From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/input/mouse/logips2pp.c | 444 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 444 insertions(+) create mode 100644 drivers/input/mouse/logips2pp.c (limited to 'drivers/input/mouse/logips2pp.c') diff --git a/drivers/input/mouse/logips2pp.c b/drivers/input/mouse/logips2pp.c new file mode 100644 index 000000000..ed5a848db --- /dev/null +++ b/drivers/input/mouse/logips2pp.c @@ -0,0 +1,444 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Logitech PS/2++ mouse driver + * + * Copyright (c) 1999-2003 Vojtech Pavlik + * Copyright (c) 2003 Eric Wong + */ + +#include +#include +#include +#include +#include +#include "psmouse.h" +#include "logips2pp.h" + +/* Logitech mouse types */ +#define PS2PP_KIND_WHEEL 1 +#define PS2PP_KIND_MX 2 +#define PS2PP_KIND_TP3 3 +#define PS2PP_KIND_TRACKMAN 4 + +/* Logitech mouse features */ +#define PS2PP_WHEEL BIT(0) +#define PS2PP_HWHEEL BIT(1) +#define PS2PP_SIDE_BTN BIT(2) +#define PS2PP_EXTRA_BTN BIT(3) +#define PS2PP_TASK_BTN BIT(4) +#define PS2PP_NAV_BTN BIT(5) + +struct ps2pp_info { + u8 model; + u8 kind; + u16 features; +}; + +/* + * Process a PS2++ or PS2T++ packet. + */ + +static psmouse_ret_t ps2pp_process_byte(struct psmouse *psmouse) +{ + struct input_dev *dev = psmouse->dev; + u8 *packet = psmouse->packet; + + if (psmouse->pktcnt < 3) + return PSMOUSE_GOOD_DATA; + +/* + * Full packet accumulated, process it + */ + + if ((packet[0] & 0x48) == 0x48 && (packet[1] & 0x02) == 0x02) { + + /* Logitech extended packet */ + switch ((packet[1] >> 4) | (packet[0] & 0x30)) { + + case 0x0d: /* Mouse extra info */ + + input_report_rel(dev, + packet[2] & 0x80 ? REL_HWHEEL : REL_WHEEL, + -sign_extend32(packet[2], 3)); + input_report_key(dev, BTN_SIDE, packet[2] & BIT(4)); + input_report_key(dev, BTN_EXTRA, packet[2] & BIT(5)); + + break; + + case 0x0e: /* buttons 4, 5, 6, 7, 8, 9, 10 info */ + + input_report_key(dev, BTN_SIDE, packet[2] & BIT(0)); + input_report_key(dev, BTN_EXTRA, packet[2] & BIT(1)); + input_report_key(dev, BTN_TASK, packet[2] & BIT(2)); + input_report_key(dev, BTN_BACK, packet[2] & BIT(3)); + input_report_key(dev, BTN_FORWARD, packet[2] & BIT(4)); + + break; + + case 0x0f: /* TouchPad extra info */ + + input_report_rel(dev, + packet[2] & 0x08 ? REL_HWHEEL : REL_WHEEL, + -sign_extend32(packet[2] >> 4, 3)); + packet[0] = packet[2] | BIT(3); + break; + + default: + psmouse_dbg(psmouse, + "Received PS2++ packet #%x, but don't know how to handle.\n", + (packet[1] >> 4) | (packet[0] & 0x30)); + break; + } + + psmouse_report_standard_buttons(dev, packet[0]); + + } else { + /* Standard PS/2 motion data */ + psmouse_report_standard_packet(dev, packet); + } + + input_sync(dev); + + return PSMOUSE_FULL_PACKET; + +} + +/* + * ps2pp_cmd() sends a PS2++ command, sliced into two bit + * pieces through the SETRES command. This is needed to send extended + * commands to mice on notebooks that try to understand the PS/2 protocol + * Ugly. + */ + +static int ps2pp_cmd(struct psmouse *psmouse, u8 *param, u8 command) +{ + int error; + + error = ps2_sliced_command(&psmouse->ps2dev, command); + if (error) + return error; + + error = ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_POLL | 0x0300); + if (error) + return error; + + return 0; +} + +/* + * SmartScroll / CruiseControl for some newer Logitech mice Defaults to + * enabled if we do nothing to it. Of course I put this in because I want it + * disabled :P + * 1 - enabled (if previously disabled, also default) + * 0 - disabled + */ + +static void ps2pp_set_smartscroll(struct psmouse *psmouse, bool smartscroll) +{ + struct ps2dev *ps2dev = &psmouse->ps2dev; + u8 param[4]; + + ps2pp_cmd(psmouse, param, 0x32); + + param[0] = 0; + ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES); + ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES); + ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES); + + param[0] = smartscroll; + ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES); +} + +static ssize_t ps2pp_attr_show_smartscroll(struct