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* printk: fix exclusive_console replayingJohn Ogness2020-01-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | Commit f92b070f2dc8 ("printk: Do not miss new messages when replaying the log") introduced a new variable @exclusive_console_stop_seq to store when an exclusive console should stop printing. It should be set to the @console_seq value at registration. However, @console_seq is previously set to @syslog_seq so that the exclusive console knows where to begin. This results in the exclusive console immediately reactivating all the other consoles and thus repeating the messages for those consoles. Set @console_seq after @exclusive_console_stop_seq has stored the current @console_seq value. Fixes: f92b070f2dc8 ("printk: Do not miss new messages when replaying the log") Link: http://lkml.kernel.org/r/20191219115322.31160-1-john.ogness@linutronix.de Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: John Ogness <john.ogness@linutronix.de> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2019-12-031-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Ingo Molnar: "Most of the IRQ subsystem changes in this cycle were irq-chip driver updates: - Qualcomm PDC wakeup interrupt support - Layerscape external IRQ support - Broadcom bcm7038 PM and wakeup support - Ingenic driver cleanup and modernization - GICv3 ITS preparation for GICv4.1 updates - GICv4 fixes There's also the series from Frederic Weisbecker that fixes memory ordering bugs for the irq-work logic, whose primary fix is to turn work->irq_work.flags into an atomic variable and then convert the complex (and buggy) atomic_cmpxchg() loop in irq_work_claim() into a much simpler atomic_fetch_or() call. There are also various smaller cleanups" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) pinctrl/sdm845: Add PDC wakeup interrupt map for GPIOs pinctrl/msm: Setup GPIO chip in hierarchy irqchip/qcom-pdc: Add irqchip set/get state calls irqchip/qcom-pdc: Add irqdomain for wakeup capable GPIOs irqchip/qcom-pdc: Do not toggle IRQ_ENABLE during mask/unmask irqchip/qcom-pdc: Update max PDC interrupts of/irq: Document properties for wakeup interrupt parent genirq: Introduce irq_chip_get/set_parent_state calls irqdomain: Add bus token DOMAIN_BUS_WAKEUP genirq: Fix function documentation of __irq_alloc_descs() irq_work: Fix IRQ_WORK_BUSY bit clearing irqchip/ti-sci-inta: Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...)) irq_work: Slightly simplify IRQ_WORK_PENDING clearing irq_work: Fix irq_work_claim() memory ordering irq_work: Convert flags to atomic_t irqchip: Ingenic: Add process for more than one irq at the same time. irqchip: ingenic: Alloc generic chips from IRQ domain irqchip: ingenic: Get virq number from IRQ domain irqchip: ingenic: Error out if IRQ domain creation failed irqchip: ingenic: Drop redundant irq_suspend / irq_resume functions ...
| * irq_work: Convert flags to atomic_tFrederic Weisbecker2019-11-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to convert flags to atomic_t in order to later fix an ordering issue on atomic_cmpxchg() failure. This will allow us to use atomic_fetch_or(). Also clarify the nature of those flags. [ mingo: Converted two more usage site the original patch missed. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191108160858.31665-2-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | locking/lockdep: Remove unused @nested argument from lock_release()Qian Cai2019-10-091-5/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the following commit: b4adfe8e05f1 ("locking/lockdep: Remove unused argument in __lock_release") @nested is no longer used in lock_release(), so remove it from all lock_release() calls and friends. Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: alexander.levin@microsoft.com Cc: daniel@iogearbox.net Cc: davem@davemloft.net Cc: dri-devel@lists.freedesktop.org Cc: duyuyang@gmail.com Cc: gregkh@linuxfoundation.org Cc: hannes@cmpxchg.org Cc: intel-gfx@lists.freedesktop.org Cc: jack@suse.com Cc: jlbec@evilplan.or Cc: joonas.lahtinen@linux.intel.com Cc: joseph.qi@linux.alibaba.com Cc: jslaby@suse.com Cc: juri.lelli@redhat.com Cc: maarten.lankhorst@linux.intel.com Cc: mark@fasheh.com Cc: mhocko@kernel.org Cc: mripard@kernel.org Cc: ocfs2-devel@oss.oracle.com Cc: rodrigo.vivi@intel.com Cc: sean@poorly.run Cc: st@kernel.org Cc: tj@kernel.org Cc: tytso@mit.edu Cc: vdavydov.dev@gmail.com Cc: vincent.guittot@linaro.org Cc: viro@zeniv.linux.org.uk Link: https://lkml.kernel.org/r/1568909380-32199-1-git-send-email-cai@lca.pw Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'for-5.4' into for-linusPetr Mladek2019-09-162-10/+27
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| * printk: Replace strncmp() with str_has_prefix()Chuhong Yuan2019-08-162-10/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | strncmp(str, const, len) is error-prone because len is easy to have typo. An example is the hard-coded len has counting error or sizeof(const) forgets - 1. So we prefer using newly introduced str_has_prefix() to substitute such strncmp() to make code better. Link: http://lkml.kernel.org/r/20190809071034.17279-1-hslester96@gmail.com Cc: "Steven Rostedt" <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: Slightly updated and reformatted the commit message.] Signed-off-by: Petr Mladek <pmladek@suse.com>
