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* Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'char-misc-4.19-rc1' of ↵Linus Torvalds2018-08-181-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here is the bit set of char/misc drivers for 4.19-rc1 There is a lot here, much more than normal, seems like everyone is writing new driver subsystems these days... Anyway, major things here are: - new FSI driver subsystem, yet-another-powerpc low-level hardware bus - gnss, finally an in-kernel GPS subsystem to try to tame all of the crazy out-of-tree drivers that have been floating around for years, combined with some really hacky userspace implementations. This is only for GNSS receivers, but you have to start somewhere, and this is great to see. Other than that, there are new slimbus drivers, new coresight drivers, new fpga drivers, and loads of DT bindings for all of these and existing drivers. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits) android: binder: Rate-limit debug and userspace triggered err msgs fsi: sbefifo: Bump max command length fsi: scom: Fix NULL dereference misc: mic: SCIF Fix scif_get_new_port() error handling misc: cxl: changed asterisk position genwqe: card_base: Use true and false for boolean values misc: eeprom: assignment outside the if statement uio: potential double frees if __uio_register_device() fails eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency misc: ti-st: Fix memory leak in the error path of probe() android: binder: Show extra_buffers_size in trace firmware: vpd: Fix section enabled flag on vpd_section_destroy platform: goldfish: Retire pdev_bus goldfish: Use dedicated macros instead of manual bit shifting goldfish: Add missing includes to goldfish.h mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux dt-bindings: mux: add adi,adgs1408 Drivers: hv: vmbus: Cleanup synic memory free path Drivers: hv: vmbus: Remove use of slow_virt_to_phys() Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind() ...
| * /dev/mem: Mark expected switch fall-throughGustavo A. R. Silva2018-07-071-0/+1
| | | | | | | | | | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | mm: fix vma_is_anonymous() false-positivesKirill A. Shutemov2018-07-271-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous VMA. This is unreliable as ->mmap may not set ->vm_ops. False-positive vma_is_anonymous() may lead to crashes: next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0 prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000 pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000 flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare) ------------[ cut here ]------------ kernel BUG at mm/memory.c:1422! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline] RIP: 0010:zap_pud_range mm/memory.c:1466 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline] RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508 Call Trace: unmap_single_vma+0x1a0/0x310 mm/memory.c:1553 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644 unmap_mapping_range_vma mm/memory.c:2792 [inline] unmap_mapping_range_tree mm/memory.c:2813 [inline] unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845 unmap_mapping_range+0x48/0x60 mm/memory.c:2880 truncate_pagecache+0x54/0x90 mm/truncate.c:800 truncate_setsize+0x70/0xb0 mm/truncate.c:826 simple_setattr+0xe9/0x110 fs/libfs.c:409 notify_change+0xf13/0x10f0 fs/attr.c:335 do_truncate+0x1ac/0x2b0 fs/open.c:63 do_sys_ftruncate+0x492/0x560 fs/open.c:205 __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x59/0x80 fs/open.c:213 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reproducer: #include <stdio.h> #include <stddef.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <unistd.h> #include <fcntl.h> #define KCOV_INIT_TRACE _IOR('c', 1, unsigned long) #define KCOV_ENABLE _IO('c', 100) #define KCOV_DISABLE _IO('c', 101) #define COVER_SIZE (1024<<10) #define KCOV_TRACE_PC 0 #define KCOV_TRACE_CMP 1 int main(int argc, char **argv) { int fd; unsigned long *cover; system("mount -t debugfs none /sys/kernel/debug"); fd = open("/sys/kernel/debug/kcov", O_RDWR); ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE); cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); munmap(cover, COVER_SIZE * sizeof(unsigned long)); cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long), PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); memset(cover, 0, COVER_SIZE * sizeof(unsigned long)); ftruncate(fd, 3UL << 20); return 0; } This can be fixed by assigning anonymous VMAs own vm_ops and not relying on it being NULL. If ->mmap() failed to set ->vm_ops, mmap_region() will set it to dummy_vm_ops. This way we will have non-NULL ->vm_ops for all VMAs. Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* /dev/mem: Avoid overwriting "err" in read_mem()Kees Cook2018-03-281-3/+3
