From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/input/mouse/vmmouse.c | 468 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 468 insertions(+) create mode 100644 drivers/input/mouse/vmmouse.c (limited to 'drivers/input/mouse/vmmouse.c') diff --git a/drivers/input/mouse/vmmouse.c b/drivers/input/mouse/vmmouse.c new file mode 100644 index 000000000..aaecdd3d5 --- /dev/null +++ b/drivers/input/mouse/vmmouse.c @@ -0,0 +1,468 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Virtual PS/2 Mouse on VMware and QEMU hypervisors. + * + * Copyright (C) 2014, VMware, Inc. All Rights Reserved. + * + * Twin device code is hugely inspired by the ALPS driver. + * Authors: + * Dmitry Torokhov + * Thomas Hellstrom + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "psmouse.h" +#include "vmmouse.h" + +/* + * Main commands supported by the vmmouse hypervisor port. + */ +#define VMWARE_CMD_ABSPOINTER_DATA 39 +#define VMWARE_CMD_ABSPOINTER_STATUS 40 +#define VMWARE_CMD_ABSPOINTER_COMMAND 41 +#define VMWARE_CMD_ABSPOINTER_RESTRICT 86 + +/* + * Subcommands for VMWARE_CMD_ABSPOINTER_COMMAND + */ +#define VMMOUSE_CMD_ENABLE 0x45414552U +#define VMMOUSE_CMD_DISABLE 0x000000f5U +#define VMMOUSE_CMD_REQUEST_RELATIVE 0x4c455252U +#define VMMOUSE_CMD_REQUEST_ABSOLUTE 0x53424152U + +#define VMMOUSE_ERROR 0xffff0000U + +#define VMMOUSE_VERSION_ID 0x3442554aU + +#define VMMOUSE_RELATIVE_PACKET 0x00010000U + +#define VMMOUSE_LEFT_BUTTON 0x20 +#define VMMOUSE_RIGHT_BUTTON 0x10 +#define VMMOUSE_MIDDLE_BUTTON 0x08 + +/* + * VMMouse Restrict command + */ +#define VMMOUSE_RESTRICT_ANY 0x00 +#define VMMOUSE_RESTRICT_CPL0 0x01 +#define VMMOUSE_RESTRICT_IOPL 0x02 + +#define VMMOUSE_MAX_X 0xFFFF +#define VMMOUSE_MAX_Y 0xFFFF + +#define VMMOUSE_VENDOR "VMware" +#define VMMOUSE_NAME "VMMouse" + +/** + * struct vmmouse_data - private data structure for the vmmouse driver + * + * @abs_dev: "Absolute" device used to report absolute mouse movement. + * @phys: Physical path for the absolute device. + * @dev_name: Name attribute name for the absolute device. + */ +struct vmmouse_data { + struct input_dev *abs_dev; + char phys[32]; + char dev_name[128]; +}; + +/** + * vmmouse_report_button - report button state on the correct input device + * + * @psmouse: Pointer to the psmouse struct + * @abs_dev: The absolute input device + * @rel_dev: The relative input device + * @pref_dev: The preferred device for reporting + * @code: Button code + * @value: Button value + * + * Report @value and @code on @pref_dev, unless the button is already + * pressed on the other device, in which case the state is reported on that + * device. + */ +static void vmmouse_report_button(struct psmouse *psmouse, + struct input_dev *abs_dev, + struct input_dev *rel_dev, + struct input_dev *pref_dev, + unsigned int code, int value) +{ + if (test_bit(code, abs_dev->key)) + pref_dev = abs_dev; + else if (test_bit(code, rel_dev->key)) + pref_dev = rel_dev; + + input_report_key(pref_dev, code, value); +} + +/** + * vmmouse_report_events - process events on the vmmouse communications channel + * + * @psmouse: Pointer to the psmouse struct + * + * This function pulls events from the vmmouse communications channel and + * reports them on the correct (absolute