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2020-08-15all arch: remove system call sys_sysctlXiaoming Ni1-4/+2
Since commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"), sys_sysctl is actually unavailable: any input can only return an error. We have been warning about people using the sysctl system call for years and believe there are no more users. Even if there are users of this interface if they have not complained or fixed their code by now they probably are not going to, so there is no point in warning them any longer. So completely remove sys_sysctl on all architectures. [nixiaoming@huawei.com: s390: fix build error for sys_call_table_emu] Link: http://lkml.kernel.org/r/20200618141426.16884-1-nixiaoming@huawei.com Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Will Deacon <will@kernel.org> [arm/arm64] Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bin Meng <bin.meng@windriver.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: chenzefeng <chenzefeng2@huawei.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christian Brauner <christian@brauner.io> Cc: Chris Zankel <chris@zankel.net> Cc: David Howells <dhowells@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Diego Elio Pettenò <flameeyes@flameeyes.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kars de Jong <jongk@linux-m68k.org> Cc: Kees Cook <keescook@chromium.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Olof Johansson <olof@lixom.net> Cc: Paul Burton <paulburton@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Sven Schnelle <svens@stackframe.org> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zhou Yanjie <zhouyanjie@wanyeetech.com> Link: http://lkml.kernel.org/r/20200616030734.87257-1-nixiaoming@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08kernel/sysctl: support setting sysctl parameters from kernel command lineVlastimil Babka1-0/+4
Patch series "support setting sysctl parameters from kernel command line", v3. This series adds support for something that seems like many people always wanted but nobody added it yet, so here's the ability to set sysctl parameters via kernel command line options in the form of sysctl.vm.something=1 The important part is Patch 1. The second, not so important part is an attempt to clean up legacy one-off parameters that do the same thing as a sysctl. I don't want to remove them completely for compatibility reasons, but with generic sysctl support the idea is to remove the one-off param handlers and treat the parameters as aliases for the sysctl variants. I have identified several parameters that mention sysctl counterparts in Documentation/admin-guide/kernel-parameters.txt but there might be more. The conversion also has varying level of success: - numa_zonelist_order is converted in Patch 2 together with adding the necessary infrastructure. It's easy as it doesn't really do anything but warn on deprecated value these days. - hung_task_panic is converted in Patch 3, but there's a downside that now it only accepts 0 and 1, while previously it was any integer value - nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic, so there's no straighforward conversion possible - traceoff_on_warning is a flag without value and it would be required to handle that somehow in the conversion infractructure, which seems pointless for a single flag This patch (of 5): A recently proposed patch to add vm_swappiness command line parameter in addition to existing sysctl [1] made me wonder why we don't have a general support for passing sysctl parameters via command line. Googling found only somebody else wondering the same [2], but I haven't found any prior discussion with reasons why not to do this. Settings the vm_swappiness issue aside (the underlying issue might be solved in a different way), quick search of kernel-parameters.txt shows there are already some that exist as both sysctl and kernel parameter - hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning. A general mechanism would remove the need to add more of those one-offs and might be handy in situations where configuration by e.g. /etc/sysctl.d/ is impractical. Hence, this patch adds a new parse_args() pass that looks for parameters prefixed by 'sysctl.' and tries to interpret them as writes to the corresponding sys/ files using an temporary in-kernel procfs mount. This mechanism was suggested by Eric W. Biederman [3], as it handles all