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, 480 insertions, 0 deletions

diff --git a/drivers/mtd/tests/torturetest.c b/drivers/mtd/tests/torturetest.c
new file mode 100644
index 000000000..841689b4d
--- /dev/null
+++ b/drivers/mtd/tests/torturetest.c
@@ -0,0 +1,480 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2006-2008 Artem Bityutskiy
+ * Copyright (C) 2006-2008 Jarkko Lavinen
+ * Copyright (C) 2006-2008 Adrian Hunter
+ *
+ * Authors: Artem Bityutskiy, Jarkko Lavinen, Adria Hunter
+ *
+ * WARNING: this test program may kill your flash and your device. Do not
+ * use it unless you know what you do. Authors are not responsible for any
+ * damage caused by this program.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/err.h>
+#include <linux/mtd/mtd.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include "mtd_test.h"
+
+#define RETRIES 3
+
+static int eb = 8;
+module_param(eb, int, S_IRUGO);
+MODULE_PARM_DESC(eb, "eraseblock number within the selected MTD device");
+
+static int ebcnt = 32;
+module_param(ebcnt, int, S_IRUGO);
+MODULE_PARM_DESC(ebcnt, "number of consecutive eraseblocks to torture");
+
+static int pgcnt;
+module_param(pgcnt, int, S_IRUGO);
+MODULE_PARM_DESC(pgcnt, "number of pages per eraseblock to torture (0 => all)");
+
+static int dev = -EINVAL;
+module_param(dev, int, S_IRUGO);
+MODULE_PARM_DESC(dev, "MTD device number to use");
+
+static int gran = 512;
+module_param(gran, int, S_IRUGO);
+MODULE_PARM_DESC(gran, "how often the status information should be printed");
+
+static int check = 1;
+module_param(check, int, S_IRUGO);
+MODULE_PARM_DESC(check, "if the written data should be checked");
+
+static unsigned int cycles_count;
+module_param(cycles_count, uint, S_IRUGO);
+MODULE_PARM_DESC(cycles_count, "how many erase cycles to do "
+			       "(infinite by default)");
+
+static struct mtd_info *mtd;
+
+/* This buffer contains 0x555555...0xAAAAAA... pattern */
+static unsigned char *patt_5A5;
+/* This buffer contains 0xAAAAAA...0x555555... pattern */
+static unsigned char *patt_A5A;
+/* This buffer contains all 0xFF bytes */
+static unsigned char *patt_FF;
+/* This a temporary buffer is use when checking data */
+static unsigned char *check_buf;
+/* How many erase cycles were done */
+static unsigned int erase_cycles;
+
+static int pgsize;
+static ktime_t start, finish;
+
+static void report_corrupt(unsigned char *read, unsigned char *written);
+
+static inline void start_timing(void)
+{
+	start = ktime_get();
+}
+
+static inline void stop_timing(void)
+{
+	finish = ktime_get();
+}
+
+/*
+ * Check that the contents of eraseblock number @enbum is equivalent to the
+ * @buf buffer.
+ */
+static inline int check_eraseblock(int ebnum, unsigned char *buf)
+{
+	int err, retries = 0;
+	size_t read;
+	loff_t addr = (loff_t)ebnum * mtd->erasesize;
+	size_t len = mtd->erasesize;
+
+	if (pgcnt) {
+		addr = (loff_t)(ebnum + 1) * mtd->erasesize - pgcnt * pgsize;
+		len = pgcnt * pgsize;
+	}
+
+retry:
+	err = mtd_read(mtd, addr, len, &read, check_buf);
+	if (mtd_is_bitflip(err))
+		pr_err("single bit flip occurred at EB %d "
+		       "MTD reported that it was fixed.\n", ebnum);
+	else if (err) {
+		pr_err("error %d while reading EB %d, "
+		       "read %zd\n", err, ebnum, read);
+		return err;
+	}
+
+	if (read != len) {
+		pr_err("failed to read %zd bytes from EB %d, "
+		       "read only %zd, but no error reported\n",
+		       len, ebnum, read);
+		return -EIO;
+	}
+
+	if (memcmp(buf, check_buf, len)) {
+		pr_err("read wrong data from EB %d\n", ebnum);
+		report_corrupt(check_buf, buf);
+
+		if (retries++ < RETRIES) {
+			/* Try read again */
+			yield();
+			pr_info("re-try reading data from EB %d\n",
+			       ebnum);
+			goto retry;
+		} else {
+			pr_info("retried %d times, still errors, "
+			       "give-up\n", RETRIES);
+			return -EINVAL;
+		}
+	}
+
+	if (retries != 0)
+		pr_info("only attempt number %d was OK (!!!)\n",
+		       retries);
+
+	return 0;
+}
+
