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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c
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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(). ...
Diffstat (limited to 'tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c')
-rw-r--r--tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c b/tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c
new file mode 100644
index 000000000..0b84c9208
--- /dev/null
+++ b/tools/testing/selftests/powerpc/tm/tm-signal-pagefault.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020, Gustavo Luiz Duarte, IBM Corp.
+ *
+ * This test starts a transaction and triggers a signal, forcing a pagefault to
+ * happen when the kernel signal handling code touches the user signal stack.
+ *
+ * In order to avoid pre-faulting the signal stack memory and to force the
+ * pagefault to happen precisely in the kernel signal handling code, the
+ * pagefault handling is done in userspace using the userfaultfd facility.
+ *
+ * Further pagefaults are triggered by crafting the signal handler's ucontext
+ * to point to additional memory regions managed by the userfaultfd, so using
+ * the same mechanism used to avoid pre-faulting the signal stack memory.
+ *
+ * On failure (bug is present) kernel crashes or never returns control back to
+ * userspace. If bug is not present, tests completes almost immediately.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/userfaultfd.h>
+#include <poll.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <pthread.h>
+#include <signal.h>
+#include <errno.h>
+
+#include "tm.h"
+
+
+#define UF_MEM_SIZE 655360 /* 10 x 64k pages */
+
+/* Memory handled by userfaultfd */
+static char *uf_mem;
+static size_t uf_mem_offset = 0;
+
+/*
+ * Data that will be copied into the faulting pages (instead of zero-filled
+ * pages). This is used to make the test more reliable and avoid segfaulting
+ * when we return from the signal handler. Since we are making the signal
+ * handler's ucontext point to newly allocated memory, when that memory is
+ * paged-in it will contain the expected content.
+ */
+static char backing_mem[UF_MEM_SIZE];
+
+static size_t pagesize;
+
+/*
+ * Return a chunk of at least 'size' bytes of memory that will be handled by
+ * userfaultfd. If 'backing_data' is not NULL, its content will be save to
+ * 'backing_mem' and then copied into the faulting pages when the page fault
+ * is handled.
+ */
+void *get_uf_mem(size_t size, void *backing_data)
+{
+ void *ret;
+
+ if (uf_mem_offset + size > UF_MEM_SIZE) {
+ fprintf(stderr, "Requesting more uf_mem than expected!\n");
+ exit(EXIT_FAILURE);
+ }
+
+ ret = &uf_mem[uf_mem_offset];
+
+ /* Save the data that will be copied into the faulting page */
+ if (backing_data != NULL)
+ memcpy(&backing_mem[uf_mem_offset], backing_data, size);
+
+ /* Reserve the requested amount of uf_mem */
+ uf_mem_offset += size;
+ /* Keep uf_mem_offset aligned to the page size (round up) */
+ uf_mem_offset = (uf_mem_offset + pagesize - 1) & ~(pagesize - 1);
+
+ return ret;
+}
+
+void *fault_handler_thread(void *arg)
+{
+ struct uffd_msg msg; /* Data read from userfaultfd */
+ long uffd; /* userfaultfd file descriptor */
+ struct uffdio_copy uffdio_copy;
+ struct pollfd pollfd;
+ ssize_t nread, offset;
+
+ uffd = (long) arg;
+
+ for (;;) {
+ pollfd.fd = uffd;
+ pollfd.events = POLLIN;
+ if (poll(&pollfd, 1, -1) == -1) {
+ perror("poll() failed");
+ exit(EXIT_FAILURE);
+ }
+
+ nread = read(uffd, &msg, sizeof(msg));
+ if (nread == 0) {
+ fprintf(stderr, "read(): EOF on userfaultfd\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (nread == -1) {
+ perror("read() failed");
+ exit(EXIT_FAILURE);
+ }
+
+ /* We expect only one kind of event */
+ if (msg.event != UFFD_EVENT_PAGEFAULT) {
+ fprintf(stderr, "Unexpected event on userfaultfd\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * We need to handle page faults in units of pages(!).
+ * So, round faulting address down to page boundary.