dynamically registered sysctl tables, even though we don't handle modular sysctls. Errors due to e.g. invalid parameter name or value are reported in the kernel log. The processing is hooked right before the init process is loaded, as some handlers might be more complicated than simple setters and might need some subsystems to be initialized. At the moment the init process can be started and eventually execute a process writing to /proc/sys/ then it should be also fine to do that from the kernel. Sysctls registered later on module load time are not set by this mechanism - it's expected that in such scenarios, setting sysctl values from userspace is practical enough. [1] https://lore.kernel.org/r/BL0PR02MB560167492CA4094C91589930E9FC0@BL0PR02MB5601.namprd02.prod.outlook.com/ [2] https://unix.stackexchange.com/questions/558802/how-to-set-sysctl-using-kernel-command-line-parameter [3] https://lore.kernel.org/r/87bloj2skm.fsf@x220.int.ebiederm.org/ Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Christian Brauner <christian.brauner@ubuntu.com> Link: http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz Link: http://lkml.kernel.org/r/20200427180433.7029-2-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig1-31/+22
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27sysctl: remove all extern declaration from sysctl.cChristoph Hellwig1-0/+8
Extern declarations in .c files are a bad style and can lead to mismatches. Use existing definitions in headers where they exist, and otherwise move the external declarations to suitable header files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-05include/linux/sysctl.h: inline braces for ctl_table and ctl_table_headerAlessio Balsini1-4/+2
Fix coding style of "struct ctl_table" and "struct ctl_table_header" to have inline braces. Besides the wide use of this proposed cose style, this change helps to find at a glance the struct definition when navigating the code. Link: http://lkml.kernel.org/r/20190903154906.188651-1-balsini@android.com Signed-off-by: Alessio Balsini <balsini@android.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-19proc/sysctl: add shared variables for range checkMatteo Croce1-0/+7
In the sysctl code the proc_dointvec_minmax() function is often used to validate the user supplied value between an allowed range. This function uses the extra1 and extra2 members from struct ctl_table as minimum and maximum allowed value. On sysctl handler declaration, in every source file there are some readonly variables containing just an integer which address is assigned to the extra1 and extra2 members, so the sysctl range is enforced. The special values 0, 1 and INT_MAX are very often used as range boundary, leading duplication of variables like zero=0, one=1, int_max=INT_MAX in different source files: $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l 248 Add a const int array containing the most commonly used values, some macros to refer more easily to the correct array member, and use them instead of creating a local one for every object file. This is the bloat-o-meter output comparing the old and new binary compiled with the default Fedora config: # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164) Data old new delta sysctl_vals - 12 +12 __kstrtab_sysctl_vals - 12 +12 max 14 10 -4 int_max 16 - -16 one 68 - -68 zero 128 28 -100 Total: Before=20583249, After=20583085, chg -0.00% [mcroce@redhat.com: tipc: remove two unused variables] Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com [akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c] [arnd@arndb.de: proc/sysctl: make firmware loader table conditional] Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de [akpm@linux-foundation.org: fix fs/eventpoll.c] Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-15sysctl: define proc_do_static_key()Eric Dumazet1-0/+3
Convert proc_dointvec_minmax_bpf_stats() into a more generic helper, since we are going to use jump labels more often. Note that sysctl_bpf_stats_enabled is removed, since it is no longer needed/used. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-07pipe, sysctl: remove pipe_proc_fn()Eric Biggers1-3/+0