| | | | | | | | | | | Successes in probe_kernel_read() would mask failures in copy_to_user() during read_mem(). Reported-by: Brad Spengler <spender@grsecurity.net> Fixes: 22ec1a2aea73 ("/dev/mem: Add bounce buffer for copy-out") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* /dev/mem: Add bounce buffer for copy-outKees Cook2017-12-181-5/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | As done for /proc/kcore in commit df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data") this adds a bounce buffer when reading memory via /dev/mem. This is needed to allow kernel text memory to be read out when built with CONFIG_HARDENED_USERCOPY (which refuses to read out kernel text) and without CONFIG_STRICT_DEVMEM (which would have refused to read any RAM contents at all). Since this build configuration isn't common (most systems with CONFIG_HARDENED_USERCOPY also have CONFIG_STRICT_DEVMEM), this also tries to inform Kconfig about the recommended settings. This patch is modified from Brad Spengler/PaX Team's changes to /dev/mem 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. Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/mm: Limit mmap() of /dev/mem to valid physical addressesCraig Bergstrom2017-11-161-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One thing /dev/mem access APIs should verify is that there's no way that excessively large pfn's can leak into the high bits of the page table entry. In particular, if people can use "very large physical page addresses" through /dev/mem to set the bits past bit 58 - SOFTW4 and permission key bits and NX bit, that could *really* confuse the kernel. We had an earlier attempt: ce56a86e2ade ("x86/mm: Limit mmap() of /dev/mem to valid physical addresses") ... which turned out to be too restrictive (breaking mem=... bootups for example) and had to be reverted in: 90edaac62729 ("Revert "x86/mm: Limit mmap() of /dev/mem to valid physical addresses"") This v2 attempt modifies the original patch and makes sure that mmap(/dev/mem) limits the pfns so that it at least fits in the actual pteval_t architecturally: - Make sure mmap_mem() actually validates that the offset fits in phys_addr_t ( This may be indirectly true due to some other check, but it's not entirely obvious. ) - Change valid_mmap_phys_addr_range() to just use phys_addr_valid() on the top byte ( Top byte is sufficient, because mmap_mem() has already checked that it cannot wrap. ) - Add a few comments about what the valid_phys_addr_range() vs. valid_mmap_phys_addr_range() difference is. Signed-off-by: Craig Bergstrom <craigb@google.com> [ Fixed the checks and added comments. ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ Collected the discussion and patches into a commit. ] Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hans Verkuil <hans.verkuil@cisco.com> Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sander Eikelenboom <linux@eikelenboom.it> Cc: Sean Young <sean@mess.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/CA+55aFyEcOMb657vWSmrM13OxmHxC-XxeBmNis=DwVvpJUOogQ@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+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>
* drivers: char: mem: Fix wraparound check to allow mappings up to the endJulius Werner2017-06-031-1/+1
| | | | | | | | | | | | | | | A recent fix to /dev/mem prevents mappings from wrapping around the end of physical address space. However, the check was written in a way that also prevents a mapping reaching just up to the end of physical address space, which may be a valid use case (especially on 32-bit systems). This patch fixes it by checking the last mapped address (instead of the first address behind that) for overflow. Fixes: b299cde245 ("drivers: char: mem: Check for address space wraparound with mmap()") Cc: <stable@vger.kernel.org> Reported-by: Nico Huber <nico.h@gmx.de> Signed-off-by: Julius Werner <jwerner@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: char: mem: Check for address space wraparound with mmap()Julius Werner2017-05-181-0/+5
| | | | | | | | | | | | | | | | /dev/mem currently allows mmap() mappings that wrap around the end of the physical address space, which should probably be illegal. It circumvents the existing STRICT_DEVMEM permission check because the loop immediately terminates (as the start address is already higher than the end address). On the x86_64 architecture it will then cause a panic (from the BUG(start >= end) in arch/x86/mm/pat.c:reserve_memtype()). This patch adds an explicit check to make sure offset + size will not wrap around in the physical address type. Signed-off-by: Julius Werner <jwerner@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: Tighten x86 /dev/mem with zeroing readsKees Cook2017-04-121-30/+52
| | | | | | | | | | | | | | | | | | | Under CONFIG_STRICT_DEVMEM, reading System RAM through /dev/mem is disallowed. However, on x86, the first 1MB was always allowed for BIOS and similar things, regardless of it actually being System RAM. It was possible for heap to end up getting allocated in low 1MB RAM, and then read by things like x86info or dd, which would trip hardened usercopy: usercopy: kernel memory exposure attempt detected from ffff880000090000 (dma-kmalloc-256) (4096 bytes) This changes the x86 exception for the low 1MB by reading back zeros for System RAM areas instead of blindly allowing them. More work is needed to extend this to mmap, but currently mmap doesn't go through usercopy, so hardened usercopy won't Oops the kernel. Reported-by: Tommi Rantala <tommi.t.rantala@nokia.com> Tested-by: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* drivers: char: mem: Fix thinkos in kmem address checksRobin Murphy2017-01-111-6/+4
