#
68279f9c |
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11-Oct-2023 |
Alexey Dobriyan <adobriyan@gmail.com> |
treewide: mark stuff as __ro_after_init __read_mostly predates __ro_after_init. Many variables which are marked __read_mostly should have been __ro_after_init from day 1. Also, mark some stuff as "const" and "__init" while I'm at it. [akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning] [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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#
e311ba29 |
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13-Oct-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
chardev: Simplify usage of try_module_get() try_module_get(NULL) is true, so there is no need to check owner being NULL. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231013132441.1406200-2-u.kleine-koenig@pengutronix.de Signed-off-by: Christian Brauner <brauner@kernel.org>
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#
c642256b |
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10-May-2023 |
Azeem Shaikh <azeemshaikh38@gmail.com> |
vfs: Replace all non-returning strlcpy with strscpy strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Message-Id: <20230510221119.3508930-1-azeemshaikh38@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
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#
11fa7fef |
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01-Dec-2022 |
Yang Yingliang <yangyingliang@huawei.com> |
chardev: fix error handling in cdev_device_add() While doing fault injection test, I got the following report: ------------[ cut here ]------------ kobject: '(null)' (0000000039956980): is not initialized, yet kobject_put() is being called. WARNING: CPU: 3 PID: 6306 at kobject_put+0x23d/0x4e0 CPU: 3 PID: 6306 Comm: 283 Tainted: G W 6.1.0-rc2-00005-g307c1086d7c9 #1253 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:kobject_put+0x23d/0x4e0 Call Trace: <TASK> cdev_device_add+0x15e/0x1b0 __iio_device_register+0x13b4/0x1af0 [industrialio] __devm_iio_device_register+0x22/0x90 [industrialio] max517_probe+0x3d8/0x6b4 [max517] i2c_device_probe+0xa81/0xc00 When device_add() is injected fault and returns error, if dev->devt is not set, cdev_add() is not called, cdev_del() is not needed. Fix this by checking dev->devt in error path. Fixes: 233ed09d7fda ("chardev: add helper function to register char devs with a struct device") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20221202030237.520280-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4634c973 |
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02-Nov-2022 |
Shang XiaoJing <shangxiaojing@huawei.com> |
chardev: Fix potential memory leak when cdev_add() failed Some init function of cdev(like comedi) will call kobject_set_name() before cdev_add(), but won't free the cdev.kobj.name or put the ref cnt of cdev.kobj when cdev_add() failed. As the result, cdev.kobj.name will be leaked. Free the name of kobject in cdev_add() fail path to prevent memleak. With this fix, the callers don't need to care about freeing the name of kobject if cdev_add() fails. unreferenced object 0xffff8881000fa8c0 (size 8): comm "modprobe", pid 239, jiffies 4294905173 (age 51.308s) hex dump (first 8 bytes): 63 6f 6d 65 64 69 00 ff comedi.. backtrace: [<000000005f9878f7>] __kmalloc_node_track_caller+0x4c/0x1c0 [<000000000fd70302>] kstrdup+0x3f/0x70 [<000000009428bc33>] kstrdup_const+0x46/0x60 [<00000000ed50d9de>] kvasprintf_const+0xdb/0xf0 [<00000000b2766964>] kobject_set_name_vargs+0x3c/0xe0 [<00000000f2424ef7>] kobject_set_name+0x62/0x90 [<000000005d5a125b>] 0xffffffffa0013098 [<00000000f331e663>] do_one_initcall+0x7a/0x380 [<00000000aa7bac96>] do_init_module+0x5c/0x230 [<000000005fd72335>] load_module+0x227d/0x2420 [<00000000ad550cf1>] __do_sys_finit_module+0xd5/0x140 [<00000000069a60c5>] do_syscall_64+0x3f/0x90 [<00000000c5e0d521>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Suggested-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Link: https://lore.kernel.org/r/20221102072659.23671-1-shangxiaojing@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a3c751a5 |
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14-May-2020 |
Miklos Szeredi <mszeredi@redhat.com> |
vfs: allow unprivileged whiteout creation Whiteouts, unlike real device node should not require privileges to create. The general concern with device nodes is that opening them can have side effects. The kernel already avoids zero major (see Documentation/admin-guide/devices.txt). To be on the safe side the patch explicitly forbids registering a char device with 0/0 number (see cdev_add()). This guarantees that a non-O_PATH open on a whiteout will fail with ENODEV; i.e. it won't have any side effect. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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#
68faa679 |
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18-Dec-2019 |
Will Deacon <will@kernel.org> |