pipe_proc_fn() is no longer needed, as it only calls through to proc_dopipe_max_size(). Just put proc_dopipe_max_size() in the ctl_table entry directly, and remove the unneeded EXPORT_SYMBOL() and the ENOSYS stub for it. (The reason the ENOSYS stub isn't needed is that the pipe-max-size ctl_table entry is located directly in 'kern_table' rather than being registered separately. Therefore, the entry is already only defined when the kernel is built with sysctl support.) Link: http://lkml.kernel.org/r/20180111052902.14409-3-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-18pipe: add proc_dopipe_max_size() to safely assign pipe_max_sizeJoe Lawrence1-0/+3
pipe_max_size is assigned directly via procfs sysctl: static struct ctl_table fs_table[] = { ... { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, ... int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, size_t *lenp, loff_t *ppos) { ... ret = proc_dointvec_minmax(table, write, buf, lenp, ppos) ... and then later rounded in-place a few statements later: ... pipe_max_size = round_pipe_size(pipe_max_size); ... This leaves a window of time between initial assignment and rounding that may be visible to other threads. (For example, one thread sets a non-rounded value to pipe_max_size while another reads its value.) Similar reads of pipe_max_size are potentially racy: pipe.c :: alloc_pipe_info() pipe.c :: pipe_set_size() Add a new proc_dopipe_max_size() that consolidates reading the new value from the user buffer, verifying bounds, and calling round_pipe_size() with a single assignment to pipe_max_size. Link: http://lkml.kernel.org/r/1507658689-11669-4-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-10sysctl: add register_sysctl() dummy helperArnd Bergmann1-0/+5
register_sysctl() has been around for five years with commit fea478d4101a ("sysctl: Add register_sysctl for normal sysctl users") but now that arm64 started using it, I ran into a compile error: arch/arm64/kernel/armv8_deprecated.c: In function 'register_insn_emulation_sysctl': arch/arm64/kernel/armv8_deprecated.c:257:2: error: implicit declaration of function 'register_sysctl' This adds a inline function like we already have for register_sysctl_paths() and register_sysctl_table(). Link: http://lkml.kernel.org/r/20171106133700.558647-1-arnd@arndb.de Fixes: 38b9aeb32fa7 ("arm64: Port deprecated instruction emulation to new sysctl interface") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Alex Benne <alex.bennee@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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>
2017-07-19Merge tag 'gcc-plugins-v4.13-rc2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization
2017-07-13Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+3
Merge yet more updates from Andrew Morton: - various misc things - kexec updates - sysctl core updates - scripts/gdb udpates - checkpoint-restart updates - ipc updates - kernel/watchdog updates - Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature" - "stackprotector: ascii armor the stack canary" - more MM bits - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits) writeback: rework wb_[dec|inc]_stat family of functions ARM: samsung: usb-ohci: move inline before return type video: fbdev: omap: move inline before return type video: fbdev: intelfb: move inline before return type USB: serial: safe_serial: move __inline__ before return type drivers: tty: serial: move inline before return type drivers: s390: move static and inline before return type x86/efi: move asmlinkage before return type sh: move inline before return type MIPS: SMP: move asmlinkage before return type m68k: coldfire: move inline before return type ia64: sn: pci: move inline before type ia64: move inline before return type FRV: tlbflush: move asmlinkage before return type CRIS: gpio: move inline before return type ARM: HP Jornada 7XX: move inline before return type ARM: KVM: move asmlinkage before type checkpatch: improve the STORAGE_CLASS test mm, migration: do not trigger OOM killer when migrating memory drm/i915: use __GFP_RETRY_MAYFAIL ...
2017-07-13sysctl: add unsigned int range supportLuis R. Rodriguez1-0/+3
To keep parity with regular int interfaces provide the an unsigned int proc_douintvec_minmax() which allows you to specify a range of allowed valid numbers. Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an actual user for that. Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11proc: Fix proc_sys_prune_dcache to hold a sb referenceEric W. Biederman1-1/+1
