From patchwork Tue Jun 15 15:49:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin He X-Patchwork-Id: 12322247 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC612C48BDF for ; Tue, 15 Jun 2021 15:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B704C60FE9 for ; Tue, 15 Jun 2021 15:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232714AbhFOPxf (ORCPT ); Tue, 15 Jun 2021 11:53:35 -0400 Received: from foss.arm.com ([217.140.110.172]:39038 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232319AbhFOPwN (ORCPT ); Tue, 15 Jun 2021 11:52:13 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EA22C13D5; Tue, 15 Jun 2021 08:50:08 -0700 (PDT) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.103]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4058C3F694; Tue, 15 Jun 2021 08:50:04 -0700 (PDT) From: Jia He To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Linus Torvalds Cc: "Peter Zijlstra (Intel)" , Eric Biggers , "Ahmed S. Darwish" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Matthew Wilcox , Jia He Subject: [PATCH RFCv4 1/4] fs: introduce helper d_path_unsafe() Date: Tue, 15 Jun 2021 23:49:49 +0800 Message-Id: <20210615154952.2744-2-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210615154952.2744-1-justin.he@arm.com> References: <20210615154952.2744-1-justin.he@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This helper is similar to d_path except that it doesn't take any seqlock/spinlock. It is typical for debugging purpose. Besides, an additional return value *prenpend_len* is used to get the full path length of the dentry. prepend_name_with_len() enhances the behavior of prepend_name(). Previously it will skip the loop at once in __prepen_path() when the space is not enough. __prepend_path() gets the full length of dentry together with the parent recusively. Besides, if someone invokes snprintf with small but positive space, prepend_name_with() needs to move and copy the string partially. More than that, kasnprintf will pass NULL _buf_ and _end_, hence it returns at the very beginning with false in this case; Suggested-by: Matthew Wilcox Signed-off-by: Jia He --- fs/d_path.c | 83 +++++++++++++++++++++++++++++++++++++++++- include/linux/dcache.h | 1 + 2 files changed, 82 insertions(+), 2 deletions(-) diff --git a/fs/d_path.c b/fs/d_path.c index 23a53f7b5c71..4fc224eadf58 100644 --- a/fs/d_path.c +++ b/fs/d_path.c @@ -68,9 +68,66 @@ static bool prepend_name(struct prepend_buffer *p, const struct qstr *name) return true; } +static bool prepend_name_with_len(struct prepend_buffer *p, const struct qstr *name, + int orig_buflen) +{ + const char *dname = smp_load_acquire(&name->name); /* ^^^ */ + int dlen = READ_ONCE(name->len); + char *s; + int last_len = p->len; + + p->len -= dlen + 1; + + if (unlikely(!p->buf)) + return false; + + if (orig_buflen <= 0) + return false; + /* + * The first time we overflow the buffer. Then fill the string + * partially from the beginning + */ + if (unlikely(p->len < 0)) { + int buflen = strlen(p->buf); + + s = p->buf; + + /* Still have small space to fill partially */ + if (last_len > 0) { + p->buf -= last_len; + buflen += last_len; + } + + if (buflen > dlen + 1) { + /* This dentry name can be fully filled */ + memmove(p->buf + dlen + 1, s, buflen - dlen - 1); + p->buf[0] = '/'; + memcpy(p->buf + 1, dname, dlen); + } else if (buflen > 0) { + /* Partially filled, and drop last dentry name */ + p->buf[0] = '/'; + memcpy(p->buf + 1, dname, buflen - 1); + } + + return false; + } + + s = p->buf -= dlen + 1; + *s++ = '/'; + while (dlen--) { + char c = *dname++; + + if (!c) + break; + *s++ = c; + } + return true; +} static int __prepend_path(const struct dentry *dentry, const struct mount *mnt, const struct path *root, struct prepend_buffer *p) { + int orig_buflen = p->len; + while (dentry != root->dentry || &mnt->mnt != root->mnt) { const struct dentry *parent = READ_ONCE(dentry->d_parent); @@ -97,8 +154,7 @@ static int __prepend_path(const struct dentry *dentry, const struct mount *mnt, return 3; prefetch(parent); - if (!prepend_name(p, &dentry->d_name)) - break; + prepend_name_with_len(p, &dentry->d_name, orig_buflen); dentry = parent; } return 0; @@ -263,6 +319,29 @@ char *d_path(const struct path *path, char *buf, int buflen) } EXPORT_SYMBOL(d_path); +/** + * d_path_unsafe - fast return the full path of a dentry without taking + * any seqlock/spinlock. This helper is typical for debugging purpose. + */ +char *d_path_unsafe(const struct path *path, char *buf, int buflen, + int *prepend_len) +{ + struct path root; + struct mount *mnt = real_mount(path->mnt); + DECLARE_BUFFER(b, buf, buflen); + + rcu_read_lock(); + get_fs_root_rcu(current->fs, &root); + + prepend(&b, "", 1); + __prepend_path(path->dentry, mnt, &root, &b); + rcu_read_unlock(); + + *prepend_len = b.len; + + return b.buf; +} + /* * Helper function for dentry_operations.d_dname() members */ diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 9e23d33bb6f1..ec118b684055 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -301,6 +301,7 @@ char *dynamic_dname(struct dentry *, char *, int, const char *, ...); extern char *__d_path(const struct path *, const struct path *, char *, int); extern char *d_absolute_path(const struct path *, char *, int); extern char *d_path(const struct path *, char *, int); +extern char *d_path_unsafe(const struct path *, char *, int, int*); extern char *dentry_path_raw(const struct dentry *, char *, int); extern char *dentry_path(const struct dentry *, char *, int); From patchwork Tue Jun 15 15:49:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin He X-Patchwork-Id: 12322249 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6F69C49EA2 for ; Tue, 15 Jun 2021 15:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4D7E61476 for ; Tue, 15 Jun 2021 15:51:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232742AbhFOPxw (ORCPT ); Tue, 15 Jun 2021 11:53:52 -0400 Received: from foss.arm.com ([217.140.110.172]:39072 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232343AbhFOPwT (ORCPT ); Tue, 15 Jun 2021 11:52:19 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1D8BC1424; Tue, 15 Jun 2021 08:50:14 -0700 (PDT) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.103]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6F5003F694; Tue, 15 Jun 2021 08:50:09 -0700 (PDT) From: Jia He To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Linus Torvalds Cc: "Peter Zijlstra (Intel)" , Eric Biggers , "Ahmed S. Darwish" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Matthew Wilcox , Jia He Subject: [PATCH RFCv4 2/4] lib/vsprintf.c: make '%pD' print full path for file Date: Tue, 15 Jun 2021 23:49:50 +0800 Message-Id: <20210615154952.2744-3-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210615154952.2744-1-justin.he@arm.com> References: <20210615154952.2744-1-justin.he@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Previously, the specifier '%pD' is for printing dentry name of struct file. It may not be perfect (by default it only prints one component.) As suggested by Linus at [1]: A dentry has a parent, but at the same time, a dentry really does inherently have "one name" (and given just the dentry pointers, you can't show mount-related parenthood, so in many ways the "show just one name" makes sense for "%pd" in ways it doesn't necessarily for "%pD"). But while a dentry arguably has that "one primary component", a _file_ is certainly not exclusively about that last component. Hence change the behavior of '%pD' to print full path of that file. Precision is never going to be used with %p (or any of its kernel extensions) if -Wformat is turned on. . [1] https://lore.kernel.org/lkml/CAHk-=wimsMqGdzik187YWLb-ru+iktb4MYbMQG1rnZ81dXYFVg@mail.gmail.com/ Suggested-by: Linus Torvalds Signed-off-by: Jia He --- Documentation/core-api/printk-formats.rst | 5 +-- lib/vsprintf.c | 37 ++++++++++++++++++++--- 2 files changed, 36 insertions(+), 6 deletions(-) diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index f063a384c7c8..95ba14dc529b 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -408,12 +408,13 @@ dentry names :: %pd{,2,3,4} - %pD{,2,3,4} + %pD For printing dentry name; if we race with :c:func:`d_move`, the name might be a mix of old and new ones, but it won't oops. %pd dentry is a safer equivalent of %s dentry->d_name.name we used to use, %pd prints ``n`` -last components. %pD does the same thing for struct file. +last components. %pD prints full file path together with mount-related +parenthood. Passed by reference. diff --git a/lib/vsprintf.c b/lib/vsprintf.c index f0c35d9b65bf..9d3166332726 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -920,13 +921,41 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp } static noinline_for_stack -char *file_dentry_name(char *buf, char *end, const struct file *f, +char *file_d_path_name(char *buf, char *end, const struct file *f, struct