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/ipc3-loader.c | 419 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 419 insertions(+) create mode 100644 sound/soc/sof/ipc3-loader.c (limited to 'sound/soc/sof/ipc3-loader.c') diff --git a/sound/soc/sof/ipc3-loader.c b/sound/soc/sof/ipc3-loader.c new file mode 100644 index 000000000..7e9c76d5b --- /dev/null +++ b/sound/soc/sof/ipc3-loader.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) +// +// This file is provided under a dual BSD/GPLv2 license. When using or +// redistributing this file, you may do so under either license. +// +// Copyright(c) 2022 Intel Corporation + +#include +#include "sof-priv.h" +#include "sof-audio.h" +#include "ipc3-priv.h" +#include "ops.h" + +static int ipc3_fw_ext_man_get_version(struct snd_sof_dev *sdev, + const struct sof_ext_man_elem_header *hdr) +{ + const struct sof_ext_man_fw_version *v = + container_of(hdr, struct sof_ext_man_fw_version, hdr); + + memcpy(&sdev->fw_ready.version, &v->version, sizeof(v->version)); + sdev->fw_ready.flags = v->flags; + + /* log ABI versions and check FW compatibility */ + return sof_ipc3_validate_fw_version(sdev); +} + +static int ipc3_fw_ext_man_get_windows(struct snd_sof_dev *sdev, + const struct sof_ext_man_elem_header *hdr) +{ + const struct sof_ext_man_window *w; + + w = container_of(hdr, struct sof_ext_man_window, hdr); + + return sof_ipc3_get_ext_windows(sdev, &w->ipc_window.ext_hdr); +} + +static int ipc3_fw_ext_man_get_cc_info(struct snd_sof_dev *sdev, + const struct sof_ext_man_elem_header *hdr) +{ + const struct sof_ext_man_cc_version *cc; + + cc = container_of(hdr, struct sof_ext_man_cc_version, hdr); + + return sof_ipc3_get_cc_info(sdev, &cc->cc_version.ext_hdr); +} + +static int ipc3_fw_ext_man_get_dbg_abi_info(struct snd_sof_dev *sdev, + const struct sof_ext_man_elem_header *hdr) +{ + const struct ext_man_dbg_abi *dbg_abi = + container_of(hdr, struct ext_man_dbg_abi, hdr); + + if (sdev->first_boot) + dev_dbg(sdev->dev, + "Firmware: DBG_ABI %d:%d:%d\n", + SOF_ABI_VERSION_MAJOR(dbg_abi->dbg_abi.abi_dbg_version), + SOF_ABI_VERSION_MINOR(dbg_abi->dbg_abi.abi_dbg_version), + SOF_ABI_VERSION_PATCH(dbg_abi->dbg_abi.abi_dbg_version)); + + return 0; +} + +static int ipc3_fw_ext_man_get_config_data(struct snd_sof_dev *sdev, + const struct sof_ext_man_elem_header *hdr) +{ + const struct sof_ext_man_config_data *config = + container_of(hdr, struct sof_ext_man_config_data, hdr); + const struct sof_config_elem *elem; + int elems_counter; + int elems_size; + int ret = 0; + int i; + + /* calculate elements counter */ + elems_size = config->hdr.size - sizeof(struct sof_ext_man_elem_header); + elems_counter = elems_size / sizeof(struct sof_config_elem); + + dev_dbg(sdev->dev, "manifest can hold up to %d config elements\n", elems_counter); + + for (i = 0; i < elems_counter; ++i) { + elem = &config->elems[i]; + dev_dbg(sdev->dev, "get index %d token %d val %d\n", + i, elem->token, elem->value); + switch (elem->token) { + case SOF_EXT_MAN_CONFIG_EMPTY: + /* unused memory space is zero filled - mapped to EMPTY elements */ + break; + case SOF_EXT_MAN_CONFIG_IPC_MSG_SIZE: + /* TODO: use ipc msg size from config data */ + break; + case SOF_EXT_MAN_CONFIG_MEMORY_USAGE_SCAN: + if (sdev->first_boot && elem->value) + ret = snd_sof_dbg_memory_info_init(sdev); + break; + default: + dev_info(sdev->dev, + "Unknown firmware configuration token %d value %d", + elem->token, elem->value); + break; + } + if (ret < 0) { + dev_err(sdev->dev, + "%s: processing failed for token %d value %#x, %d\n", + __func__, elem->token, elem->value, ret); + return ret; + } + } + + return 0; +} + +static ssize_t ipc3_fw_ext_man_size(struct snd_sof_dev *sdev, const struct firmware *fw) +{ + const struct sof_ext_man_header *head; + + head = (struct sof_ext_man_header *)fw->data; + + /* + * assert fw size is big enough to contain extended manifest header, + * it prevents from reading unallocated memory from `head` in following + * step. + */ + if (fw->size < sizeof(*head)) + return -EINVAL; + + /* + * When fw points to extended manifest, + * then