From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/crypto/ccp/sev-dev.h | 89 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 drivers/crypto/ccp/sev-dev.h (limited to 'drivers/crypto/ccp/sev-dev.h') diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h new file mode 100644 index 000000000..d5e596606 --- /dev/null +++ b/drivers/crypto/ccp/sev-dev.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AMD Platform Security Processor (PSP) interface driver + * + * Copyright (C) 2017-2019 Advanced Micro Devices, Inc. + * + * Author: Brijesh Singh + */ + +#ifndef __SEV_DEV_H__ +#define __SEV_DEV_H__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SEV_CMDRESP_CMD GENMASK(26, 16) +#define SEV_CMD_COMPLETE BIT(1) +#define SEV_CMDRESP_IOC BIT(0) + +struct sev_misc_dev { + struct kref refcount; + struct miscdevice misc; +}; + +struct sev_tio_status; + +struct sev_device { + struct device *dev; + struct psp_device *psp; + + void __iomem *io_regs; + + struct sev_vdata *vdata; + + unsigned int int_rcvd; + wait_queue_head_t int_queue; + struct sev_misc_dev *misc; + + u8 api_major; + u8 api_minor; + u8 build; + + void *cmd_buf; + void *cmd_buf_backup; + bool cmd_buf_active; + bool cmd_buf_backup_active; + + bool snp_initialized; + + struct kobject *sev_kobj; + struct kobject *verify_mit; + + struct sev_user_data_status sev_plat_status; + + struct sev_user_data_snp_status snp_plat_status; + struct snp_feature_info snp_feat_info_0; + + struct tsm_dev *tsmdev; + struct sev_tio_status *tio_status; +}; + +int sev_dev_init(struct psp_device *psp); +void sev_dev_destroy(struct psp_device *psp); + +int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret); + +void sev_pci_init(void); +void sev_pci_exit(void); + +struct page *snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages); +void snp_free_hv_fixed_pages(struct page *page); + +void sev_tsm_init_locked(struct sev_device *sev, void *tio_status_page); +void sev_tsm_uninit(struct sev_device *sev); +int sev_tio_cmd_buffer_len(int cmd); + +#endif /* __SEV_DEV_H */ -- cgit v1.3.1