chardev: Avoid potential use-after-free in 'chrdev_open()' 'chrdev_open()' calls 'cdev_get()' to obtain a reference to the 'struct cdev *' stashed in the 'i_cdev' field of the target inode structure. If the pointer is NULL, then it is initialised lazily by looking up the kobject in the 'cdev_map' and so the whole procedure is protected by the 'cdev_lock' spinlock to serialise initialisation of the shared pointer. Unfortunately, it is possible for the initialising thread to fail *after* installing the new pointer, for example if the subsequent '->open()' call on the file fails. In this case, 'cdev_put()' is called, the reference count on the kobject is dropped and, if nobody else has taken a reference, the release function is called which finally clears 'inode->i_cdev' from 'cdev_purge()' before potentially freeing the object. The problem here is that a racing thread can happily take the 'cdev_lock' and see the non-NULL pointer in the inode, which can result in a refcount increment from zero and a warning: | ------------[ cut here ]------------ | refcount_t: addition on 0; use-after-free. | WARNING: CPU: 2 PID: 6385 at lib/refcount.c:25 refcount_warn_saturate+0x6d/0xf0 | Modules linked in: | CPU: 2 PID: 6385 Comm: repro Not tainted 5.5.0-rc2+ #22 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 | RIP: 0010:refcount_warn_saturate+0x6d/0xf0 | Code: 05 55 9a 15 01 01 e8 9d aa c8 ff 0f 0b c3 80 3d 45 9a 15 01 00 75 ce 48 c7 c7 00 9c 62 b3 c6 08 | RSP: 0018:ffffb524c1b9bc70 EFLAGS: 00010282 | RAX: 0000000000000000 RBX: ffff9e9da1f71390 RCX: 0000000000000000 | RDX: ffff9e9dbbd27618 RSI: ffff9e9dbbd18798 RDI: ffff9e9dbbd18798 | RBP: 0000000000000000 R08: 000000000000095f R09: 0000000000000039 | R10: 0000000000000000 R11: ffffb524c1b9bb20 R12: ffff9e9da1e8c700 | R13: ffffffffb25ee8b0 R14: 0000000000000000 R15: ffff9e9da1e8c700 | FS: 00007f3b87d26700(0000) GS:ffff9e9dbbd00000(0000) knlGS:0000000000000000 | CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 | CR2: 00007fc16909c000 CR3: 000000012df9c000 CR4: 00000000000006e0 | DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 | DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 | Call Trace: | kobject_get+0x5c/0x60 | cdev_get+0x2b/0x60 | chrdev_open+0x55/0x220 | ? cdev_put.part.3+0x20/0x20 | do_dentry_open+0x13a/0x390 | path_openat+0x2c8/0x1470 | do_filp_open+0x93/0x100 | ? selinux_file_ioctl+0x17f/0x220 | do_sys_open+0x186/0x220 | do_syscall_64+0x48/0x150 | entry_SYSCALL_64_after_hwframe+0x44/0xa9 | RIP: 0033:0x7f3b87efcd0e | Code: 89 54 24 08 e8 a3 f4 ff ff 8b 74 24 0c 48 8b 3c 24 41 89 c0 44 8b 54 24 08 b8 01 01 00 00 89 f4 | RSP: 002b:00007f3b87d259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 | RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b87efcd0e | RDX: 0000000000000000 RSI: 00007f3b87d25a80 RDI: 00000000ffffff9c | RBP: 00007f3b87d25e90 R08: 0000000000000000 R09: 0000000000000000 | R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe188f504e | R13: 00007ffe188f504f R14: 00007f3b87d26700 R15: 0000000000000000 | ---[ end trace 24f53ca58db8180a ]--- Since 'cdev_get()' can already fail to obtain a reference, simply move it over to use 'kobject_get_unless_zero()' instead of 'kobject_get()', which will cause the racing thread to return -ENXIO if the initialising thread fails unexpectedly. Cc: Hillf Danton <hdanton@sina.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Reported-by: syzbot+82defefbbd8527e1c2cb@syzkaller.appspotmail.com Signed-off-by: Will Deacon <will@kernel.org> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191219120203.32691-1-will@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
7ef0b152 |
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02-May-2019 |
Chengguang Xu <cgxu519@gmail.com> |
chardev: set variable ret to -EBUSY before checking minor range overlap When allocating dynamic major, the minor range overlap check in __register_chrdev_region() will not fail, so actually there is no real case to passing non negative error code to caller. However, set variable ret to -EBUSY before checking minor range overlap will avoid false-positive warning from code analyzing tool(like Smatch) and also make the code more easy to understand. Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chengguang Xu <cgxu519@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d358b173 |
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15-Feb-2019 |
Chengguang Xu <cgxu519@gmx.com> |
chardev: update comment based on the code The function comment of __register_chrdev_region() is out of date, so update it based on the code. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4b0be572 |
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15-Feb-2019 |
Chengguang Xu <cgxu519@gmx.com> |
chardev: code cleanup for __register_chrdev_region() It's just code cleanup, not functional change. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
4712d379 |
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15-Feb-2019 |
Chengguang Xu <cgxu519@gmx.com> |
chardev: add a check for given minor range register_chrdev_region() carefully checks minor range before calling __register_chrdev_region() but there is another path from alloc_chrdev_region() which does not check the range properly. So add a check for given minor range in __register_chrdev_region(). Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
de36e16d |
|
15-Feb-2019 |
Chengguang Xu <cgxu519@gmx.com> |
