- 02 Aug, 2016 40 commits
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Minfei Huang authored
This is a cleanup patch to make kexec more clear to return error number directly. The variable result is useless, because there is no other function's return value assignes to it. So remove it. Link: http://lkml.kernel.org/r/1464179273-57668-1-git-send-email-mnghuan@gmail.comSigned-off-by:
Minfei Huang <mnghuan@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Xunlei Pang <xlpang@redhat.com> Cc: Atsushi Kumagai <ats-kumagai@wm.jp.nec.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Geliang Tang authored
Fix code comment for cpumask_parse(). Link: http://lkml.kernel.org/r/71aae2c60ae5dae0cf554199ce6aea8f88c69347.1465380581.git.geliangtang@gmail.comSigned-off-by:
Geliang Tang <geliangtang@gmail.com> Acked-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Anton Blanchard authored
Many targets enable CONFIG_DEBUG_STACK_USAGE, and while the information is useful, it isn't worthy of pr_warn(). Reduce it to pr_info(). Link: http://lkml.kernel.org/r/1466982072-29836-1-git-send-email-anton@ozlabs.orgSigned-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Andy Lutomirski authored
In general, there's no need for the "restore sigmask" flag to live in ti->flags. alpha, ia64, microblaze, powerpc, sh, sparc (64-bit only), tile, and x86 use essentially identical alternative implementations, placing the flag in ti->status. Replace those optimized implementations with an equally good common implementation that stores it in a bitfield in struct task_struct and drop the custom implementations. Additional architectures can opt in by removing their TIF_RESTORE_SIGMASK defines. Link: http://lkml.kernel.org/r/8a14321d64a28e40adfddc90e18a96c086a6d6f9.1468522723.git.luto@kernel.orgSigned-off-by:
Andy Lutomirski <luto@kernel.org> Tested-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Jeff Mahoney authored
new_insert_key only makes any sense when it's associated with a new_insert_ptr, which is initialized to NULL and changed to a buffer_head when we also initialize new_insert_key. We can key off of that to avoid the uninitialized warning. Link: http://lkml.kernel.org/r/5eca5ffb-2155-8df2-b4a2-f162f105efed@suse.comSigned-off-by:
Jeff Mahoney <jeffm@suse.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Ryusuke Konishi authored
The header file "include/linux/nilfs2_fs.h" is composed of parts for ioctl and disk format, and both are intended to be shared with user space programs. This moves them to the uapi directory "include/uapi/linux" splitting the file to "nilfs2_api.h" and "nilfs2_ondisk.h". The following minor changes are accompanied by this migration: - nilfs_direct_node struct in nilfs2/direct.h is converged to nilfs2_ondisk.h because it's an on-disk structure. - inline functions nilfs_rec_len_from_disk() and nilfs_rec_len_to_disk() are moved to nilfs2/dir.c. Link: http://lkml.kernel.org/r/1465825507-3407-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by:
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Ryusuke Konishi authored
Replace bit shifts by BIT macro for clarity. Link: http://lkml.kernel.org/r/1465825507-3407-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Variables ns_seg_seq, ns_segnum, ns_nextnum, ns_pseg_offset, ns_cno, ns_ctime, ns_nongc_ctime, and ns_ndirtyblks, are protected by ns_segctor_sem, but ns_sem is wrongly used by the nilfs sysfs code when reading these variables. This fixes the misuse and clarifies which semaphore protects them in the comment of the_nilfs struct. Link: http://lkml.kernel.org/r/1465825507-3407-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Move parser of snapshot mount option to a separate function nilfs_parse_snapshot_option(), replace simple_strtoull() with kstrtoull() to avoid checkpatch.pl warning "WARNING: simple_strtoull is obsolete, use kstrtoull instead", and refine the error message of the parser. Link: http://lkml.kernel.org/r/1464875891-5443-9-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Use cond_resched() instead of yield() in the loop of nilfs_transaction_lock() since the usage corresponds to the "be nice for others" case that the comment of yield() says. This removes the following checkpatch.pl warning: "WARNING: Using yield() is generally wrong. See yield() kernel-doc (sched/core.c)" Link: http://lkml.kernel.org/r/1464875891-5443-8-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