Andrei Vagin writes: FYI: This bug has been reproduced on 4.11.7 > BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (1) [unmount of proc proc] > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80 > CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 #1 > Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015 > Workqueue: events proc_cleanup_work > Call Trace: > dump_stack+0x63/0x86 > __warn+0xcb/0xf0 > warn_slowpath_null+0x1d/0x20 > umount_check+0x6e/0x80 > d_walk+0xc6/0x270 > ? dentry_free+0x80/0x80 > do_one_tree+0x26/0x40 > shrink_dcache_for_umount+0x2d/0x90 > generic_shutdown_super+0x1f/0xf0 > kill_anon_super+0x12/0x20 > proc_kill_sb+0x40/0x50 > deactivate_locked_super+0x43/0x70 > deactivate_super+0x5a/0x60 > cleanup_mnt+0x3f/0x90 > mntput_no_expire+0x13b/0x190 > kern_unmount+0x3e/0x50 > pid_ns_release_proc+0x15/0x20 > proc_cleanup_work+0x15/0x20 > process_one_work+0x197/0x450 > worker_thread+0x4e/0x4a0 > kthread+0x109/0x140 > ? process_one_work+0x450/0x450 > ? kthread_park+0x90/0x90 > ret_from_fork+0x2c/0x40 > ---[ end trace e1c109611e5d0b41 ]--- > VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds. Have a nice day... > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: _raw_spin_lock+0xc/0x30 > PGD 0 Fix this by taking a reference to the super block in proc_sys_prune_dcache. The superblock reference is the core of the fix however the sysctl_inodes list is converted to a hlist so that hlist_del_init_rcu may be used. This allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while not causing problems for proc_sys_evict_inode when if it later choses to remove the inode from the sysctl_inodes list. Removing inodes from the sysctl_inodes list allows proc_sys_prune_dcache to have a progress guarantee, while still being able to drop all locks. The fact that head->unregistering is set in start_unregistering ensures that no more inodes will be added to the the sysctl_inodes list. Previously the code did a dance where it delayed calling iput until the next entry in the list was being considered to ensure the inode remained on the sysctl_inodes list until the next entry was walked to. The structure of the loop in this patch does not need that so is much easier to understand and maintain. Cc: stable@vger.kernel.org Reported-by: Andrei Vagin <avagin@gmail.com> Tested-by: Andrei Vagin <avagin@openvz.org> Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.") Fixes: d6cffbbe9a7e ("proc/sysctl: prune stale dentries during unregistering") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-06-30randstruct: Mark various structs for randomizationKees Cook1-1/+1
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-04-17sysctl: Remove dead register_sysctl_rootEric W. Biederman1-1/+0
The function no longer does anything. The is only a single caller of register_sysctl_root when semantically there should be two. Remove this function so that if someone decides this functionality is needed again it will be obvious all of the callers of setup_sysctl_set need to be audited and modified appropriately. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-02-13proc/sysctl: prune stale dentries during unregisteringKonstantin Khlebnikov1-0/+1
Currently unregistering sysctl table does not prune its dentries. Stale dentries could slowdown sysctl operations significantly. For example, command: # for i in {1..100000} ; do unshare -n -- sysctl -a &> /dev/null ; done creates a millions of stale denties around sysctls of loopback interface: # sysctl fs.dentry-state fs.dentry-state = 25812579 24724135 45 0 0 0 All of them have matching names thus lookup have to scan though whole hash chain and call d_compare (proc_sys_compare) which checks them under system-wide spinlock (sysctl_lock). # time sysctl -a > /dev/null real 1m12.806s user 0m0.016s sys 1m12.400s Currently only memory reclaimer could remove this garbage. But without significant memory pressure this never happens. This patch collects sysctl inodes into list on sysctl table header and prunes all their dentries once that table unregisters. Konstantin Khlebnikov <khlebnikov@yandex-team.ru> writes: > On 10.02.2017 10:47, Al Viro wrote: >> how about >> the matching stats *after* that patch? > > dcache size doesn't grow endlessly, so stats are fine > > # sysctl fs.dentry-state > fs.dentry-state = 92712 58376 45 0 0 0 > > # time sysctl -a &>/dev/null > > real 0m0.013s > user 0m0.004s > sys 0m0.008s Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-10-06Merge branch 'for-linus' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ...