| | | | | | | | | | | | | | | | | | | | When borrowing the pfn_valid() check from mmap_kmem(), somebody managed to get physical and virtual addresses spectacularly muddled up, such that we've ended up with checks for one being the other. Whilst this does indeed prevent out-of-bounds accesses crashing, on most systems it also prevents the more desirable use-case of working at all ever. Check the *virtual* offset correctly for what it is. Furthermore, do so in the right place - a read or write may span multiple pages, so a single up-front check is insufficient. High memory accesses already have a similar validity check just before the copy_to_user() call, so just make the low memory path fully consistent with that. Reported-by: Jason A. Donenfeld <Jason@zx2c4.com> CC: stable@vger.kernel.org Fixes: 148a1bc84398 ("drivers: char: mem: Check {read,write}_kmem() addresses") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: char: mem: Check {read,write}_kmem() addressesRobin Murphy2016-08-311-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | Arriving at read_kmem() with an offset representing a bogus kernel address (e.g. 0 from a simple "cat /dev/kmem") leads to copy_to_user faulting on the kernel-side read. x86_64 happens to get away with this since the optimised implementation uses "rep movs*", thus the user write (which is allowed to fault) and the kernel read are the same instruction, the kernel-side fault falls into the user-side fixup handler and the chain of events which transpires ends up returning an error as one might expect, even if it's an inappropriate -EFAULT. On other architectures, though, the read is not covered by the fixup entry for the write, and we get a big scary "Unable to hande kernel paging request..." dump. The more typical use-case of mmap_kmem() has always (within living memory at least) returned -EIO for addresses which don't satisfy pfn_valid(), so let's make that consistent across {read,write}_kem() too. Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* shmem: get_unmapped_area align huge pageHugh Dickins2016-07-271-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a shmem_get_unmapped_area method in file_operations, called at mmap time to decide the mapping address. It could be conditional on CONFIG_TRANSPARENT_HUGEPAGE, but save #ifdefs in other places by making it unconditional. shmem_get_unmapped_area() first calls the usual mm->get_unmapped_area (which we treat as a black box, highly dependent on architecture and config and executable layout). Lots of conditions, and in most cases it just goes with the address that chose; but when our huge stars are rightly aligned, yet that did not provide a suitable address, go back to ask for a larger arena, within which to align the mapping suitably. There have to be some direct calls to shmem_get_unmapped_area(), not via the file_operations: because of the way shmem_zero_setup() is called to create a shmem object late in the mmap sequence, when MAP_SHARED is requested with MAP_ANONYMOUS or /dev/zero. Though this only matters when /proc/sys/vm/shmem_huge has been set. Link: http://lkml.kernel.org/r/1466021202-61880-29-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/mm/pat, /dev/mem: Remove superfluous error messageJiri Kosina2016-07-081-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it's possible for broken (or malicious) userspace to flood a kernel log indefinitely with messages a-la Program dmidecode tried to access /dev/mem between f0000->100000 because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on dumps this information each and every time devmem_is_allowed() fails. Reportedly userspace that is able to trigger contignuous flow of these messages exists. It would be possible to rate limit this message, but that'd have a questionable value; the administrator wouldn't get information about all the failing accessess, so then the information would be both superfluous and incomplete at the same time :) Returning EPERM (which is what is actually happening) is enough indication for userspace what has happened; no need to log this particular error as some sort of special condition. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pm Signed-off-by: Ingo Molnar <mingo@kernel.org>
* drivers: char: mem: fix IS_ERROR_VALUE usageAndrzej Hajda2016-03-051-1/+1
| | | | | | | | | | | | | | IS_ERR_VALUE macro should be used only with unsigned long type. Specifically it works incorrectly with longer types. The patch follows conclusion from discussion on LKML [1][2]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2120927 [2]: http://permalink.gmane.org/gmane.linux.kernel/2150581 Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* wrappers for ->i_mutex accessAl Viro2016-01-231-2/+2
| | | | | | | | | | | parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch drivers/char/mem.c to ->read_iter/->write_iterAl Viro2015-04-121-9/+9
| | | | | | | | Note that _these_ guys have ->read() and ->write() left in place - they are eqiuvalent to what we'd get if we replaced those with NULL, but we are talking about hot paths here. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* make new_sync_{read,write}() staticAl Viro2015-04-121-2/+0