+static inline int write_pattern(int ebnum, void *buf)
+{
+	int err;
+	size_t written;
+	loff_t addr = (loff_t)ebnum * mtd->erasesize;
+	size_t len = mtd->erasesize;
+
+	if (pgcnt) {
+		addr = (loff_t)(ebnum + 1) * mtd->erasesize - pgcnt * pgsize;
+		len = pgcnt * pgsize;
+	}
+	err = mtd_write(mtd, addr, len, &written, buf);
+	if (err) {
+		pr_err("error %d while writing EB %d, written %zd"
+		      " bytes\n", err, ebnum, written);
+		return err;
+	}
+	if (written != len) {
+		pr_info("written only %zd bytes of %zd, but no error"
+		       " reported\n", written, len);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int __init tort_init(void)
+{
+	int err = 0, i, infinite = !cycles_count;
+	unsigned char *bad_ebs;
+
+	printk(KERN_INFO "\n");
+	printk(KERN_INFO "=================================================\n");
+	pr_info("Warning: this program is trying to wear out your "
+	       "flash, stop it if this is not wanted.\n");
+
+	if (dev < 0) {
+		pr_info("Please specify a valid mtd-device via module parameter\n");
+		pr_crit("CAREFUL: This test wipes all data on the specified MTD device!\n");
+		return -EINVAL;
+	}
+
+	pr_info("MTD device: %d\n", dev);
+	pr_info("torture %d eraseblocks (%d-%d) of mtd%d\n",
+	       ebcnt, eb, eb + ebcnt - 1, dev);
+	if (pgcnt)
+		pr_info("torturing just %d pages per eraseblock\n",
+			pgcnt);
+	pr_info("write verify %s\n", check ? "enabled" : "disabled");
+
+	mtd = get_mtd_device(NULL, dev);
+	if (IS_ERR(mtd)) {
+		err = PTR_ERR(mtd);
+		pr_err("error: cannot get MTD device\n");
+		return err;
+	}
+
+	if (mtd->writesize == 1) {
+		pr_info("not NAND flash, assume page size is 512 "
+		       "bytes.\n");
+		pgsize = 512;
+	} else
+		pgsize = mtd->writesize;
+
+	if (pgcnt && (pgcnt > mtd->erasesize / pgsize || pgcnt < 0)) {
+		pr_err("error: invalid pgcnt value %d\n", pgcnt);
+		goto out_mtd;
+	}
+
+	err = -ENOMEM;
+	patt_5A5 = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!patt_5A5)
+		goto out_mtd;
+
+	patt_A5A = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!patt_A5A)
+		goto out_patt_5A5;
+
+	patt_FF = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!patt_FF)
+		goto out_patt_A5A;
+
+	check_buf = kmalloc(mtd->erasesize, GFP_KERNEL);
+	if (!check_buf)
+		goto out_patt_FF;
+
+	bad_ebs = kzalloc(ebcnt, GFP_KERNEL);
+	if (!bad_ebs)
+		goto out_check_buf;
+
+	/* Initialize patterns */
+	memset(patt_FF, 0xFF, mtd->erasesize);
+	for (i = 0; i < mtd->erasesize / pgsize; i++) {
+		if (!(i & 1)) {
+			memset(patt_5A5 + i * pgsize, 0x55, pgsize);
+			memset(patt_A5A + i * pgsize, 0xAA, pgsize);
+		} else {
+			memset(patt_5A5 + i * pgsize, 0xAA, pgsize);
+			memset(patt_A5A + i * pgsize, 0x55, pgsize);
+		}
+	}
+
+	err = mtdtest_scan_for_bad_eraseblocks(mtd, bad_ebs, eb, ebcnt);
+	if (err)
+		goto out;
+
+	start_timing();
+	while (1) {
+		int i;
+		void *patt;
+
+		err = mtdtest_erase_good_eraseblocks(mtd, bad_ebs, eb, ebcnt);
+		if (err)
+			goto out;
+
+		/* Check if the eraseblocks contain only 0xFF bytes */
+		if (check) {
+			for (i = eb; i < eb + ebcnt; i++) {
+				if (bad_ebs[i - eb])
+					continue;
+				err = check_eraseblock(i, patt_FF);
+				if (err) {
+					pr_info("verify failed"
+					       " for 0xFF... pattern\n");
+					goto out;
+				}
+
+				err = mtdtest_relax();
+				if (err)
+					goto out;
+			}
+		}
+
+		/* Write the pattern */
+		for (i = eb; i < eb + ebcnt; i++) {
+			if (bad_ebs[i - eb])
+				continue;
+			if ((eb + erase_cycles) & 1)
+				patt = patt_5A5;
+			else
+				patt = patt_A5A;
+			err = write_pattern(i, patt);
+			if (err)
+				goto out;
+
+			err = mtdtest_relax();
+			if (err)
+				goto out;
+		}
+
+		/* Verify what we wrote */
+		if (check) {
+			for (i = eb; i < eb + ebcnt; i++) {
+				if (bad_ebs[i - eb])
+					continue;
+				if ((eb + erase_cycles) & 1)
+					patt = patt_5A5;
+				else
+					patt = patt_A5A;
+				err = check_eraseblock(i, patt);
+				if (err) {
+					pr_info("verify failed for %s"
+					       " pattern\n",
+					       ((eb + erase_cycles) & 1) ?
