From: farah kassabri fkassabri@habana.ai
[ Upstream commit ac5af9900f82b7034de7c9eb1d70d030ba325607 ]
Protect re-using the same timestamp buffer record before actually adding it to the to interrupt wait list. Mark ts buff offset as in use in the spinlock protection area of the interrupt wait list to avoid getting in the re-use section in ts_buff_get_kernel_ts_record before adding the node to the list. this scenario might happen when multiple threads are racing on same offset and one thread could set data in the ts buff in ts_buff_get_kernel_ts_record then the other thread takes over and get to ts_buff_get_kernel_ts_record and we will try to re-use the same ts buff offset then we will try to delete a non existing node from the list.
Signed-off-by: farah kassabri fkassabri@habana.ai Reviewed-by: Oded Gabbay ogabbay@kernel.org Signed-off-by: Oded Gabbay ogabbay@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../habanalabs/common/command_submission.c | 33 ++++++++++++------- 1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/drivers/misc/habanalabs/common/command_submission.c b/drivers/misc/habanalabs/common/command_submission.c index ea0e5101c10ed..6367cbea4ca2a 100644 --- a/drivers/misc/habanalabs/common/command_submission.c +++ b/drivers/misc/habanalabs/common/command_submission.c @@ -3119,19 +3119,18 @@ static int ts_buff_get_kernel_ts_record(struct hl_mmap_mem_buf *buf, goto start_over; } } else { + /* Fill up the new registration node info */ + requested_offset_record->ts_reg_info.buf = buf; + requested_offset_record->ts_reg_info.cq_cb = cq_cb; + requested_offset_record->ts_reg_info.timestamp_kernel_addr = + (u64 *) ts_buff->user_buff_address + ts_offset; + requested_offset_record->cq_kernel_addr = + (u64 *) cq_cb->kernel_address + cq_offset; + requested_offset_record->cq_target_value = target_value; + spin_unlock_irqrestore(wait_list_lock, flags); }
- /* Fill up the new registration node info */ - requested_offset_record->ts_reg_info.in_use = 1; - requested_offset_record->ts_reg_info.buf = buf; - requested_offset_record->ts_reg_info.cq_cb = cq_cb; - requested_offset_record->ts_reg_info.timestamp_kernel_addr = - (u64 *) ts_buff->user_buff_address + ts_offset; - requested_offset_record->cq_kernel_addr = - (u64 *) cq_cb->kernel_address + cq_offset; - requested_offset_record->cq_target_value = target_value; - *pend = requested_offset_record;
dev_dbg(buf->mmg->dev, "Found available node in TS kernel CB %p\n", @@ -3179,7 +3178,7 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, goto put_cq_cb; }
- /* Find first available record */ + /* get ts buffer record */ rc = ts_buff_get_kernel_ts_record(buf, cq_cb, ts_offset, cq_counters_offset, target_value, &interrupt->wait_list_lock, &pend); @@ -3227,7 +3226,19 @@ static int _hl_interrupt_wait_ioctl(struct hl_device *hdev, struct hl_ctx *ctx, * Note that we cannot have sorted list by target value, * in order to shorten the list pass loop, since * same list could have nodes for different cq counter handle. + * Note: + * Mark ts buff offset as in use here in the spinlock protection area + * to avoid getting in the re-use section in ts_buff_get_kernel_ts_record + * before adding the node to the list. this scenario might happen when + * multiple threads are racing on same offset and one thread could + * set the ts buff in ts_buff_get_kernel_ts_record then the other thread + * takes over and get to ts_buff_get_kernel_ts_record and then we will try + * to re-use the same ts buff offset, and will try to delete a non existing + * node from the list. */ + if (register_ts_record) + pend->ts_reg_info.in_use = 1; + list_add_tail(&pend->wait_list_node, &interrupt->wait_list_head); spin_unlock_irqrestore(&interrupt->wait_list_lock, flags);