printf_spec spec, const char *fmt) { + const struct path *path; + char *p; + int prepend_len, reserved_size, dpath_len; + if (check_pointer(&buf, end, f, spec)) return buf; - return dentry_name(buf, end, f->f_path.dentry, spec, fmt); + path = &f->f_path; + if (check_pointer(&buf, end, path, spec)) + return buf; + + p = d_path_unsafe(path, buf, end - buf, &prepend_len); + + /* Calculate the full d_path length, ignoring the tail '\0' */ + dpath_len = end - buf - prepend_len - 1; + + reserved_size = max_t(int, dpath_len, spec.field_width); + + /* case 1: no space at all, forward the buf with reserved size */ + if (buf >= end) + return buf + reserved_size; + + /* + * case 2: small scratch space for long d_path name. The space + * [buf,end] has been filled with truncated string. Hence use the + * full dpath_len for further string widening. + */ + if (prepend_len < 0) + return widen_string(buf + dpath_len, dpath_len, end, spec); + + /* case3: space is big enough */ + return string_nocheck(buf, end, p, spec); } #ifdef CONFIG_BLOCK static noinline_for_stack @@ -2296,7 +2325,7 @@ early_param("no_hash_pointers", no_hash_pointers_enable); * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives * (default assumed to be phys_addr_t, passed by reference) * - 'd[234]' For a dentry name (optionally 2-4 last components) - * - 'D[234]' Same as 'd' but for a struct file + * - 'D' For full path name of a struct file * - 'g' For block_device name (gendisk + partition number) * - 't[RT][dt][r]' For time and date as represented by: * R struct rtc_time @@ -2395,7 +2424,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'C': return clock(buf, end, ptr, spec, fmt); case 'D': - return file_dentry_name(buf, end, ptr, spec, fmt); + return file_d_path_name(buf, end, ptr, spec, fmt); #ifdef CONFIG_BLOCK case 'g': return bdev_name(buf, end, ptr, spec, fmt); From patchwork Tue Jun 15 15:49:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin He X-Patchwork-Id: 12322251 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DE86C48BE8 for ; Tue, 15 Jun 2021 15:51:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 820D961476 for ; Tue, 15 Jun 2021 15:51:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232520AbhFOPx4 (ORCPT ); Tue, 15 Jun 2021 11:53:56 -0400 Received: from foss.arm.com ([217.140.110.172]:39096 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232373AbhFOPwY (ORCPT ); Tue, 15 Jun 2021 11:52:24 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4390E143B; Tue, 15 Jun 2021 08:50:19 -0700 (PDT) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.103]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 98EE73F694; Tue, 15 Jun 2021 08:50:14 -0700 (PDT) From: Jia He To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Linus Torvalds Cc: "Peter Zijlstra (Intel)" , Eric Biggers , "Ahmed S. Darwish" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Matthew Wilcox , Jia He Subject: [PATCH RFCv4 3/4] lib/test_printf.c: split write-beyond-buffer check in two Date: Tue, 15 Jun 2021 23:49:51 +0800 Message-Id: <20210615154952.2744-4-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210615154952.2744-1-justin.he@arm.com> References: <20210615154952.2744-1-justin.he@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Rasmus Villemoes Before each invocation of vsnprintf(), do_test() memsets the entire allocated buffer to a sentinel value. That buffer includes leading and trailing padding which is never included in the buffer area handed to vsnprintf (spaces merely for clarity): pad test_buffer pad **** **************** **** Then vsnprintf() is invoked with a bufsize argument <= BUF_SIZE. Suppose bufsize=10, then we'd have e.g. |pad | test_buffer |pad | **** pizza0 **** ****** **** A B C D E where vsnprintf() was given the area from B to D. It is obviously a bug for vsnprintf to touch anything between A and B or between D and E. The former is checked for as one would expect. But for the latter, we are actually a little stricter in that we check the area between C and E. Split that check in two, providing a clearer error message in case it was a genuine buffer overrun and not merely a write within the provided buffer, but after the end of the generated string. So far, no part of the vsnprintf() implementation has had any use for using the whole buffer as scratch space, but it's not unreasonable to allow that, as long as the result is properly nul-terminated and the return value is the right