or relative) input device. When the + * communications channel is drained, or if we've processed more than 255 + * psmouse commands, the function returns PSMOUSE_FULL_PACKET. If there is a + * host- or synchronization error, the function returns PSMOUSE_BAD_DATA in + * the hope that the caller will reset the communications channel. + */ +static psmouse_ret_t vmmouse_report_events(struct psmouse *psmouse) +{ + struct input_dev *rel_dev = psmouse->dev; + struct vmmouse_data *priv = psmouse->private; + struct input_dev *abs_dev = priv->abs_dev; + struct input_dev *pref_dev; + u32 status, x, y, z; + unsigned int queue_length; + unsigned int count = 255; + + while (count--) { + /* See if we have motion data. */ + status = vmware_hypercall1(VMWARE_CMD_ABSPOINTER_STATUS, 0); + if ((status & VMMOUSE_ERROR) == VMMOUSE_ERROR) { + psmouse_err(psmouse, "failed to fetch status data\n"); + /* + * After a few attempts this will result in + * reconnect. + */ + return PSMOUSE_BAD_DATA; + } + + queue_length = status & 0xffff; + if (queue_length == 0) + break; + + if (queue_length % 4) { + psmouse_err(psmouse, "invalid queue length\n"); + return PSMOUSE_BAD_DATA; + } + + /* Now get it */ + status = vmware_hypercall4(VMWARE_CMD_ABSPOINTER_DATA, 4, + &x, &y, &z); + + /* + * And report what we've got. Prefer to report button + * events on the same device where we report motion events. + * This doesn't work well with the mouse wheel, though. See + * below. Ideally we would want to report that on the + * preferred device as well. + */ + if (status & VMMOUSE_RELATIVE_PACKET) { + pref_dev = rel_dev; + input_report_rel(rel_dev, REL_X, (s32)x); + input_report_rel(rel_dev, REL_Y, -(s32)y); + } else { + pref_dev = abs_dev; + input_report_abs(abs_dev, ABS_X, x); + input_report_abs(abs_dev, ABS_Y, y); + } + + /* Xorg seems to ignore wheel events on absolute devices */ + input_report_rel(rel_dev, REL_WHEEL, -(s8)((u8) z)); + + vmmouse_report_button(psmouse, abs_dev, rel_dev, + pref_dev, BTN_LEFT, + status & VMMOUSE_LEFT_BUTTON); + vmmouse_report_button(psmouse, abs_dev, rel_dev, + pref_dev, BTN_RIGHT, + status & VMMOUSE_RIGHT_BUTTON); + vmmouse_report_button(psmouse, abs_dev, rel_dev, + pref_dev, BTN_MIDDLE, + status & VMMOUSE_MIDDLE_BUTTON); + input_sync(abs_dev); + input_sync(rel_dev); + } + + return PSMOUSE_FULL_PACKET; +} + +/** + * vmmouse_process_byte - process data on the ps/2 channel + * + * @psmouse: Pointer to the psmouse struct + * + * When the ps/2 channel indicates that there is vmmouse data available, + * call vmmouse channel processing. Otherwise, continue to accept bytes. If + * there is a synchronization or communication data error, return + * PSMOUSE_BAD_DATA in the hope that the caller will reset the mouse. + */ +static psmouse_ret_t vmmouse_process_byte(struct psmouse *psmouse) +{ + unsigned char *packet = psmouse->packet; + + switch (psmouse->pktcnt) { + case 1: + return (packet[0] & 0x8) == 0x8 ? + PSMOUSE_GOOD_DATA : PSMOUSE_BAD_DATA; + + case 2: + return PSMOUSE_GOOD_DATA; + + default: + return vmmouse_report_events(psmouse); + } +} + +/** + * vmmouse_disable - Disable vmmouse + * + * @psmouse: Pointer to the psmouse struct + * + * Tries to disable vmmouse mode. + */ +static void vmmouse_disable(struct