Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 941 insertions, 0 deletions

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
new file mode 100644
index 000000000..658170b8d
--- /dev/null
+++ b/tools/perf/util/config.c
@@ -0,0 +1,941 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * config.c
+ *
+ * Helper functions for parsing config items.
+ * Originally copied from GIT source.
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ * Copyright (C) Johannes Schindelin, 2005
+ *
+ */
+#include <errno.h>
+#include <sys/param.h>
+#include "cache.h"
+#include "callchain.h"
+#include <subcmd/exec-cmd.h>
+#include "util/event.h"  /* proc_map_timeout */
+#include "util/hist.h"  /* perf_hist_config */
+#include "util/llvm-utils.h"   /* perf_llvm_config */
+#include "util/stat.h"  /* perf_stat__set_big_num */
+#include "util/evsel.h"  /* evsel__hw_names, evsel__use_bpf_counters */
+#include "build-id.h"
+#include "debug.h"
+#include "config.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/string.h>
+#include <linux/zalloc.h>
+#include <linux/ctype.h>
+
+#define MAXNAME (256)
+
+#define DEBUG_CACHE_DIR ".debug"
+
+
+char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
+
+static FILE *config_file;
+static const char *config_file_name;
+static int config_linenr;
+static int config_file_eof;
+static struct perf_config_set *config_set;
+
+const char *config_exclusive_filename;
+
+static int get_next_char(void)
+{
+	int c;
+	FILE *f;
+
+	c = '\n';
+	if ((f = config_file) != NULL) {
+		c = fgetc(f);
+		if (c == '\r') {
+			/* DOS like systems */
+			c = fgetc(f);
+			if (c != '\n') {
+				ungetc(c, f);
+				c = '\r';
+			}
+		}
+		if (c == '\n')
+			config_linenr++;
+		if (c == EOF) {
+			config_file_eof = 1;
+			c = '\n';
+		}
+	}
+	return c;
+}
+
+static char *parse_value(void)
+{
+	static char value[1024];
+	int quote = 0, comment = 0, space = 0;
+	size_t len = 0;
+
+	for (;;) {
+		int c = get_next_char();
+
+		if (len >= sizeof(value) - 1)
+			return NULL;
+		if (c == '\n') {
+			if (quote)
+				return NULL;
+			value[len] = 0;
+			return value;
+		}
+		if (comment)
+			continue;
+		if (isspace(c) && !quote) {
+			space = 1;
+			continue;
+		}
+		if (!quote) {
+			if (c == ';' || c == '#') {
+				comment = 1;
+				continue;
+			}
+		}
+		if (space) {
+			if (len)
+				value[len++] = ' ';
+			space = 0;
+		}
+		if (c == '\\') {
+			c = get_next_char();
+			switch (c) {
+			case '\n':
+				continue;
+			case 't':
+				c = '\t';
+				break;
+			case 'b':
+				c = '\b';
+				break;
+			case 'n':
+				c = '\n';
+				break;
+			/* Some characters escape as themselves */
+			case '\\': case '"':
+				break;
+			/* Reject unknown escape sequences */
+			default:
+				return NULL;
+			}
+			value[len++] = c;
+			continue;
+		}
+		if (c == '"') {
+			quote = 1-quote;
+			continue;
+		}
+		value[len++] = c;
+	}
+}
+
+static inline int iskeychar(int c)
+{
+	return isalnum(c) || c == '-' || c == '_';
+}
+
+static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
+{
+	int c;
+	char *value;
+
+	/* Get the full name */
+	for (;;) {
+		c = get_next_char();
+		if (config_file_eof)
+			break;
+		if (!iskeychar(c))
+			break;
+		name[len++] = c;
+		if (len >= MAXNAME)
+			return -1;
+	}
+	name[len] = 0;
+	while (c == ' ' || c == '\t')
+		c = get_next_char();
+
+	value = NULL;
+	if (c != '\n') {
+		if (c != '=')
+			return -1;
+		value = parse_value();
+		if (!value)
+			return -1;
+	}
+	return fn(name, value, data);
+}
+
+static int get_extended_base_var(char *name, int baselen, int c)
+{
+	do {
+		if (c == '\n')
+			return -1;
+		c = get_next_char();
+	} while (isspace(c));
+
+	/* We require the format to be '[base "extension"]' */
+	if (c != '"')
+		return -1;
+	name[baselen++] = '.';
+
+	for (;;) {
+		int ch = get_next_char();
+
+		if (ch == '\n')
+			return -1;
+		if (ch == '"')
+			break;
+		if (ch == '\\') {
+			ch = get_next_char();
+			if (ch == '\n')
+				return -1;
+		}
+		name[baselen++] = ch;
+		if (baselen > MAXNAME / 2)
+			return -1;
+	}
+
+	/* Final ']' */
+	if (get_next_char() != ']')
+		return -1;
+	return baselen;
+}
+
+static int get_base_var(char *name)
+{
+	int baselen = 0;
+
+	for (;;) {
+		int c = get_next_char();
+		if (config_file_eof)
+			return -1;
+		if (c == ']')
+			return baselen;
+		if (isspace(c))
+			return get_extended_base_var(name, baselen, c);
+		if (!iskeychar(c) && c != '.')
