x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

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) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 275 insertions, 0 deletions

diff --git a/drivers/mfd/88pm805.c b/drivers/mfd/88pm805.c
new file mode 100644
index 000000000..f5d666317
--- /dev/null
+++ b/drivers/mfd/88pm805.c
@@ -0,0 +1,275 @@
+/*
+ * Base driver for Marvell 88PM805
+ *
+ * Copyright (C) 2012 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang@marvell.com>
+ * Joseph(Yossi) Hanin <yhanin@marvell.com>
+ * Qiao Zhou <zhouqiao@marvell.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/88pm80x.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+static const struct i2c_device_id pm80x_id_table[] = {
+	{ "88PM805" },
+	{} /* NULL terminated */
+};
+MODULE_DEVICE_TABLE(i2c, pm80x_id_table);
+
+/* Interrupt Number in 88PM805 */
+enum {
+	PM805_IRQ_LDO_OFF,	/*0 */
+	PM805_IRQ_SRC_DPLL_LOCK,	/*1 */
+	PM805_IRQ_CLIP_FAULT,
+	PM805_IRQ_MIC_CONFLICT,
+	PM805_IRQ_HP2_SHRT,
+	PM805_IRQ_HP1_SHRT,	/*5 */
+	PM805_IRQ_FINE_PLL_FAULT,
+	PM805_IRQ_RAW_PLL_FAULT,
+	PM805_IRQ_VOLP_BTN_DET,
+	PM805_IRQ_VOLM_BTN_DET,
+	PM805_IRQ_SHRT_BTN_DET,	/*10 */
+	PM805_IRQ_MIC_DET,	/*11 */
+
+	PM805_MAX_IRQ,
+};
+
+static struct resource codec_resources[] = {
+	/* Headset microphone insertion or removal */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_MIC_DET, "micin"),
+
+	/* Audio short HP1 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP1_SHRT, "audio-short1"),
+
+	/* Audio short HP2 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP2_SHRT, "audio-short2"),
+};
+
+static const struct mfd_cell codec_devs[] = {
+	{
+	 .name = "88pm80x-codec",
+	 .num_resources = ARRAY_SIZE(codec_resources),
+	 .resources = &codec_resources[0],
+	 .id = -1,
+	 },
+};
+
+static const struct regmap_irq pm805_irqs[] = {
+	/* INT0 */
+	[PM805_IRQ_LDO_OFF] = {
+		.mask = PM805_INT1_HP1_SHRT,
+	},
+	[PM805_IRQ_SRC_DPLL_LOCK] = {
+		.mask = PM805_INT1_HP2_SHRT,
+	},
+	[PM805_IRQ_CLIP_FAULT] = {
+		.mask = PM805_INT1_MIC_CONFLICT,
+	},
+	[PM805_IRQ_MIC_CONFLICT] = {
+		.mask = PM805_INT1_CLIP_FAULT,
+	},
+	[PM805_IRQ_HP2_SHRT] = {
+		.mask = PM805_INT1_LDO_OFF,
+	},
+	[PM805_IRQ_HP1_SHRT] = {
+		.mask = PM805_INT1_SRC_DPLL_LOCK,
+	},
+	/* INT1 */
+	[PM805_IRQ_FINE_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_MIC_DET,
+	},
+	[PM805_IRQ_RAW_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_SHRT_BTN_DET,
+	},
+	[PM805_IRQ_VOLP_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLM_BTN_DET,
+	},
+	[PM805_IRQ_VOLM_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLP_BTN_DET,
+	},
+	[PM805_IRQ_SHRT_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_RAW_PLL_FAULT,
+	},
+	[PM805_IRQ_MIC_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_FINE_PLL_FAULT,
+	},
+};
+
+static int device_irq_init_805(struct pm80x_chip *chip)
+{
+	struct regmap *map = chip->regmap;
+	unsigned long flags = IRQF_ONESHOT;
+	int data, mask, ret = -EINVAL;
+
+	if (!map || !chip->irq) {
+		dev_err(chip->dev, "incorrect parameters\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * irq_mode defines the way of clearing interrupt. it's read-clear by
+	 * default.