psmouse *psmouse) +{ + u32 status; + + vmware_hypercall1(VMWARE_CMD_ABSPOINTER_COMMAND, VMMOUSE_CMD_DISABLE); + + status = vmware_hypercall1(VMWARE_CMD_ABSPOINTER_STATUS, 0); + if ((status & VMMOUSE_ERROR) != VMMOUSE_ERROR) + psmouse_warn(psmouse, "failed to disable vmmouse device\n"); +} + +/** + * vmmouse_enable - Enable vmmouse and request absolute mode. + * + * @psmouse: Pointer to the psmouse struct + * + * Tries to enable vmmouse mode. Performs basic checks and requests + * absolute vmmouse mode. + * Returns 0 on success, -ENODEV on failure. + */ +static int vmmouse_enable(struct psmouse *psmouse) +{ + u32 status, version; + + /* + * Try enabling the device. If successful, we should be able to + * read valid version ID back from it. + */ + vmware_hypercall1(VMWARE_CMD_ABSPOINTER_COMMAND, VMMOUSE_CMD_ENABLE); + + /* + * See if version ID can be retrieved. + */ + status = vmware_hypercall1(VMWARE_CMD_ABSPOINTER_STATUS, 0); + if ((status & 0x0000ffff) == 0) { + psmouse_dbg(psmouse, "empty flags - assuming no device\n"); + return -ENXIO; + } + + version = vmware_hypercall1(VMWARE_CMD_ABSPOINTER_DATA, + 1 /* single item */); + if (version != VMMOUSE_VERSION_ID) { + psmouse_dbg(psmouse, "Unexpected version value: %u vs %u\n", + (unsigned) version, VMMOUSE_VERSION_ID); + vmmouse_disable(psmouse); + return -ENXIO; + } + + /* + * Restrict ioport access, if possible. + */ + vmware_hypercall1(VMWARE_CMD_ABSPOINTER_RESTRICT, + VMMOUSE_RESTRICT_CPL0); + + vmware_hypercall1(VMWARE_CMD_ABSPOINTER_COMMAND, + VMMOUSE_CMD_REQUEST_ABSOLUTE); + + return 0; +} + +/* + * Array of supported hypervisors. + */ +static enum x86_hypervisor_type vmmouse_supported_hypervisors[] = { + X86_HYPER_VMWARE, + X86_HYPER_KVM, +}; + +/** + * vmmouse_check_hypervisor - Check if we're running on a supported hypervisor + */ +static bool vmmouse_check_hypervisor(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(vmmouse_supported_hypervisors); i++) + if (vmmouse_supported_hypervisors[i] == x86_hyper_type) + return true; + + return false; +} + +/** + * vmmouse_detect - Probe whether vmmouse is available + * + * @psmouse: Pointer to the psmouse struct + * @set_properties: Whether to set psmouse name and vendor + * + * Returns 0 if vmmouse channel is available. Negative error code if not. + */ +int vmmouse_detect(struct psmouse *psmouse, bool set_properties) +{ + u32 response, version, type; + + if (!vmmouse_check_hypervisor()) { + psmouse_dbg(psmouse, + "VMMouse not running on supported hypervisor.\n"); + return -ENXIO; + } + + /* Check if the device is present */ + response = ~VMWARE_HYPERVISOR_MAGIC; + version = vmware_hypercall3(VMWARE_CMD_GETVERSION, 0, &response, &type); + if (response != VMWARE_HYPERVISOR_MAGIC || version == 0xffffffffU) + return -ENXIO; + + if (set_properties) { + psmouse->vendor = VMMOUSE_VENDOR; + psmouse->name = VMMOUSE_NAME; + psmouse->model = version; + } + + return 0; +} + +/** + * vmmouse_reset - Disable vmmouse and reset + * + * @psmouse: Pointer to the psmouse struct + * + * Tries to disable vmmouse mode before enter suspend. + */ +static void vmmouse_reset(struct psmouse *psmouse) +{ + vmmouse_disable(psmouse); + psmouse_reset(psmouse); +} + +/** + * vmmouse_disconnect - Take down