+			return -1;
+		if (baselen > MAXNAME / 2)
+			return -1;
+		name[baselen++] = tolower(c);
+	}
+}
+
+static int perf_parse_file(config_fn_t fn, void *data)
+{
+	int comment = 0;
+	int baselen = 0;
+	static char var[MAXNAME];
+
+	/* U+FEFF Byte Order Mark in UTF8 */
+	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
+	const unsigned char *bomptr = utf8_bom;
+
+	for (;;) {
+		int line, c = get_next_char();
+
+		if (bomptr && *bomptr) {
+			/* We are at the file beginning; skip UTF8-encoded BOM
+			 * if present. Sane editors won't put this in on their
+			 * own, but e.g. Windows Notepad will do it happily. */
+			if ((unsigned char) c == *bomptr) {
+				bomptr++;
+				continue;
+			} else {
+				/* Do not tolerate partial BOM. */
+				if (bomptr != utf8_bom)
+					break;
+				/* No BOM at file beginning. Cool. */
+				bomptr = NULL;
+			}
+		}
+		if (c == '\n') {
+			if (config_file_eof)
+				return 0;
+			comment = 0;
+			continue;
+		}
+		if (comment || isspace(c))
+			continue;
+		if (c == '#' || c == ';') {
+			comment = 1;
+			continue;
+		}
+		if (c == '[') {
+			baselen = get_base_var(var);
+			if (baselen <= 0)
+				break;
+			var[baselen++] = '.';
+			var[baselen] = 0;
+			continue;
+		}
+		if (!isalpha(c))
+			break;
+		var[baselen] = tolower(c);
+
+		/*
+		 * The get_value function might or might not reach the '\n',
+		 * so saving the current line number for error reporting.
+		 */
+		line = config_linenr;
+		if (get_value(fn, data, var, baselen+1) < 0) {
+			config_linenr = line;
+			break;
+		}
+	}
+	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
+	return -1;
+}
+
+static int parse_unit_factor(const char *end, unsigned long *val)
+{
+	if (!*end)
+		return 1;
+	else if (!strcasecmp(end, "k")) {
+		*val *= 1024;
+		return 1;
+	}
+	else if (!strcasecmp(end, "m")) {
+		*val *= 1024 * 1024;
+		return 1;
+	}
+	else if (!strcasecmp(end, "g")) {
+		*val *= 1024 * 1024 * 1024;
+		return 1;
+	}
+	return 0;
+}
+
+static int perf_parse_llong(const char *value, long long *ret)
+{
+	if (value && *value) {
+		char *end;
+		long long val = strtoll(value, &end, 0);
+		unsigned long factor = 1;
+
+		if (!parse_unit_factor(end, &factor))
+			return 0;
+		*ret = val * factor;
+		return 1;
+	}
+	return 0;
+}
+
+static int perf_parse_long(const char *value, long *ret)
+{
+	if (value && *value) {
+		char *end;
+		long val = strtol(value, &end, 0);
+		unsigned long factor = 1;
+		if (!parse_unit_factor(end, &factor))
+			return 0;
+		*ret = val * factor;
+		return 1;
+	}
+	return 0;
+}
+
+static void bad_config(const char *name)
+{
+	if (config_file_name)
+		pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
+	else
+		pr_warning("bad config value for '%s', ignoring...\n", name);
+}
+
+int perf_config_u64(u64 *dest, const char *name, const char *value)
+{
+	long long ret = 0;
+
+	if (!perf_parse_llong(value, &ret)) {
+		bad_config(name);
+		return -1;
+	}
+
+	*dest = ret;
+	return 0;
+}
+
+int perf_config_int(int *dest, const char *name, const char *value)
+{
+	long ret = 0;
+	if (!perf_parse_long(value, &ret)) {
+		bad_config(name);
+		return -1;
+	}
+	*dest = ret;
+	return 0;
+}
+
+int perf_config_u8(u8 *dest, const char *name, const char *value)
+{
+	long ret = 0;
+
+	if (!perf_parse_long(value, &ret)) {
+		bad_config(name);
+		return -1;
+	}
+	*dest = ret;
+	return 0;
+}
+
+static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
+{
+	int ret;
+
+	*is_bool = 1;
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
+		return 1;
