE_X1_A,
+	COUNTER_FUNCTION_QUADRATURE_X1_B,
+	COUNTER_FUNCTION_QUADRATURE_X2_A,
+	COUNTER_FUNCTION_QUADRATURE_X2_B,
+	COUNTER_FUNCTION_QUADRATURE_X4,
+};
+
+/* Signal values */
+enum counter_signal_level {
+	COUNTER_SIGNAL_LEVEL_LOW,
+	COUNTER_SIGNAL_LEVEL_HIGH,
+};
+
+/* Action mode values */
+enum counter_synapse_action {
+	COUNTER_SYNAPSE_ACTION_NONE,
+	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+	COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
+	COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+};
+
+#endif /* _COUNTER_H_ */
diff --git a/src/Makefile.am b/src/Makefile.am
index 7773bb040..101b304f6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -81,6 +81,7 @@ libstrace_a_SOURCES =	\
 	close_range.c	\
 	copy_file_range.c \
 	count.c		\
+	counter_ioctl.c	\
 	defs.h		\
 	delay.c		\
 	delay.h		\
diff --git a/src/counter_ioctl.c b/src/counter_ioctl.c
new file mode 100644
index 000000000..82d054f27
--- /dev/null
+++ b/src/counter_ioctl.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2021 Eugene Syromyatnikov <evgsyr@gmail.com>.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+
+#include <linux/ioctl.h>
+#include <linux/counter.h>
+
+#include "xlat/counter_ioctl_component_types.h"
+#include "xlat/counter_ioctl_event_types.h"
+#include "xlat/counter_ioctl_scopes.h"
+
+
+static void
+print_struct_counter_component(const struct counter_component *const cc)
+{
+	tprint_struct_begin();
+	PRINT_FIELD_XVAL(*cc, type, counter_ioctl_component_types,
+			 "COUNTER_COMPONENT_???");
+	tprint_struct_next();
+	PRINT_FIELD_XVAL(*cc, scope, counter_ioctl_scopes,
+			 "COUNTER_SCOPE_???");
+	tprint_struct_next();
+	PRINT_FIELD_U(*cc, parent);
+	tprint_struct_next();
+	PRINT_FIELD_U(*cc, id);
+	tprint_struct_end();
+}
+
+static void
+print_struct_counter_watch(struct tcb *const tcp, const kernel_ulong_t addr)
+{
+	CHECK_IOCTL_SIZE(COUNTER_ADD_WATCH_IOCTL, 6);
+	CHECK_TYPE_SIZE(struct counter_watch, 6);
+	struct counter_watch w;
+
+	if (umove_or_printaddr(tcp, addr, &w))
+		return;
+
+	tprint_struct_begin();
+	PRINT_FIELD_OBJ_PTR(w, component, print_struct_counter_component);
+	tprint_struct_next();
+	PRINT_FIELD_XVAL(w, event, counter_ioctl_event_types,
+			 "COUNTER_EVENT_???");
+	tprint_struct_next();
+	PRINT_FIELD_U(w, channel);
+	tprint_struct_end();
+}
+
+int
+counter_ioctl(struct tcb *const tcp, const unsigned int code,
+	      const kernel_ulong_t arg)
+{
+	switch (code) {
+	case COUNTER_ADD_WATCH_IOCTL:
+		tprint_arg_next();
+		print_struct_counter_watch(tcp, arg);
+		return RVAL_IOCTL_DECODED;
+
+	case COUNTER_ENABLE_EVENTS_IOCTL:
+	case COUNTER_DISABLE_EVENTS_IOCTL:
+		return RVAL_IOCTL_DECODED;
+
+	default:
+		return RVAL_DECODED;
+	}
+}
diff --git a/src/defs.h b/src/defs.h
index addd85962..2f9b27fa0 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -1353,6 +1353,7 @@ extern int								\
 name ## _ioctl(struct tcb *, unsigned int request, kernel_ulong_t arg)	\
