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, 351 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt5575.c b/sound/soc/codecs/rt5575.c
new file mode 100644
index 000000000..5c3e60eaa
--- /dev/null
+++ b/sound/soc/codecs/rt5575.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rt5575.c  --  ALC5575 ALSA SoC audio component driver
+ *
+ * Copyright(c) 2025 Realtek Semiconductor Corp.
+ *
+ */
+
+#include <linux/i2c.h>
+#include <sound/soc.h>
+#include <sound/tlv.h>
+
+#include "rt5575.h"
+#include "rt5575-spi.h"
+
+static bool rt5575_readable_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case RT5575_BOOT:
+	case RT5575_ID:
+	case RT5575_ID_1:
+	case RT5575_MIXL_VOL:
+	case RT5575_MIXR_VOL:
+	case RT5575_PROMPT_VOL:
+	case RT5575_SPK01_VOL:
+	case RT5575_SPK23_VOL:
+	case RT5575_MIC1_VOL:
+	case RT5575_MIC2_VOL:
+	case RT5575_WNC_CTRL:
+	case RT5575_MODE_CTRL:
+	case RT5575_I2S_RATE_CTRL:
+	case RT5575_SLEEP_CTRL:
+	case RT5575_ALG_BYPASS_CTRL:
+	case RT5575_PINMUX_CTRL_2:
+	case RT5575_GPIO_CTRL_1:
+	case RT5575_DSP_BUS_CTRL:
+	case RT5575_SW_INT:
+	case RT5575_DSP_BOOT_ERR:
+	case RT5575_DSP_READY:
+	case RT5575_DSP_CMD_ADDR:
+	case RT5575_EFUSE_DATA_2:
+	case RT5575_EFUSE_DATA_3:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const DECLARE_TLV_DB_SCALE(ob_tlv, -9525, 75, 0);
+
+static const struct snd_kcontrol_new rt5575_snd_controls[] = {
+	SOC_DOUBLE("Speaker CH-01 Playback Switch", RT5575_SPK01_VOL, 31, 15, 1, 1),
+	SOC_DOUBLE_TLV("Speaker CH-01 Playback Volume", RT5575_SPK01_VOL, 17, 1, 167, 0, ob_tlv),
+	SOC_DOUBLE("Speaker CH-23 Playback Switch", RT5575_SPK23_VOL, 31, 15, 1, 1),
+	SOC_DOUBLE_TLV("Speaker CH-23 Playback Volume", RT5575_SPK23_VOL, 17, 1, 167, 0, ob_tlv),
+	SOC_DOUBLE("Mic1 Capture Switch", RT5575_MIC1_VOL, 31, 15, 1, 1),
+	SOC_DOUBLE_TLV("Mic1 Capture Volume", RT5575_MIC1_VOL, 17, 1, 167, 0, ob_tlv),
+	SOC_DOUBLE("Mic2 Capture Switch", RT5575_MIC2_VOL, 31, 15, 1, 1),
+	SOC_DOUBLE_TLV("Mic2 Capture Volume", RT5575_MIC2_VOL, 17, 1, 167, 0, ob_tlv),
+	SOC_DOUBLE_R("Mix Playback Switch", RT5575_MIXL_VOL, RT5575_MIXR_VOL, 31, 1, 1),
+	SOC_DOUBLE_R_TLV("Mix Playback Volume", RT5575_MIXL_VOL, RT5575_MIXR_VOL, 1, 127, 0,
+		ob_tlv),
+	SOC_DOUBLE("Prompt Playback Switch", RT5575_PROMPT_VOL, 31, 15, 1, 1),
+	SOC_DOUBLE_TLV("Prompt Playback Volume", RT5575_PROMPT_VOL, 17, 1, 167, 0, ob_tlv),
+};
+
+static const struct snd_soc_dapm_widget rt5575_dapm_widgets[] = {
+	SND_SOC_DAPM_AIF_IN("AIF1RX", "AIF1 Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF1TX", "AIF1 Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("AIF2RX", "AIF2 Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF2TX", "AIF2 Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("AIF3RX", "AIF3 Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF3TX", "AIF3 Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("AIF4RX", "AIF4 Playback", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF4TX", "AIF4 Capture", 0, SND_SOC_NOPM, 0, 0),
+
+	SND_SOC_DAPM_INPUT("INPUT"),
+	SND_SOC_DAPM_OUTPUT("OUTPUT"),
+};
+
+static const struct snd_soc_dapm_route rt5575_dapm_routes[] = {
+	{ "AIF1TX", NULL, "INPUT" },
+	{ "AIF2TX", NULL, "INPUT" },
+	{ "AIF3TX", NULL, "INPUT" },
+	{ "AIF4TX", NULL, "INPUT" },
+	{ "OUTPUT", NULL, "AIF1RX" },