first u32 must be equal SOF_EXT_MAN_MAGIC_NUMBER. + */ + if (head->magic == SOF_EXT_MAN_MAGIC_NUMBER) + return head->full_size; + + /* otherwise given fw don't have an extended manifest */ + dev_dbg(sdev->dev, "Unexpected extended manifest magic number: %#x\n", + head->magic); + return 0; +} + +static size_t sof_ipc3_fw_parse_ext_man(struct snd_sof_dev *sdev) +{ + const struct firmware *fw = sdev->basefw.fw; + const struct sof_ext_man_elem_header *elem_hdr; + const struct sof_ext_man_header *head; + ssize_t ext_man_size; + ssize_t remaining; + uintptr_t iptr; + int ret = 0; + + head = (struct sof_ext_man_header *)fw->data; + remaining = head->full_size - head->header_size; + if (remaining < 0 || remaining > sdev->basefw.fw->size) + return -EINVAL; + ext_man_size = ipc3_fw_ext_man_size(sdev, fw); + + /* Assert firmware starts with extended manifest */ + if (ext_man_size <= 0) + return ext_man_size; + + /* incompatible version */ + if (SOF_EXT_MAN_VERSION_INCOMPATIBLE(SOF_EXT_MAN_VERSION, + head->header_version)) { + dev_err(sdev->dev, + "extended manifest version %#x differ from used %#x\n", + head->header_version, SOF_EXT_MAN_VERSION); + return -EINVAL; + } + + /* get first extended manifest element header */ + iptr = (uintptr_t)fw->data + head->header_size; + + while (remaining > sizeof(*elem_hdr)) { + elem_hdr = (struct sof_ext_man_elem_header *)iptr; + + dev_dbg(sdev->dev, "found sof_ext_man header type %d size %#x\n", + elem_hdr->type, elem_hdr->size); + + if (elem_hdr->size < sizeof(*elem_hdr) || + elem_hdr->size > remaining) { + dev_err(sdev->dev, + "invalid sof_ext_man header size, type %d size %#x\n", + elem_hdr->type, elem_hdr->size); + return -EINVAL; + } + + /* process structure data */ + switch (elem_hdr->type) { + case SOF_EXT_MAN_ELEM_FW_VERSION: + ret = ipc3_fw_ext_man_get_version(sdev, elem_hdr); + break; + case SOF_EXT_MAN_ELEM_WINDOW: + ret = ipc3_fw_ext_man_get_windows(sdev, elem_hdr); + break; + case SOF_EXT_MAN_ELEM_CC_VERSION: + ret = ipc3_fw_ext_man_get_cc_info(sdev, elem_hdr); + break; + case SOF_EXT_MAN_ELEM_PROBE_INFO: + dev_dbg(sdev->dev, "Probe info (not parsed)\n"); + break; + case SOF_EXT_MAN_ELEM_DBG_ABI: + ret = ipc3_fw_ext_man_get_dbg_abi_info(sdev, elem_hdr); + break; + case SOF_EXT_MAN_ELEM_CONFIG_DATA: + ret = ipc3_fw_ext_man_get_config_data(sdev, elem_hdr); + break; + case SOF_EXT_MAN_ELEM_PLATFORM_CONFIG_DATA: + ret = snd_sof_dsp_parse_platform_ext_manifest(sdev, elem_hdr); + break; + default: + dev_info(sdev->dev, + "unknown sof_ext_man header type %d size %#x\n", + elem_hdr->type, elem_hdr->size); + break; + } + + if (ret < 0) { + dev_err(sdev->dev, + "failed to parse sof_ext_man header type %d size %#x\n", + elem_hdr->type, elem_hdr->size); + return ret; + } + + remaining -= elem_hdr->size; + iptr += elem_hdr->size; + } + + if (remaining) { + dev_err(sdev->dev, "error: sof_ext_man header is inconsistent\n"); + return -EINVAL; + } + + return ext_man_size; +} + +/* generic module parser for mmaped DSPs */ +static int sof_ipc3_parse_module_memcpy(struct snd_sof_dev *sdev, + struct snd_sof_mod_hdr *module) +{ + struct snd_sof_blk_hdr *block; + int count, ret; + u32 offset; + size_t remaining; + + dev_dbg(sdev->dev, "new module size %#x blocks %#x type %#x\n", + module->size, module->num_blocks, module->type); + + block = (struct snd_sof_blk_hdr *)((u8 *)module + sizeof(*module)); + + /* module->size doesn't include header size */ + remaining = module->size; + for (count = 0; count < module->num_blocks; count++) { + /* check for wrap */ + if (remaining < sizeof(*block)) { + dev_err(sdev->dev, "not enough data remaining\n"); + return -EINVAL; + } + + /* minus header size of block */ + remaining -= sizeof(*block); + + if (block->size == 0) { + dev_warn(sdev->dev, + "warning: block %d size zero\n", count); + dev_warn(sdev->dev, " type %#x offset %#x\n", + block->type, block->offset); + continue; + } + + switch (block->type) { + case SOF_FW_BLK_TYPE_RSRVD0: + case SOF_FW_BLK_TYPE_ROM...SOF_FW_BLK_TYPE_RSRVD14: + continue; /* not handled atm */ + case SOF_FW_BLK_TYPE_IRAM: + case SOF_FW_BLK_TYPE_DRAM: + case SOF_FW_BLK_TYPE_SRAM: + offset = block->offset; + break; + default: + dev_err(sdev->dev, "%s: bad type %#x for block %#x\n", + __func__, block->type, count); + return -EINVAL; + } + + dev_dbg(sdev->dev, "block %d type %#x size %#x ==> offset %#x\n", + count, block->type, block->size, offset); + + /* checking block->size to avoid unaligned access */ + if (block->size % sizeof(u32)) { + dev_err(sdev->dev, "%s: invalid block size %#x\n", + __func__, block->size); + return -EINVAL; + } + ret = snd_sof_dsp_block_write(sdev, block->type, offset, + block + 1, block->size); + if (ret < 0) { + dev_err(sdev->dev, "%s: write to block type %#x failed\n", + __func__, block->type); + return ret; + } + + if (remaining < block->size) { + dev_err(sdev->dev, "%s: not enough data remaining\n", __func__); + return -EINVAL; + } + + /* minus body size of block */ + remaining -= block->size; + /* next block */ + block = (struct snd_sof_blk_hdr *)((u8 *)block + sizeof(*block) + + block->size); + } + + return 0; +} + +static int sof_ipc3_load_fw_to_dsp(struct snd_sof_dev *sdev) +{ + u32 payload_offset = sdev->basefw.payload_offset; + const struct firmware *fw = sdev->basefw.fw; + struct snd_sof_fw_header *header; + struct snd_sof_mod_hdr *module; + int (*load_module)(struct snd_sof_dev *sof_dev, struct snd_sof_mod_hdr *hdr); + size_t remaining; + int ret, count; + + if (!fw) + return -EINVAL; + + header = (struct snd_sof_fw_header *)(fw->data + payload_offset); + load_module = sof_ops(sdev)->load_module; + if (!load_module) { + dev_dbg(sdev->dev, "Using generic module loading\n"); + load_module = sof_ipc3_parse_module_memcpy; + } else { + dev_dbg(sdev->dev, "Using custom module loading\n"); + } + + /* parse each module */ + module = (struct snd_sof_mod_hdr *)(fw->data + payload_offset + sizeof(*header)); + remaining = fw->size - sizeof(*header) - payload_offset; + /* check for wrap */ + if (remaining > fw->size) { + dev_err(sdev->dev, "%s: fw size smaller than header size\n", __func__); + return -EINVAL; + } + + for (count = 0; count < header->num_modules; count++) { + /* check for wrap */ + if (remaining < sizeof(*module)) { + dev_err(sdev->dev, "%s: not enough data for a module\n", + __func__); + return -EINVAL; + } + + /* minus header size of module */ + remaining -= sizeof(*module); + + /* module */ + ret = load_module(sdev, module); + if (ret < 0) { + dev_err(sdev->dev, "%s: invalid module %d\n", __func__, count); + return ret; + } + + if (remaining < module->size) { + dev_err(sdev->dev, "%s: not enough data remaining\n", __func__); + return -EINVAL; + } + + /* minus body size of module */ + remaining -= module->size; + module = (struct snd_sof_mod_hdr *)((u8 *)module + + sizeof(*module) + module->size); + } + + return 0; +} + +static int sof_ipc3_validate_firmware(struct snd_sof_dev *sdev) +{ + u32 payload_offset = sdev->basefw.payload_offset; + const struct firmware *fw = sdev->basefw.fw; + struct snd_sof_fw_header *header; + size_t fw_size = fw->size - payload_offset; + + if (fw->size <= payload_offset) { + dev_err(sdev->dev, + "firmware size must be greater than firmware offset\n"); + return -EINVAL; + } + + /* Read the header information from the data pointer */ + header = (struct snd_sof_fw_header *)(fw->data + payload_offset); + + /* verify FW sig */ + if (strncmp(header->sig, SND_SOF_FW_SIG, SND_SOF_FW_SIG_SIZE) != 0) { + dev_err(sdev->dev, "invalid firmware signature\n"); + return -EINVAL; + } + + /* check size is valid */ + if (fw_size != header->file_size + sizeof(*header)) { + dev_err(sdev->dev, + "invalid filesize mismatch got 0x%zx expected 0x%zx\n", + fw_size, header->file_size + sizeof(*header)); + return -EINVAL; + } + + dev_dbg(sdev->dev, "header size=0x%x modules=0x%x abi=0x%x size=%zu\n", + header->file_size, header->num_modules, + header->abi, sizeof(*header)); + + return 0; +} + +const struct sof_ipc_fw_loader_ops ipc3_loader_ops = { + .validate = sof_ipc3_validate_firmware, + .parse_ext_manifest = sof_ipc3_fw_parse_ext_man, + .load_fw_to_dsp = sof_ipc3_load_fw_to_dsp, +}; 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