2016-08-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+2
All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-27sysctl: handle error writing UINT_MAX to u32 fieldsSubash Abhinov Kasiviswanathan1-0/+2
We have scripts which write to certain fields on 3.18 kernels but this seems to be failing on 4.4 kernels. An entry which we write to here is xfrm_aevent_rseqth which is u32. echo 4294967295 > /proc/sys/net/core/xfrm_aevent_rseqth Commit 230633d109e3 ("kernel/sysctl.c: detect overflows when converting to int") prevented writing to sysctl entries when integer overflow occurs. However, this does not apply to unsigned integers. Heinrich suggested that we introduce a new option to handle 64 bit limits and set min as 0 and max as UINT_MAX. This might not work as it leads to issues similar to __do_proc_doulongvec_minmax. Alternatively, we would need to change the datatype of the entry to 64 bit. static int __do_proc_doulongvec_minmax(void *data, struct ctl_table { i = (unsigned long *) data; //This cast is causing to read beyond the size of data (u32) vleft = table->maxlen / sizeof(unsigned long); //vleft is 0 because maxlen is sizeof(u32) which is lesser than sizeof(unsigned long) on x86_64. Introduce a new proc handler proc_douintvec. Individual proc entries will need to be updated to use the new handler. [akpm@linux-foundation.org: coding-style fixes] Fixes: 230633d109e3 ("kernel/sysctl.c:detect overflows when converting to int") Link: http://lkml.kernel.org/r/1471479806-5252-1-git-send-email-subashab@codeaurora.org Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Kees Cook <keescook@chromium.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-15net: make net namespace sysctls belong to container's ownerDmitry Torokhov1-0/+4
If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of global root. This also allows us to clean up net_ctl_permissions() because we do not need to fudge permissions anymore for the container's owner since it now owns the objects in question. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08sysctl: Stop implicitly passing current into sysctl_table_root.lookupEric W. Biederman1-2/+1
Passing nsproxy into sysctl_table_root.lookup was a premature optimization in attempt to avoid depending on current. The directory /proc/self/sys has not appeared and if and when it does this code will need to be reviewed closely and reworked anyway. So remove the premature optimization. Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-08-03uapi: move forward declarations of internal structuresAlexey Dobriyan1-0/+1
Don't user forward declarations of internal kernel structures in headers exported to userspace. Move "struct completion;". Move "struct task_struct;". Link: http://lkml.kernel.org/r/20160713215808.GA22486@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-01sysctl: Allow creating permanently empty directories that serve as mountpoints.Eric W. Biederman1-0/+3
Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanently empty. Update the code to use make_empty_dir_inode when accessing permanently empty directories. Update the code to not allow adding to permanently empty directories. Update /proc/sys/fs/binfmt_misc to be a permanently empty directory. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-04-17kernel/sysctl.c: threads-max observe limitsHeinrich Schuchardt1-0/+3
Users can change the maximum number of threads by writing to /proc/sys/kernel/threads-max. With the patch the value entered is checked against the same limits that apply when fork_init is called. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-09sysctl: remove typedef ctl_tableJoe Perches1-2/+0
Remove the final user, and the typedef itself. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-19sysctl: Pass useful parameters to sysctl permissionsEric W. Biederman1-2/+1
- Current is implicitly avaiable so passing current->nsproxy isn't useful. - The ctl_table_header is needed to find how the sysctl table is connected to the rest of sysctl. - ctl_table_root is avaiable in the ctl_table_header so no need to it. With these changes it becomes possible to write a version of net_sysctl_permission that takes into account the network namespace of the sysctl table, an important feature in extending the user namespace. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells1-910/+1
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-01-25sysctl: Add register_sysctl for normal sysctl usersEric W. Biederman1-0/+1
The plan is to convert all callers of register_sysctl_table and register_sysctl_paths to register_sysctl. The interface to register_sysctl is enough nicer this should make the callers a bit more readable. Additionally after the conversion the 230 lines of backwards compatibility can be removed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Index sysctl directories with rbtrees.Eric W. Biederman1-2/+8
