aboutsummaryrefslogtreecommitdiff
path: root/mm/process_vm_access.c
diff options
context:
space:
mode:
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 /mm/process_vm_access.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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 'mm/process_vm_access.c')
-rw-r--r--mm/process_vm_access.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
new file mode 100644
index 000000000..78dfaf9e8
--- /dev/null
+++ b/mm/process_vm_access.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * linux/mm/process_vm_access.c
+ *
+ * Copyright (C) 2010-2011 Christopher Yeoh <cyeoh@au1.ibm.com>, IBM Corp.
+ */
+
+#include <linux/compat.h>
+#include <linux/mm.h>
+#include <linux/uio.h>
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+/**
+ * process_vm_rw_pages - read/write pages from task specified
+ * @pages: array of pointers to pages we want to copy
+ * @offset: offset in page to start copying from/to
+ * @len: number of bytes to copy
+ * @iter: where to copy to/from locally
+ * @vm_write: 0 means copy from, 1 means copy to
+ * Returns 0 on success, error code otherwise
+ */
+static int process_vm_rw_pages(struct page **pages,
+ unsigned offset,
+ size_t len,
+ struct iov_iter *iter,
+ int vm_write)
+{
+ /* Do the copy for each page */
+ while (len && iov_iter_count(iter)) {
+ struct page *page = *pages++;
+ size_t copy = PAGE_SIZE - offset;
+ size_t copied;
+
+ if (copy > len)
+ copy = len;
+
+ if (vm_write)
+ copied = copy_page_from_iter(page, offset, copy, iter);
+ else
+ copied = copy_page_to_iter(page, offset, copy, iter);
+
+ len -= copied;
+ if (copied < copy && iov_iter_count(iter))
+ return -EFAULT;
+ offset = 0;
+ }
+ return 0;
+}
+
+/* Maximum number of pages kmalloc'd to hold struct page's during copy */
+#define PVM_MAX_KMALLOC_PAGES (PAGE_SIZE * 2)
+
+/**
+ * process_vm_rw_single_vec - read/write pages from task specified
+ * @addr: start memory address of target process
+ * @len: size of area to copy to/from
+ * @iter: where to copy to/from locally
+ * @process_pages: struct pages area that can store at least
+ * nr_pages_to_copy struct page pointers
+ * @mm: mm for task
+ * @task: task to read/write from
+ * @vm_write: 0 means copy from, 1 means copy to
+ * Returns 0 on success or on failure error code
+ */
+static int process_vm_rw_single_vec(unsigned long addr,
+ unsigned long len,
+ struct iov_iter *iter,
+ struct page **process_pages,
+ struct mm_struct *mm,
+ struct task_struct *task,
+ int vm_write)
+{
+ unsigned long pa = addr & PAGE_MASK;
+ unsigned long start_offset = addr - pa;
+ unsigned long nr_pages;
+ ssize_t rc = 0;
+ unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
+ / sizeof(struct pages *);
+ unsigned int flags = 0;
+
+ /* Work out address and page range required */
+ if (len == 0)
+ return 0;
+ nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
+
+ if (vm_write)
+ flags |= FOLL_WRITE;
+
+ while (!rc && nr_pages && iov_iter_count(iter)) {
+ int pinned_pages = min(nr_pages, max_pages_per_loop);
+ int locked = 1;
+ size_t bytes;
+
+ /*
+ * Get the pages we're interested in. We must
+ * access remotely because task/mm might not
+ * current/current->mm
+ */
+ mmap_read_lock(mm);
+ pinned_pages = pin_user_pages_remote(mm, pa, pinned_pages,
+ flags, process_pages,
+ NULL, &locked);
+ if (locked)
+ mmap_read_unlock(mm);
+ if (pinned_pages <= 0)
+ return -EFAULT;
+
+ bytes = pinned_pages * PAGE_SIZE - start_offset;
+ if (bytes > len)
+ bytes = len;
+
+ rc = process_vm_rw_pages(process_pages,
+ start_offset, bytes, iter,
+ vm_write);
+ len -= bytes;
+ start_offset = 0;
+ nr_pages -= pinned_pages;
+ pa += pinned_pages * PAGE_SIZE;
+
+ /* If vm_write is set, the pages need to be made dirty: */
+ unpin_user_pages_dirty_lock(process_pages, pinned_pages,
+ vm_write);
+ }
+
+ return rc;
+}
+
+/* Maximum number of entries for process pages array
+ which lives on stack */
+#define PVM_MAX_PP_ARRAY_COUNT 16
+
+/**
+ * process_vm_rw_core - core of reading/writing pages from task specified
+ * @pid: PID of process to read/write from/to
+ * @iter: where to copy to/from locally
+ * @rvec: iovec array specifying where to copy to/from in the other process
+ * @riovcnt: size of rvec array
+ * @flags: currently unused
+ * @vm_write: 0 if reading from other process, 1 if writing to other process
+ *
+ * Returns the number of bytes read/written or error code. May
+ * return less bytes than expected if an error occurs during the copying
+ * process.
