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, 382 insertions, 0 deletions

diff --git a/sound/soc/codecs/max98504.c b/sound/soc/codecs/max98504.c
new file mode 100644
index 000000000..8b2620eaf
--- /dev/null
+++ b/sound/soc/codecs/max98504.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MAX98504 ALSA SoC Audio driver
+ *
+ * Copyright 2013 - 2014 Maxim Integrated Products
+ * Copyright 2016 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <sound/soc.h>
+
+#include "max98504.h"
+
+static const char * const max98504_supply_names[] = {
+	"DVDD",
+	"DIOVDD",
+	"PVDD",
+};
+#define MAX98504_NUM_SUPPLIES ARRAY_SIZE(max98504_supply_names)
+
+struct max98504_priv {
+	struct regmap *regmap;
+	struct regulator_bulk_data supplies[MAX98504_NUM_SUPPLIES];
+	unsigned int pcm_rx_channels;
+	bool brownout_enable;
+	unsigned int brownout_threshold;
+	unsigned int brownout_attenuation;
+	unsigned int brownout_attack_hold;
+	unsigned int brownout_timed_hold;
+	unsigned int brownout_release_rate;
+};
+
+static const struct reg_default max98504_reg_defaults[] = {
+	{ 0x01,	0},
+	{ 0x02,	0},
+	{ 0x03,	0},
+	{ 0x04,	0},
+	{ 0x10, 0},
+	{ 0x11, 0},
+	{ 0x12, 0},
+	{ 0x13, 0},
+	{ 0x14, 0},
+	{ 0x15, 0},
+	{ 0x16, 0},
+	{ 0x17, 0},
+	{ 0x18, 0},
+	{ 0x19, 0},
+	{ 0x1A, 0},
+	{ 0x20, 0},
+	{ 0x21, 0},
+	{ 0x22, 0},
+	{ 0x23, 0},
+	{ 0x24, 0},
+	{ 0x25, 0},
+	{ 0x26, 0},
+	{ 0x27, 0},
+	{ 0x28, 0},
+	{ 0x30, 0},
+	{ 0x31, 0},
+	{ 0x32, 0},
+	{ 0x33, 0},
+	{ 0x34, 0},
+	{ 0x35, 0},
+	{ 0x36, 0},
+	{ 0x37, 0},
+	{ 0x38, 0},
+	{ 0x39, 0},
+	{ 0x40, 0},
+	{ 0x41, 0},
+};
+
+static bool max98504_volatile_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX98504_INTERRUPT_STATUS:
+	case MAX98504_INTERRUPT_FLAGS:
+	case MAX98504_INTERRUPT_FLAG_CLEARS:
+	case MAX98504_WATCHDOG_CLEAR:
+	case MAX98504_GLOBAL_ENABLE:
+	case MAX98504_SOFTWARE_RESET:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool max98504_readable_register(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case MAX98504_SOFTWARE_RESET:
+	case MAX98504_WATCHDOG_CLEAR:
+	case MAX98504_INTERRUPT_FLAG_CLEARS:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static int max98504_pcm_rx_ev(struct snd_soc_dapm_widget *w,
+			      struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
+	struct max98504_priv *max98504 = snd_soc_component_get_drvdata(c);
+
+	switch (event) {
+	case SND_SOC_DAPM_PRE_PMU:
+		regmap_write(max98504->regmap, MAX98504_PCM_RX_ENABLE,
+			     max98504->pcm_rx_channels);
+		break;
+	case SND_SOC_DAPM_POST_PMD:
+		regmap_write(max98504->regmap, MAX98504_PCM_RX_ENABLE, 0);
+		break;
+	}
+
+	return 0;
+}
+
+static int max98504_component_probe(struct snd_soc_component *c)
+{
+	struct max98504_priv *max98504 = snd_soc_component_get_drvdata(c);
+	struct regmap *map = max98504->regmap;
+	int ret;
+
+	ret = regulator_bulk_enable(MAX98504_NUM_SUPPLIES, max98504->supplies);
+	if (ret < 0)
+		return ret;
+
+	regmap_write(map, MAX98504_SOFTWARE_RESET, 0x1);
+	msleep(20);
+
+	if (!max98504->brownout_enable)
+		return 0;
+
+	regmap_write(map, MAX98504_PVDD_BROWNOUT_ENABLE, 0x1);
+
+	regmap_write(map, MAX98504_PVDD_BROWNOUT_CONFIG_1,
+		     (max98504->brownout_threshold & 0x1f) << 3 |
+		     (max98504->brownout_attenuation & 0x3));
+
+	regmap_write(map, MAX98504_PVDD_BROWNOUT_CONFIG_2,
+		     max98504->brownout_attack_hold & 0xff);
+
+	regmap_write(map, MAX98504_PVDD_BROWNOUT_CONFIG_3,
+		     max98504->brownout_timed_hold & 0xff);
+
