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, 307 insertions, 0 deletions

diff --git a/sound/soc/codecs/cs40l50-codec.c b/sound/soc/codecs/cs40l50-codec.c
new file mode 100644
index 000000000..676367163
--- /dev/null
+++ b/sound/soc/codecs/cs40l50-codec.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// CS40L50 Advanced Haptic Driver with waveform memory,
+// integrated DSP, and closed-loop algorithms
+//
+// Copyright 2024 Cirrus Logic, Inc.
+//
+// Author: James Ogletree <james.ogletree@cirrus.com>
+
+#include <linux/bitfield.h>
+#include <linux/mfd/cs40l50.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define CS40L50_REFCLK_INPUT		0x2C04
+#define CS40L50_ASP_CONTROL2		0x4808
+#define CS40L50_ASP_DATA_CONTROL5	0x4840
+
+/* PLL Config */
+#define CS40L50_PLL_REFCLK_BCLK		0x0
+#define CS40L50_PLL_REFCLK_MCLK		0x5
+#define CS40L50_PLL_REEFCLK_MCLK_CFG	0x00
+#define CS40L50_PLL_REFCLK_LOOP_MASK	BIT(11)
+#define CS40L50_PLL_REFCLK_OPEN_LOOP	1
+#define CS40L50_PLL_REFCLK_CLOSED_LOOP	0
+#define CS40L50_PLL_REFCLK_LOOP_SHIFT	11
+#define CS40L50_PLL_REFCLK_FREQ_MASK	GENMASK(10, 5)
+#define CS40L50_PLL_REFCLK_FREQ_SHIFT	5
+#define CS40L50_PLL_REFCLK_SEL_MASK	GENMASK(2, 0)
+#define CS40L50_BCLK_RATIO_DEFAULT	32
+
+/* ASP Config */
+#define CS40L50_ASP_RX_WIDTH_SHIFT	24
+#define CS40L50_ASP_RX_WIDTH_MASK	GENMASK(31, 24)
+#define CS40L50_ASP_RX_WL_MASK		GENMASK(5, 0)
+#define CS40L50_ASP_FSYNC_INV_MASK	BIT(2)
+#define CS40L50_ASP_BCLK_INV_MASK	BIT(6)
+#define CS40L50_ASP_FMT_MASK		GENMASK(10, 8)
+#define CS40L50_ASP_FMT_I2S		0x2
+
+struct cs40l50_pll_config {
+	unsigned int freq;
+	unsigned int cfg;
+};
+
+struct cs40l50_codec {
+	struct device *dev;
+	struct regmap *regmap;
+	unsigned int daifmt;
+	unsigned int bclk_ratio;
+	unsigned int rate;
+};
+
+static const struct cs40l50_pll_config cs40l50_pll_cfg[] = {
+	{ 32768, 0x00 },
+	{ 1536000, 0x1B },
+	{ 3072000, 0x21 },
+	{ 6144000, 0x28 },
+	{ 9600000, 0x30 },
+	{ 12288000, 0x33 },
+};
+
+static int cs40l50_get_clk_config(const unsigned int freq, unsigned int *cfg)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(cs40l50_pll_cfg); i++) {
+		if (cs40l50_pll_cfg[i].freq == freq) {
+			*cfg = cs40l50_pll_cfg[i].cfg;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int cs40l50_swap_ext_clk(struct cs40l50_codec *codec, const unsigned int clk_src)
+{
+	unsigned int cfg;
+	int ret;
+
+	switch (clk_src) {
+	case CS40L50_PLL_REFCLK_BCLK:
+		ret = cs40l50_get_clk_config(codec->bclk_ratio * codec->rate, &cfg);
+		if (ret)
+			return ret;
+		break;
+	case CS40L50_PLL_REFCLK_MCLK:
+		cfg = CS40L50_PLL_REEFCLK_MCLK_CFG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(codec->regmap, CS40L50_REFCLK_INPUT,
+				 CS40L50_PLL_REFCLK_LOOP_MASK,
+				 CS40L50_PLL_REFCLK_OPEN_LOOP <<
+				 CS40L50_PLL_REFCLK_LOOP_SHIFT);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(codec->regmap, CS40L50_REFCLK_INPUT,