chardev: add additional check for minor range overlap Current overlap checking cannot correctly handle a case which is baseminor < existing baseminor && baseminor + minorct > existing baseminor + minorct. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
f33ff110 |
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05-Feb-2018 |
Srivatsa S. Bhat <srivatsa@csail.mit.edu> |
block, char_dev: Use correct format specifier for unsigned ints register_blkdev() and __register_chrdev_region() treat the major number as an unsigned int. So print it the same way to avoid absurd error statements such as: "... major requested (-1) is greater than the maximum (511) ..." (and also fix off-by-one bugs in the error prints). While at it, also update the comment describing register_blkdev(). Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
652d703b |
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05-Feb-2018 |
Srivatsa S. Bhat <srivatsa@csail.mit.edu> |
char_dev: Fix off-by-one bugs in find_dynamic_major() CHRDEV_MAJOR_DYN_END and CHRDEV_MAJOR_DYN_EXT_END are valid major numbers. So fix the loop iteration to include them in the search for free major numbers. While at it, also remove a redundant if condition ("cd->major != i"), as it will never be true. Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b2441318 |
|
01-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
8a932f73 |
|
15-Jun-2017 |
Logan Gunthorpe <logang@deltatee.com> |
char_dev: order /proc/devices by major number Presently, the order of the char devices listed in /proc/devices is not entirely sequential. If a char device has a major number greater than CHRDEV_MAJOR_HASH_SIZE (255), it will be ordered as if its major were module 255. For example, 511 appears after 1. This patch cleans that up and prints each major number in the correct order, regardless of where they are stored in the hash table. In order to do this, we introduce CHRDEV_MAJOR_MAX as an artificial limit (chosen to be 511). It will then print all devices in major order number from 0 to the maximum. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
a5d31a3f |
|
15-Jun-2017 |
Logan Gunthorpe <logang@deltatee.com> |
char_dev: extend dynamic allocation of majors into a higher range We've run into problems with running out of dynamicly assign char device majors particullarly on automated test systems with all-yes-configs. Roughly 40 dynamic assignments can be made with such kernels at this time while space is reserved for only 20. Currently, the kernel only prints a warning when dynamic allocation overflows the reserved region. And when this happens drivers that have fixed assignments can randomly fail depending on the order of initialization of other drivers. Thus, adding a new char device can cause unexpected failures in completely unrelated parts of the kernel. This patch solves the problem by extending dynamic major number allocations down from 511 once the 234-254 region fills up. Fixed majors already exist above 255 so the infrastructure to support high number majors is already in place. The patch reserves an additional 128 major numbers which should hopefully last us a while. Kernels that don't require more than 20 dynamic majors assigned (which is pretty typical) should not be affected by this change. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Linus Walleij <linus.walleij@linaro.org> Link: https://lkml.org/lkml/2017/6/4/107 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
233ed09d |
|
17-Mar-2017 |
Logan Gunthorpe <logang@deltatee.com> |
chardev: add helper function to register char devs with a struct device Credit for this patch goes is shared with Dan Williams [1]. I've taken things one step further to make the helper function more useful and clean up calling code. There's a common pattern in the kernel whereby a struct cdev is placed in a structure along side a struct device which manages the life-cycle of both. In the naive approach, the reference counting is broken and the struct device can free everything before the chardev code is entirely released. Many developers have solved this problem by linking the internal kobjs in this fashion: cdev.kobj.parent = &parent_dev.kobj; The cdev code explicitly gets and puts a reference to it's kobj parent. So this seems like it was intended to be used this way. Dmitrty Torokhov first put this in place in 2012 with this commit: 2f0157f char_dev: pin parent kobject and the first instance of the fix was then done in the input subsystem in the following commit: 4a215aa Input: fix use-after-free introduced with dynamic minor changes Subsequently over the years, however, this issue seems to have tripped up multiple developers independently. For example, see these commits: 0d5b7da iio: Prevent race between IIO chardev opening and IIO device (by Lars-Peter Clausen in 2013) ba0ef85 tpm: Fix initialization of the cdev (by Jason Gunthorpe in 2015) 5b28dde [media] media: fix use-after-free in cdev_put() when app exits after driver unbind (by Shauh Khan in 2016) This technique is similarly done in at least 15 places within the kernel and probably should have been done so in another, at least, 5 places. The kobj line also looks very suspect in that