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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/x86/fsgsbase_restore.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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/x86/fsgsbase_restore.c')
-rw-r--r--tools/testing/selftests/x86/fsgsbase_restore.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/tools/testing/selftests/x86/fsgsbase_restore.c b/tools/testing/selftests/x86/fsgsbase_restore.c
new file mode 100644
index 000000000..6fffadc51
--- /dev/null
+++ b/tools/testing/selftests/x86/fsgsbase_restore.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fsgsbase_restore.c, test ptrace vs fsgsbase
+ * Copyright (c) 2020 Andy Lutomirski
+ *
+ * This test case simulates a tracer redirecting tracee execution to
+ * a function and then restoring tracee state using PTRACE_GETREGS and
+ * PTRACE_SETREGS. This is similar to what gdb does when doing
+ * 'p func()'. The catch is that this test has the called function
+ * modify a segment register. This makes sure that ptrace correctly
+ * restores segment state when using PTRACE_SETREGS.
+ *
+ * This is not part of fsgsbase.c, because that test is 64-bit only.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <err.h>
+#include <sys/user.h>
+#include <asm/prctl.h>
+#include <sys/prctl.h>
+#include <asm/ldt.h>
+#include <sys/mman.h>
+#include <stddef.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <stdint.h>
+
+#define EXPECTED_VALUE 0x1337f00d
+
+#ifdef __x86_64__
+# define SEG "%gs"
+#else
+# define SEG "%fs"
+#endif
+
+static unsigned int dereference_seg_base(void)
+{
+ int ret;
+ asm volatile ("mov %" SEG ":(0), %0" : "=rm" (ret));
+ return ret;
+}
+
+static void init_seg(void)
+{
+ unsigned int *target = mmap(
+ NULL, sizeof(unsigned int),
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0);
+ if (target == MAP_FAILED)
+ err(1, "mmap");
+
+ *target = EXPECTED_VALUE;
+
+ printf("\tsegment base address = 0x%lx\n", (unsigned long)target);
+
+ struct user_desc desc = {
+ .entry_number = 0,
+ .base_addr = (unsigned int)(uintptr_t)target,
+ .limit = sizeof(unsigned int) - 1,
+ .seg_32bit = 1,
+ .contents = 0, /* Data, grow-up */
+ .read_exec_only = 0,
+ .limit_in_pages = 0,
+ .seg_not_present = 0,
+ .useable = 0
+ };
+ if (syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)) == 0) {
+ printf("\tusing LDT slot 0\n");
+ asm volatile ("mov %0, %" SEG :: "rm" ((unsigned short)0x7));
+ } else {
+ /* No modify_ldt for us (configured out, perhaps) */
+
+ struct user_desc *low_desc = mmap(
+ NULL, sizeof(desc),
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_32BIT, -1, 0);
+ memcpy(low_desc, &desc, sizeof(desc));
+
+ low_desc->entry_number = -1;
+
+ /* 32-bit set_thread_area */
+ long ret;
+ asm volatile ("int $0x80"
+ : "=a" (ret), "+m" (*low_desc)
+ : "a" (243), "b" (low_desc)
+#ifdef __x86_64__
+ : "r8", "r9", "r10", "r11"
+#endif
+ );
+ memcpy(&desc, low_desc, sizeof(desc));
+ munmap(low_desc, sizeof(desc));
+
+ if (ret != 0) {
+ printf("[NOTE]\tcould not create a segment -- can't test anything\n");
+ exit(0);
+ }
+ printf("\tusing GDT slot %d\n", desc.entry_number);
+
+ unsigned short sel = (unsigned short)((desc.entry_number << 3) | 0x3);
+ asm volatile ("mov %0, %" SEG :: "rm" (sel));
+ }
+}
+
+static void tracee_zap_segment(void)
+{
+ /*
+ * The tracer will redirect execution here. This is meant to
+ * work like gdb's 'p func()' feature. The tricky bit is that
+ * we modify a segment register in order to make sure that ptrace
+ * can correctly restore segment registers.
+ */
+ printf("\tTracee: in tracee_zap_segment()\n");
+
+ /*
+ * Write a nonzero selector with base zero to the segment register.
+ * Using a null selector would defeat the test on AMD pre-Zen2
+ * CPUs, as such CPUs don't clear the base when loading a null
+ * selector.
