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, 239 insertions, 0 deletions

diff --git a/sound/soc/codecs/bd28623.c b/sound/soc/codecs/bd28623.c
new file mode 100644
index 000000000..07e7bd79c
--- /dev/null
+++ b/sound/soc/codecs/bd28623.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// ROHM BD28623MUV class D speaker amplifier codec driver.
+//
+// Copyright (c) 2018 Socionext Inc.
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+
+#define BD28623_NUM_SUPPLIES    3
+
+static const char *const bd28623_supply_names[BD28623_NUM_SUPPLIES] = {
+	"VCCA",
+	"VCCP1",
+	"VCCP2",
+};
+
+struct bd28623_priv {
+	struct device *dev;
+	struct regulator_bulk_data supplies[BD28623_NUM_SUPPLIES];
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *mute_gpio;
+
+	int switch_spk;
+};
+
+static const struct snd_soc_dapm_widget bd28623_widgets[] = {
+	SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
+	SND_SOC_DAPM_OUTPUT("OUT1P"),
+	SND_SOC_DAPM_OUTPUT("OUT1N"),
+	SND_SOC_DAPM_OUTPUT("OUT2P"),
+	SND_SOC_DAPM_OUTPUT("OUT2N"),
+};
+
+static const struct snd_soc_dapm_route bd28623_routes[] = {
+	{ "OUT1P", NULL, "DAC" },
+	{ "OUT1N", NULL, "DAC" },
+	{ "OUT2P", NULL, "DAC" },
+	{ "OUT2N", NULL, "DAC" },
+};
+
+static int bd28623_power_on(struct bd28623_priv *bd)
+{
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(bd->supplies), bd->supplies);
+	if (ret) {
+		dev_err(bd->dev, "Failed to enable supplies: %d\n", ret);
+		return ret;
+	}
+
+	gpiod_set_value_cansleep(bd->reset_gpio, 0);
+	usleep_range(300000, 400000);
+
+	return 0;
+}
+
+static void bd28623_power_off(struct bd28623_priv *bd)
+{
+	gpiod_set_value_cansleep(bd->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(bd->supplies), bd->supplies);
+}
+
+static int bd28623_get_switch_spk(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	ucontrol->value.integer.value[0] = bd->switch_spk;
+
+	return 0;
+}
+
+static int bd28623_set_switch_spk(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	if (bd->switch_spk == ucontrol->value.integer.value[0])
+		return 0;
+
+	bd->switch_spk = ucontrol->value.integer.value[0];
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new bd28623_controls[] = {
+	SOC_SINGLE_BOOL_EXT("Speaker Switch", 0,
+			    bd28623_get_switch_spk, bd28623_set_switch_spk),
+};
+
+static int bd28623_codec_probe(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	bd->switch_spk = 1;
+
+	ret = bd28623_power_on(bd);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static void bd28623_codec_remove(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	bd28623_power_off(bd);
+}
+
+static int bd28623_codec_suspend(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+
+	bd28623_power_off(bd);
+
+	return 0;
+}
+
+static int bd28623_codec_resume(struct snd_soc_component *component)
+{
+	struct bd28623_priv *bd = snd_soc_component_get_drvdata(component);
+	int ret;
+
+	ret = bd28623_power_on(bd);
+	if (ret)
+		return ret;
+
+	gpiod_set_value_cansleep(bd->mute_gpio, bd->switch_spk ? 0 : 1);
+
+	return 0;
+}
+
+static const struct snd_soc_component_driver soc_codec_bd = {
+	.probe			= bd28623_codec_probe,
+	.remove			= bd28623_codec_remove,
+	.suspend		= bd28623_codec_suspend,
+	.resume			= bd28623_codec_resume,
+	.dapm_widgets		= bd28623_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(bd28623_widgets),
+	.dapm_routes		= bd28623_routes,
+	.num_dapm_routes	= ARRAY_SIZE(bd28623_routes),
+	.controls		= bd28623_controls,
+	.num_controls		= ARRAY_SIZE(bd28623_controls),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.endianness		= 1,
+};
+
+static struct snd_soc_dai_driver soc_dai_bd = {
+	.name     = "bd28623-speaker",
+	.playback = {
+		.stream_name  = "Playback",
+		.formats      = SNDRV_PCM_FMTBIT_S32_LE |
+				SNDRV_PCM_FMTBIT_S24_LE |
+				SNDRV_PCM_FMTBIT_S16_LE,
+		.rates        = SNDRV_PCM_RATE_48000 |
+				SNDRV_PCM_RATE_44100 |
+				SNDRV_PCM_RATE_32000,
+		.channels_min = 2,
+		.channels_max = 2,
+	},
+};
+
+static int bd28623_probe(struct platform_device *pdev)
+{
+	struct bd28623_priv *bd;
+	struct device *dev = &pdev->dev;
+	int i, ret;
+
+	bd = devm_kzalloc(&pdev->dev, sizeof(struct bd28623_priv), GFP_KERNEL);
+	if (!bd)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(bd->supplies); i++)
+		bd->supplies[i].supply = bd28623_supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(bd->supplies),
+				      bd->supplies);
+	if (ret) {
+		dev_err(dev, "Failed to get supplies: %d\n", ret);
+		return ret;
+	}
+
+	bd->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(bd->reset_gpio)) {
+		dev_err(dev, "Failed to request reset_gpio: %ld\n",
+			PTR_ERR(bd->reset_gpio));
+		return PTR_ERR(bd->reset_gpio);
+	}
+
+	bd->mute_gpio = devm_gpiod_get_optional(dev, "mute",
+						GPIOD_OUT_HIGH);
+	if (IS_ERR(bd->mute_gpio)) {
+		dev_err(dev, "Failed to request mute_gpio: %ld\n",
+			PTR_ERR(bd->mute_gpio));
+		return PTR_ERR(bd->mute_gpio);
+	}
+
+	platform_set_drvdata(pdev, bd);
+	bd->dev = dev;
+
+	return devm_snd_soc_register_component(dev, &soc_codec_bd,
+					       &soc_dai_bd, 1);
+}
+
+static const struct of_device_id bd28623_of_match[] __maybe_unused = {
+	{ .compatible = "rohm,bd28623", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, bd28623_of_match);
+
+static struct platform_driver bd28623_codec_driver = {
+	.driver = {
+		.name = "bd28623",
+		.of_match_table = of_match_ptr(bd28623_of_match),
+	},
+	.probe  = bd28623_probe,
+};
+module_platform_driver(bd28623_codec_driver);
+
+MODULE_AUTHOR("Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>");
+MODULE_DESCRIPTION("ROHM BD28623 speaker amplifier driver");
+MODULE_LICENSE("GPL v2");