+					       "0x55AA55..." : "0xAA55AA...");
+					goto out;
+				}
+
+				err = mtdtest_relax();
+				if (err)
+					goto out;
+			}
+		}
+
+		erase_cycles += 1;
+
+		if (erase_cycles % gran == 0) {
+			long ms;
+
+			stop_timing();
+			ms = ktime_ms_delta(finish, start);
+			pr_info("%08u erase cycles done, took %lu "
+			       "milliseconds (%lu seconds)\n",
+			       erase_cycles, ms, ms / 1000);
+			start_timing();
+		}
+
+		if (!infinite && --cycles_count == 0)
+			break;
+	}
+out:
+
+	pr_info("finished after %u erase cycles\n",
+	       erase_cycles);
+	kfree(bad_ebs);
+out_check_buf:
+	kfree(check_buf);
+out_patt_FF:
+	kfree(patt_FF);
+out_patt_A5A:
+	kfree(patt_A5A);
+out_patt_5A5:
+	kfree(patt_5A5);
+out_mtd:
+	put_mtd_device(mtd);
+	if (err)
+		pr_info("error %d occurred during torturing\n", err);
+	printk(KERN_INFO "=================================================\n");
+	return err;
+}
+module_init(tort_init);
+
+static void __exit tort_exit(void)
+{
+	return;
+}
+module_exit(tort_exit);
+
+static int countdiffs(unsigned char *buf, unsigned char *check_buf,
+		      unsigned offset, unsigned len, unsigned *bytesp,
+		      unsigned *bitsp);
+static void print_bufs(unsigned char *read, unsigned char *written, int start,
+		       int len);
+
+/*
+ * Report the detailed information about how the read EB differs from what was
+ * written.
+ */
+static void report_corrupt(unsigned char *read, unsigned char *written)
+{
+	int i;
+	int bytes, bits, pages, first;
+	int offset, len;
+	size_t check_len = mtd->erasesize;
+
+	if (pgcnt)
+		check_len = pgcnt * pgsize;
+
+	bytes = bits = pages = 0;
+	for (i = 0; i < check_len; i += pgsize)
+		if (countdiffs(written, read, i, pgsize, &bytes,
+			       &bits) >= 0)
+			pages++;
+
+	pr_info("verify fails on %d pages, %d bytes/%d bits\n",
+	       pages, bytes, bits);
+	pr_info("The following is a list of all differences between"
+	       " what was read from flash and what was expected\n");
+
+	for (i = 0; i < check_len; i += pgsize) {
+		cond_resched();
+		bytes = bits = 0;
+		first = countdiffs(written, read, i, pgsize, &bytes,
+				   &bits);
+		if (first < 0)
+			continue;
+
+		printk("-------------------------------------------------------"
+		       "----------------------------------\n");
+
+		pr_info("Page %zd has %d bytes/%d bits failing verify,"
+		       " starting at offset 0x%x\n",
+		       (mtd->erasesize - check_len + i) / pgsize,
+		       bytes, bits, first);
+
+		offset = first & ~0x7;
+		len = ((first + bytes) | 0x7) + 1 - offset;
+
+		print_bufs(read, written, offset, len);
+	}
+}
+
+static void print_bufs(unsigned char *read, unsigned char *written, int start,
+		       int len)
+{
+	int i = 0, j1, j2;
+	char *diff;
+
+	printk("Offset       Read                          Written\n");
+	while (i < len) {
+		printk("0x%08x: ", start + i);
+		diff = "   ";
+		for (j1 = 0; j1 < 8 && i + j1 < len; j1++) {
+			printk(" %02x", read[start + i + j1]);
+			if (read[start + i + j1] != written[start + i + j1])
+				diff = "***";
+		}
+
+		while (j1 < 8) {
+			printk(" ");
+			j1 += 1;
+		}
+
+		printk("  %s ", diff);
+
+		for (j2 = 0; j2 < 8 && i + j2 < len; j2++)
+			printk(" %02x", written[start + i + j2]);
+		printk("\n");
+		i += 8;
+	}
+}
+
+/*
+ * Count the number of differing bytes and bits and return the first differing
+ * offset.
+ */
+static int countdiffs(unsigned char *buf, unsigned char *check_buf,
+		      unsigned offset, unsigned len, unsigned *bytesp,
+		      unsigned *bitsp)
+{
+	unsigned i, bit;
+	int first = -1;
+
+	for (i = offset; i < offset + len; i++)
+		if (buf[i] != check_buf[i]) {
+			first = i;
+			break;
+		}
+
+	while (i < offset + len) {
+		if (buf[i] != check_buf[i]) {
+			(*bytesp)++;
+			bit = 1;
+			while (bit < 256) {
+				if ((buf[i] & bit) != (check_buf[i] & bit))
+					(*bitsp)++;
+				bit <<= 1;
+			}
+		}
+		i++;
+	}
+
+	return first;
+}
+
+MODULE_DESCRIPTION("Eraseblock torturing module");
+MODULE_AUTHOR("Artem Bityutskiy, Jarkko Lavinen, Adrian Hunter");
+MODULE_LICENSE("GPL");