+ */
+ unsigned short sel;
+ asm volatile ("mov %%ss, %0\n\t"
+ "mov %0, %" SEG
+ : "=rm" (sel));
+
+ pid_t pid = getpid(), tid = syscall(SYS_gettid);
+
+ printf("\tTracee is going back to sleep\n");
+ syscall(SYS_tgkill, pid, tid, SIGSTOP);
+
+ /* Should not get here. */
+ while (true) {
+ printf("[FAIL]\tTracee hit unreachable code\n");
+ pause();
+ }
+}
+
+int main()
+{
+ printf("\tSetting up a segment\n");
+ init_seg();
+
+ unsigned int val = dereference_seg_base();
+ if (val != EXPECTED_VALUE) {
+ printf("[FAIL]\tseg[0] == %x; should be %x\n", val, EXPECTED_VALUE);
+ return 1;
+ }
+ printf("[OK]\tThe segment points to the right place.\n");
+
+ pid_t chld = fork();
+ if (chld < 0)
+ err(1, "fork");
+
+ if (chld == 0) {
+ prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0, 0);
+
+ if (ptrace(PTRACE_TRACEME, 0, 0, 0) != 0)
+ err(1, "PTRACE_TRACEME");
+
+ pid_t pid = getpid(), tid = syscall(SYS_gettid);
+
+ printf("\tTracee will take a nap until signaled\n");
+ syscall(SYS_tgkill, pid, tid, SIGSTOP);
+
+ printf("\tTracee was resumed. Will re-check segment.\n");
+
+ val = dereference_seg_base();
+ if (val != EXPECTED_VALUE) {
+ printf("[FAIL]\tseg[0] == %x; should be %x\n", val, EXPECTED_VALUE);
+ exit(1);
+ }
+
+ printf("[OK]\tThe segment points to the right place.\n");
+ exit(0);
+ }
+
+ int status;
+
+ /* Wait for SIGSTOP. */
+ if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))
+ err(1, "waitpid");
+
+ struct user_regs_struct regs;
+
+ if (ptrace(PTRACE_GETREGS, chld, NULL, &regs) != 0)
+ err(1, "PTRACE_GETREGS");
+
+#ifdef __x86_64__
+ printf("\tChild GS=0x%lx, GSBASE=0x%lx\n", (unsigned long)regs.gs, (unsigned long)regs.gs_base);
+#else
+ printf("\tChild FS=0x%lx\n", (unsigned long)regs.xfs);
+#endif
+
+ struct user_regs_struct regs2 = regs;
+#ifdef __x86_64__
+ regs2.rip = (unsigned long)tracee_zap_segment;
+ regs2.rsp -= 128; /* Don't clobber the redzone. */
+#else
+ regs2.eip = (unsigned long)tracee_zap_segment;
+#endif
+
+ printf("\tTracer: redirecting tracee to tracee_zap_segment()\n");
+ if (ptrace(PTRACE_SETREGS, chld, NULL, &regs2) != 0)
+ err(1, "PTRACE_GETREGS");
+ if (ptrace(PTRACE_CONT, chld, NULL, NULL) != 0)
+ err(1, "PTRACE_GETREGS");
+
+ /* Wait for SIGSTOP. */
+ if (waitpid(chld, &status, 0) != chld || !WIFSTOPPED(status))
+ err(1, "waitpid");
+
+ printf("\tTracer: restoring tracee state\n");
+ if (ptrace(PTRACE_SETREGS, chld, NULL, &regs) != 0)
+ err(1, "PTRACE_GETREGS");
+ if (ptrace(PTRACE_DETACH, chld, NULL, NULL) != 0)
+ err(1, "PTRACE_GETREGS");
+
+ /* Wait for SIGSTOP. */
+ if (waitpid(chld, &status, 0) != chld)
+ err(1, "waitpid");
+
+ if (WIFSIGNALED(status)) {
+ printf("[FAIL]\tTracee crashed\n");
+ return 1;
+ }
+
+ if (!WIFEXITED(status)) {
+ printf("[FAIL]\tTracee stopped for an unexpected reason: %d\n", status);
+ return 1;
+ }
+
+ int exitcode = WEXITSTATUS(status);
+ if (exitcode != 0) {
+ printf("[FAIL]\tTracee reported failure\n");
+ return 1;
+ }
+
+ printf("[OK]\tAll is well.\n");
+ return 0;
+}