+				 CS40L50_PLL_REFCLK_FREQ_MASK |
+				 CS40L50_PLL_REFCLK_SEL_MASK,
+				 (cfg << CS40L50_PLL_REFCLK_FREQ_SHIFT) | clk_src);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(codec->regmap, CS40L50_REFCLK_INPUT,
+				  CS40L50_PLL_REFCLK_LOOP_MASK,
+				  CS40L50_PLL_REFCLK_CLOSED_LOOP <<
+				  CS40L50_PLL_REFCLK_LOOP_SHIFT);
+}
+
+static int cs40l50_clk_en(struct snd_soc_dapm_widget *w,
+			  struct snd_kcontrol *kcontrol,
+			  int event)
+{
+	struct snd_soc_component *comp = snd_soc_dapm_to_component(w->dapm);
+	struct cs40l50_codec *codec = snd_soc_component_get_drvdata(comp);
+	int ret;
+
+	switch (event) {
+	case SND_SOC_DAPM_POST_PMU:
+		ret = cs40l50_dsp_write(codec->dev, codec->regmap, CS40L50_STOP_PLAYBACK);
+		if (ret)
+			return ret;
+
+		ret = cs40l50_dsp_write(codec->dev, codec->regmap, CS40L50_START_I2S);
+		if (ret)
+			return ret;
+
+		ret = cs40l50_swap_ext_clk(codec, CS40L50_PLL_REFCLK_BCLK);
+		if (ret)
+			return ret;
+		break;
+	case SND_SOC_DAPM_PRE_PMD:
+		ret = cs40l50_swap_ext_clk(codec, CS40L50_PLL_REFCLK_MCLK);
+		if (ret)
+			return ret;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_dapm_widget cs40l50_dapm_widgets[] = {
+	SND_SOC_DAPM_SUPPLY_S("ASP PLL", 0, SND_SOC_NOPM, 0, 0, cs40l50_clk_en,
+			      SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
+	SND_SOC_DAPM_AIF_IN("ASPRX1", NULL, 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_AIF_IN("ASPRX2", NULL, 0, SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_OUTPUT("OUT"),
+};
+
+static const struct snd_soc_dapm_route cs40l50_dapm_routes[] = {
+	{ "ASP Playback", NULL, "ASP PLL" },
+	{ "ASPRX1", NULL, "ASP Playback" },
+	{ "ASPRX2", NULL, "ASP Playback" },
+
+	{ "OUT", NULL, "ASPRX1" },
+	{ "OUT", NULL, "ASPRX2" },
+};
+
+static int cs40l50_set_dai_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
+{
+	struct cs40l50_codec *codec = snd_soc_component_get_drvdata(codec_dai->component);
+
+	if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBC_CFC)
+		return -EINVAL;
+
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		codec->daifmt = 0;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		codec->daifmt = CS40L50_ASP_FSYNC_INV_MASK;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		codec->daifmt = CS40L50_ASP_BCLK_INV_MASK;
+		break;
+	case SND_SOC_DAIFMT_IB_IF:
+		codec->daifmt = CS40L50_ASP_FSYNC_INV_MASK | CS40L50_ASP_BCLK_INV_MASK;
+		break;
+	default:
+		dev_err(codec->dev, "Invalid clock invert\n");
+		return -EINVAL;
+	}
+
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		codec->daifmt |= FIELD_PREP(CS40L50_ASP_FMT_MASK, CS40L50_ASP_FMT_I2S);
+		break;
+	default:
+		dev_err(codec->dev, "Unsupported DAI format\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cs40l50_hw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *params,
