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 --- drivers/tee/amdtee/call.c | 451 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 451 insertions(+) create mode 100644 drivers/tee/amdtee/call.c (limited to 'drivers/tee/amdtee/call.c') diff --git a/drivers/tee/amdtee/call.c b/drivers/tee/amdtee/call.c new file mode 100644 index 000000000..23ccd0f03 --- /dev/null +++ b/drivers/tee/amdtee/call.c @@ -0,0 +1,451 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright 2019 Advanced Micro Devices, Inc. + */ + +#include +#include +#include +#include +#include +#include +#include "amdtee_if.h" +#include "amdtee_private.h" + +static int tee_params_to_amd_params(struct tee_param *tee, u32 count, + struct tee_operation *amd) +{ + int i; + u32 type; + + if (!count) + return 0; + + if (!tee || !amd || count > TEE_MAX_PARAMS) + return -EINVAL; + + amd->param_types = 0; + for (i = 0; i < count; i++) { + /* AMD TEE does not support meta parameter */ + if (tee[i].attr > TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT) + return -EINVAL; + + amd->param_types |= ((tee[i].attr & 0xF) << i * 4); + } + + for (i = 0; i < count; i++) { + type = TEE_PARAM_TYPE_GET(amd->param_types, i); + pr_debug("%s: type[%d] = 0x%x\n", __func__, i, type); + + if (type == TEE_OP_PARAM_TYPE_INVALID) + return -EINVAL; + + if (type == TEE_OP_PARAM_TYPE_NONE) + continue; + + /* It is assumed that all values are within 2^32-1 */ + if (type > TEE_OP_PARAM_TYPE_VALUE_INOUT) { + u32 buf_id = (u32)tee[i].u.memref.shm->sec_world_id; + + amd->params[i].mref.buf_id = buf_id; + amd->params[i].mref.offset = tee[i].u.memref.shm_offs; + amd->params[i].mref.size = tee[i].u.memref.size; + pr_debug("%s: bufid[%d] = 0x%x, offset[%d] = 0x%x, size[%d] = 0x%x\n", + __func__, + i, amd->params[i].mref.buf_id, + i, amd->params[i].mref.offset, + i, amd->params[i].mref.size); + } else { + if (tee[i].u.value.c) + pr_warn("%s: Discarding value c", __func__); + + amd->params[i].val.a = tee[i].u.value.a; + amd->params[i].val.b = tee[i].u.value.b; + pr_debug("%s: a[%d] = 0x%x, b[%d] = 0x%x\n", __func__, + i, amd->params[i].val.a, + i, amd->params[i].val.b); + } + } + return 0; +} + +static int amd_params_to_tee_params(struct tee_param *tee, u32 count, + struct tee_operation *amd) +{ + int i; + u32 type; + + if (!count) + return 0; + + if (!tee || !amd || count > TEE_MAX_PARAMS) + return -EINVAL; + + /* Assumes amd->param_types is valid */ + for (i = 0; i < count; i++) { + type = TEE_PARAM_TYPE_GET(amd->param_types, i); + pr_debug("%s: type[%d] = 0x%x\n", __func__, i, type); + + if (type == TEE_OP_PARAM_TYPE_INVALID || + type > TEE_OP_PARAM_TYPE_MEMREF_INOUT) + return -EINVAL; + + if (type == TEE_OP_PARAM_TYPE_NONE || + type == TEE_OP_PARAM_TYPE_VALUE_INPUT || + type == TEE_OP_PARAM_TYPE_MEMREF_INPUT) + continue; + + /* + * It is assumed that buf_id remains unchanged for + * both open_session and invoke_cmd call + */ + if (type > TEE_OP_PARAM_TYPE_MEMREF_INPUT) { + tee[i].u.memref.shm_offs = amd->params[i].mref.offset; + tee[i].u.memref.size = amd->params[i].mref.size; + pr_debug("%s: bufid[%d] = 0x%x, offset[%d] = 0x%x, size[%d] = 0x%x\n", + __func__, + i, amd->params[i].mref.buf_id, + i, amd->params[i].mref.offset, + i, amd->params[i].mref.size); + } else { + /* field 'c' not supported by AMD TEE */ + tee[i].u.value.a = amd->params[i].val.a; + tee[i].u.value.b = amd->params[i].val.b; + tee[i].u.value.c = 0; + pr_debug("%s: a[%d] = 0x%x, b[%d] = 0x%x\n", + __func__, + i, amd->params[i].val.a, + i, amd->params[i].val.b); + } + } + return 0; +} + +static DEFINE_MUTEX(ta_refcount_mutex); +static LIST_HEAD(ta_list); + +static u32 get_ta_refcount(u32 ta_handle) +{ + struct amdtee_ta_data *ta_data; + u32 count = 