When nilfs returned -EIO as an error code, it's not always clear if it came from the underlying block device or not. This will mend the issue by having low level I/O routines of nilfs output an error message when they detected an I/O error. Link: http://lkml.kernel.org/r/1464875891-5443-7-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Use nilfs_msg() to output warning messages and get rid of nilfs_warning() function. This also removes function names from the messages unless we embed them explicitly in format strings. Instead, some messages are revised to clarify the context. [arnd@arndb.de: avoid warning about unused variables] Link: http://lkml.kernel.org/r/20160615201945.3348205-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1464875891-5443-6-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Replace most use of printk() in nilfs2 implementation with nilfs_msg(), and reduce the following checkpatch.pl warning: "WARNING: Prefer [subsystem eg: netdev]_crit([subsystem]dev, ... then dev_crit(dev, ... then pr_crit(... to printk(KERN_CRIT ..." This patch also fixes a minor checkpatch warning "WARNING: quoted string split across lines" that often accompanies the prior warning, and amends message format as needed. Link: http://lkml.kernel.org/r/1464875891-5443-5-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Insert a back pointer to super block instance in nilfs object so that functions of nilfs2 easily refer to the super block instance. This simplifies replacement of printk() in the successive change. Link: http://lkml.kernel.org/r/1464875891-5443-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Define an own output routine to replace bare use of printk() function. The output routine is implemented with a macro and a helper function, which are named nilfs_msg() and __nilfs_msg(), respectively. __nilfs_msg() formats a message like "NILFS (<device-name>): <message>", prefixing it with a given log level, and terminates the statement with a newline. The "device-name" is optional to make it available in early stages; it will be omitted if a NULL pointer is passed to super block instance argument. nilfs_msg() wraps __nilfs_msg() and is removed if CONFIG_PRINTK is not set. Link: http://lkml.kernel.org/r/1464875891-5443-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Ryusuke Konishi authored
Simplify nilfs_error(), an output function used to report critical issues in file system. This renames the original nilfs_error() function to __nilfs_error() and redefines it as a macro to hide its function name argument within the macro. Every call site of nilfs_error() is changed to strip __func__ argument except nilfs_bmap_convert_error(); nilfs_bmap_convert_error() directly calls __nilfs_error() because it inherits caller's function name. Link: http://lkml.kernel.org/r/1464875891-5443-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by:
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Daniel Wagner authored
Since the -Wincompatible-pointer-types is reported as error, alpha doesn't build anymore. Let's fix it in a minimal way. fs/binfmt_em86.c:73:35: error: passing argument 2 of `copy_strings_kernel' from incompatible pointer type [-Werror=incompatible-pointer-types] retval = copy_strings_kernel(1, &i_arg, bprm); ^ ^ fs/binfmt_em86.c:77:34: error: passing argument 2 of `copy_strings_kernel' from incompatible pointer type [-Werror=incompatible-pointer-types] retval = copy_strings_kernel(1, &i_name, bprm); ^ Link: http://lkml.kernel.org/r/1469525978-23359-1-git-send-email-wagi@monom.orgSigned-off-by:Daniel Wagner <daniel.wagner@bmw-carit.de> Signed-off-by:
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Kees Cook authored
The vm_brk() alignment calculations should refuse to overflow. The ELF loader depending on this, but it has been fixed now. No other unsafe callers have been found. Link: http://lkml.kernel.org/r/1468014494-25291-3-git-send-email-keescook@chromium.orgSigned-off-by:
Kees Cook <keescook@chromium.org> Reported-by:
Hector Marco-Gisbert <hecmargi@upv.es> Cc: Ismael Ripoll Ripoll <iripoll@upv.es> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by:
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Kees Cook authored