psmouse *psmouse, + void *data, char *buf) +{ + return sprintf(buf, "%d\n", psmouse->smartscroll); +} + +static ssize_t ps2pp_attr_set_smartscroll(struct psmouse *psmouse, void *data, + const char *buf, size_t count) +{ + unsigned int value; + int err; + + err = kstrtouint(buf, 10, &value); + if (err) + return err; + + if (value > 1) + return -EINVAL; + + ps2pp_set_smartscroll(psmouse, value); + psmouse->smartscroll = value; + return count; +} + +PSMOUSE_DEFINE_ATTR(smartscroll, S_IWUSR | S_IRUGO, NULL, + ps2pp_attr_show_smartscroll, ps2pp_attr_set_smartscroll); + +/* + * Support 800 dpi resolution _only_ if the user wants it (there are good + * reasons to not use it even if the mouse supports it, and of course there are + * also good reasons to use it, let the user decide). + */ + +static void ps2pp_set_resolution(struct psmouse *psmouse, + unsigned int resolution) +{ + if (resolution > 400) { + struct ps2dev *ps2dev = &psmouse->ps2dev; + u8 param = 3; + + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + ps2_command(ps2dev, ¶m, PSMOUSE_CMD_SETRES); + psmouse->resolution = 800; + } else + psmouse_set_resolution(psmouse, resolution); +} + +static void ps2pp_disconnect(struct psmouse *psmouse) +{ + device_remove_file(&psmouse->ps2dev.serio->dev, + &psmouse_attr_smartscroll.dattr); +} + +static const struct ps2pp_info *get_model_info(unsigned char model) +{ + static const struct ps2pp_info ps2pp_list[] = { + { 1, 0, 0 }, /* Simple 2-button mouse */ + { 12, 0, PS2PP_SIDE_BTN}, + { 13, 0, 0 }, + { 15, PS2PP_KIND_MX, /* MX1000 */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | PS2PP_TASK_BTN | + PS2PP_EXTRA_BTN | PS2PP_NAV_BTN | PS2PP_HWHEEL }, + { 40, 0, PS2PP_SIDE_BTN }, + { 41, 0, PS2PP_SIDE_BTN }, + { 42, 0, PS2PP_SIDE_BTN }, + { 43, 0, PS2PP_SIDE_BTN }, + { 50, 0, 0 }, + { 51, 0, 0 }, + { 52, PS2PP_KIND_WHEEL, PS2PP_SIDE_BTN | PS2PP_WHEEL }, + { 53, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 56, PS2PP_KIND_WHEEL, PS2PP_SIDE_BTN | PS2PP_WHEEL }, /* Cordless MouseMan Wheel */ + { 61, PS2PP_KIND_MX, /* MX700 */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | PS2PP_TASK_BTN | + PS2PP_EXTRA_BTN | PS2PP_NAV_BTN }, + { 66, PS2PP_KIND_MX, /* MX3100 receiver */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | PS2PP_TASK_BTN | + PS2PP_EXTRA_BTN | PS2PP_NAV_BTN | PS2PP_HWHEEL }, + { 72, PS2PP_KIND_TRACKMAN, 0 }, /* T-CH11: TrackMan Marble */ + { 73, PS2PP_KIND_TRACKMAN, PS2PP_SIDE_BTN }, /* TrackMan FX */ + { 75, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 76, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 79, PS2PP_KIND_TRACKMAN, PS2PP_WHEEL }, /* TrackMan with wheel */ + { 80, PS2PP_KIND_WHEEL, PS2PP_SIDE_BTN | PS2PP_WHEEL }, + { 81, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 83, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 85, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 86, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 87, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 88, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 96, 0, 0 }, + { 97, PS2PP_KIND_TP3, PS2PP_WHEEL | PS2PP_HWHEEL }, + { 99, PS2PP_KIND_WHEEL, PS2PP_WHEEL }, + { 100, PS2PP_KIND_MX, /* MX510 */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | PS2PP_TASK_BTN | + PS2PP_EXTRA_BTN | PS2PP_NAV_BTN }, + { 111, PS2PP_KIND_MX, PS2PP_WHEEL | PS2PP_SIDE_BTN }, /* MX300 reports task button as side */ + { 112, PS2PP_KIND_MX, /* MX500 */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | PS2PP_TASK_BTN | + PS2PP_EXTRA_BTN | PS2PP_NAV_BTN }, + { 114, PS2PP_KIND_MX, /* MX310 */ + PS2PP_WHEEL | PS2PP_SIDE_BTN | + PS2PP_TASK_BTN | PS2PP_EXTRA_BTN } + }; + int i; + + for (i = 0; i < ARRAY_SIZE(ps2pp_list); i++) + if (model == ps2pp_list[i].model) + return &ps2pp_list[i]; + + return NULL; +} + +/* + * Set up input device's properties based on the detected mouse model. + */ + +static void ps2pp_set_model_properties(struct psmouse *psmouse, + const struct ps2pp_info *model_info, + bool using_ps2pp) +{ + struct input_dev *input_dev = psmouse->dev; + + if (model_info->features & PS2PP_SIDE_BTN) + input_set_capability(input_dev, EV_KEY, BTN_SIDE); + + if (model_info->features & PS2PP_EXTRA_BTN) + input_set_capability(input_dev, EV_KEY, BTN_EXTRA); + + if (model_info->features & PS2PP_TASK_BTN) + input_set_capability(input_dev, EV_KEY, BTN_TASK); + + if (model_info->features & PS2PP_NAV_BTN) { + input_set_capability(input_dev, EV_KEY, BTN_FORWARD); + input_set_capability(input_dev, EV_KEY, BTN_BACK); + } + + if (model_info->features & PS2PP_WHEEL) + input_set_capability(input_dev, EV_REL, REL_WHEEL); + + if (model_info->features & PS2PP_HWHEEL) + input_set_capability(input_dev, EV_REL, REL_HWHEEL); + + switch (model_info->kind) { + + case PS2PP_KIND_WHEEL: + psmouse->name = "Wheel Mouse"; + break; + + case PS2PP_KIND_MX: + psmouse->name = "MX Mouse"; + break; + + case PS2PP_KIND_TP3: + psmouse->name = "TouchPad 3"; + break; + + case PS2PP_KIND_TRACKMAN: + psmouse->name = "TrackMan"; + break; + + default: + /* + * Set name to "Mouse" only when using PS2++, + * otherwise let other protocols define suitable + * name + */ + if (using_ps2pp) + psmouse->name = "Mouse"; + break; + } +} + +static int ps2pp_setup_protocol(struct psmouse *psmouse, + const struct ps2pp_info *model_info) +{ + int error; + + psmouse->protocol_handler = ps2pp_process_byte; + psmouse->pktsize = 3; + + if (model_info->kind != PS2PP_KIND_TP3) { + psmouse->set_resolution = ps2pp_set_resolution; + psmouse->disconnect = ps2pp_disconnect; + + error = device_create_file(&psmouse->ps2dev.serio->dev, + &psmouse_attr_smartscroll.dattr); + if (error) { + psmouse_err(psmouse, + "failed to create smartscroll sysfs attribute, error: %d\n", + error); + return error; + } + } + + return 0; +} + +/* + * Logitech magic init. Detect whether the mouse is a Logitech one + * and its exact model and try turning on extended protocol for ones + * that support it. + */ + +int ps2pp_detect(struct psmouse *psmouse, bool set_properties) +{ + struct ps2dev *ps2dev = &psmouse->ps2dev; + const struct ps2pp_info *model_info; + u8 param[4]; + u8 model, buttons; + bool use_ps2pp = false; + int error; + + param[0] = 0; + ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES); + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + ps2_command(ps2dev, NULL, PSMOUSE_CMD_SETSCALE11); + param[1] = 0; + ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO); + + model = ((param[0] >> 4) & 0x07) | ((param[0] << 3) & 0x78); + buttons = param[1]; + + if (!model || !buttons) + return -ENXIO; + + model_info = get_model_info(model); + if (model_info) { + +/* + * Do Logitech PS2++ / PS2T++ magic init. + */ + if (model_info->kind == PS2PP_KIND_TP3) { /* Touch Pad 3 */ + + /* Unprotect RAM */ + param[0] = 0x11; param[1] = 0x04; param[2] = 0x68; + ps2_command(ps2dev, param, 0x30d1); + /* Enable features */ + param[0] = 0x11; param[1] = 0x05; param[2] = 0x0b; + ps2_command(ps2dev, param, 0x30d1); + /* Enable PS2++ */ + param[0] = 0x11; param[1] = 0x09; param[2] = 0xc3; + ps2_command(ps2dev, param, 0x30d1); + + param[0] = 0; + if (!ps2_command(ps2dev, param, 0x13d1) && + param[0] == 0x06 && param[1] == 0x00 && + param[2] == 0x14) { + use_ps2pp = true; + } + + } else { + + param[0] = param[1] = param[2] = 0; + ps2pp_cmd(psmouse, param, 0x39); /* Magic knock */ + ps2pp_cmd(psmouse, param, 0xDB); + + if ((param[0] & 0x78) == 0x48 && + (param[1] & 0xf3) == 0xc2 && + (param[2] & 0x03) == ((param[1] >> 2) & 3)) { + ps2pp_set_smartscroll(psmouse, false); + use_ps2pp = true; + } + } + + } else { + psmouse_warn(psmouse, + "Detected unknown Logitech mouse model %d\n", + model); + } + + if (set_properties) { + psmouse->vendor = "Logitech"; + psmouse->model = model; + + if (use_ps2pp) { + error = ps2pp_setup_protocol(psmouse, model_info); + if (error) + return error; + } + + if (buttons >= 3) + input_set_capability(psmouse->dev, EV_KEY, BTN_MIDDLE); + + if (model_info) + ps2pp_set_model_properties(psmouse, model_info, use_ps2pp); + } + + return use_ps2pp ? 0 : -ENXIO; +} + -- cgit v1.3.1