0; + + /* Caller must hold a mutex */ + list_for_each_entry(ta_data, &ta_list, list_node) + if (ta_data->ta_handle == ta_handle) + return ++ta_data->refcount; + + ta_data = kzalloc_obj(*ta_data); + if (ta_data) { + ta_data->ta_handle = ta_handle; + ta_data->refcount = 1; + count = ta_data->refcount; + list_add(&ta_data->list_node, &ta_list); + } + + return count; +} + +static u32 put_ta_refcount(u32 ta_handle) +{ + struct amdtee_ta_data *ta_data; + u32 count = 0; + + /* Caller must hold a mutex */ + list_for_each_entry(ta_data, &ta_list, list_node) + if (ta_data->ta_handle == ta_handle) { + count = --ta_data->refcount; + if (count == 0) { + list_del(&ta_data->list_node); + kfree(ta_data); + break; + } + } + + return count; +} + +int handle_unload_ta(u32 ta_handle) +{ + struct tee_cmd_unload_ta cmd = {0}; + u32 status, count; + int ret; + + if (!ta_handle) + return -EINVAL; + + mutex_lock(&ta_refcount_mutex); + + count = put_ta_refcount(ta_handle); + + if (count) { + pr_debug("unload ta: not unloading %u count %u\n", + ta_handle, count); + ret = -EBUSY; + goto unlock; + } + + cmd.ta_handle = ta_handle; + + ret = psp_tee_process_cmd(TEE_CMD_ID_UNLOAD_TA, (void *)&cmd, + sizeof(cmd), &status); + if (!ret && status != 0) { + pr_err("unload ta: status = 0x%x\n", status); + ret = -EBUSY; + } else { + pr_debug("unloaded ta handle %u\n", ta_handle); + } + +unlock: + mutex_unlock(&ta_refcount_mutex); + return ret; +} + +int handle_close_session(u32 ta_handle, u32 info) +{ + struct tee_cmd_close_session cmd = {0}; + u32 status; + int ret; + + if (ta_handle == 0) + return -EINVAL; + + cmd.ta_handle = ta_handle; + cmd.session_info = info; + + ret = psp_tee_process_cmd(TEE_CMD_ID_CLOSE_SESSION, (void *)&cmd, + sizeof(cmd), &status); + if (!ret && status != 0) { + pr_err("close session: status = 0x%x\n", status); + ret = -EBUSY; + } + + return ret; +} + +void handle_unmap_shmem(u32 buf_id) +{ + struct tee_cmd_unmap_shared_mem cmd = {0}; + u32 status; + int ret; + + cmd.buf_id = buf_id; + + ret = psp_tee_process_cmd(TEE_CMD_ID_UNMAP_SHARED_MEM, (void *)&cmd, + sizeof(cmd), &status); + if (!ret) + pr_debug("unmap shared memory: buf_id %u status = 0x%x\n", + buf_id, status); +} + +int handle_invoke_cmd(struct tee_ioctl_invoke_arg *arg, u32 sinfo, + struct tee_param *p) +{ + struct tee_cmd_invoke_cmd cmd = {0}; + int ret; + + if (!arg || (!p && arg->num_params)) + return -EINVAL; + + arg->ret_origin = TEEC_ORIGIN_COMMS; + + if (arg->session == 0) { + arg->ret = TEEC_ERROR_BAD_PARAMETERS; + return -EINVAL; + } + + ret = tee_params_to_amd_params(p, arg->num_params, &cmd.op); + if (ret) { + pr_err("invalid Params. Abort invoke command\n"); + arg->ret = TEEC_ERROR_BAD_PARAMETERS; + return ret; + } + + cmd.ta_handle = get_ta_handle(arg->session); + cmd.cmd_id = arg->func; + cmd.session_info = sinfo; + + ret = psp_tee_process_cmd(TEE_CMD_ID_INVOKE_CMD, (void *)&cmd, + sizeof(cmd), &arg->ret); + if (ret) { + arg->ret = TEEC_ERROR_COMMUNICATION; + } else { + ret = amd_params_to_tee_params(p, arg->num_params, &cmd.op); + if (unlikely(ret)) { + pr_err("invoke command: failed to copy output\n"); + arg->ret = TEEC_ERROR_GENERIC; + return ret; + } + arg->ret_origin = cmd.return_origin; + pr_debug("invoke command: RO = 0x%x ret = 0x%x\n", + arg->ret_origin, arg->ret); + } + + return ret; +} + +int handle_map_shmem(u32 count, struct shmem_desc *start, u32 *buf_id) +{ + struct tee_cmd_map_shared_mem *cmd; + phys_addr_t paddr; + int ret, i; + u32 status; + + if (!count || !start || !buf_id) + return -EINVAL; + + cmd = kzalloc_obj(*cmd); + if (!cmd) + return -ENOMEM; + + /* Size must be page aligned */ + for (i = 0; i < count ; i++) { + if (!start[i].kaddr || (start[i].size & (PAGE_SIZE - 1))) { + ret = -EINVAL; + goto free_cmd; + } + + if ((u64)start[i].kaddr & (PAGE_SIZE - 1)) { + pr_err("map shared memory: page unaligned. addr 0x%llx", + (u64)start[i].kaddr); + ret = -EINVAL; + goto free_cmd; + } + } + + cmd->sg_list.count = count; + + /* Create buffer list */ + for (i = 0; i < count ; i++) { + paddr = __psp_pa(start[i].kaddr); + cmd->sg_list.buf[i].hi_addr = upper_32_bits(paddr); + cmd->sg_list.buf[i].low_addr = lower_32_bits(paddr); + cmd->sg_list.buf[i].size = start[i].size; + cmd->sg_list.size += cmd->sg_list.buf[i].size; + + pr_debug("buf[%d]:hi addr = 0x%x\n", i, + cmd->sg_list.buf[i].hi_addr); + pr_debug("buf[%d]:low addr = 0x%x\n", i, + cmd->sg_list.buf[i].low_addr); + pr_debug("buf[%d]:size = 0x%x\n", i, cmd->sg_list.buf[i].size); + pr_debug("list size = 0x%x\n", cmd->sg_list.size); + } + + *buf_id = 0; + + ret = psp_tee_process_cmd(TEE_CMD_ID_MAP_SHARED_MEM, (void *)cmd, + sizeof(*cmd), &status); + if (!ret && !status) { + *buf_id = cmd->buf_id; + pr_debug("mapped buffer ID = 0x%x\n", *buf_id); + } else { + pr_err("map shared memory: status = 0x%x\n", status); + ret = -ENOMEM; + } + +free_cmd: + kfree(cmd); + + return ret; +} + +int handle_open_session(struct tee_ioctl_open_session_arg *arg, u32 *info, + struct tee_param *p) +{ + struct tee_cmd_open_session cmd = {0}; + int ret; + + if (!arg || !info || (!p && arg->num_params)) + return -EINVAL; + + arg->ret_origin = TEEC_ORIGIN_COMMS; + + if (arg->session == 0) { + arg->ret = TEEC_ERROR_GENERIC; + return -EINVAL; + } + + ret = tee_params_to_amd_params(p, arg->num_params, &cmd.op); + if (ret) { + pr_err("invalid Params. Abort open session\n"); + arg->ret = TEEC_ERROR_BAD_PARAMETERS; + return ret; + } + + cmd.ta_handle = get_ta_handle(arg->session); + *info = 0; + + ret = psp_tee_process_cmd(TEE_CMD_ID_OPEN_SESSION, (void *)&cmd, + sizeof(cmd), &arg->ret); + if (ret) { + arg->ret = TEEC_ERROR_COMMUNICATION; + } else { + ret = amd_params_to_tee_params(p, arg->num_params, &cmd.op); + if (unlikely(ret)) { + pr_err("open session: failed to copy output\n"); + arg->ret = TEEC_ERROR_GENERIC; + return ret; + } + arg->ret_origin = cmd.return_origin; + *info = cmd.session_info; + pr_debug("open session: session info = 0x%x\n", *info); + } + + pr_debug("open session: ret = 0x%x RO = 0x%x\n", arg->ret, + arg->ret_origin); + + return ret; +} + +int handle_load_ta(void *data, u32 size, struct tee_ioctl_open_session_arg *arg) +{ + struct tee_cmd_unload_ta unload_cmd = {}; + struct tee_cmd_load_ta load_cmd = {}; + phys_addr_t blob; + int ret; + + if (size == 0 || !data || !arg) + return -EINVAL; + + blob = __psp_pa(data); + if (blob & (PAGE_SIZE - 1)) { + pr_err("load TA: page unaligned. blob 0x%llx", blob); + return -EINVAL; + } + + load_cmd.hi_addr = upper_32_bits(blob); + load_cmd.low_addr = lower_32_bits(blob); + load_cmd.size = size; + + mutex_lock(&ta_refcount_mutex); + + ret = psp_tee_process_cmd(TEE_CMD_ID_LOAD_TA, (void *)&load_cmd, + sizeof(load_cmd), &arg->ret); + if (ret) { + arg->ret_origin = TEEC_ORIGIN_COMMS; + arg->ret = TEEC_ERROR_COMMUNICATION; + } else { + arg->ret_origin = load_cmd.return_origin; + + if (arg->ret == TEEC_SUCCESS) { + ret = get_ta_refcount(load_cmd.ta_handle); + if (!ret) { + arg->ret_origin = TEEC_ORIGIN_COMMS; + arg->ret = TEEC_ERROR_OUT_OF_MEMORY; + + /* Unload the TA on error */ + unload_cmd.ta_handle = load_cmd.ta_handle; + psp_tee_process_cmd(TEE_CMD_ID_UNLOAD_TA, + (void *)&unload_cmd, + sizeof(unload_cmd), &ret); + } else { + set_session_id(load_cmd.ta_handle, 0, &arg->session); + } + } + } + mutex_unlock(&ta_refcount_mutex); + + pr_debug("load TA: TA handle = 0x%x, RO = 0x%x, ret = 0x%x\n", + load_cmd.ta_handle, arg->ret_origin, arg->ret); + + return 0; +} -- cgit v1.3.1