One of the most important jobs of sysctl is to export network stack tunables. Several of those tunables are per network device. In several instances people are running with 1000+ network devices in there network stacks, which makes the simple per directory linked list in sysctl a scaling bottleneck. Replace O(N^2) sysctl insertion and lookup times with O(NlogN) by using an rbtree to index the sysctl directories. Benchmark before: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Benchmark after: make-dummies 0 999 -> 0.074s rmmod dummy -> 0.070s make-dummies 0 9999 -> 3.4s rmmod dummy -> 0.44s Benchmark after (without dev_snmp6): make-dummies 0 9999 -> 0.75s rmmod dummy -> 0.44s make-dummies 0 99999 -> 11s rmmod dummy -> 4.3s At 10,000 dummy devices the bottleneck becomes the time to add and remove the files under /proc/sys/net/dev_snmp6. I have commented out the code that adds and removes files under /proc/sys/net/dev_snmp6 and taken measurments of creating and destroying 100,000 dummies to verify the sysctl continues to scale. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Make the header lists per directory.Eric W. Biederman1-1/+1
Slightly enhance efficiency and clarity of the code by making the header list per directory instead of per set. Benchmark before: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s Benchmark after: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Modify __register_sysctl_paths to take a set instead of a root and ↵Eric W. Biederman1-2/+2
an nsproxy An nsproxy argument here has always been awkard and now the nsproxy argument is completely unnecessary so remove it, replacing it with the set we want the registered tables to show up in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Replace root_list with links between sysctl_table_sets.Eric W. Biederman1-2/+1
Piecing together directories by looking first in one directory tree, than in another directory tree and finally in a third directory tree makes it hard to verify that some directory entries are not multiply defined and makes it hard to create efficient implementations the sysctl filesystem. Replace the sysctl wide list of roots with autogenerated links from the core sysctl directory tree to the other sysctl directory trees. This simplifies sysctl directory reading and lookups as now only entries in a single sysctl directory tree need to be considered. Benchmark before: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s The slowdown is caused by the lookups used in insert_headers and put_links to see if we need to add links or remove links. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Stop requiring explicit management of sysctl directoriesEric W. Biederman1-3/+7
Simplify the code and the sysctl semantics by autogenerating sysctl directories when a sysctl table is registered that needs the directories and autodeleting the directories when there are no more sysctl tables registered that need them. Autogenerating directories keeps sysctl tables from depending on each other, removing all of the arcane register/unregister ordering constraints and makes it impossible to get the order wrong when reigsering and unregistering sysctl tables. Autogenerating directories yields one unique entity that dentries can point to, retaining the current effective use of the dcache. Add struct ctl_dir as the type of these new autogenerated directories. The attached_by and attached_to fields in ctl_table_header are removed as they are no longer needed. The child field in ctl_table is no longer needed by the core of the sysctl code. ctl_table.child can be removed once all of the existing users have been updated. Benchmark before: make-dummies 0 999 -> 0.7s rmmod dummy -> 0.07s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Add a root pointer to ctl_table_setEric W. Biederman1-0/+3
Add a ctl_table_root pointer to ctl_table set so it is easy to go from a ctl_table_set to a ctl_table_root. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Initial support for auto-unregistering sysctl tables.Eric W. Biederman1-0/+1
Add nreg to ctl_table_header. When nreg drops to 0 the ctl_table_header will be unregistered. Factor out drop_sysctl_table from unregister_sysctl_table, and add the logic for decrementing nreg. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Remove the now unused ctl_table parent field.Eric W. Biederman1-1/+0
While useful at one time for selinux and the sysctl sanity checks those users no longer use the parent field and we can safely remove it. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmil.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: register only tables of sysctl filesEric W. Biederman1-1/+1
Split the registration of a complex ctl_table array which may have arbitrary numbers of directories (->child != NULL) and tables of files into a series of simpler registrations that only register tables of files. Graphically: register('dir', { + file-a + file-b + subdir1 + file-c + subdir2 + file-d + file-e }) is transformed into: wrapper->subheaders[0] = register('dir', {file1-a, file1-b}) wrapper->subheaders[1] = register('dir/subdir1', {file-c}) wrapper->subheaders[2] = register('dir/subdir2', {file-d, file-e}) return wrapper This guarantees that __register_sysctl_table will only see a simple ctl_table array with all entries having (->child == NULL). Care was taken to pass the original simple ctl_table arrays to __register_sysctl_table whenever possible. This change is derived from a similar patch written by Lucrian Grijincu. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Add support for register sysctl tables with a normal cstring path.Eric W. Biederman1-0/+3