vmmouse driver + * + * @psmouse: Pointer to the psmouse struct + * + * Takes down vmmouse driver and frees resources set up in vmmouse_init(). + */ +static void vmmouse_disconnect(struct psmouse *psmouse) +{ + struct vmmouse_data *priv = psmouse->private; + + vmmouse_disable(psmouse); + psmouse_reset(psmouse); + input_unregister_device(priv->abs_dev); + kfree(priv); +} + +/** + * vmmouse_reconnect - Reset the ps/2 - and vmmouse connections + * + * @psmouse: Pointer to the psmouse struct + * + * Attempts to reset the mouse connections. Returns 0 on success and + * -1 on failure. + */ +static int vmmouse_reconnect(struct psmouse *psmouse) +{ + int error; + + psmouse_reset(psmouse); + vmmouse_disable(psmouse); + error = vmmouse_enable(psmouse); + if (error) { + psmouse_err(psmouse, + "Unable to re-enable mouse when reconnecting, err: %d\n", + error); + return error; + } + + return 0; +} + +/** + * vmmouse_init - Initialize the vmmouse driver + * + * @psmouse: Pointer to the psmouse struct + * + * Requests the device and tries to enable vmmouse mode. + * If successful, sets up the input device for relative movement events. + * It also allocates another input device and sets it up for absolute motion + * events. Returns 0 on success and -1 on failure. + */ +int vmmouse_init(struct psmouse *psmouse) +{ + struct vmmouse_data *priv; + struct input_dev *rel_dev = psmouse->dev, *abs_dev; + int error; + + psmouse_reset(psmouse); + error = vmmouse_enable(psmouse); + if (error) + return error; + + priv = kzalloc_obj(*priv); + abs_dev = input_allocate_device(); + if (!priv || !abs_dev) { + error = -ENOMEM; + goto init_fail; + } + + priv->abs_dev = abs_dev; + psmouse->private = priv; + + /* Set up and register absolute device */ + snprintf(priv->phys, sizeof(priv->phys), "%s/input1", + psmouse->ps2dev.serio->phys); + + /* Mimic name setup for relative device in psmouse-base.c */ + snprintf(priv->dev_name, sizeof(priv->dev_name), "%s %s %s", + VMMOUSE_PSNAME, VMMOUSE_VENDOR, VMMOUSE_NAME); + abs_dev->phys = priv->phys; + abs_dev->name = priv->dev_name; + abs_dev->id.bustype = BUS_I8042; + abs_dev->id.vendor = 0x0002; + abs_dev->id.product = PSMOUSE_VMMOUSE; + abs_dev->id.version = psmouse->model; + abs_dev->dev.parent = &psmouse->ps2dev.serio->dev; + + /* Set absolute device capabilities */ + input_set_capability(abs_dev, EV_KEY, BTN_LEFT); + input_set_capability(abs_dev, EV_KEY, BTN_RIGHT); + input_set_capability(abs_dev, EV_KEY, BTN_MIDDLE); + input_set_capability(abs_dev, EV_ABS, ABS_X); + input_set_capability(abs_dev, EV_ABS, ABS_Y); + input_set_abs_params(abs_dev, ABS_X, 0, VMMOUSE_MAX_X, 0, 0); + input_set_abs_params(abs_dev, ABS_Y, 0, VMMOUSE_MAX_Y, 0, 0); + + error = input_register_device(priv->abs_dev); + if (error) + goto init_fail; + + /* Add wheel capability to the relative device */ + input_set_capability(rel_dev, EV_REL, REL_WHEEL); + + psmouse->protocol_handler = vmmouse_process_byte; + psmouse->disconnect = vmmouse_disconnect; + psmouse->reconnect = vmmouse_reconnect; + psmouse->cleanup = vmmouse_reset; + + return 0; + +init_fail: + vmmouse_disable(psmouse); + psmouse_reset(psmouse); + input_free_device(abs_dev); + kfree(priv); + psmouse->private = NULL; + + return error; +} -- cgit v1.3.1