From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions 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) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- sound/soc/sof/compress.c | 404 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 404 insertions(+) create mode 100644 sound/soc/sof/compress.c (limited to 'sound/soc/sof/compress.c') diff --git a/sound/soc/sof/compress.c b/sound/soc/sof/compress.c new file mode 100644 index 000000000..93f237658 --- /dev/null +++ b/sound/soc/sof/compress.c @@ -0,0 +1,404 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) +// +// Copyright 2021 NXP +// +// Author: Daniel Baluta + +#include +#include +#include +#include "sof-audio.h" +#include "sof-priv.h" +#include "sof-utils.h" +#include "ops.h" + +static void sof_set_transferred_bytes(struct sof_compr_stream *sstream, + u64 host_pos, u64 buffer_size) +{ + u64 prev_pos; + unsigned int copied; + + div64_u64_rem(sstream->copied_total, buffer_size, &prev_pos); + + if (host_pos < prev_pos) + copied = (buffer_size - prev_pos) + host_pos; + else + copied = host_pos - prev_pos; + + sstream->copied_total += copied; +} + +static void snd_sof_compr_fragment_elapsed_work(struct work_struct *work) +{ + struct snd_sof_pcm_stream *sps = + container_of(work, struct snd_sof_pcm_stream, + period_elapsed_work); + + snd_compr_fragment_elapsed(sps->cstream); +} + +void snd_sof_compr_init_elapsed_work(struct work_struct *work) +{ + INIT_WORK(work, snd_sof_compr_fragment_elapsed_work); +} + +/* + * sof compr fragment elapse, this could be called in irq thread context + */ +void snd_sof_compr_fragment_elapsed(struct snd_compr_stream *cstream) +{ + struct snd_soc_pcm_runtime *rtd; + struct snd_compr_runtime *crtd; + struct snd_soc_component *component; + struct sof_compr_stream *sstream; + struct snd_sof_pcm *spcm; + + if (!cstream) + return; + + rtd = cstream->private_data; + crtd = cstream->runtime; + sstream = crtd->private_data; + component = snd_soc_rtdcom_lookup(rtd, SOF_AUDIO_PCM_DRV_NAME); + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) { + dev_err(component->dev, + "fragment elapsed called for unknown stream!\n"); + return; + } + + sof_set_transferred_bytes(sstream, spcm->stream[cstream->direction].posn.host_posn, + crtd->buffer_size); + + /* use the same workqueue-based solution as for PCM, cf. snd_sof_pcm_elapsed */ + schedule_work(&spcm->stream[cstream->direction].period_elapsed_work); +} + +static int create_page_table(struct snd_soc_component *component, + struct snd_compr_stream *cstream, + unsigned char *dma_area, size_t size) +{ + struct snd_dma_buffer *dmab = cstream->runtime->dma_buffer_p; + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + int dir = cstream->direction; + struct snd_sof_pcm *spcm; + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) + return -EINVAL; + + return snd_sof_create_page_table(component->dev, dmab, + spcm->stream[dir].page_table.area, size); +} + +static int sof_compr_open(struct snd_soc_component *component, + struct snd_compr_stream *cstream) +{ + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + struct snd_compr_runtime *crtd = cstream->runtime; + struct sof_compr_stream *sstream; + struct snd_sof_pcm *spcm; + int dir; + + sstream = kzalloc_obj(*sstream); + if (!sstream) + return -ENOMEM; + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) { + kfree(sstream); + return -EINVAL; + } + + dir = cstream->direction; + + if (spcm->stream[dir].cstream) { + kfree(sstream); + return -EBUSY; + } + + spcm->stream[dir].cstream = cstream; + spcm->stream[dir].posn.host_posn = 0; + spcm->stream[dir].posn.dai_posn = 0; + spcm->prepared[dir] = false; + + crtd->private_data = sstream; + + return 0; +} + +static int sof_compr_free(struct snd_soc_component *component, + struct snd_compr_stream *cstream) +{ + struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component); + struct sof_compr_stream *sstream = cstream->runtime->private_data; + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + struct sof_ipc_stream stream; + struct snd_sof_pcm *spcm; + int ret = 0; + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) + return -EINVAL; + + stream.hdr.size = sizeof(stream); + stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE; + stream.comp_id = spcm->stream[cstream->direction].comp_id; + + if (spcm->prepared[cstream->direction]) { + ret = sof_ipc_tx_message_no_reply(sdev->ipc, &stream, sizeof(stream)); + if (!ret) + spcm->prepared[cstream->direction] = false; + } + + cancel_work_sync(&spcm->stream[cstream->direction].period_elapsed_work); + spcm->stream[cstream->direction].cstream = NULL; + kfree(sstream); + + return ret; +} + +static int sof_compr_set_params(struct snd_soc_component *component, + struct snd_compr_stream *cstream, struct snd_compr_params *params) +{ + struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component); + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + struct snd_compr_runtime *crtd = cstream->runtime; + struct sof_ipc_pcm_params_reply ipc_params_reply; + struct sof_ipc_fw_ready *ready = &sdev->fw_ready; + struct sof_ipc_fw_version *v = &ready->version; + struct sof_compr_stream *sstream; + struct sof_ipc_pcm_params *pcm; + struct snd_sof_pcm *spcm; + size_t ext_data_size; + int ret; + + if (v->abi_version < SOF_ABI_VER(3, 22, 0)) { + dev_err(component->dev, + "Compress params not supported with FW ABI version %d:%d:%d\n", + SOF_ABI_VERSION_MAJOR(v->abi_version), + SOF_ABI_VERSION_MINOR(v->abi_version), + SOF_ABI_VERSION_PATCH(v->abi_version)); + return -EINVAL; + } + + sstream = crtd->private_data; + + spcm = snd_sof_find_spcm_dai(component, rtd); + + if (!spcm) + return -EINVAL; + + ext_data_size = sizeof(params->codec); + + if (sizeof(*pcm) + ext_data_size > sdev->ipc->max_payload_size) + return -EINVAL; + + /* + * Make sure that the DSP is booted up, which might not be the + * case if the on-demand DSP boot is used + */ + ret = snd_sof_boot_dsp_firmware(sdev); + if (ret) + return ret; + + pcm = kzalloc(sizeof(*pcm) + ext_data_size, GFP_KERNEL); + if (!pcm) + return -ENOMEM; + + cstream->dma_buffer.dev.type = SNDRV_DMA_TYPE_DEV_SG; + cstream->dma_buffer.dev.dev = sdev->dev; + ret = snd_compr_malloc_pages(cstream, crtd->buffer_size); + if (ret < 0) + goto out; + + ret = create_page_table(component, cstream, crtd->dma_area, crtd->dma_bytes); + if (ret < 0) + goto out; + + pcm->params.buffer.pages = PFN_UP(crtd->dma_bytes); + pcm->hdr.size = sizeof(*pcm) + ext_data_size; + pcm->hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_PARAMS; + + pcm->comp_id = spcm->stream[cstream->direction].comp_id; + pcm->params.hdr.size = sizeof(pcm->params) + ext_data_size; + pcm->params.buffer.phy_addr = spcm->stream[cstream->direction].page_table.addr; + pcm->params.buffer.size = crtd->dma_bytes; + pcm->params.direction = cstream->direction; + pcm->params.channels = params->codec.ch_out; + pcm->params.rate = params->codec.sample_rate; + pcm->params.buffer_fmt = SOF_IPC_BUFFER_INTERLEAVED; + pcm->params.frame_fmt = SOF_IPC_FRAME_S32_LE; + pcm->params.sample_container_bytes = + snd_pcm_format_physical_width(SNDRV_PCM_FORMAT_S32) >> 3; + pcm->params.host_period_bytes = params->buffer.fragment_size; + pcm->params.ext_data_length = ext_data_size; + + memcpy((u8 *)pcm->params.ext_data, ¶ms->codec, ext_data_size); + + ret = sof_ipc_tx_message(sdev->ipc, pcm, sizeof(*pcm) + ext_data_size, + &ipc_params_reply, sizeof(ipc_params_reply)); + if (ret < 0) { + dev_err(component->dev, "error ipc failed\n"); + goto out; + } + + ret = snd_sof_set_stream_data_offset(sdev, &spcm->stream[cstream->direction], + ipc_params_reply.posn_offset); + if (ret < 0) { + dev_err(component->dev, "Invalid stream data offset for Compr %u\n", + le32_to_cpu(spcm->pcm.pcm_id)); + goto out; + } + + sstream->sampling_rate = params->codec.sample_rate; + sstream->channels = params->codec.ch_out; + sstream->sample_container_bytes = pcm->params.sample_container_bytes; + sstream->codec_params = params->codec; + + spcm->prepared[cstream->direction] = true; + +out: + kfree(pcm); + + return ret; +} + +static int sof_compr_get_params(struct snd_soc_component *component, + struct snd_compr_stream *cstream, struct snd_codec *params) +{ + struct sof_compr_stream *sstream = cstream->runtime->private_data; + + *params = sstream->codec_params; + + return 0; +} + +static int sof_compr_trigger(struct snd_soc_component *component, + struct snd_compr_stream *cstream, int cmd) +{ + struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component); + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + struct sof_ipc_stream stream; + struct snd_sof_pcm *spcm; + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) + return -EINVAL; + + stream.hdr.size = sizeof(stream); + stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG; + stream.comp_id = spcm->stream[cstream->direction].comp_id; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_START; + break; + case SNDRV_PCM_TRIGGER_STOP: + stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_STOP; + break; + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_PAUSE; + break; + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_RELEASE; + break; + default: + dev_err(component->dev, "error: unhandled trigger cmd %d\n", cmd); + break; + } + + return sof_ipc_tx_message_no_reply(sdev->ipc, &stream, sizeof(stream)); +} + +static int sof_compr_copy_playback(struct snd_compr_runtime *rtd, + char __user *buf, size_t count) +{ + void *ptr; + unsigned int offset, n; + int ret; + + div_u64_rem(rtd->total_bytes_available, rtd->buffer_size, &offset); + ptr = rtd->dma_area + offset; + n = rtd->buffer_size - offset; + + if (count < n) { + ret = copy_from_user(ptr, buf, count); + } else { + ret = copy_from_user(ptr, buf, n); + ret += copy_from_user(rtd->dma_area, buf + n, count - n); + } + + return count - ret; +} + +static int sof_compr_copy_capture(struct snd_compr_runtime *rtd, + char __user *buf, size_t count) +{ + void *ptr; + unsigned int offset, n; + int ret; + + div_u64_rem(rtd->total_bytes_transferred, rtd->buffer_size, &offset); + ptr = rtd->dma_area + offset; + n = rtd->buffer_size - offset; + + if (count < n) { + ret = copy_to_user(buf, ptr, count); + } else { + ret = copy_to_user(buf, ptr, n); + ret += copy_to_user(buf + n, rtd->dma_area, count - n); + } + + return count - ret; +} + +static int sof_compr_copy(struct snd_soc_component *component, + struct snd_compr_stream *cstream, + char __user *buf, size_t count) +{ + struct snd_compr_runtime *rtd = cstream->runtime; + + if (count > rtd->buffer_size) + count = rtd->buffer_size; + + if (cstream->direction == SND_COMPRESS_PLAYBACK) + return sof_compr_copy_playback(rtd, buf, count); + else + return sof_compr_copy_capture(rtd, buf, count); +} + +static int sof_compr_pointer(struct snd_soc_component *component, + struct snd_compr_stream *cstream, + struct snd_compr_tstamp64 *tstamp) +{ + struct snd_sof_pcm *spcm; + struct snd_soc_pcm_runtime *rtd = cstream->private_data; + struct sof_compr_stream *sstream = cstream->runtime->private_data; + + spcm = snd_sof_find_spcm_dai(component, rtd); + if (!spcm) + return -EINVAL; + + if (!sstream->channels || !sstream->sample_container_bytes) + return -EBUSY; + + tstamp->sampling_rate = sstream->sampling_rate; + tstamp->copied_total = sstream->copied_total; + tstamp->pcm_io_frames = div_u64(spcm->stream[cstream->direction].posn.dai_posn, + sstream->channels * sstream->sample_container_bytes); + + return 0; +} + +struct snd_compress_ops sof_compressed_ops = { + .open = sof_compr_open, + .free = sof_compr_free, + .set_params = sof_compr_set_params, + .get_params = sof_compr_get_params, + .trigger = sof_compr_trigger, + .pointer = sof_compr_pointer, + .copy = sof_compr_copy, +}; +EXPORT_SYMBOL(sof_compressed_ops); -- cgit v1.3.1