 /* End of DECL_IOCTL definition. */
 
+DECL_IOCTL(counter);
 DECL_IOCTL(dm);
 DECL_IOCTL(evdev);
 DECL_IOCTL(fs_0x94);
diff --git a/src/ioctl.c b/src/ioctl.c
index c24cdb8bc..60dffa7aa 100644
--- a/src/ioctl.c
+++ b/src/ioctl.c
@@ -362,6 +362,8 @@ ioctl_decode(struct tcb *tcp)
 		return perf_ioctl(tcp, code, arg);
 	case '=': /* 0x3d */
 		return ptp_ioctl(tcp, code, arg);
+	case '>': /* 0x3e */
+		return counter_ioctl(tcp, code, arg);
 	case 'E':
 		return evdev_ioctl(tcp, code, arg);
 	case 'I':
diff --git a/src/xlat/counter_ioctl_component_types.in b/src/xlat/counter_ioctl_component_types.in
new file mode 100644
index 000000000..a99ccb544
--- /dev/null
+++ b/src/xlat/counter_ioctl_component_types.in
@@ -0,0 +1,9 @@
+#enum
+#value_indexed
+#unconditional
+COUNTER_COMPONENT_NONE			0
+COUNTER_COMPONENT_SIGNAL		1
+COUNTER_COMPONENT_COUNT			2
+COUNTER_COMPONENT_FUNCTION		3
+COUNTER_COMPONENT_SYNAPSE_ACTION	4
+COUNTER_COMPONENT_EXTENSION		5
diff --git a/src/xlat/counter_ioctl_event_types.in b/src/xlat/counter_ioctl_event_types.in
new file mode 100644
index 000000000..58092bcd6
--- /dev/null
+++ b/src/xlat/counter_ioctl_event_types.in
@@ -0,0 +1,9 @@
+#enum
+#value_indexed
+#unconditional
+COUNTER_EVENT_OVERFLOW			0
+COUNTER_EVENT_UNDERFLOW			1
+COUNTER_EVENT_OVERFLOW_UNDERFLOW	2
+COUNTER_EVENT_THRESHOLD			3
+COUNTER_EVENT_INDEX			4
+COUNTER_EVENT_CHANGE_OF_STATE		5
diff --git a/src/xlat/counter_ioctl_scopes.in b/src/xlat/counter_ioctl_scopes.in
new file mode 100644
index 000000000..cd115716f
--- /dev/null
+++ b/src/xlat/counter_ioctl_scopes.in
@@ -0,0 +1,6 @@
+#enum
+#value_indexed
+#unconditional
+COUNTER_SCOPE_DEVICE	0
+COUNTER_SCOPE_SIGNAL	1
+COUNTER_SCOPE_COUNT	2
diff --git a/tests/.gitignore b/tests/.gitignore
index d7137cbb7..863806844 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -235,6 +235,10 @@ io_uring_setup
 ioctl
 ioctl_block
 ioctl_block--pidns-translation
+ioctl_counter
+ioctl_counter-Xabbrev
+ioctl_counter-Xraw
+ioctl_counter-Xverbose
 ioctl_dm
 ioctl_dm-v
 ioctl_evdev
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 9e83d33d7..35d6b6fce 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -252,6 +252,10 @@ io_uring_setup	-a26 -y
 ioctl_block	+ioctl.test
 ioctl_dm	+ioctl.test -s9
 ioctl_dm-v	+ioctl.test -v -s9
+ioctl_counter	+ioctl.test -a39
+ioctl_counter-Xabbrev	+ioctl.test -a39 -Xabbrev
+ioctl_counter-Xraw	+ioctl.test -a18 -Xraw
+ioctl_counter-Xverbose	+ioctl.test -a52 -Xverbose
 ioctl_evdev	+ioctl.test -a26
 ioctl_evdev-Xabbrev	+ioctl.test -a26 -Xabbrev
 ioctl_evdev-Xraw	+ioctl.test -a28 -Xraw
diff --git a/tests/ioctl_counter-Xabbrev.c b/tests/ioctl_counter-Xabbrev.c
new file mode 100644
index 000000000..55cbfebb1
--- /dev/null
+++ b/tests/ioctl_counter-Xabbrev.c
@@ -0,0 +1,2 @@
+#define XLAT_ABBREV 1
+#include "ioctl_counter.c"
diff --git a/tests/ioctl_counter-Xraw.c b/tests/ioctl_counter-Xraw.c
new file mode 100644
index 000000000..8b9ff3437
--- /dev/null
+++ b/tests/ioctl_counter-Xraw.c