+ */
+static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
+ const struct iovec *rvec,
+ unsigned long riovcnt,
+ unsigned long flags, int vm_write)
+{
+ struct task_struct *task;
+ struct page *pp_stack[PVM_MAX_PP_ARRAY_COUNT];
+ struct page **process_pages = pp_stack;
+ struct mm_struct *mm;
+ unsigned long i;
+ ssize_t rc = 0;
+ unsigned long nr_pages = 0;
+ unsigned long nr_pages_iov;
+ ssize_t iov_len;
+ size_t total_len = iov_iter_count(iter);
+
+ /*
+ * Work out how many pages of struct pages we're going to need
+ * when eventually calling get_user_pages
+ */
+ for (i = 0; i < riovcnt; i++) {
+ iov_len = rvec[i].iov_len;
+ if (iov_len > 0) {
+ nr_pages_iov = ((unsigned long)rvec[i].iov_base
+ + iov_len)
+ / PAGE_SIZE - (unsigned long)rvec[i].iov_base
+ / PAGE_SIZE + 1;
+ nr_pages = max(nr_pages, nr_pages_iov);
+ }
+ }
+
+ if (nr_pages == 0)
+ return 0;
+
+ if (nr_pages > PVM_MAX_PP_ARRAY_COUNT) {
+ /* For reliability don't try to kmalloc more than
+ 2 pages worth */
+ process_pages = kmalloc(min_t(size_t, PVM_MAX_KMALLOC_PAGES,
+ sizeof(struct pages *)*nr_pages),
+ GFP_KERNEL);
+
+ if (!process_pages)
+ return -ENOMEM;
+ }
+
+ /* Get process information */
+ task = find_get_task_by_vpid(pid);
+ if (!task) {
+ rc = -ESRCH;
+ goto free_proc_pages;
+ }
+
+ mm = mm_access(task, PTRACE_MODE_ATTACH_REALCREDS);
+ if (!mm || IS_ERR(mm)) {
+ rc = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
+ /*
+ * Explicitly map EACCES to EPERM as EPERM is a more
+ * appropriate error code for process_vw_readv/writev
+ */
+ if (rc == -EACCES)
+ rc = -EPERM;
+ goto put_task_struct;
+ }
+
+ for (i = 0; i < riovcnt && iov_iter_count(iter) && !rc; i++)
+ rc = process_vm_rw_single_vec(
+ (unsigned long)rvec[i].iov_base, rvec[i].iov_len,
+ iter, process_pages, mm, task, vm_write);
+
+ /* copied = space before - space after */
+ total_len -= iov_iter_count(iter);
+
+ /* If we have managed to copy any data at all then
+ we return the number of bytes copied. Otherwise
+ we return the error code */
+ if (total_len)
+ rc = total_len;
+
+ mmput(mm);
+
+put_task_struct:
+ put_task_struct(task);
+
+free_proc_pages:
+ if (process_pages != pp_stack)
+ kfree(process_pages);
+ return rc;
+}
+
+/**
+ * process_vm_rw - check iovecs before calling core routine
+ * @pid: PID of process to read/write from/to
+ * @lvec: iovec array specifying where to copy to/from locally
+ * @liovcnt: size of lvec array
+ * @rvec: iovec array specifying where to copy to/from in the other process
+ * @riovcnt: size of rvec array
+ * @flags: currently unused
+ * @vm_write: 0 if reading from other process, 1 if writing to other process
+ *
+ * Returns the number of bytes read/written or error code. May
+ * return less bytes than expected if an error occurs during the copying
+ * process.
+ */
+static ssize_t process_vm_rw(pid_t pid,
+ const struct iovec __user *lvec,
+ unsigned long liovcnt,
+ const struct iovec __user *rvec,
+ unsigned long riovcnt,
+ unsigned long flags, int vm_write)
+{
+ struct iovec iovstack_l[UIO_FASTIOV];
+ struct iovec iovstack_r[UIO_FASTIOV];
+ struct iovec *iov_l = iovstack_l;
+ struct iovec *iov_r;
+ struct iov_iter iter;
+ ssize_t rc;
+ int dir = vm_write ? ITER_SOURCE : ITER_DEST;
+
+ if (flags != 0)
+ return -EINVAL;
+
+ /* Check iovecs */
+ rc = import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
+ if (rc < 0)
+ return rc;
+ if (!iov_iter_count(&iter))
+ goto free_iov_l;
+ iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r,
+ in_compat_syscall());
+ if (IS_ERR(iov_r)) {
+ rc = PTR_ERR(iov_r);
+ goto free_iov_l;
+ }
+ rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
+ if (iov_r != iovstack_r)
+ kfree(iov_r);
+free_iov_l:
+ kfree(iov_l);
+ return rc;
+}
+
+SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec,
+ unsigned long, liovcnt, const struct iovec __user *, rvec,
+ unsigned long, riovcnt, unsigned long, flags)
+{
+ return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 0);
+}
+
+SYSCALL_DEFINE6(process_vm_writev, pid_t, pid,
+ const struct iovec __user *, lvec,
+ unsigned long, liovcnt, const struct iovec __user *, rvec,
+ unsigned long, riovcnt, unsigned long, flags)
+{
+ return process_vm_rw(pid, lvec, liovcnt, rvec, riovcnt, flags, 1);
+}