| | | | | | | | All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: move struct kiocb to fs.hChristoph Hellwig2015-03-261-1/+1
| | | | | | | | struct kiocb now is a generic I/O container, so move it to fs.h. Also do a #include diet for aio.h while we're at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'char-misc-3.20-rc1' of ↵Linus Torvalds2015-02-151-14/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc patches from Greg KH: "Here's the big char/misc driver update for 3.20-rc1. Lots of little things in here, all described in the changelog. Nothing major or unusual, except maybe the binder selinux stuff, which was all acked by the proper selinux people and they thought it best to come through this tree. All of this has been in linux-next with no reported issues for a while" * tag 'char-misc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits) coresight: fix function etm_writel_cp14() parameter order coresight-etm: remove check for unknown Kconfig macro coresight: fixing CPU hwid lookup in device tree coresight: remove the unnecessary function coresight_is_bit_set() coresight: fix the debug AMBA bus name coresight: remove the extra spaces coresight: fix the link between orphan connection and newly added device coresight: remove the unnecessary replicator property coresight: fix the replicator subtype value pdfdocs: Fix 'make pdfdocs' failure for 'uio-howto.tmpl' mcb: Fix error path of mcb_pci_probe virtio/console: verify device has config space ti-st: clean up data types (fix harmless memory corruption) mei: me: release hw from reset only during the reset flow mei: mask interrupt set bit on clean reset bit extcon: max77693: Constify struct regmap_config extcon: adc-jack: Release IIO channel on driver remove extcon: Remove duplicated include from extcon-class.c Drivers: hv: vmbus: hv_process_timer_expiration() can be static Drivers: hv: vmbus: serialize Offer and Rescind offer ...
| * drivers: char: mem: Fix Missing blank line issuesRob Ward2015-01-121-0/+2
| | | | | | | | | | | | | | | | | | | | Fixes "Missing a blank line after declarations" reported by checkpatch. This patch introduces no functional changes. Signed-off-by: Rob Ward <robert.ward114@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * drivers: char: mem: Replace usage of asm includeRob Ward2015-01-121-1/+1
| | | | | | | | | | | | | | Replaces the use of asm/uaccess.h with linux/uaccess.h. Signed-off-by: Rob Ward <robert.ward114@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * drivers: char: mem: Simplify DEVPORT configurationRob Ward2015-01-121-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify the use of CONFIG_DEVPORT by making the port_fops so that it includes __maybe_unused. This enabled the multiple #ifdef's used for this structure to be removed and brings it in line with the use of CONFIG_DEVMEM This change should introduce no functional changes. Signed-off-by: Rob Ward <robert.ward114@googlemail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * drivers: char: mem: Simplify DEVKMEM configurationRob Ward2015-01-121-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify the use of CONFIG_DEVKMEM by making the kmem_fops so that it is __maybe_unused. This enabled the multiple #ifdef's used for this structure to be removed and brings it in line with the use of CONFIG_DEVMEM This change should introduce no functional changes. Signed-off-by: Rob Ward <robert.ward114@googlemail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * drivers: char: mem: Make /dev/mem an optional deviceRob Ward2015-01-121-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | Adds Kconfig option CONFIG_DEVMEM that allows the /dev/mem device to be disabled. Option defaults to /dev/mem enabled. Signed-off-by: Rob Ward <robert.ward114@googlemail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | fs: introduce f_op->mmap_capabilities for nommu mmap supportChristoph Hellwig2015-01-201-32/+32
|/ | | | | | | | | | | | | | | | | | | 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>
* /dev/mem: Use more consistent data typesThierry Reding2014-11-101-5/+8
| | | | | | | | | | | | | The xlate_dev_{kmem,mem}_ptr() functions take either a physical address or a kernel virtual address, so data types should be phys_addr_t and void *. They both return a kernel virtual address which is only ever used in calls to copy_{from,to}_user(), so make variables that store it void * rather than char * for consistency. Also only define a weak unxlate_dev_mem_ptr() function if architectures haven't overridden them in the asm/io.h header file. Signed-off-by: Thierry Reding <treding@nvidia.com>
* switch /dev/zero and /dev/full to ->read_iter()Al Viro2014-10-091-43/+13
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* /dev/mem: handle out-of-bounds read/writePetr Tesarik2014-02-151-0/+6