@@ -0,0 +1,2 @@
+#define XLAT_RAW 1
+#include "ioctl_counter.c"
diff --git a/tests/ioctl_counter-Xverbose.c b/tests/ioctl_counter-Xverbose.c
new file mode 100644
index 000000000..19d175259
--- /dev/null
+++ b/tests/ioctl_counter-Xverbose.c
@@ -0,0 +1,2 @@
+#define XLAT_VERBOSE 1
+#include "ioctl_counter.c"
diff --git a/tests/ioctl_counter.c b/tests/ioctl_counter.c
new file mode 100644
index 000000000..a68aa1c3f
--- /dev/null
+++ b/tests/ioctl_counter.c
@@ -0,0 +1,133 @@
+/*
+ * Check decoding of COUNTER_* commands of ioctl syscall.
+ *
+ * Copyright (c) 2022 Eugene Syromyatnikov <evgsyr@gmail.com>.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include "scno.h"
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/ioctl.h>
+#include <linux/counter.h>
+
+
+/* A hack for handling different types of _IOC() on various platforms */
+#if XLAT_RAW
+# define XLAT_ARGS_U(a_) (unsigned int) (a_)
+#elif XLAT_VERBOSE
+# define XLAT_ARGS_U(a_) (unsigned int) (a_), #a_
+#else
+# define XLAT_ARGS_U(a_) #a_
+#endif
+
+static const char *errstr;
+
+static long
+sys_ioctl(kernel_long_t fd, kernel_ulong_t cmd, kernel_ulong_t arg)
+{
+	const long rc = syscall(__NR_ioctl, fd, cmd, arg);
+	errstr = sprintrc(rc);
+	return rc;
+}
+
+int
+main(void)
+{
+	static const struct {
+		uint32_t val;
+		const char *str;
+	} dirs[] = {
+		{ ARG_STR(_IOC_NONE) },
+		{ ARG_STR(_IOC_READ) },
+		{ ARG_STR(_IOC_WRITE) },
+		{ ARG_STR(_IOC_READ|_IOC_WRITE) },
+	};
+	static const kernel_ulong_t magic =
+		(kernel_ulong_t) 0xdeadbeefbadc0dedULL;
+
+	/* Unknown counter ioctl */
+	for (size_t i = 0; i < ARRAY_SIZE(dirs); i++) {
+		for (unsigned int j = 0; j < 32; j += 1) {
+			sys_ioctl(-1, _IOC(dirs[i].val, '>', 3, j), magic);
+			printf("ioctl(-1, "
+			       XLAT_KNOWN(%#x, "_IOC(%s, 0x3e, 0x3, %#x)")
+			       ", %#lx) = %s\n",
+#if XLAT_RAW || XLAT_VERBOSE
+			       (unsigned int) _IOC(dirs[i].val, '>', 3, j),
+#endif
+#if !XLAT_RAW
+			       dirs[i].str, j,
+#endif
+			       (unsigned long) magic, errstr);
+		}
+	}
+
+	/* COUNTER_ADD_WATCH_IOCTL */
+	static const struct {
+		struct counter_watch val;;
+		const char *str;
+	} watches[] = {
+		{ { { 0 } },
+		  "{component={type=" XLAT_KNOWN(0, "COUNTER_COMPONENT_NONE")
+		  ", scope=" XLAT_KNOWN(0, "COUNTER_SCOPE_DEVICE")
+		  ", parent=0, id=0}"
+		  ", event=" XLAT_KNOWN(0, "COUNTER_EVENT_OVERFLOW")
+		  ", channel=0}" },
+		{ { { COUNTER_COMPONENT_EXTENSION, COUNTER_SCOPE_COUNT,
+		      23, 42 }, COUNTER_EVENT_CHANGE_OF_STATE, 69 },
+		  "{component="
+		  "{type=" XLAT_KNOWN(0x5, "COUNTER_COMPONENT_EXTENSION")
+		  ", scope=" XLAT_KNOWN(0x2, "COUNTER_SCOPE_COUNT")
+		  ", parent=23, id=42}"
+		  ", event=" XLAT_KNOWN(0x5, "COUNTER_EVENT_CHANGE_OF_STATE")
+		  ", channel=69}" },
+		{ { { COUNTER_COMPONENT_EXTENSION + 1, COUNTER_SCOPE_COUNT + 1,
+		      142, 160 }, COUNTER_EVENT_CHANGE_OF_STATE + 1, 173 },
+		  "{component={type=" XLAT_UNKNOWN(0x6, "COUNTER_COMPONENT_???")