+			     struct snd_soc_dai *dai)
+{
+	struct cs40l50_codec *codec = snd_soc_component_get_drvdata(dai->component);
+	unsigned int asp_rx_wl = params_width(params);
+	int ret;
+
+	codec->rate = params_rate(params);
+
+	ret = regmap_update_bits(codec->regmap, CS40L50_ASP_DATA_CONTROL5,
+				 CS40L50_ASP_RX_WL_MASK, asp_rx_wl);
+	if (ret)
+		return ret;
+
+	codec->daifmt |= (asp_rx_wl << CS40L50_ASP_RX_WIDTH_SHIFT);
+
+	return regmap_update_bits(codec->regmap, CS40L50_ASP_CONTROL2,
+				  CS40L50_ASP_FSYNC_INV_MASK |
+				  CS40L50_ASP_BCLK_INV_MASK |
+				  CS40L50_ASP_FMT_MASK |
+				  CS40L50_ASP_RX_WIDTH_MASK, codec->daifmt);
+}
+
+static int cs40l50_set_dai_bclk_ratio(struct snd_soc_dai *dai, unsigned int ratio)
+{
+	struct cs40l50_codec *codec = snd_soc_component_get_drvdata(dai->component);
+
+	codec->bclk_ratio = ratio;
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops cs40l50_dai_ops = {
+	.set_fmt = cs40l50_set_dai_fmt,
+	.set_bclk_ratio = cs40l50_set_dai_bclk_ratio,
+	.hw_params = cs40l50_hw_params,
+};
+
+static struct snd_soc_dai_driver cs40l50_dai[] = {
+	{
+		.name = "cs40l50-pcm",
+		.id = 0,
+		.playback = {
+			.stream_name = "ASP Playback",
+			.channels_min = 1,
+			.channels_max = 2,
+			.rates = SNDRV_PCM_RATE_48000,
+			.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE,
+		},
+		.ops = &cs40l50_dai_ops,
+	},
+};
+
+static int cs40l50_codec_probe(struct snd_soc_component *component)
+{
+	struct cs40l50_codec *codec = snd_soc_component_get_drvdata(component);
+
+	codec->bclk_ratio = CS40L50_BCLK_RATIO_DEFAULT;
+
+	return 0;
+}
+
+static const struct snd_soc_component_driver soc_codec_dev_cs40l50 = {
+	.probe = cs40l50_codec_probe,
+	.dapm_widgets = cs40l50_dapm_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(cs40l50_dapm_widgets),
+	.dapm_routes = cs40l50_dapm_routes,
+	.num_dapm_routes = ARRAY_SIZE(cs40l50_dapm_routes),
+};
+
+static int cs40l50_codec_driver_probe(struct platform_device *pdev)
+{
+	struct cs40l50 *cs40l50 = dev_get_drvdata(pdev->dev.parent);
+	struct cs40l50_codec *codec;
+
+	codec = devm_kzalloc(&pdev->dev, sizeof(*codec), GFP_KERNEL);
+	if (!codec)
+		return -ENOMEM;
+
+	codec->regmap = cs40l50->regmap;
+	codec->dev = &pdev->dev;
+
+	return devm_snd_soc_register_component(&pdev->dev, &soc_codec_dev_cs40l50,
+					       cs40l50_dai, ARRAY_SIZE(cs40l50_dai));
+}
+
+static const struct platform_device_id cs40l50_id[] = {
+	{ .name = "cs40l50-codec" },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, cs40l50_id);
+
+static struct platform_driver cs40l50_codec_driver = {
+	.probe = cs40l50_codec_driver_probe,
+	.id_table = cs40l50_id,
+	.driver = {
+		.name = "cs40l50-codec",
+	},
+};
+module_platform_driver(cs40l50_codec_driver);
+
+MODULE_DESCRIPTION("ASoC CS40L50 driver");
+MODULE_AUTHOR("James Ogletree <james.ogletree@cirrus.com>");
+MODULE_LICENSE("GPL");