Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932405AbdCFWZM (ORCPT ); Mon, 6 Mar 2017 17:25:12 -0500 Received: from mail-pf0-f181.google.com ([209.85.192.181]:33754 "EHLO mail-pf0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754074AbdCFWYo (ORCPT ); Mon, 6 Mar 2017 17:24:44 -0500 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Nobuhiro Iwamatsu , Qiuxu Zhuo , Ard Biesheuvel , Anton Vorontsov , Colin Cross , Tony Luck , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "Rafael J. Wysocki" , Len Brown , Matt Fleming , Nathan Fontenot , Pan Xinhui , Daniel Axtens , Paul Gortmaker , Geliang Tang , linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH 18/18] pstore: Remove write_buf() callback Date: Mon, 6 Mar 2017 13:55:32 -0800 Message-Id: <1488837332-71582-19-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488837332-71582-1-git-send-email-keescook@chromium.org> References: <1488837332-71582-1-git-send-email-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7353 Lines: 218 Now that write() and write_buf() are functionally identical, this removes write_buf(), and renames write_buf_user() to write_user(). Additionally adds sanity-checks for pstore_info's declared functions and flags at registration time. Signed-off-by: Kees Cook --- fs/pstore/ftrace.c | 4 ++-- fs/pstore/platform.c | 35 ++++++++++++++++++++--------------- fs/pstore/pmsg.c | 4 ++-- fs/pstore/ram.c | 10 +++++----- include/linux/pstore.h | 29 ++++++++++------------------- 5 files changed, 39 insertions(+), 43 deletions(-) diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index a5506ec6995e..06aab07b6bb7 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -53,7 +53,7 @@ static void notrace pstore_ftrace_call(unsigned long ip, rec.parent_ip = parent_ip; pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++); pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id()); - psinfo->write_buf(&record); + psinfo->write(&record); local_irq_restore(flags); } @@ -122,7 +122,7 @@ void pstore_register_ftrace(void) { struct dentry *file; - if (!psinfo->write_buf) + if (!psinfo->write) return; pstore_ftrace_dir = debugfs_create_dir("pstore", NULL); diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 1e6642a2063e..e79f170fa79b 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -604,7 +604,7 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) } record.buf = (char *)s; record.size = c; - psinfo->write_buf(&record); + psinfo->write(&record); spin_unlock_irqrestore(&psinfo->buf_lock, flags); s += c; c = e - s; @@ -632,15 +632,8 @@ static void pstore_register_console(void) {} static void pstore_unregister_console(void) {} #endif -static int pstore_write_compat(struct pstore_record *record) -{ - record->buf = psinfo->buf; - - return record->psi->write_buf(record); -} - -static int pstore_write_buf_user_compat(struct pstore_record *record, - const char __user *buf) +static int pstore_write_user_compat(struct pstore_record *record, + const char __user *buf) { unsigned long flags = 0; size_t i, bufsize, total_size = record->size; @@ -662,7 +655,7 @@ static int pstore_write_buf_user_compat(struct pstore_record *record, break; } record->size = c; - ret = record->psi->write_buf(record); + ret = record->psi->write(record); if (unlikely(ret < 0)) break; i += c; @@ -687,6 +680,20 @@ int pstore_register(struct pstore_info *psi) return -EPERM; } + /* Sanity check flags. */ + if (!psi->flags) { + pr_warn("backend '%s' must support at least one frontend\n", + psi->name); + return -EINVAL; + } + + /* Check for required functions. */ + if (!psi->read || !psi->write) { + pr_warn("backend '%s' must implement read() and write()\n", + psi->name); + return -EINVAL; + } + spin_lock(&pstore_lock); if (psinfo) { pr_warn("backend '%s' already loaded: ignoring '%s'\n", @@ -695,10 +702,8 @@ int pstore_register(struct pstore_info *psi) return -EBUSY; } - if (!psi->write) - psi->write = pstore_write_compat; - if (!psi->write_buf_user) - psi->write_buf_user = pstore_write_buf_user_compat; + if (!psi->write_user) + psi->write_user = pstore_write_user_compat; psinfo = psi; mutex_init(&psinfo->read_mutex); spin_unlock(&pstore_lock); diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c index ce35907602de..c16a2477e106 100644 --- a/fs/pstore/pmsg.c +++ b/fs/pstore/pmsg.c @@ -33,12 +33,12 @@ static ssize_t write_pmsg(struct file *file, const char __user *buf, if (!count) return 0; - /* check outside lock, page in any data. write_buf_user also checks */ + /* check outside lock, page in any data. write_user also checks */ if (!access_ok(VERIFY_READ, buf, count)) return -EFAULT; mutex_lock(&pmsg_lock); - ret = psinfo->write_buf_user(&record, buf); + ret = psinfo->write_user(&record, buf); mutex_unlock(&pmsg_lock); return ret ? ret : count; } diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index d85e1adae1b6..5523df7f17ef 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -378,7 +378,7 @@ static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, return len; } -static int notrace ramoops_pstore_write_buf(struct pstore_record *record) +static int notrace ramoops_pstore_write(struct pstore_record *record) { struct ramoops_context *cxt = record->psi->data; struct persistent_ram_zone *prz; @@ -451,8 +451,8 @@ static int notrace ramoops_pstore_write_buf(struct pstore_record *record) return 0; } -static int notrace ramoops_pstore_write_buf_user(struct pstore_record *record, - const char __user *buf) +static int notrace ramoops_pstore_write_user(struct pstore_record *record, + const char __user *buf) { if (record->type == PSTORE_TYPE_PMSG) { struct ramoops_context *cxt = record->psi->data; @@ -503,8 +503,8 @@ static struct ramoops_context oops_cxt = { .name = "ramoops", .open = ramoops_pstore_open, .read = ramoops_pstore_read, - .write_buf = ramoops_pstore_write_buf, - .write_buf_user = ramoops_pstore_write_buf_user, + .write = ramoops_pstore_write, + .write_user = ramoops_pstore_write_user, .erase = ramoops_pstore_erase, }, }; diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 7f6eaa71504e..936744221171 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -130,27 +130,19 @@ struct pstore_record { * available, or negative on error. * * @write: - * Perform a frontend notification of a write to a backend record. The - * data to be stored has already been written to the registered @buf - * of the @psi structure. + * A newly generated record needs to be written to backend storage. * * @record: - * pointer to record metadata. Note that @buf is NULL, since - * the @buf registered with @psi is what has been written. The - * backend is expected to update @id. + * pointer to record metadata. When @type is PSTORE_TYPE_DMESG, + * @buf will be pointing to the preallocated @psi.buf, since + * memory allocation may be broken during an Oops. Regardless, + * @buf must be proccesed or copied before returning. The + * backend is also expected to write @id with something that + 8 can help identify this record to a future @erase callback. * * Returns 0 on success, and non-zero on error. * - * @write_buf: - * Perform a frontend write to a backend record. The record contains - * all metadata and the buffer to write to backend storage. (Unlike - * @write, this does not use the @psi @buf.) - * - * @record: pointer to record metadata. - * - * Returns 0 on success, and non-zero on error. - * - * @write_buf_user: + * @write_user: * Perform a frontend write to a backend record, using a specified * buffer that is coming directly from userspace, instead of the * @record @buf. @@ -188,9 +180,8 @@ struct pstore_info { int (*close)(struct pstore_info *psi); ssize_t (*read)(struct pstore_record *record); int (*write)(struct pstore_record *record); - int (*write_buf)(struct pstore_record *record); - int (*write_buf_user)(struct pstore_record *record, - const char __user *buf); + int (*write_user)(struct pstore_record *record, + const char __user *buf); int (*erase)(struct pstore_record *record); }; -- 2.7.4