+	regmap_write(map, MAX98504_PVDD_BROWNOUT_CONFIG_4,
+		     max98504->brownout_release_rate & 0xff);
+
+	return 0;
+}
+
+static void max98504_component_remove(struct snd_soc_component *c)
+{
+	struct max98504_priv *max98504 = snd_soc_component_get_drvdata(c);
+
+	regulator_bulk_disable(MAX98504_NUM_SUPPLIES, max98504->supplies);
+}
+
+static const char *spk_source_mux_text[] = {
+	"PCM Monomix", "Analog In", "PDM Left", "PDM Right"
+};
+
+static const struct soc_enum spk_source_mux_enum =
+	SOC_ENUM_SINGLE(MAX98504_SPEAKER_SOURCE_SELECT,
+			0, ARRAY_SIZE(spk_source_mux_text),
+			spk_source_mux_text);
+
+static const struct snd_kcontrol_new spk_source_mux =
+	SOC_DAPM_ENUM("SPK Source", spk_source_mux_enum);
+
+static const struct snd_soc_dapm_route max98504_dapm_routes[] = {
+	{ "SPKOUT", NULL, "Global Enable" },
+	{ "SPK Source", "PCM Monomix", "DAC PCM" },
+	{ "SPK Source", "Analog In", "AIN" },
+	{ "SPK Source", "PDM Left", "DAC PDM" },
+	{ "SPK Source", "PDM Right", "DAC PDM" },
+};
+
+static const struct snd_soc_dapm_widget max98504_dapm_widgets[] = {
+	SND_SOC_DAPM_SUPPLY("Global Enable", MAX98504_GLOBAL_ENABLE,
+		0, 0, NULL, 0),
+	SND_SOC_DAPM_INPUT("AIN"),
+	SND_SOC_DAPM_AIF_OUT("AIF2OUTL", "AIF2 Capture", 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_OUT("AIF2OUTR", "AIF2 Capture", 1, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_DAC_E("DAC PCM", NULL, SND_SOC_NOPM, 0, 0,
+		max98504_pcm_rx_ev,
+		SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
+	SND_SOC_DAPM_DAC("DAC PDM", NULL, MAX98504_PDM_RX_ENABLE, 0, 0),
+	SND_SOC_DAPM_MUX("SPK Source", SND_SOC_NOPM, 0, 0, &spk_source_mux),
+	SND_SOC_DAPM_REG(snd_soc_dapm_spk, "SPKOUT",
+		MAX98504_SPEAKER_ENABLE, 0, 1, 1, 0),
+};
+
+static int max98504_set_tdm_slot(struct snd_soc_dai *dai,
+		unsigned int tx_mask, unsigned int rx_mask,
+		int slots, int slot_width)
+{
+	struct max98504_priv *max98504 = snd_soc_dai_get_drvdata(dai);
+	struct regmap *map = max98504->regmap;
+
+
+	switch (dai->id) {
+	case MAX98504_DAI_ID_PCM:
+		regmap_write(map, MAX98504_PCM_TX_ENABLE, tx_mask);
+		max98504->pcm_rx_channels = rx_mask;
+		break;
+
+	case MAX98504_DAI_ID_PDM:
+		regmap_write(map, MAX98504_PDM_TX_ENABLE, tx_mask);
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	return 0;
+}
+static int max98504_set_channel_map(struct snd_soc_dai *dai,
+				    unsigned int tx_num,
+				    const unsigned int *tx_slot,
+				    unsigned int rx_num,
+				    const unsigned int *rx_slot)
+{
+	struct max98504_priv *max98504 = snd_soc_dai_get_drvdata(dai);
+	struct regmap *map = max98504->regmap;
+	unsigned int i, sources = 0;
+
+	for (i = 0; i < tx_num; i++)
+		if (tx_slot[i])
+			sources |= (1 << i);
+
+	switch (dai->id) {
+	case MAX98504_DAI_ID_PCM:
+		regmap_write(map, MAX98504_PCM_TX_CHANNEL_SOURCES,
+			     sources);
+		break;
+
+	case MAX98504_DAI_ID_PDM:
+		regmap_write(map, MAX98504_PDM_TX_CONTROL, sources);
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	regmap_write(map, MAX98504_MEASUREMENT_ENABLE, sources ? 0x3 : 0x01);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops max98504_dai_ops = {
+	.set_tdm_slot		= max98504_set_tdm_slot,
+	.set_channel_map	= max98504_set_channel_map,
+};
+
+#define MAX98504_FORMATS	(SNDRV_PCM_FMTBIT_S8|SNDRV_PCM_FMTBIT_S16_LE|\
+				SNDRV_PCM_FMTBIT_S24_LE|SNDRV_PCM_FMTBIT_S32_LE)
+#define MAX98504_PDM_RATES	(SNDRV_PCM_RATE_8000|SNDRV_PCM_RATE_16000|\
+				SNDRV_PCM_RATE_32000|SNDRV_PCM_RATE_44100|\