| | | | | | | | | | | | | | | | | The loff_t type may be wider than phys_addr_t (e.g. on 32-bit systems). Consequently, the file offset may be truncated in the assignment. Currently, /dev/mem wraps around, which may cause applications to read or write incorrect regions of memory by accident. Let's follow POSIX file semantics here and return 0 when reading from and -EFBIG when writing to an offset that cannot be represented by a phys_addr_t. Note that the conditional is optimized out by the compiler if loff_t has the same size as phys_addr_t. Signed-off-by: Petr Tesarik <ptesarik@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm/memblock: remove unnecessary inclusions of bootmem.hGrygorii Strashko2014-01-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | Clean-up to remove depedency with bootmem headers. Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Paul Walmsley <paul@pwsan.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Lindgren <tony@atomide.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* /dev/oldmem: Remove the interfaceZhang Yanfei2013-07-041-47/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /dev/oldmem provides the interface for us to access the "old memory" in the dump-capture kernel. Unfortunately, no one actually uses this interface. And this interface could actually cause some real problems if used on ia64 where the cached/uncached accesses are mixed. See the discussion from the link: https://lkml.org/lkml/2013/4/12/386. So Eric suggested that we should remove /dev/oldmem as an unused piece of code. [akpm@linux-foundation.org: mention /dev/oldmem obsolescence in devices.txt] Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Hansen <dave@sr71.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers: char: mem: use IS_ERR_VALUE() in memory_lseek()Rasmus Villemoes2013-06-061-1/+1
| | | | | | | | | Use IS_ERR_VALUE() instead of comparing the new offset to a hard-coded value of -MAX_ERRNO (which is also off-by-one due to the use of ~ instead of -). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* aio: don't include aio.h in sched.hKent Overstreet2013-05-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* char: add aio_{read,write} to /dev/{null,zero}Zach Brown2013-05-081-0/+35
| | | | | | | | | | | | | | | | | | | | | | | These are handy for measuring the cost of the aio infrastructure with operations that do very little and complete immediately. Signed-off-by: Zach Brown <zab@redhat.com> Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-02-271-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
| * new helper: file_inode(file)Al Viro2013-02-231-2/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | drivers/char/mem.c: fix small coding style issuesHans Grob2013-02-061-5/+5
|/ | | | | | | | This patch fixes four foo * bar errors, and one trailing whitespace complaint from checkpatch.pl Signed-off-by: Hans Grob <H.Grob@physik.uni-muenchen.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* /dev/mem: use phys_addr_t for physical addressesCyril Chemparathy2012-10-251-5/+5
| | | | | | | | | This patch fixes the /dev/mem driver to use phys_addr_t for physical addresses. This is required on PAE systems, especially those that run entirely out of >4G physical memory space. Signed-off-by: Cyril Chemparathy <cyril@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: kill vma flag VM_RESERVED and mm->reserved_vm counterKonstantin Khlebnikov2012-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA, currently it lost original meaning but still has some effects: | effect | alternative flags -+------------------------+--------------------------------------------- 1| account as reserved_vm | VM_IO 2| skip in core dump | VM_IO, VM_DONTDUMP 3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP 4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP This patch removes reserved_vm counter from mm_struct. Seems like nobody cares about it, it does not exported into userspace directly, it only reduces total_vm showed in proc. Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP. remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP. remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP. [akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup] Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Paris <eparis@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Venkatesh Pallipadi <venki@google.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: Disable /dev/port interface on systems without an ISA bridgeHaren Myneni2012-07-111-1/+10
| | | | | | | | | | | | | Some power systems do not have legacy ISA devices. So, /dev/port is not a valid interface on these systems. User level tools such as kbdrate is trying to access the device using this interface which is causing the system crash. This patch will fix this issue by not creating this interface on these powerpc systems. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* printk - fix compilation for CONFIG_PRINTK=nKay Sievers2012-05-101-0/+2