+	{ "OUTPUT", NULL, "AIF2RX" },
+	{ "OUTPUT", NULL, "AIF3RX" },
+	{ "OUTPUT", NULL, "AIF4RX" },
+};
+
+static long long rt5575_get_priv_id(struct rt5575_priv *rt5575)
+{
+	int priv_id_low, priv_id_high;
+
+	regmap_write(rt5575->regmap, RT5575_EFUSE_PID, 0xa0000000);
+	regmap_read(rt5575->regmap, RT5575_EFUSE_DATA_2, &priv_id_low);
+	regmap_read(rt5575->regmap, RT5575_EFUSE_DATA_3, &priv_id_high);
+	regmap_write(rt5575->regmap, RT5575_EFUSE_PID, 0);
+
+	return ((long long)priv_id_high << 32) | (long long)priv_id_low;
+}
+
+static int rt5575_probe(struct snd_soc_component *component)
+{
+	struct rt5575_priv *rt5575 = snd_soc_component_get_drvdata(component);
+	struct device *dev = component->dev;
+
+	rt5575->component = component;
+
+	dev_info(dev, "Private ID: %llx\n", rt5575_get_priv_id(rt5575));
+
+	return 0;
+}
+
+#define RT5575_STEREO_RATES SNDRV_PCM_RATE_8000_192000
+#define RT5575_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | \
+			SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S8 | \
+			SNDRV_PCM_FMTBIT_S32_LE)
+
+static struct snd_soc_dai_driver rt5575_dai[] = {
+	{
+		.name = "rt5575-aif1",
+		.id = RT5575_AIF1,
+		.playback = {
+			.stream_name = "AIF1 Playback",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+		.capture = {
+			.stream_name = "AIF1 Capture",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+	},
+	{
+		.name = "rt5575-aif2",
+		.id = RT5575_AIF2,
+		.playback = {
+			.stream_name = "AIF2 Playback",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+		.capture = {
+			.stream_name = "AIF2 Capture",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+	},
+	{
+		.name = "rt5575-aif3",
+		.id = RT5575_AIF3,
+		.playback = {
+			.stream_name = "AIF3 Playback",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+		.capture = {
+			.stream_name = "AIF3 Capture",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+	},
+	{
+		.name = "rt5575-aif4",
+		.id = RT5575_AIF4,
+		.playback = {
+			.stream_name = "AIF4 Playback",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+		.capture = {
+			.stream_name = "AIF4 Capture",
+			.channels_min = 1,
+			.channels_max = 8,
+			.rates = RT5575_STEREO_RATES,
+			.formats = RT5575_FORMATS,
+		},
+	},
+};
+
+static const struct snd_soc_component_driver rt5575_soc_component_dev = {
+	.probe = rt5575_probe,
+	.controls = rt5575_snd_controls,
+	.num_controls = ARRAY_SIZE(rt5575_snd_controls),
+	.dapm_widgets = rt5575_dapm_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(rt5575_dapm_widgets),
+	.dapm_routes = rt5575_dapm_routes,
+	.num_dapm_routes = ARRAY_SIZE(rt5575_dapm_routes),
+	.use_pmdown_time = 1,
+	.endianness = 1,
+};
+
+static const struct regmap_config rt5575_dsp_regmap = {
+	.name = "dsp",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 2,
+};
+
+static int rt5575_i2c_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct i2c_client *client = context;
+	struct rt5575_priv *rt5575 = i2c_get_clientdata(client);
+
+	return regmap_read(rt5575->dsp_regmap, reg | RT5575_DSP_MAPPING, val);
+}
+
+static int rt5575_i2c_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct i2c_client *client = context;
+	struct rt5575_priv *rt5575 = i2c_get_clientdata(client);
+
+	return regmap_write(rt5575->dsp_regmap, reg | RT5575_DSP_MAPPING, val);