one would not expect drivers to have to mess with kobject internals in this way. Even highly experienced kernel developers can be surprised by this code, as seen in [2]. To help alleviate this situation, and hopefully prevent future wasted effort on this problem, this patch introduces a helper function to register a char device along with its parent struct device. This creates a more regular API for tying a char device to its parent without the developer having to set members in the underlying kobject. This patch introduce cdev_device_add and cdev_device_del which replaces a common pattern including setting the kobj parent, calling cdev_add and then calling device_add. It also introduces cdev_set_parent for the few cases that set the kobject parent without using device_add. [1] https://lkml.org/lkml/2017/2/13/700 [2] https://lkml.org/lkml/2017/2/10/370 Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
3bc52c45 |
|
24-Jul-2016 |
Dan Williams <dan.j.williams@intel.com> |
dax: define a unified inode/address_space for device-dax mappings In support of enabling resize / truncate of device-dax instances, define a pseudo-fs to provide a unified inode/address space for vm operations. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#
077e2642 |
|
12-Jul-2016 |
Fengguang Wu <fengguang.wu@intel.com> |
chardev: add missing line break in pr_warn To fix super long dmesg error lines like CHRDEV "dummy_stm.0" major number 224 goes below the dynamic allocation rangeCHRDEV "dummy_stm.1" major number 223 goes below the dynamic allocation rangeswapper: page allocation failure: order:8, mode:0x26040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK) After fix, it should look like CHRDEV "dummy_stm.0" major number 224 goes below the dynamic allocation range CHRDEV "dummy_stm.1" major number 223 goes below the dynamic allocation range swapper: page allocation failure: order:8, mode:0x26040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK) Reported-by: Philip Li <philip.li@intel.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
49db08c3 |
|
19-Feb-2016 |
Linus Walleij <linus.walleij@linaro.org> |
chrdev: emit a warning when we go below dynamic major range Currently a dynamically allocated character device major is taken from 254 and downward. This mechanism is used for RTC, IIO and a few other subsystems. The kernel currently has no check prevening these dynamic allocations from eating into the assigned numbers at 233 and downward. In a recent test it was reported that so many dynamic device majors were used on a test server, that the major number for infiniband (231) was stolen. This occurred when allocating a new major number for GPIO chips. The error messages from the kernel were not helpful. (See: https://lkml.org/lkml/2016/2/14/124) This patch adds a defined lower limit of the dynamic major allocation region will henceforth emit a warning if we start to eat into the assigned numbers. It does not do any semantic changes and will not change the kernels behaviour: numbers will still continue to be stolen, but we will know from dmesg what is going on. This also updates the Documentation/devices.txt to clearly reflect that we are using this range of major numbers for dynamic allocation. Reported-by: Ying Huang <ying.huang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
594069bc |
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27-Jul-2015 |
Partha Pratim Mukherjee <ppm.floss@gmail.com> |
fs/char_dev.c: fix incorrect documentation for unregister_chrdev_region The current documentation for unregister_chrdev_region says that it return a range of device numbers which is incorrect. Instead it unregister a range of device numbers. Fix the documentation to make this clear. Signed-off-by: Partha Pratim Mukherjee <ppm.floss@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b4caecd4 |
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14-Jan-2015 |
Christoph Hellwig <hch@lst.de> |
fs: introduce f_op->mmap_capabilities for nommu mmap support Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
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#
e2ab879e |
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10-Dec-2014 |
Jan Kara <jack@suse.cz> |
fs/char_dev.c: remove pointless assignment from __register_chrdev_region() At one place we assign major number we found to ret. That assignment is then never used and actually doesn't make any sense given how the code is currently structured (the assignment comes from pre-git times). Just remove it. Coverity id: 1226852. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
8077c0d9 |
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13-Oct-2013 |
Mikulas Patocka <mpatocka@redhat.com> |
bdi: test bdi_init failure There were two places where return value from bdi_init was not tested. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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#
e84f9e57 |
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22-Sep-2013 |
Al Viro <viro@zeniv.linux.org.uk> |
consolidate the reassignments of ->f_op in ->open() instances Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
2f0157f1 |