+	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
+		return 0;
+	*is_bool = 0;
+	return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
+}
+
+int perf_config_bool(const char *name, const char *value)
+{
+	int discard;
+	return !!perf_config_bool_or_int(name, value, &discard);
+}
+
+static const char *perf_config_dirname(const char *name, const char *value)
+{
+	if (!name)
+		return NULL;
+	return value;
+}
+
+static int perf_buildid_config(const char *var, const char *value)
+{
+	/* same dir for all commands */
+	if (!strcmp(var, "buildid.dir")) {
+		const char *dir = perf_config_dirname(var, value);
+
+		if (!dir) {
+			pr_err("Invalid buildid directory!\n");
+			return -1;
+		}
+		strncpy(buildid_dir, dir, MAXPATHLEN-1);
+		buildid_dir[MAXPATHLEN-1] = '\0';
+	}
+
+	return 0;
+}
+
+static int perf_default_core_config(const char *var __maybe_unused,
+				    const char *value __maybe_unused)
+{
+	if (!strcmp(var, "core.proc-map-timeout"))
+		proc_map_timeout = strtoul(value, NULL, 10);
+
+	/* Add other config variables here. */
+	return 0;
+}
+
+static int perf_ui_config(const char *var, const char *value)
+{
+	/* Add other config variables here. */
+	if (!strcmp(var, "ui.show-headers"))
+		symbol_conf.show_hist_headers = perf_config_bool(var, value);
+
+	return 0;
+}
+
+static int perf_stat_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "stat.big-num"))
+		perf_stat__set_big_num(perf_config_bool(var, value));
+
+	if (!strcmp(var, "stat.no-csv-summary"))
+		perf_stat__set_no_csv_summary(perf_config_bool(var, value));
+
+	if (!strcmp(var, "stat.bpf-counter-events"))
+		evsel__bpf_counter_events = strdup(value);
+
+	/* Add other config variables here. */
+	return 0;
+}
+
+int perf_default_config(const char *var, const char *value,
+			void *dummy __maybe_unused)
+{
+	if (strstarts(var, "core."))
+		return perf_default_core_config(var, value);
+
+	if (strstarts(var, "hist."))
+		return perf_hist_config(var, value);
+
+	if (strstarts(var, "ui."))
+		return perf_ui_config(var, value);
+
+	if (strstarts(var, "call-graph."))
+		return perf_callchain_config(var, value);
+
+	if (strstarts(var, "llvm."))
+		return perf_llvm_config(var, value);
+
+	if (strstarts(var, "buildid."))
+		return perf_buildid_config(var, value);
+
+	if (strstarts(var, "stat."))
+		return perf_stat_config(var, value);
+
+	/* Add other config variables here. */
+	return 0;
+}
+
+static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	int ret;
+	FILE *f = fopen(filename, "r");
+
+	ret = -1;
+	if (f) {
+		config_file = f;
+		config_file_name = filename;
+		config_linenr = 1;
+		config_file_eof = 0;
+		ret = perf_parse_file(fn, data);
+		fclose(f);
+		config_file_name = NULL;
+	}
+	return ret;
+}
+
+const char *perf_etc_perfconfig(void)
+{
+	static const char *system_wide;
+	if (!system_wide)
+		system_wide = system_path(ETC_PERFCONFIG);
+	return system_wide;
+}
+
+static int perf_env_bool(const char *k, int def)
+{
+	const char *v = getenv(k);
+	return v ? perf_config_bool(k, v) : def;
+}
+
+int perf_config_system(void)
+{
+	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
+}
+
+int perf_config_global(void)
+{
+	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
+}
+
+static char *home_perfconfig(void)
+{
+	const char *home = NULL;
+	char *config;
+	struct stat st;
+
+	home = getenv("HOME");
+
+	/*
+	 * Skip reading user config if:
+	 *   - there is no place to read it from (HOME)
+	 *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
+	 */