+		  ", scope=" XLAT_UNKNOWN(0x3, "COUNTER_SCOPE_???")
+		  ", parent=142, id=160}"
+		  ", event=" XLAT_UNKNOWN(0x6, "COUNTER_EVENT_???")
+		  ", channel=173}" },
+	};
+	TAIL_ALLOC_OBJECT_CONST_PTR(struct counter_watch, watch);
+
+	sys_ioctl(-1, COUNTER_ADD_WATCH_IOCTL, 0);
+	printf("ioctl(-1, " XLAT_FMT ", NULL) = %s\n",
+	       XLAT_ARGS_U(COUNTER_ADD_WATCH_IOCTL), errstr);
+
+	sys_ioctl(-1, COUNTER_ADD_WATCH_IOCTL, (uintptr_t) watch + 1);
+	printf("ioctl(-1, " XLAT_FMT ", %p) = %s\n",
+	       XLAT_ARGS_U(COUNTER_ADD_WATCH_IOCTL),
+	       (char *) watch + 1, errstr);
+
+	for (size_t i = 0; i < ARRAY_SIZE(watches); i++) {
+		memcpy(watch, &watches[i].val, sizeof(watches[i].val));
+		sys_ioctl(-1, COUNTER_ADD_WATCH_IOCTL, (uintptr_t) watch);
+		printf("ioctl(-1, " XLAT_FMT ", %s) = %s\n",
+		       XLAT_ARGS_U(COUNTER_ADD_WATCH_IOCTL),
+		       watches[i].str, errstr);
+	}
+
+	/* COUNTER_ENABLE_EVENTS_IOCTL */
+	sys_ioctl(-1, COUNTER_ENABLE_EVENTS_IOCTL, magic);
+	printf("ioctl(-1, " XLAT_FMT ") = %s\n",
+	       XLAT_ARGS_U(COUNTER_ENABLE_EVENTS_IOCTL), errstr);
+
+	/* COUNTER_DISABLE_EVENTS_IOCTL */
+	sys_ioctl(-1, COUNTER_DISABLE_EVENTS_IOCTL, magic);
+	printf("ioctl(-1, " XLAT_FMT ") = %s\n",
+	       XLAT_ARGS_U(COUNTER_DISABLE_EVENTS_IOCTL), errstr);
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}
diff --git a/tests/pure_executables.list b/tests/pure_executables.list
index 7277c4473..30c9132ea 100755
--- a/tests/pure_executables.list
+++ b/tests/pure_executables.list
@@ -171,6 +171,10 @@ io_uring_register-Xverbose
 io_uring_setup
 ioctl
 ioctl_block
+ioctl_counter
+ioctl_counter-Xabbrev
+ioctl_counter-Xraw
+ioctl_counter-Xverbose
 ioctl_dm
 ioctl_evdev
 ioctl_evdev-Xabbrev