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21-Oct-2012 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
char_dev: pin parent kobject In certain cases (for example when a cdev structure is embedded into another object whose lifetime is controlled by a separate kobject) it is beneficial to tie lifetime of another object to the lifetime of character device so that related object is not freed until after char_dev object is freed. To achieve this let's pin kobject's parent when doing cdev_add() and unpin when last reference to cdev structure is being released. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
1ff97647 |
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13-Dec-2011 |
Greg Kroah-Hartman <gregkh@suse.de> |
char_dev.c: fix up some whitespace errors Remove some minor whitespace errors (2 trailing spaces, and one space needed for a comma) to make the file checkpatch.pl clean with the exception of the exports, which is fine for now. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
e6d7202b |
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12-Jan-2011 |
Namhyung Kim <namhyung@gmail.com> |
fs/char_dev.c: remove unused cdev_index() Commit 66fa12c571d3 ("ieee1394: remove the old IEEE 1394 driver stack") eliminated the only user of cdev_index(). So it can be removed too. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
e61eb2e9 |
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17-Dec-2010 |
Yang Zhang <kthreadd@gmail.com> |
fs/block: type signature of major_to_index(int) to major_to_index(unsigned) The major/minor device numbers are always defined and used as `unsigned'. Signed-off-by: Yang Zhang <kthreadd@gmail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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#
6038f373 |
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15-Aug-2010 |
Arnd Bergmann <arnd@arndb.de> |
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
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371d217e |
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21-Sep-2010 |
Jan Kara <jack@suse.cz> |
char: Mark /dev/zero and /dev/kmem as not capable of writeback These devices don't do any writeback but their device inodes still can get dirty so mark bdi appropriately so that bdi code does the right thing and files inodes to lists of bdi carrying the device inodes. Cc: stable@kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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#
31d1d48e |
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06-Aug-2010 |
David Howells <dhowells@redhat.com> |
Fix init ordering of /dev/console vs callers of modprobe Make /dev/console get initialised before any initialisation routine that invokes modprobe because if modprobe fails, it's going to want to open /dev/console, presumably to write an error message to. The problem with that is that if the /dev/console driver is not yet initialised, the chardev handler will call request_module() to invoke modprobe, which will fail, because we never compile /dev/console as a module. This will lead to a modprobe loop, showing the following in the kernel log: request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 This can happen, for example, when the built in md5 module can't find the built in cryptomgr module (because the latter fails to initialise). The md5 module comes before the call to tty_init(), presumably because 'crypto' comes before 'drivers' alphabetically. Fix this by calling tty_init() from chrdev_init(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
dd5d81f3 |
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23-Sep-2009 |
Renzo Davoli <renzo@cs.unibo.it> |
fs/char_dev.c: remove useless loop There are two useless lines in fs/char_dev.c. In register_chrdev there is a loop to change all '/' into '!' in the kernel object name. This code is useless as the same substitution is in kobject_set_name_vargs in lib/kobject.c: 228 /* ewww... some of these buggers have '/' in the name ... */ 229 while ((s = strchr(kobj->name, '/'))) 230 s[0] = '!'; kobject_set_name_vargs is called by kobject_set_name. kobject_set_name is called just above the useless loop. [hidave.darkstar@gmail.com: fix warning, remove the unused char *s] Signed-off-by: Renzo Davoli <renzo@cs.unibo.it> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
d993831f |
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12-Jun-2009 |
Jens Axboe <jens.axboe@oracle.com> |
writeback: add name to backing_dev_info This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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1905b1bf |
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06-Aug-2009 |
Tejun Heo <tj@kernel.org> |
chrdev: implement __[un]register_chrdev() [un]register_chrdev() assume minor range 0-255. This patch adds __ prefixed versions which take @minorbase and @count explicitly. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
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#
405f5571 |
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11-Jul-2009 |
Alexey Dobriyan <adobriyan@gmail.com> |
headers: smp_lock.h redux * Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
9fd5746f |
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21-May-2009 |
