From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/crypto/ccp/tee-dev.c | 399 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 399 insertions(+) create mode 100644 drivers/crypto/ccp/tee-dev.c (limited to 'drivers/crypto/ccp/tee-dev.c') diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c new file mode 100644 index 000000000..3e3645980 --- /dev/null +++ b/drivers/crypto/ccp/tee-dev.c @@ -0,0 +1,399 @@ +// SPDX-License-Identifier: MIT +/* + * AMD Trusted Execution Environment (TEE) interface + * + * Author: Rijo Thomas + * Author: Devaraj Rangasamy + * + * Copyright (C) 2019,2021 Advanced Micro Devices, Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "psp-dev.h" +#include "tee-dev.h" + +static bool psp_dead; + +static int tee_alloc_ring(struct psp_tee_device *tee, int ring_size) +{ + struct ring_buf_manager *rb_mgr = &tee->rb_mgr; + void *start_addr; + + if (!ring_size) + return -EINVAL; + + /* We need actual physical address instead of DMA address, since + * Trusted OS running on AMD Secure Processor will map this region + */ + start_addr = (void *)__get_free_pages(GFP_KERNEL, get_order(ring_size)); + if (!start_addr) + return -ENOMEM; + + memset(start_addr, 0x0, ring_size); + rb_mgr->ring_start = start_addr; + rb_mgr->ring_size = ring_size; + rb_mgr->ring_pa = __psp_pa(start_addr); + mutex_init(&rb_mgr->mutex); + + return 0; +} + +static void tee_free_ring(struct psp_tee_device *tee) +{ + struct ring_buf_manager *rb_mgr = &tee->rb_mgr; + + if (!rb_mgr->ring_start) + return; + + free_pages((unsigned long)rb_mgr->ring_start, + get_order(rb_mgr->ring_size)); + + rb_mgr->ring_start = NULL; + rb_mgr->ring_size = 0; + rb_mgr->ring_pa = 0; + mutex_destroy(&rb_mgr->mutex); +} + +static +struct tee_init_ring_cmd *tee_alloc_cmd_buffer(struct psp_tee_device *tee) +{ + struct tee_init_ring_cmd *cmd; + + cmd = kzalloc_obj(*cmd); + if (!cmd) + return NULL; + + cmd->hi_addr = upper_32_bits(tee->rb_mgr.ring_pa); + cmd->low_addr = lower_32_bits(tee->rb_mgr.ring_pa); + cmd->size = tee->rb_mgr.ring_size; + + dev_dbg(tee->dev, "tee: ring address: high = 0x%x low = 0x%x size = %u\n", + cmd->hi_addr, cmd->low_addr, cmd->size); + + return cmd; +} + +static inline void tee_free_cmd_buffer(struct tee_init_ring_cmd *cmd) +{ + kfree(cmd); +} + +static bool tee_send_destroy_cmd(struct psp_tee_device *tee) +{ + unsigned int reg; + int ret; + + ret = psp_mailbox_command(tee->psp, PSP_CMD_TEE_RING_DESTROY, NULL, + TEE_DEFAULT_CMD_TIMEOUT, ®); + if (ret) { + dev_err(tee->dev, "tee: ring destroy command timed out, disabling TEE support\n"); + psp_dead = true; + return false; + } + + if (FIELD_GET(PSP_CMDRESP_STS, reg)) { + dev_err(tee->dev, "tee: ring destroy command failed (%#010lx)\n", + FIELD_GET(PSP_CMDRESP_STS, reg)); + psp_dead = true; + return false; + } + + return true; +} + +static int tee_init_ring(struct psp_tee_device *tee) +{ + int ring_size = MAX_RING_BUFFER_ENTRIES * sizeof(struct tee_ring_cmd); + struct tee_init_ring_cmd *cmd; + bool retry = false; + unsigned int reg; + int ret; + + BUILD_BUG_ON(sizeof(struct tee_ring_cmd) != 