+	if (!home || !*home || !perf_config_global())
+		return NULL;
+
+	config = strdup(mkpath("%s/.perfconfig", home));
+	if (config == NULL) {
+		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.\n", home);
+		return NULL;
+	}
+
+	if (stat(config, &st) < 0)
+		goto out_free;
+
+	if (st.st_uid && (st.st_uid != geteuid())) {
+		pr_warning("File %s not owned by current user or root, ignoring it.\n", config);
+		goto out_free;
+	}
+
+	if (st.st_size)
+		return config;
+
+out_free:
+	free(config);
+	return NULL;
+}
+
+const char *perf_home_perfconfig(void)
+{
+	static const char *config;
+	static bool failed;
+
+	if (failed || config)
+		return config;
+
+	config = home_perfconfig();
+	if (!config)
+		failed = true;
+
+	return config;
+}
+
+static struct perf_config_section *find_section(struct list_head *sections,
+						const char *section_name)
+{
+	struct perf_config_section *section;
+
+	list_for_each_entry(section, sections, node)
+		if (!strcmp(section->name, section_name))
+			return section;
+
+	return NULL;
+}
+
+static struct perf_config_item *find_config_item(const char *name,
+						 struct perf_config_section *section)
+{
+	struct perf_config_item *item;
+
+	list_for_each_entry(item, &section->items, node)
+		if (!strcmp(item->name, name))
+			return item;
+
+	return NULL;
+}
+
+static struct perf_config_section *add_section(struct list_head *sections,
+					       const char *section_name)
+{
+	struct perf_config_section *section = zalloc(sizeof(*section));
+
+	if (!section)
+		return NULL;
+
+	INIT_LIST_HEAD(&section->items);
+	section->name = strdup(section_name);
+	if (!section->name) {
+		pr_debug("%s: strdup failed\n", __func__);
+		free(section);
+		return NULL;
+	}
+
+	list_add_tail(&section->node, sections);
+	return section;
+}
+
+static struct perf_config_item *add_config_item(struct perf_config_section *section,
+						const char *name)
+{
+	struct perf_config_item *item = zalloc(sizeof(*item));
+
+	if (!item)
+		return NULL;
+
+	item->name = strdup(name);
+	if (!item->name) {
+		pr_debug("%s: strdup failed\n", __func__);
+		free(item);
+		return NULL;
+	}
+
+	list_add_tail(&item->node, &section->items);
+	return item;
+}
+
+static int set_value(struct perf_config_item *item, const char *value)
+{
+	char *val = strdup(value);
+
+	if (!val)
+		return -1;
+
+	zfree(&item->value);
+	item->value = val;
+	return 0;
+}
+
+static int collect_config(const char *var, const char *value,
+			  void *perf_config_set)
+{
+	int ret = -1;
+	char *ptr, *key;
+	char *section_name, *name;
+	struct perf_config_section *section = NULL;
+	struct perf_config_item *item = NULL;
+	struct perf_config_set *set = perf_config_set;
+	struct list_head *sections;
+
+	if (set == NULL)
+		return -1;
+
+	sections = &set->sections;
+	key = ptr = strdup(var);
+	if (!key) {
+		pr_debug("%s: strdup failed\n", __func__);
+		return -1;
+	}
+
+	section_name = strsep(&ptr, ".");
+	name = ptr;
+	if (name == NULL || value == NULL)
+		goto out_free;
+
+	section = find_section(sections, section_name);
+	if (!section) {
+		section = add_section(sections, section_name);
+		if (!section)
+			goto out_free;
+	}
+
+	item = find_config_item(name, section);
+	if (!item) {
+		item = add_config_item(section, name);
+		if (!item)
+			goto out_free;
+	}
+
+	/* perf_config_set can contain both user and system config items.
+	 * So we should know where each value is from.
+	 * The classification would be needed when a particular config file
+	 * is overwritten by setting feature i.e. set_config().