Theodore Ts'o <tytso@mit.edu> |
fs: Remove i_cindex from struct inode The only user of the i_cindex element in the inode structure is used is by the firewire drivers. As part of an attempt to slim down the inode structure to save memory --- since a typical Linux system will have hundreds of thousands if not millions of inodes cached, a reduction in the size inode has high leverage. The firewire driver does not need i_cindex in any fast path, so it's simple enough to calculate when it is needed, instead of wasting space in the inode structure. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: krh@redhat.com Cc: stefanr@s5r6.in-berlin.de Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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8c401888 |
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06-Jan-2009 |
Cyrill Gorcunov <gorcunov@gmail.com> |
fs: fix name overwrite in __register_chrdev_region() It's possible to register a chrdev with a name size exactly the same as was allocated in structure. It seems it was not intended behaviour. At least chrdev_show does not like it. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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a518ab93 |
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11-Aug-2008 |
Christoph Hellwig <hch@lst.de> |
[PATCH] tidy up chrdev_open Use a single goto label for chrdev_put + return error cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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5f4123be |
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09-Jul-2008 |
Johannes Berg <johannes@sipsolutions.net> |
remove CONFIG_KMOD from fs Just always compile the code when the kernel is modular. Convert load_nls to use try_then_request_module to tidy up the code. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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9514dff9 |
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18-May-2008 |
Jonathan Corbet <corbet@lwn.net> |
Remove the lock_kernel() call from chrdev_open() All in-kernel char device open() functions now either have their own lock_kernel() calls or clearly do not need one. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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a30427d9 |
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18-May-2008 |
Jonathan Corbet <corbet@lwn.net> |
Add a comment in chrdev_open() I stared at this code for a while and almost deleted it before understanding crept into my slow brain. Hopefully this makes life easier for the next person to happen on it. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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61d64576 |
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29-Apr-2008 |
Jiri Olsa <olsajiri@gmail.com> |
fs: remove unused fops from struct char_device_struct struct char_device_struct::fops is no longer used: remove it. Signed-off-by: Jiri Olsa <olsajiri@gmail.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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922f9cfa |
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08-Feb-2008 |
Denis Cheng <crquan@gmail.com> |
fs/char_dev.c: chrdev_open marked static and removed from fs.h There is an outdated comment in serial_core.c also fixed. Signed-off-by: Denis Cheng <crquan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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f9cb074b |
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17-Dec-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Kobject: rename kobject_init_ng() to kobject_init() Now that the old kobject_init() function is gone, rename kobject_init_ng() to kobject_init() to clean up the namespace. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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a5815ddf |
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17-Dec-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Kobject: convert fs/char_dev.c to use kobject_init/add_ng() This converts the code to use the new kobject functions, cleaning up the logic in doing so. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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e0bf68dd |
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17-Oct-2007 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
mm: bdi init hooks provide BDI constructor/destructor hooks [akpm@linux-foundation.org: compile fix] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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e53252d9 |
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19-Jul-2007 |
Akinobu Mita <akinobu.mita@gmail.com> |
unregister_chrdev() return void unregister_chrdev() does not return meaningful value. This patch makes it return void like most unregister_* functions. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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2363cc02 |
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04-Apr-2007 |
Andrew Morton <akpm@linux-foundation.org> |