one. However, it is somewhat unusual, and most % won't need this, so keep the [C,D] check, but make it easy for a later patch to make that part opt-out for certain tests. Signed-off-by: Rasmus Villemoes Tested-by: Jia He Signed-off-by: Jia He Reviewed-by: Petr Mladek --- lib/test_printf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/lib/test_printf.c b/lib/test_printf.c index ec0d5976bb69..d1d2f898ebae 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -78,12 +78,17 @@ do_test(int bufsize, const char *expect, int elen, return 1; } - if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) { + if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) { pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n", bufsize, fmt); return 1; } + if (memchr_inv(test_buffer + bufsize, FILL_CHAR, BUF_SIZE + PAD_SIZE - bufsize)) { + pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond buffer\n", bufsize, fmt); + return 1; + } + if (memcmp(test_buffer, expect, written)) { pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n", bufsize, fmt, test_buffer, written, expect); From patchwork Tue Jun 15 15:49:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin He X-Patchwork-Id: 12322253 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42C8CC48BE8 for ; Tue, 15 Jun 2021 15:52:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E367614A7 for ; Tue, 15 Jun 2021 15:52:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232404AbhFOPyF (ORCPT ); Tue, 15 Jun 2021 11:54:05 -0400 Received: from foss.arm.com ([217.140.110.172]:39130 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231766AbhFOPw3 (ORCPT ); Tue, 15 Jun 2021 11:52:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 71922143D; Tue, 15 Jun 2021 08:50:24 -0700 (PDT) Received: from entos-ampere-02.shanghai.arm.com (entos-ampere-02.shanghai.arm.com [10.169.214.103]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C1CAC3F694; Tue, 15 Jun 2021 08:50:19 -0700 (PDT) From: Jia He To: Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Jonathan Corbet , Alexander Viro , Linus Torvalds Cc: "Peter Zijlstra (Intel)" , Eric Biggers , "Ahmed S. Darwish" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Matthew Wilcox , Jia He Subject: [PATCH RFCv4 4/4] lib/test_printf.c: add test cases for '%pD' Date: Tue, 15 Jun 2021 23:49:52 +0800 Message-Id: <20210615154952.2744-5-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210615154952.2744-1-justin.he@arm.com> References: <20210615154952.2744-1-justin.he@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org After the behaviour of specifier '%pD' is changed to print full path of struct file, the related test cases are also updated. Given the string of '%pD' is prepended from the end of the buffer, the check of "wrote beyond the nul-terminator" should be skipped. Signed-off-by: Jia He --- lib/test_printf.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/lib/test_printf.c b/lib/test_printf.c index d1d2f898ebae..9f851a82b3af 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -16,6 +16,7 @@ #include #include +#include #include #include @@ -34,6 +35,7 @@ KSTM_MODULE_GLOBALS(); static char *test_buffer __initdata; static char *alloced_buffer __initdata; +static bool is_prepended_buf __initdata; extern bool no_hash_pointers; @@ -78,7 +80,7 @@ do_test(int bufsize, const char *expect, int elen, return 1; } - if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) { + if (!is_prepended_buf && memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) { pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n", bufsize, fmt); return 1; @@ -501,6 +503,27 @@ dentry(void) test(" bravo/alfa| bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]); } +static struct vfsmount test_vfsmnt __initdata = {}; + +static struct file test_file __initdata = { + .f_path = { .dentry = &test_dentry[2], + .mnt = &test_vfsmnt, + }, +}; + +static void __init +f_d_path(void) +{ + test("(null)", "%pD", NULL); + test("(efault)", "%pD", PTR_INVALID); + + is_prepended_buf = true; + test("/bravo/alfa |/bravo/alfa ", "%-14pD|%*pD", &test_file, -14, &test_file); + test(" /bravo/alfa| /bravo/alfa", "%14pD|%*pD", &test_file, 14, &test_file); + test(" /bravo/alfa|/bravo/alfa ", "%14pD|%-14pD", &test_file, &test_file); + is_prepended_buf = false; +} + static void __init struct_va_format(void) { @@ -784,6 +807,7 @@ test_pointer(void) ip(); uuid(); dentry(); + f_d_path(); struct_va_format(); time_and_date(); struct_clk();