1024); + + ret = tee_alloc_ring(tee, ring_size); + if (ret) { + dev_err(tee->dev, "tee: ring allocation failed %d\n", ret); + return ret; + } + + tee->rb_mgr.wptr = 0; + + cmd = tee_alloc_cmd_buffer(tee); + if (!cmd) { + tee_free_ring(tee); + return -ENOMEM; + } + + /* Send command buffer details to Trusted OS by writing to + * CPU-PSP message registers + */ +retry_init: + ret = psp_mailbox_command(tee->psp, PSP_CMD_TEE_RING_INIT, cmd, + TEE_DEFAULT_CMD_TIMEOUT, ®); + if (ret) { + dev_err(tee->dev, "tee: ring init command timed out, disabling TEE support\n"); + tee_free_ring(tee); + psp_dead = true; + goto free_buf; + } + + if (FIELD_GET(PSP_CMDRESP_STS, reg)) { + /* + * During the hibernate resume sequence driver may have gotten loaded + * but the ring not properly destroyed. If the ring doesn't work, try + * to destroy and re-init once. + */ + if (!retry && FIELD_GET(PSP_CMDRESP_STS, reg) == PSP_TEE_STS_RING_BUSY) { + dev_info(tee->dev, "tee: ring init command failed with busy status, retrying\n"); + if (tee_send_destroy_cmd(tee)) { + retry = true; + goto retry_init; + } + } + dev_err(tee->dev, "tee: ring init command failed (%#010lx)\n", + FIELD_GET(PSP_CMDRESP_STS, reg)); + tee_free_ring(tee); + psp_dead = true; + ret = -EIO; + } + +free_buf: + tee_free_cmd_buffer(cmd); + + return ret; +} + +static void tee_destroy_ring(struct psp_tee_device *tee) +{ + if (!tee->rb_mgr.ring_start) + return; + + if (psp_dead) + goto free_ring; + + tee_send_destroy_cmd(tee); + +free_ring: + tee_free_ring(tee); +} + +int tee_dev_init(struct psp_device *psp) +{ + struct device *dev = psp->dev; + struct psp_tee_device *tee; + int ret; + + ret = -ENOMEM; + tee = devm_kzalloc(dev, sizeof(*tee), GFP_KERNEL); + if (!tee) + goto e_err; + + psp->tee_data = tee; + + tee->dev = dev; + tee->psp = psp; + + tee->io_regs = psp->io_regs; + + tee->vdata = (struct tee_vdata *)psp->vdata->tee; + if (!tee->vdata) { + ret = -ENODEV; + dev_err(dev, "tee: missing driver data\n"); + goto e_err; + } + + ret = tee_init_ring(tee); + if (ret) { + dev_err(dev, "tee: failed to init ring buffer\n"); + goto e_err; + } + + dev_notice(dev, "tee enabled\n"); + + return 0; + +e_err: + psp->tee_data = NULL; + + dev_notice(dev, "tee initialization failed\n"); + + return ret; +} + +void tee_dev_destroy(struct psp_device *psp) +{ + struct psp_tee_device *tee = psp->tee_data; + + if (!tee) + return; + + tee_destroy_ring(tee); +} + +static int tee_submit_cmd(struct psp_tee_device *tee, enum tee_cmd_id cmd_id, + void *buf, size_t len, struct tee_ring_cmd **resp) +{ + struct tee_ring_cmd *cmd; + int nloop = 1000, ret = 0; + u32 rptr; + + *resp = NULL; + + mutex_lock(&tee->rb_mgr.mutex); + + /* Loop until empty entry found in ring buffer */ + do { + /* Get pointer to ring buffer command entry */ + cmd = (struct tee_ring_cmd *) + (tee->rb_mgr.ring_start + tee->rb_mgr.wptr); + + rptr = ioread32(tee->io_regs + tee->vdata->ring_rptr_reg); + + /* Check if ring buffer is full or command entry is waiting + * for response from TEE + */ + if (!