[PATCH] remove protection of LANANA-reserved majors Revert all this. It can cause device-mapper to receive a different major from earlier kernels and it turns out that the Amanda backup program (via GNU tar, apparently) checks major numbers on files when performing incremental backups. Which is a bit broken of Amanda (or tar), but this feature isn't important enough to justify the churn. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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b446b60e |
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20-Feb-2007 |
Andrew Morton <akpm@linux-foundation.org> |
[PATCH] rework reserved major handling Several people have reported failures in dynamic major device number handling due to the recent changes in there to avoid handing out the local/experimental majors. Rolf reports that this is due to a gcc-4.1.0 bug. The patch refactors that code a lot in an attempt to provoke the compiler into behaving. Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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215122e1 |
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12-Feb-2007 |
Andrew Morton <akpm@osdl.org> |
[PATCH] register_chrdev_region() don't hand out the LOCAL/EXPERIMENTAL majors As pointed out in http://bugzilla.kernel.org/show_bug.cgi?id=7922, dynamic chardev major allocation can hand out majors which LANANA has defined as being for local/experimental use. Cc: Torben Mathiasen <device@lanana.org> Cc: Greg KH <greg@kroah.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Tomas Klas <tomas.klas@mepatek.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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07f3f05c |
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30-Sep-2006 |
David Howells <dhowells@redhat.com> |
[PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6] Create a new header file, fs/internal.h, for common definitions local to the sources in the fs/ directory. Move extern definitions that should be in header files from fs/*.c to fs/internal.h or other main header files where they span directories. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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cf3e43db |
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29-Sep-2006 |
Jonathan Corbet <corbet@lwn.net> |
[PATCH] cdev documentation Add some documentation comments for the cdev interface. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Acked-by: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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01d553d0 |
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29-Sep-2006 |
Amos Waterland <apw@us.ibm.com> |
[PATCH] Chardev checking of overlapping ranges The code in __register_chrdev_region checks that if the driver wishing to register has the same major as an existing driver the new minor range is strictly less than the existing minor range. However, it does not also check that the new minor range is strictly greater than the existing minor range. That is, if driver X has registered with major=x and minor=0-3, __register_chrdev_region will allow driver Y to register with major=x and minor=1-4. Signed-off-by: Amos Waterland <apw@us.ibm.com> Cc: Linas Vepstas <linas@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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5da6185b |
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27-Sep-2006 |
David Howells <dhowells@redhat.com> |
[PATCH] NOMMU: Set BDI capabilities for /dev/mem and /dev/kmem Set the backing device info capabilities for /dev/mem and /dev/kmem to permit direct sharing under no-MMU conditions and full mapping capabilities under MMU conditions. Make the BDI used by these available to all directly mappable character devices. Also comment the capabilities for /dev/zero. [akpm@osdl.org: ifdef reductions] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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d247e2c6 |
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14-Jul-2006 |
Rolf Eike Beer <eike-kernel@sf-tec.de> |
[PATCH] add function documentation for register_chrdev() Documentation for register_chrdev() was missing completely. [akpm@osdl.org: kerneldocification] Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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6ab3d562 |
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30-Jun-2006 |
Jörn Engel <joern@wohnheim.fh-wedel.de> |
Remove obsolete #include <linux/config.h> Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
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ff23eca3 |
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20-Jun-2005 |
Greg Kroah-Hartman <gregkh@suse.de> |
[PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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68eef3b4 |
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31-Mar-2006 |
Joe Korty <joe.korty@ccur.com> |
[PATCH] Simplify proc/devices and fix early termination regression Make baby-simple the code for /proc/devices. Based on the proven design for /proc/interrupts. This also fixes the early-termination regression 2.6.16 introduced, as demonstrated by: # dd if=/proc/devices bs=1 Character devices: 1 mem 27+0 records in 27+0 records out This should also work (but is untested) when /proc/devices >4096 bytes, which I believe is what the original 2.6.16 rewrite fixed. [akpm@osdl.org: cleanups, simplifications] Signed-off-by: Joe Korty <joe.korty@ccur.com> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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4b6f5d20 |