+}
+
+static const struct regmap_config rt5575_regmap = {
+	.reg_bits = 16,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0xfffc,
+	.readable_reg = rt5575_readable_register,
+	.reg_read = rt5575_i2c_read,
+	.reg_write = rt5575_i2c_write,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+
+static int rt5575_fw_load_by_spi(struct rt5575_priv *rt5575)
+{
+	struct i2c_client *i2c = rt5575->i2c;
+	struct spi_device *spi;
+	struct device *dev = &i2c->dev;
+	int ret;
+
+	spi = rt5575_spi_get_device(dev);
+	if (!spi) {
+		dev_err(dev, "Failed to get spi_device\n");
+		return -ENODEV;
+	}
+
+	regmap_write(rt5575->dsp_regmap, 0xfafafafa, 0x00000004);
+	regmap_write(rt5575->dsp_regmap, 0x18008064, 0x00000000);
+	regmap_write(rt5575->dsp_regmap, 0x18008068, 0x0002ffff);
+
+	ret = rt5575_spi_fw_load(spi);
+	if (ret) {
+		dev_err(dev, "Load firmware failure: %d\n", ret);
+		return -ENODEV;
+	}
+
+	regmap_write(rt5575->dsp_regmap, 0x18000000, 0x00000000);
+	regmap_update_bits(rt5575->regmap, RT5575_SW_INT, 1, 1);
+
+	regmap_read_poll_timeout(rt5575->regmap, RT5575_SW_INT, ret, !ret, 100000, 10000000);
+	if (ret) {
+		dev_err(dev, "Run firmware failure: %d\n", ret);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int rt5575_i2c_probe(struct i2c_client *i2c)
+{
+	struct rt5575_priv *rt5575;
+	int ret, val, boot;
+	struct device *dev = &i2c->dev;
+
+	rt5575 = devm_kzalloc(dev, sizeof(struct rt5575_priv), GFP_KERNEL);
+	if (!rt5575)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, rt5575);
+
+	rt5575->i2c = i2c;
+
+	rt5575->dsp_regmap = devm_regmap_init_i2c(i2c, &rt5575_dsp_regmap);
+	if (IS_ERR(rt5575->dsp_regmap)) {
+		ret = PTR_ERR(rt5575->dsp_regmap);
+		dev_err(dev, "Failed to allocate DSP register map: %d\n", ret);
+		return ret;
+	}
+
+	rt5575->regmap = devm_regmap_init(dev, NULL, i2c, &rt5575_regmap);
+	if (IS_ERR(rt5575->regmap)) {
+		ret = PTR_ERR(rt5575->regmap);
+		dev_err(dev, "Failed to allocate register map: %d\n", ret);
+		return ret;
+	}
+
+	regmap_read(rt5575->regmap, RT5575_ID, &val);
+	if (val != RT5575_DEVICE_ID) {
+		dev_err(dev, "Device with ID register %08x is not rt5575\n", val);
+		return -ENODEV;
+	}
+
+	regmap_read(rt5575->regmap, RT5575_BOOT, &boot);
+	if ((boot & RT5575_BOOT_MASK) == RT5575_BOOT_SPI) {
+		if (!IS_ENABLED(CONFIG_SND_SOC_RT5575_SPI)) {
+			dev_err(dev, "Please enable CONFIG_SND_SOC_RT5575_SPI\n");
+			return -ENODEV;
+		}
+
+		if (rt5575_fw_load_by_spi(rt5575))
+			return -ENODEV;
+	}
+
+	return devm_snd_soc_register_component(dev, &rt5575_soc_component_dev, rt5575_dai,
+					       ARRAY_SIZE(rt5575_dai));
+}
+
+static const struct i2c_device_id rt5575_i2c_id[] = {
+	{ .name = "rt5575" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rt5575_i2c_id);
+
+static const struct of_device_id rt5575_of_match[] = {
+	{ .compatible = "realtek,rt5575" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, rt5575_of_match);
+
+static struct i2c_driver rt5575_i2c_driver = {
+	.driver = {
+		.name = "rt5575",
+		.of_match_table = rt5575_of_match,
+	},
+	.probe = rt5575_i2c_probe,
+	.id_table = rt5575_i2c_id,
+};
+module_i2c_driver(rt5575_i2c_driver);
+
+MODULE_DESCRIPTION("ASoC ALC5575 driver");
+MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>");
+MODULE_LICENSE("GPL");