+ */
+ uffdio_copy.dst = msg.arg.pagefault.address & ~(pagesize-1);
+
+ offset = (char *) uffdio_copy.dst - uf_mem;
+ uffdio_copy.src = (unsigned long) &backing_mem[offset];
+
+ uffdio_copy.len = pagesize;
+ uffdio_copy.mode = 0;
+ uffdio_copy.copy = 0;
+ if (ioctl(uffd, UFFDIO_COPY, &uffdio_copy) == -1) {
+ perror("ioctl-UFFDIO_COPY failed");
+ exit(EXIT_FAILURE);
+ }
+ }
+}
+
+void setup_uf_mem(void)
+{
+ long uffd; /* userfaultfd file descriptor */
+ pthread_t thr;
+ struct uffdio_api uffdio_api;
+ struct uffdio_register uffdio_register;
+ int ret;
+
+ pagesize = sysconf(_SC_PAGE_SIZE);
+
+ /* Create and enable userfaultfd object */
+ uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+ if (uffd == -1) {
+ perror("userfaultfd() failed");
+ exit(EXIT_FAILURE);
+ }
+ uffdio_api.api = UFFD_API;
+ uffdio_api.features = 0;
+ if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1) {
+ perror("ioctl-UFFDIO_API failed");
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Create a private anonymous mapping. The memory will be demand-zero
+ * paged, that is, not yet allocated. When we actually touch the memory
+ * the related page will be allocated via the userfaultfd mechanism.
+ */
+ uf_mem = mmap(NULL, UF_MEM_SIZE, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (uf_mem == MAP_FAILED) {
+ perror("mmap() failed");
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Register the memory range of the mapping we've just mapped to be
+ * handled by the userfaultfd object. In 'mode' we request to track
+ * missing pages (i.e. pages that have not yet been faulted-in).
+ */
+ uffdio_register.range.start = (unsigned long) uf_mem;
+ uffdio_register.range.len = UF_MEM_SIZE;
+ uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
+ if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) {
+ perror("ioctl-UFFDIO_REGISTER");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Create a thread that will process the userfaultfd events */
+ ret = pthread_create(&thr, NULL, fault_handler_thread, (void *) uffd);
+ if (ret != 0) {
+ fprintf(stderr, "pthread_create(): Error. Returned %d\n", ret);
+ exit(EXIT_FAILURE);
+ }
+}
+
+/*
+ * Assumption: the signal was delivered while userspace was in transactional or
+ * suspended state, i.e. uc->uc_link != NULL.
+ */
+void signal_handler(int signo, siginfo_t *si, void *uc)
+{
+ ucontext_t *ucp = uc;
+
+ /* Skip 'trap' after returning, otherwise we get a SIGTRAP again */
+ ucp->uc_link->uc_mcontext.regs->nip += 4;
+
+ ucp->uc_mcontext.v_regs =
+ get_uf_mem(sizeof(elf_vrreg_t), ucp->uc_mcontext.v_regs);
+
+ ucp->uc_link->uc_mcontext.v_regs =
+ get_uf_mem(sizeof(elf_vrreg_t), ucp->uc_link->uc_mcontext.v_regs);
+
+ ucp->uc_link = get_uf_mem(sizeof(ucontext_t), ucp->uc_link);
+}
+
+bool have_userfaultfd(void)
+{
+ long rc;
+
+ errno = 0;
+ rc = syscall(__NR_userfaultfd, -1);
+
+ return rc == 0 || errno != ENOSYS;
+}
+
+int tm_signal_pagefault(void)
+{
+ struct sigaction sa;
+ stack_t ss;
+
+ SKIP_IF(!have_htm());
+ SKIP_IF(htm_is_synthetic());
+ SKIP_IF(!have_userfaultfd());
+
+ setup_uf_mem();
+
+ /*
+ * Set an alternative stack that will generate a page fault when the
+ * signal is raised. The page fault will be treated via userfaultfd,
+ * i.e. via fault_handler_thread.
+ */
+ ss.ss_sp = get_uf_mem(SIGSTKSZ, NULL);
+ ss.ss_size = SIGSTKSZ;
+ ss.ss_flags = 0;
+ if (sigaltstack(&ss, NULL) == -1) {
+ perror("sigaltstack() failed");
+ exit(EXIT_FAILURE);
+ }
+
+ sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
+ sa.sa_sigaction = signal_handler;
+ if (sigaction(SIGTRAP, &sa, NULL) == -1) {
+ perror("sigaction() failed");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Trigger a SIGTRAP in transactional state */
+ asm __volatile__(
+ "tbegin.;"
+ "beq 1f;"
+ "trap;"
+ "1: ;"
+ : : : "memory");
+
+ /* Trigger a SIGTRAP in suspended state */
+ asm __volatile__(
+ "tbegin.;"
+ "beq 1f;"
+ "tsuspend.;"
+ "trap;"
+ "tresume.;"
+ "1: ;"
+ : : : "memory");
+
+ return EXIT_SUCCESS;
+}
+
+int main(int argc, char **argv)
+{
+ /*
+ * Depending on kernel config, the TM Bad Thing might not result in a
+ * crash, instead the kernel never returns control back to userspace, so
+ * set a tight timeout. If the test passes it completes almost
+ * immediately.
+ */
+ test_harness_set_timeout(2);
+ return test_harness(tm_signal_pagefault, "tm_signal_pagefault");
+}