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28-Mar-2006 |
Arjan van de Ven <arjan@infradead.org> |
[PATCH] Make most file operations structs in fs/ const This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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99ac48f5 |
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28-Mar-2006 |
Arjan van de Ven <arjan@infradead.org> |
[PATCH] mark f_ops const in the inode Mark the f_ops members of inodes as const, as well as fix the ripple-through this causes by places that copy this f_ops and then "do stuff" with it. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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11b0b5ab |
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25-Mar-2006 |
Oliver Neukum <neukum@fachschaft.cup.uni-muenchen.de> |
[PATCH] use kzalloc and kcalloc in core fs code Signed-off-by: Oliver Neukum <oliver@neukum.name> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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58383af6 |
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06-Feb-2006 |
Jes Sorensen <jes@sgi.com> |
[PATCH] kobj_map semaphore to mutex conversion Convert the kobj_map code to use a mutex instead of a semaphore. It converts the single two users as well, genhd.c and char_dev.c. Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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7170be5f |
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14-Jan-2006 |
Neil Horman <nhorman@redhat.com> |
[PATCH] convert /proc/devices to use seq_file interface A Christoph suggested that the /proc/devices file be converted to use the seq_file interface. This patch does that. I've obxerved one or two installation that had sufficiently large sans that they overran the 4k limit on /proc/devices. Signed-off-by: Neil Horman <nhorman@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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7da6844c |
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12-Jul-2005 |
Brian King <brking@us.ibm.com> |
[PATCH] cdev: cdev_put oops While fixing an oops in the st driver in a dirty release path, I encountered an oops in cdev_put for cdevs allocated using cdev_alloc. If cdev_del is called when the cdev kobject still has an open user, when the last cdev_put is called, the cdev_put will call kobject_put, which will end up ultimately releasing the cdev in cdev_dynamic_release. Patch fixes the oops by preventing cdev_put from accessing freed memory. Signed-off-by: Brian King <brking@us.ibm.com> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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8d451687 |
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28-Jun-2005 |
Wen-chien Jesse Sung <jesse@cola.voip.idv.tw> |
[PATCH] fix semaphore handling in __unregister_chrdev_region This up() should be down() instead. Signed-off-by: Wen-chien Jesse Sung <jesse@cola.voip.idv.tw> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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ac20427e |
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23-Jun-2005 |
Neil Horman <nhorman@redhat.com> |
[PATCH] add check to /proc/devices read routines Patch to add check to get_chrdev_list and get_blkdev_list to prevent reads of /proc/devices from spilling over the provided page if more than 4096 bytes of string data are generated from all the registered character and block devices in a system Signed-off-by: Neil Horman <nhorman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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75c96f85 |
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05-May-2005 |
Adrian Bunk <bunk@stusta.de> |
[PATCH] make some things static This patch makes some needlessly global identifiers static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Arjan van de Ven <arjanv@infradead.org> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1d4d5b32 |
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17-Apr-2005 |
David Brownell <david-b@pacbell.net> |
[PATCH] revert fs/char_dev.c CONFIG_BASE_FULL change This reverts a fs/char_dev.c patch that was merged into BK on March 3. The problem is that it breaks things ... __register_chrdev_region() has a block of code, commented "temporary" for over two years now, which fails rudely during PCMCIA initialization or other register_chrdev() calls, because it doesn't "degrade to linked list". This keeps whole subsystems from working. A real fix to that "temporary" code should be possible, using some better scheme to allocate major numbers, but it's not something I want to spend time on just now. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1da177e4 |
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16-Apr-2005 |
Linus Torvalds <torvalds@ppc970.osdl.org> |
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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