+				SNDRV_PCM_RATE_48000|SNDRV_PCM_RATE_88200|\
+				SNDRV_PCM_RATE_96000)
+
+static struct snd_soc_dai_driver max98504_dai[] = {
+	/* TODO: Add the PCM interface definitions */
+	{
+		.name = "max98504-aif2",
+		.id = MAX98504_DAI_ID_PDM,
+		.playback = {
+			.stream_name	= "AIF2 Playback",
+			.channels_min	= 1,
+			.channels_max	= 2,
+			.rates		= MAX98504_PDM_RATES,
+			.formats	= MAX98504_FORMATS,
+		},
+		.capture = {
+			.stream_name	= "AIF2 Capture",
+			.channels_min	= 1,
+			.channels_max	= 2,
+			.rates		= MAX98504_PDM_RATES,
+			.formats	= MAX98504_FORMATS,
+		},
+		.ops = &max98504_dai_ops,
+	},
+};
+
+static const struct snd_soc_component_driver max98504_component_driver = {
+	.probe			= max98504_component_probe,
+	.remove			= max98504_component_remove,
+	.dapm_widgets		= max98504_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(max98504_dapm_widgets),
+	.dapm_routes		= max98504_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(max98504_dapm_routes),
+	.endianness		= 1,
+};
+
+static const struct regmap_config max98504_regmap = {
+	.reg_bits		= 16,
+	.val_bits		= 8,
+	.max_register		= MAX98504_MAX_REGISTER,
+	.reg_defaults		= max98504_reg_defaults,
+	.num_reg_defaults	= ARRAY_SIZE(max98504_reg_defaults),
+	.volatile_reg		= max98504_volatile_register,
+	.readable_reg		= max98504_readable_register,
+	.cache_type		= REGCACHE_RBTREE,
+};
+
+static int max98504_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *node = dev->of_node;
+	struct max98504_priv *max98504;
+	int i, ret;
+
+	max98504 = devm_kzalloc(dev, sizeof(*max98504), GFP_KERNEL);
+	if (!max98504)
+		return -ENOMEM;
+
+	if (node) {
+		if (!of_property_read_u32(node, "maxim,brownout-threshold",
+					&max98504->brownout_threshold))
+			max98504->brownout_enable = true;
+
+		of_property_read_u32(node, "maxim,brownout-attenuation",
+					&max98504->brownout_attenuation);
+		of_property_read_u32(node, "maxim,brownout-attack-hold-ms",
+					&max98504->brownout_attack_hold);
+		of_property_read_u32(node, "maxim,brownout-timed-hold-ms",
+					&max98504->brownout_timed_hold);
+		of_property_read_u32(node, "maxim,brownout-release-rate-ms",
+					&max98504->brownout_release_rate);
+	}
+
+	max98504->regmap = devm_regmap_init_i2c(client, &max98504_regmap);
+	if (IS_ERR(max98504->regmap)) {
+		ret = PTR_ERR(max98504->regmap);
+		dev_err(&client->dev, "regmap initialization failed: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < MAX98504_NUM_SUPPLIES; i++)
+		max98504->supplies[i].supply = max98504_supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, MAX98504_NUM_SUPPLIES,
+				      max98504->supplies);
+	if (ret < 0)
+		return ret;
+
+	i2c_set_clientdata(client, max98504);
+
+	return devm_snd_soc_register_component(dev, &max98504_component_driver,
+				max98504_dai, ARRAY_SIZE(max98504_dai));
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id max98504_of_match[] = {
+	{ .compatible = "maxim,max98504" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, max98504_of_match);
+#endif
+
+static const struct i2c_device_id max98504_i2c_id[] = {
+	{ .name = "max98504" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max98504_i2c_id);
+
+static struct i2c_driver max98504_i2c_driver = {
+	.driver = {
+		.name = "max98504",
+		.of_match_table = of_match_ptr(max98504_of_match),
+	},
+	.probe = max98504_i2c_probe,
+	.id_table = max98504_i2c_id,
+};
+module_i2c_driver(max98504_i2c_driver);
+
+MODULE_DESCRIPTION("ASoC MAX98504 driver");
+MODULE_LICENSE("GPL");