+	 */
+	if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
+		section->from_system_config = true;
+		item->from_system_config = true;
+	} else {
+		section->from_system_config = false;
+		item->from_system_config = false;
+	}
+
+	ret = set_value(item, value);
+
+out_free:
+	free(key);
+	return ret;
+}
+
+int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
+			     const char *var, const char *value)
+{
+	config_file_name = file_name;
+	return collect_config(var, value, set);
+}
+
+static int perf_config_set__init(struct perf_config_set *set)
+{
+	int ret = -1;
+
+	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
+	if (config_exclusive_filename)
+		return perf_config_from_file(collect_config, config_exclusive_filename, set);
+	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
+		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
+			goto out;
+	}
+	if (perf_config_global() && perf_home_perfconfig()) {
+		if (perf_config_from_file(collect_config, perf_home_perfconfig(), set) < 0)
+			goto out;
+	}
+
+out:
+	return ret;
+}
+
+struct perf_config_set *perf_config_set__new(void)
+{
+	struct perf_config_set *set = zalloc(sizeof(*set));
+
+	if (set) {
+		INIT_LIST_HEAD(&set->sections);
+		perf_config_set__init(set);
+	}
+
+	return set;
+}
+
+struct perf_config_set *perf_config_set__load_file(const char *file)
+{
+	struct perf_config_set *set = zalloc(sizeof(*set));
+
+	if (set) {
+		INIT_LIST_HEAD(&set->sections);
+		perf_config_from_file(collect_config, file, set);
+	}
+
+	return set;
+}
+
+static int perf_config__init(void)
+{
+	if (config_set == NULL)
+		config_set = perf_config_set__new();
+
+	return config_set == NULL;
+}
+
+int perf_config_set(struct perf_config_set *set,
+		    config_fn_t fn, void *data)
+{
+	int ret = 0;
+	char key[BUFSIZ];
+	struct perf_config_section *section;
+	struct perf_config_item *item;
+
+	perf_config_set__for_each_entry(set, section, item) {
+		char *value = item->value;
+
+		if (value) {
+			scnprintf(key, sizeof(key), "%s.%s",
+				  section->name, item->name);
+			ret = fn(key, value, data);
+			if (ret < 0) {
+				pr_err("Error in the given config file: wrong config key-value pair %s=%s\n",
+				       key, value);
+				/*
+				 * Can't be just a 'break', as perf_config_set__for_each_entry()
+				 * expands to two nested for() loops.
+				 */
+				goto out;
+			}
+		}
+	}
+out:
+	return ret;
+}
+
+int perf_config(config_fn_t fn, void *data)
+{
+	if (config_set == NULL && perf_config__init())
+		return -1;
+
+	return perf_config_set(config_set, fn, data);
+}
+
+void perf_config__exit(void)
+{
+	perf_config_set__delete(config_set);
+	config_set = NULL;
+}
+
+void perf_config__refresh(void)
+{
+	perf_config__exit();
+	perf_config__init();
+}
+
+static void perf_config_item__delete(struct perf_config_item *item)
+{
+	zfree(&item->name);
+	zfree(&item->value);
+	free(item);
+}
+
+static void perf_config_section__purge(struct perf_config_section *section)
+{
+	struct perf_config_item *item, *tmp;
+
+	list_for_each_entry_safe(item, tmp, &section->items, node) {
+		list_del_init(&item->node);
+		perf_config_item__delete(item);
+	}
+}
+
+static void perf_config_section__delete(struct perf_config_section *section)
+{
+	perf_config_section__purge(section);
+	zfree(&section->name);
+	free(section);
+}
+
+static void perf_config_set__purge(struct perf_config_set *set)
+{
+	struct perf_config_section *section, *tmp;
+
+	list_for_each_entry_safe(section, tmp, &set->sections, node) {
+		list_del_init(&section->node);
+		perf_config_section__delete(section);
+	}
+}
+
+void perf_config_set__delete(struct perf_config_set *set)
+{
+	if (set == NULL)
+		return;
+
+	perf_config_set__purge(set);
+	free(set);
+}
+
+/*
+ * Call this to report error for your variable that should not
+ * get a boolean value (i.e. "[my] var" means "true").
+ */
+int config_error_nonbool(const char *var)
+{
+	pr_err("Missing value for '%s'", var);
+	return -1;
+}
+
+void set_buildid_dir(const char *dir)
+{
+	if (dir)
+		scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
+
+	/* default to $HOME/.debug */
+	if (buildid_dir[0] == '\0') {
+		char *home = getenv("HOME");
+
+		if (home) {
+			snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
+				 home, DEBUG_CACHE_DIR);
+		} else {
+			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
+		}
+		buildid_dir[MAXPATHLEN-1] = '\0';
+	}
+	/* for communicating with external commands */
+	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
+}
+
+struct perf_config_scan_data {
+	const char *name;
+	const char *fmt;
+	va_list args;
+	int ret;
+};
+
+static int perf_config_scan_cb(const char *var, const char *value, void *data)
+{
+	struct perf_config_scan_data *d = data;
+
+	if (!strcmp(var, d->name))
+		d->ret = vsscanf(value, d->fmt, d->args);
+
+	return 0;
+}
+
+int perf_config_scan(const char *name, const char *fmt, ...)
+{
+	struct perf_config_scan_data d = {
+		.name = name,
+		.fmt = fmt,
+	};
+
+	va_start(d.args, fmt);
+	perf_config(perf_config_scan_cb, &d);
+	va_end(d.args);
+
+	return d.ret;
+}