| | | | | | Reported-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kmsg: export printk records to the /dev/kmsg interfaceKay Sievers2012-05-081-60/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support for multiple concurrent readers of /dev/kmsg, with read(), seek(), poll() support. Output of message sequence numbers, to allow userspace log consumers to reliably reconnect and reconstruct their state at any given time. After open("/dev/kmsg"), read() always returns *all* buffered records. If only future messages should be read, SEEK_END can be used. In case records get overwritten while /dev/kmsg is held open, or records get faster overwritten than they are read, the next read() will return -EPIPE and the current reading position gets updated to the next available record. The passed sequence numbers allow the log consumer to calculate the amount of lost messages. [root@mop ~]# cat /dev/kmsg 5,0,0;Linux version 3.4.0-rc1+ (kay@mop) (gcc version 4.7.0 20120315 ... 6,159,423091;ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff]) 7,160,424069;pci_root PNP0A03:00: host bridge window [io 0x0000-0x0cf7] (ignored) SUBSYSTEM=acpi DEVICE=+acpi:PNP0A03:00 6,339,5140900;NET: Registered protocol family 10 30,340,5690716;udevd[80]: starting version 181 6,341,6081421;FDC 0 is a S82078B 6,345,6154686;microcode: CPU0 sig=0x623, pf=0x0, revision=0x0 7,346,6156968;sr 1:0:0:0: Attached scsi CD-ROM sr0 SUBSYSTEM=scsi DEVICE=+scsi:1:0:0:0 6,347,6289375;microcode: CPU1 sig=0x623, pf=0x0, revision=0x0 Cc: Karel Zak <kzak@redhat.com> Tested-by: William Douglas <william.douglas@intel.com> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* printk: convert byte-buffer to variable-length record bufferKay Sievers2012-05-081-17/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Record-based stream instead of the traditional byte stream buffer. All records carry a 64 bit timestamp, the syslog facility and priority in the record header. - Records consume almost the same amount, sometimes less memory than the traditional byte stream buffer (if printk_time is enabled). The record header is 16 bytes long, plus some padding bytes at the end if needed. The byte-stream buffer needed 3 chars for the syslog prefix, 15 char for the timestamp and a newline. - Buffer management is based on message sequence numbers. When records need to be discarded, the reading heads move on to the next full record. Unlike the byte-stream buffer, no old logged lines get truncated or partly overwritten by new ones. Sequence numbers also allow consumers of the log stream to get notified if any message in the stream they are about to read gets discarded during the time of reading. - Better buffered IO support for KERN_CONT continuation lines, when printk() is called multiple times for a single line. The use of KERN_CONT is now mandatory to use continuation; a few places in the kernel need trivial fixes here. The buffering could possibly be extended to per-cpu variables to allow better thread-safety for multiple printk() invocations for a single line. - Full-featured syslog facility value support. Different facilities can tag their messages. All userspace-injected messages enforce a facility value > 0 now, to be able to reliably distinguish them from the kernel-generated messages. Independent subsystems like a baseband processor running its own firmware, or a kernel-related userspace process can use their own unique facility values. Multiple independent log streams can co-exist that way in the same buffer. All share the same global sequence number counter to ensure proper ordering (and interleaving) and to allow the consumers of the log to reliably correlate the events from different facilities. Tested-by: William Douglas <william.douglas@intel.com> Signed-off-by: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* switch device_get_devnode() and ->devnode() to umode_t *Al Viro2012-01-041-2/+2
| | | | | | | both callers of device_get_devnode() are only interested in lower 16bits and nobody tries to return anything wider than 16bit anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* drivers/char: Add export.h for EXPORT_SYMBOL/THIS_MODULE as requiredPaul Gortmaker2011-11-011-0/+1
| | | | | | | | They will need it called out explicitly in the near future due to a module.h usage cleanup that removes its implicit presence everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kmsg: properly support writev to avoid interleaved printk lines fixAndrew Morton2011-04-201-3/+4
| | | | | | | | | make `len' size_t, avoid multiple-assignments. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Lennart Poettering <lennart@poettering.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* printk: /dev/kmsg - properly support writev() to avoid interleaved printk() ↵Kay Sievers2011-04-201-15/+26
| | | | | | | | | | | | | | lines printk: /dev/kmsg - properly support writev() to avoid interleaved printk lines We should avoid calling printk() in a loop, when we pass a single string to /dev/kmsg with writev(). Cc: Lennart Poettering <lennart@poettering.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* drivers/char/mem.c: clean up the codeChangli Gao2011-03-241-4/+1
| | | | | | | | Reduce the lines of code and simplify the logic. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: introduce FMODE_UNSIGNED_OFFSET for allowing negative f_posKAMEZAWA Hiroyuki2010-10-261-0/+4
| | | | | | | | | | | | | | | | | | Now, rw_verify_area() checsk f_pos is negative or not. And if negative, returns -EINVAL. But, some special files as /dev/(k)mem and /proc/<pid>/mem etc.. has negative offsets. And we can't do any access via read/write to the file(device). So introduce FMODE_UNSIGNED_OFFSET to allow negative file offsets. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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