Make __register_sysctl_table the core sysctl registration operation and make it take a char * string as path. Now that binary paths have been banished into the real of backwards compatibility in kernel/binary_sysctl.c where they can be safely ignored there is no longer a need to use struct ctl_path to represent path names when registering ctl_tables. Start the transition to using normal char * strings to represent pathnames when registering sysctl tables. Normal strings are easier to deal with both in the internal sysctl implementation and for programmers registering sysctl tables. __register_sysctl_paths is turned into a backwards compatibility wrapper that converts a ctl_path array into a normal char * string. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Remove the unnecessary sysctl_set parent concept.Eric W. Biederman1-3/+0
In sysctl_net register the two networking roots in the proper order. In register_sysctl walk the sysctl sets in the reverse order of the sysctl roots. Remove parent from ctl_table_set and setup_sysctl_set as it is no longer needed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Implement retire_sysctl_setEric W. Biederman1-0/+1
This adds a small helper retire_sysctl_set to remove the intimate knowledge about the how a sysctl_set is implemented from net/sysct_net.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Move the implementation into fs/proc/proc_sysctl.cEric W. Biederman1-16/+0
Move the core sysctl code from kernel/sysctl.c and kernel/sysctl_check.c into fs/proc/proc_sysctl.c. Currently sysctl maintenance is hampered by the sysctl implementation being split across 3 files with artificial layering between them. Consolidate the entire sysctl implementation into 1 file so that it is easier to see what is going on and hopefully allowing for simpler maintenance. For functions that are now only used in fs/proc/proc_sysctl.c remove their declarations from sysctl.h and make them static in fs/proc/proc_sysctl.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Register the base sysctl table like any other sysctl table.Eric W. Biederman1-0/+1
Simplify the code by treating the base sysctl table like any other sysctl table and register it with register_sysctl_table. To ensure this table is registered early enough to avoid problems call sysctl_init from proc_sys_init. Rename sysctl_net.c:sysctl_init() to net_sysctl_init() to avoid name conflicts now that kernel/sysctl.c:sysctl_init() is no longer static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-25sysctl: Consolidate !CONFIG_SYSCTL handlingEric W. Biederman1-33/+62
- In sysctl.h move functions only available if CONFIG_SYSCL is defined inside of #ifdef CONFIG_SYSCTL - Move the stub function definitions for !CONFIG_SYSCTL into sysctl.h and make them static inlines. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-04sysctl: use umode_t for table permissionsAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-03sysctl: add support for poll()Lucas De Marchi1-0/+22
Adding support for poll() in sysctl fs allows userspace to receive notifications of changes in sysctl entries. This adds a infrastructure to allow files in sysctl fs to be pollable and implements it for hostname and domainname. [akpm@linux-foundation.org: s/declare/define/ for definitions] Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Greg KH <gregkh@suse.de> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-03ipv4: NET_IPV4_ROUTE_GC_INTERVAL removalVasily Averin1-1/+1
removing obsoleted sysctl, ip_rt_gc_interval variable no longer used since 2.6.38 Signed-off-by: Vasily Averin <vvs@sw.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10sysctl: the include of rcupdate.h is only needed in the kernelStephen Rothwell1-1/+1
Fixes this build-check error: include/linux/sysctl.h:28: included file 'linux/rcupdate.h' is not exported Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-08unfuck proc_sysctl ->d_compare()Al Viro1-4/+10
a) struct inode is not going to be freed under ->d_compare(); however, the thing PROC_I(inode)->sysctl points to just might. Fortunately, it's enough to make freeing that sucker delayed, provided that we don't step on its ->unregistering, clear the pointer to it in PROC_I(inode) before dropping the reference and check if it's NULL in ->d_compare(). b) I'm not sure that we *can* walk into NULL inode here (we recheck dentry->seq between verifying that it's still hashed / fetching dentry->d_inode and passing it to ->d_compare() and there's no negative hashed dentries in /proc/sys/*), but if we can walk into that, we really should not have ->d_compare() return 0 on it! Said that, I really suspect that this check can be simply killed. Nick? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>