A double-bug exists in the bss calculation code, where an overflow can happen in the "last_bss - elf_bss" calculation, but vm_brk internally aligns the argument, underflowing it, wrapping back around safe. We shouldn't depend on these bugs staying in sync, so this cleans up the bss padding handling to avoid the overflow. This moves the bss padzero() before the last_bss > elf_bss case, since the zero-filling of the ELF_PAGE should have nothing to do with the relationship of last_bss and elf_bss: any trailing portion should be zeroed, and a zero size is already handled by padzero(). Then it handles the math on elf_bss vs last_bss correctly. These need to both be ELF_PAGE aligned to get the comparison correct, since that's the expected granularity of the mappings. Since elf_bss already had alignment-based padding happen in padzero(), the "start" of the new vm_brk() should be moved forward as done in the original code. However, since the "end" of the vm_brk() area will already become PAGE_ALIGNed in vm_brk() then last_bss should get aligned here to avoid hiding it as a side-effect. Additionally makes a cosmetic change to the initial last_bss calculation so it's easier to read in comparison to the load_addr calculation above it (i.e. the only difference is p_filesz vs p_memsz). Link: http://lkml.kernel.org/r/1468014494-25291-2-git-send-email-keescook@chromium.orgSigned-off-by:
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Allen Hubbe authored
If no filenames are given, then read the patch from stdin. Link: http://lkml.kernel.org/r/a8784f291ccb5067361992bf5d41ff6cfb0ce5cb.1469830917.git.allenbh@gmail.comSigned-off-by:
Allen Hubbe <allenbh@gmail.com> Acked-by:
Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Signed-off-by:
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Allen Hubbe authored
Signoff was not checked if the filename is '-', indicating reading the patch from stdin. Commands such as the below would not warn about a missing signoff, because the patch filename is '-'. This change allows checkpatch to warn about a missing signoff, even if the input filename is '-', but only if the patch has a commit message. git show --pretty=email | scripts/checkpatch.pl - A more common use of checkpatch with stdin is for piping git diff through checkpatch. The diff output would not contain a commit message, and therefore it would not contain a signoff line. For this common use case, a warning should not be printed about the missing signoff. With this change we will only warn about a missing signoff if the input contains a commit message. git diff | scripts/checkpatch.pl - Before this patch, a workaround for the first command was to refer to stdin by a name other than '-'. The workaround is not an elegant solution, because elsewhere checkpatch uses the fact that filename equals '-', such as in setting '$vname' to 'Your patch' for stdin. The command below would report "/dev/stdin has style problems" instead of "Your patch has style problems." git show --pretty=email | scripts/checkpatch.pl /dev/stdin Link: http://lkml.kernel.org/r/48be31e414bddc65bccfa6b1322359be9ba032eb.1469670589.git.allenbh@gmail.comSigned-off-by:
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Joe Perches authored
Fix false positive warning of identifiers ending in signed with an = assignment of WARNING: Prefer 'signed int' to bare use of 'signed'. Link: http://lkml.kernel.org/r/6a0e24c3e9102337528ecfcbbe91a0eb5b4820ed.1469529497.git.joe@perches.comSigned-off-by:
Alan Douglas <alanjhd@gmail.com> Acked-by:
Andy Whitcroft <apw@canonical.com> Signed-off-by:
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Tomas Winkler authored
BIT macro cannot be exported to UAPI, don't complain about it. Link: http://lkml.kernel.org/r/1468707033-16173-1-git-send-email-tomas.winkler@intel.comSigned-off-by:
Tomas Winkler <tomas.winkler@intel.com> Acked-by:
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Joe Perches authored
Using \b isn't good enough to isolate what appears to be a commit id in a commit message. Make sure there is a space or a quote like character after a continuous run of hexadecimal characters that could be a commit id. Link: http://lkml.kernel.org/r/fdd22b47463a21c21132edbb8aa35e372950a1e6.1468869915.git.joe@perches.comSigned-off-by:
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Joe Perches authored
Sanitise the lines that contain c99 comments so that the error doesn't get emitted. Link: http://lkml.kernel.org/r/d4d22c34ad7bcc1bceb52f0742f76b7a6d585235.1468368420.git.joe@perches.comSigned-off-by:
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Joe Perches authored
These are also possible single line uses that exceed the generic maximum line length (typically 80 columns) Link: http://lkml.kernel.org/r/32a6a85fbd6161f1bb55ce176a464e44591afc5b.1468368420.git.joe@perches.comSigned-off-by:
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Stephen Boyd authored
Some systems are memory constrained but they need to load very large firmwares. The firmware subsystem allows drivers to request this firmware be loaded from the filesystem, but this requires that the entire firmware be loaded into kernel memory first before it's provided to the driver. This can lead to a situation where we map the firmware twice, once to load the firmware into kernel memory and once to copy the firmware into the final resting place. This creates needless memory pressure and delays loading because we have to copy from kernel memory to somewhere else. Let's add a request_firmware_into_buf() API that allows drivers to request firmware be loaded directly into a pre-allocated buffer. This skips the intermediate step of allocating a buffer in kernel memory to hold the firmware image while it's read from the filesystem. It also requires that drivers know how much memory they'll require before requesting the firmware and negates any benefits of firmware caching because the firmware layer doesn't manage the buffer lifetime. For a 16MB buffer, about half the time is spent performing a memcpy from the buffer to the final resting place. I see loading times go from 0.081171 seconds to 0.047696 seconds after applying this patch. Plus the vmalloc pressure is reduced. This is based on a patch from Vikram Mulukutla on codeaurora.org: https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.18/commit/drivers/base/firmware_class.c?h=rel/msm-3.18&id=0a328c5f6cd999f5c591f172216835636f39bcb5 Link: http://lkml.kernel.org/r/20160607164741.31849-4-stephen.boyd@linaro.orgSigned-off-by:
Stephen Boyd <stephen.boyd@linaro.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Vikram Mulukutla <markivx@codeaurora.org> Cc: Mark Brown <broonie@kernel.org> Cc: Ming Lei <ming.lei@canonical.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Vikram Mulukutla authored
Some low memory systems with complex peripherals cannot afford to have the relatively large firmware images taking up valuable memory during suspend and resume. Change the internal implementation of firmware_class to disallow caching based on a configurable option. In the near future, variants of request_firmware will take advantage of this feature. Link: http://lkml.kernel.org/r/20160607164741.31849-3-stephen.boyd@linaro.org [stephen.boyd@linaro.org: Drop firmware_desc design and use flags] Signed-off-by:
Vikram Mulukutla <markivx@codeaurora.org> Signed-off-by:
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Stephen Boyd authored
Some systems are memory constrained but they need to load very large firmwares. The firmware subsystem allows drivers to request this firmware be loaded from the filesystem, but this requires that the entire firmware be loaded into kernel memory first before it's provided to the driver. This can lead to a situation where we map the firmware twice, once to load the firmware into kernel memory and once to copy the firmware into the final resting place. This design creates needless memory pressure and delays loading because we have to copy from kernel memory to somewhere else. This patch sets adds support to the request firmware API to load the firmware directly into a pre-allocated buffer, skipping the intermediate copying step and alleviating memory pressure during firmware loading. The drawback is that we can't use the firmware caching feature because the memory for the firmware cache is not managed by the firmware layer. This patch (of 3): We use similar structured code to read and write the kmapped firmware pages. The only difference is read copies from the kmap region and write copies to it. Consolidate this into one function to reduce duplication. Link: http://lkml.kernel.org/r/20160607164741.31849-2-stephen.boyd@linaro.orgSigned-off-by:
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Ross Zwisler authored