+	 */
+	mask =
+	    PM805_STATUS0_INT_CLEAR | PM805_STATUS0_INV_INT |
+	    PM800_STATUS0_INT_MASK;
+
+	data = PM805_STATUS0_INT_CLEAR;
+	ret = regmap_update_bits(map, PM805_INT_STATUS0, mask, data);
+	/*
+	 * PM805_INT_STATUS is under 32K clock domain, so need to
+	 * add proper delay before the next I2C register access.
+	 */
+	usleep_range(1000, 3000);
+
+	if (ret < 0)
+		goto out;
+
+	ret =
+	    regmap_add_irq_chip(chip->regmap, chip->irq, flags, -1,
+				chip->regmap_irq_chip, &chip->irq_data);
+
+out:
+	return ret;
+}
+
+static void device_irq_exit_805(struct pm80x_chip *chip)
+{
+	regmap_del_irq_chip(chip->irq, chip->irq_data);
+}
+
+static const struct regmap_irq_chip pm805_irq_chip = {
+	.name = "88pm805",
+	.irqs = pm805_irqs,
+	.num_irqs = ARRAY_SIZE(pm805_irqs),
+
+	.num_regs = 2,
+	.status_base = PM805_INT_STATUS1,
+	.mask_base = PM805_INT_MASK1,
+	.ack_base = PM805_INT_STATUS1,
+};
+
+static int device_805_init(struct pm80x_chip *chip)
+{
+	int ret = 0;
+	struct regmap *map = chip->regmap;
+
+	if (!map) {
+		dev_err(chip->dev, "regmap is invalid\n");
+		return -EINVAL;
+	}
+
+	chip->regmap_irq_chip = &pm805_irq_chip;
+
+	ret = device_irq_init_805(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to init pm805 irq!\n");
+		goto out_irq_init;
+	}
+
+	ret = mfd_add_devices(chip->dev, 0, &codec_devs[0],
+			      ARRAY_SIZE(codec_devs), &codec_resources[0], 0,
+			      NULL);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to add codec subdev\n");
+		goto out_codec;
+	} else
+		dev_info(chip->dev, "[%s]:Added mfd codec_devs\n", __func__);
+
+	return 0;
+
+out_codec:
+	device_irq_exit_805(chip);
+out_irq_init:
+	return ret;
+}
+
+static int pm805_probe(struct i2c_client *client)
+{
+	int ret = 0;
+	struct pm80x_chip *chip;
+	struct pm80x_platform_data *pdata = dev_get_platdata(&client->dev);
+
+	ret = pm80x_init(client);
+	if (ret) {
+		dev_err(&client->dev, "pm805_init fail!\n");
+		goto out_init;
+	}
+
+	chip = i2c_get_clientdata(client);
+
+	ret = device_805_init(chip);
+	if (ret) {
+		dev_err(chip->dev, "Failed to initialize 88pm805 devices\n");
+		goto err_805_init;
+	}
+
+	if (pdata && pdata->plat_config)
+		pdata->plat_config(chip, pdata);
+
+err_805_init:
+	pm80x_deinit();
+out_init:
+	return ret;
+}
+
+static void pm805_remove(struct i2c_client *client)
+{
+	struct pm80x_chip *chip = i2c_get_clientdata(client);
+
+	mfd_remove_devices(chip->dev);
+	device_irq_exit_805(chip);
+
+	pm80x_deinit();
+}
+
+static struct i2c_driver pm805_driver = {
+	.driver = {
+		.name = "88PM805",
+		.pm = pm_sleep_ptr(&pm80x_pm_ops),
+		},
+	.probe = pm805_probe,
+	.remove = pm805_remove,
+	.id_table = pm80x_id_table,
+};
+
+static int __init pm805_i2c_init(void)
+{
+	return i2c_add_driver(&pm805_driver);
+}
+subsys_initcall(pm805_i2c_init);
+
+static void __exit pm805_i2c_exit(void)
+{
+	i2c_del_driver(&pm805_driver);
+}
+module_exit(pm805_i2c_exit);
+
+MODULE_DESCRIPTION("PMIC Driver for Marvell 88PM805");
+MODULE_AUTHOR("Qiao Zhou <zhouqiao@marvell.com>");
+MODULE_LICENSE("GPL");