(tee->rb_mgr.wptr + sizeof(struct tee_ring_cmd) == rptr || + cmd->flag == CMD_WAITING_FOR_RESPONSE)) + break; + + dev_dbg(tee->dev, "tee: ring buffer full. rptr = %u wptr = %u\n", + rptr, tee->rb_mgr.wptr); + + /* Wait if ring buffer is full or TEE is processing data */ + mutex_unlock(&tee->rb_mgr.mutex); + schedule_timeout_interruptible(msecs_to_jiffies(10)); + mutex_lock(&tee->rb_mgr.mutex); + + } while (--nloop); + + if (!nloop && + (tee->rb_mgr.wptr + sizeof(struct tee_ring_cmd) == rptr || + cmd->flag == CMD_WAITING_FOR_RESPONSE)) { + dev_err(tee->dev, "tee: ring buffer full. rptr = %u wptr = %u response flag %u\n", + rptr, tee->rb_mgr.wptr, cmd->flag); + ret = -EBUSY; + goto unlock; + } + + /* Do not submit command if PSP got disabled while processing any + * command in another thread + */ + if (psp_dead) { + ret = -EBUSY; + goto unlock; + } + + /* Write command data into ring buffer */ + cmd->cmd_id = cmd_id; + cmd->cmd_state = TEE_CMD_STATE_INIT; + memset(&cmd->buf[0], 0, sizeof(cmd->buf)); + memcpy(&cmd->buf[0], buf, len); + + /* Indicate driver is waiting for response */ + cmd->flag = CMD_WAITING_FOR_RESPONSE; + + /* Update local copy of write pointer */ + tee->rb_mgr.wptr += sizeof(struct tee_ring_cmd); + if (tee->rb_mgr.wptr >= tee->rb_mgr.ring_size) + tee->rb_mgr.wptr = 0; + + /* Trigger interrupt to Trusted OS */ + iowrite32(tee->rb_mgr.wptr, tee->io_regs + tee->vdata->ring_wptr_reg); + + /* The response is provided by Trusted OS in same + * location as submitted data entry within ring buffer. + */ + *resp = cmd; + +unlock: + mutex_unlock(&tee->rb_mgr.mutex); + + return ret; +} + +static int tee_wait_cmd_completion(struct psp_tee_device *tee, + struct tee_ring_cmd *resp, + unsigned int timeout) +{ + /* ~1ms sleep per loop => nloop = timeout * 1000 */ + int nloop = timeout * 1000; + + while (--nloop) { + if (resp->cmd_state == TEE_CMD_STATE_COMPLETED) + return 0; + + usleep_range(1000, 1100); + } + + dev_err(tee->dev, "tee: command 0x%x timed out, disabling PSP\n", + resp->cmd_id); + + psp_dead = true; + + return -ETIMEDOUT; +} + +int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len, + u32 *status) +{ + struct psp_device *psp = psp_get_master_device(); + struct psp_tee_device *tee; + struct tee_ring_cmd *resp; + int ret; + + if (!buf || !status || !len || len > sizeof(resp->buf)) + return -EINVAL; + + *status = 0; + + if (!psp || !psp->tee_data) + return -ENODEV; + + if (psp_dead) + return -EBUSY; + + tee = psp->tee_data; + + ret = tee_submit_cmd(tee, cmd_id, buf, len, &resp); + if (ret) + return ret; + + ret = tee_wait_cmd_completion(tee, resp, TEE_DEFAULT_RING_TIMEOUT); + if (ret) { + resp->flag = CMD_RESPONSE_TIMEDOUT; + return ret; + } + + memcpy(buf, &resp->buf[0], len); + *status = resp->status; + + resp->flag = CMD_RESPONSE_COPIED; + + return 0; +} +EXPORT_SYMBOL(psp_tee_process_cmd); + +int psp_check_tee_status(void) +{ + struct psp_device *psp = psp_get_master_device(); + + if (!psp || !psp->tee_data) + return -ENODEV; + + return 0; +} +EXPORT_SYMBOL(psp_check_tee_status); + +int tee_restore(struct psp_device *psp) +{ + return tee_init_ring(psp->tee_data); +} -- cgit v1.3.1