The bottom two bits of radix tree entries are reserved for special use by the radix tree code itself. A comment detailing their usage was added by commit 3bcadd6f ("radix-tree: free up the bottom bit of exceptional entries for reuse") This comment states that if the bottom two bits are '11', this means that this is a locked exceptional entry. It turns out that this bit combination was never actually used. Radix tree locking for DAX was indeed implemented, but it actually used the third LSB: /* We use lowest available exceptional entry bit for locking */ #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT) This locking code was also made specific to the DAX code instead of being generally implemented in radix-tree.h. So, fix the comment. Link: http://lkml.kernel.org/r/1468997731-2155-1-git-send-email-ross.zwisler@linux.intel.comSigned-off-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by:
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Arnd Bergmann authored
The crc32 test function measures the elapsed time in nanoseconds, but uses 'struct timespec' for that. We want to remove timespec from the kernel for y2038 compatibility, and ktime_get_ns() also helps make the code simpler here. It is also slightly better to use monontonic time, as we are only interested in the time difference. Link: http://lkml.kernel.org/r/20160617143932.3289626-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Cc: "David S . Miller" <davem@davemloft.net> Signed-off-by:
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Sebastian Ott authored
When a large enough area in the iommu bitmap is found but would span a boundary we continue the search starting from the next bit position. For large allocations this can lead to several useless invocations of bitmap_find_next_zero_area() and iommu_is_span_boundary(). Continue the search from the start of the next segment (which is the next bit position such that we'll not cross the same segment boundary again). Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1606081910070.3211@schleppiSigned-off-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by:
Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by:
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Joe Perches authored
If a vcs is used, look to see if the vcs tracks the file specified and so the -f option becomes optional. Link: http://lkml.kernel.org/r/7c86a8df0d48770c45778a43b6b3e4627b2a90ee.1469746395.git.joe@perches.comSigned-off-by:
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Borislav Petkov authored
Add a "printk.devkmsg" kernel command line parameter which controls how userspace writes into /dev/kmsg. It has three options: * ratelimit - ratelimit logging from userspace. * on - unlimited logging from userspace * off - logging from userspace gets ignored The default setting is to ratelimit the messages written to it. This changes the kernel default setting of "on" to "ratelimit" and we do that because we want to keep userspace spamming /dev/kmsg to sane levels. This is especially moot when a small kernel log buffer wraps around and messages get lost. So the ratelimiting setting should be a sane setting where kernel messages should have a bit higher chance of survival from all the spamming. It additionally does not limit logging to /dev/kmsg while the system is booting if we haven't disabled it on the command line. Furthermore, we can control the logging from a lower priority sysctl interface - kernel.printk_devkmsg. That interface will succeed only if printk.devkmsg *hasn't* been supplied on the command line. If it has, then printk.devkmsg is a one-time setting which remains for the duration of the system lifetime. This "locking" of the setting is to prevent userspace from changing the logging on us through sysctl(2). This patch is based on previous patches from Linus and Steven. [bp@suse.de: fixes] Link: http://lkml.kernel.org/r/20160719072344.GC25563@nazgul.tnic Link: http://lkml.kernel.org/r/20160716061745.15795-3-bp@alien8.deSigned-off-by:
Borislav Petkov <bp@suse.de> Cc: Dave Young <dyoung@redhat.com> Cc: Franck Bui <fbui@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
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Borislav Petkov authored
Extend the ratelimiting facility to print the amount of suppressed lines when it is being released. This use case is aimed at short-termed, burst-like users for which we want to output the suppressed lines stats only once, after it has been disposed of. For an example, see /dev/kmsg usage in a follow-on patch. Also, change the printk() line we issue on release to not use "callbacks" as it is misleading: we're not suppressing callbacks but printk() calls. This has been separated from a previous patch by Linus. Link: http://lkml.kernel.org/r/20160716061745.15795-2-bp@alien8.deSigned-off-by:
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Borislav Petkov authored
Move the DRIVER_NAME macro definition before the first usage site and fix build error. Link: http://lkml.kernel.org/r/20160801163937.GA28119@nazgul.tnicSigned-off-by:
kbuild test robot <fengguang.wu@intel.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by:
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Christoph Hellwig authored
asm-generic headers are generic implementations for architecture specific code and should not be included by common code. Thus use the asm/ version of sections.h to get at the linker sections. Link: http://lkml.kernel.org/r/1468285008-7331-1-git-send-email-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Sergey Senozhatsky authored
Messages' levels and console log level are inspected when the actual printing occurs, which may provoke console_unlock() and console_cont_flush() to waste CPU cycles on every message that has loglevel above the current console_loglevel. Schematically, console_unlock() does the following: console_unlock() { ... for (;;) { ... raw_spin_lock_irqsave(&logbuf_lock, flags); skip: msg = log_from_idx(console_idx); if (msg->flags & LOG_NOCONS) { ... goto skip; } level = msg->level; len += msg_print_text(); >> sprintfs memcpy, etc. if (nr_ext_console_drivers) { ext_len = msg_print_ext_header(); >> scnprintf ext_len += msg_print_ext_body(); >> scnprintfs etc. } ... raw_spin_unlock(&logbuf_lock); call_console_drivers(level, ext_text, ext_len, text, len) { if (level >= console_loglevel && >> drop the message !ignore_loglevel) return; console->write(...); } local_irq_restore(flags); } ... } The thing here is this deferred `level >= console_loglevel' check. We are wasting CPU cycles on sprintfs/memcpy/etc. preparing the messages that we will eventually drop. This can be huge when we register a new CON_PRINTBUFFER console, for instance. For every such a console register_console() resets the console_seq, console_idx, console_prev and sets a `exclusive console' pointer to replay the log buffer to that just-registered console. And there can be a lot of messages to replay, in the worst case most of which can be dropped after console_loglevel test. We know messages' levels long before we call msg_print_text() and friends, so we can just move console_loglevel check out of call_console_drivers() and format a new message only if we are sure that it won't be dropped. The patch factors out loglevel check into suppress_message_printing() function and tests message->level and console_loglevel before formatting functions in console_unlock() and console_cont_flush() are getting executed. This improves things not only for exclusive CON_PRINTBUFFER consoles, but for every console_unlock() that attempts to print a message of level above the console_loglevel. Link: http://lkml.kernel.org/r/20160627135012.8229-1-sergey.senozhatsky@gmail.comSigned-off-by:Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by:
Petr Mladek <pmladek@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Calvin Owens <calvinowens@fb.com> Signed-off-by:
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Joe Perches authored
Using functions instead of macros can reduce overall code size by eliminating unnecessary "KERN_SOH<digit>" prefixes from format strings. defconfig x86-64: $ size vmlinux* text data bss dec hex filename 10193570 4331464 1105920 15630954 ee826a vmlinux.new 10192623 4335560 1105920 15634103 ee8eb7 vmlinux.old As the return value are unimportant and unused in the kernel tree, these new functions return void. Miscellanea: - change pr_<level> macros to call new __pr_<level> functions - change vprintk_nmi and vprintk_default to add LOGLEVEL_<level> argument [akpm@linux-foundation.org: fix LOGLEVEL_INFO, per Joe] Link: http://lkml.kernel.org/r/e16cc34479dfefcae37c98b481e6646f0f69efc3.1466718827.git.joe@perches.comSigned-off-by: -
Sergey Senozhatsky authored
A trivial cosmetic change: interrupt.h header is redundant since commit 6b898c07 ("console: use might_sleep in console_lock"). Link: http://lkml.kernel.org/r/20160620132847.21930-1-sergey.senozhatsky@gmail.comSigned-off-by:
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