* | printk: Do not lose last line in kmsg buffer dumpVincent Whitchurch2019-07-121-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmsg_dump_get_buffer() is supposed to select all the youngest log messages which fit into the provided buffer. It determines the correct start index by using msg_print_text() with a NULL buffer to calculate the size of each entry. However, when performing the actual writes, msg_print_text() only writes the entry to the buffer if the written len is lesser than the size of the buffer. So if the lengths of the selected youngest log messages happen to precisely fill up the provided buffer, the last log message is not included. We don't want to modify msg_print_text() to fill up the buffer and start returning a length which is equal to the size of the buffer, since callers of its other users, such as kmsg_dump_get_line(), depend upon the current behaviour. Instead, fix kmsg_dump_get_buffer() to compensate for this. For example, with the following two final prints: [ 6.427502] AAAAAAAAAAAAA [ 6.427769] BBBBBBBB12345 A dump of a 64-byte buffer filled by kmsg_dump_get_buffer(), before this patch: 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 35 32 32 31 39 37 <0>[ 6.522197 00000010: 5d 20 41 41 41 41 41 41 41 41 41 41 41 41 41 0a ] AAAAAAAAAAAAA. 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ After this patch: 00000000: 3c 30 3e 5b 20 20 20 20 36 2e 34 35 36 36 37 38 <0>[ 6.456678 00000010: 5d 20 42 42 42 42 42 42 42 42 31 32 33 34 35 0a ] BBBBBBBB12345. 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Link: http://lkml.kernel.org/r/20190711142937.4083-1-vincent.whitchurch@axis.com Fixes: e2ae715d66bf4bec ("kmsg - kmsg_dump() use iterator to receive log buffer content") To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # v3.5+ Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13Thomas Gleixner2019-05-212-26/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details [based] [from] [clk] [highbank] [c] you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 355 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* panic: add an option to replay all the printk message in bufferFeng Tang2019-05-191-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | Currently on panic, kernel will lower the loglevel and print out pending printk msg only with console_flush_on_panic(). Add an option for users to configure the "panic_print" to replay all dmesg in buffer, some of which they may have never seen due to the loglevel setting, which will help panic debugging . [feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()] Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com [feng.tang@intel.com: use logbuf lock to protect the console log index] Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* panic: avoid the extra noise dmesgFeng Tang2019-05-151-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kernel panic happens, it will first print the panic call stack, then the ending msg like: [ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception [ 35.749975] ------------[ cut here ]------------ The above message are very useful for debugging. But if system is configured to not reboot on panic, say the "panic_timeout" parameter equals 0, it will likely print out many noisy message like WARN() call stack for each and every CPU except the panic one, messages like below: WARNING: CPU: 1 PID: 280 at kernel/sched/core.c:1198 set_task_cpu+0x183/0x190 Call Trace: <IRQ> try_to_wake_up default_wake_function autoremove_wake_function __wake_up_common __wake_up_common_lock __wake_up wake_up_klogd_work_func irq_work_run_list irq_work_tick update_process_times tick_sched_timer __hrtimer_run_queues hrtimer_interrupt smp_apic_timer_interrupt apic_timer_interrupt For people working in console mode, the screen will first show the panic call stack, but immediately overridden by these noisy extra messages, which makes debugging much more difficult, as the original context gets lost on screen. Also these noisy messages will confuse some users, as I have seen many bug reporters posted the noisy message into bugzilla, instead of the real panic call stack and context. Adding a flag "suppress_printk" which gets set in panic() to avoid those noisy messages, without changing current kernel behavior that both panic blinking and sysrq magic key can work as is, suggested by Petr Mladek. To verify this, make sure kernel is not configured to reboot on panic and in console # echo c > /proc/sysrq-trigger to see if console only prints out the panic call stack. Link: http://lkml.kernel.org/r/1551430186-24169-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Suggested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'fbdev-v5.1' of git://github.com/bzolnier/linuxLinus Torvalds2019-03-151-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull fbdev updates from Bartlomiej Zolnierkiewicz: "Just a couple of small fixes and cleanups: - fix memory access if logo is bigger than the screen (Manfred Schlaegl) - silence fbcon logo on 'quiet' boots (Prarit Bhargava) - use kvmalloc() for scrollback buffer in fbcon (Konstantin Khorenko) - misc fixes (Colin Ian King, YueHaibing, Matteo Croce, Mathieu Malaterre, Anders Roxell, Arnd Bergmann) - misc cleanups (Rob Herring, Lubomir Rintel, Greg Kroah-Hartman, Jani Nikula, Michal Vokáč)" * tag 'fbdev-v5.1' of git://github.com/bzolnier/linux: fbdev: mbx: fix a misspelled variable name fbdev: omap2: fix warnings in dss core video: fbdev: Fix potential NULL pointer dereference fbcon: Silence fbcon logo on 'quiet' boots printk: Export console_printk ARM: dts: imx28-cfa10036: Fix the reset gpio signal polarity video: ssd1307fb: Do not hard code active-low reset sequence dt-bindings: display: ssd1307fb: Remove reset-active-low from examples fbdev: fbmem: fix memory access if logo is bigger than the screen video/fbdev: refactor video= cmdline parsing fbdev: mbx: fix up debugfs file creation fbdev: omap2: no need to check return value of debugfs_create functions video: fbdev: geode: remove ifdef OLPC noise video: offb: annotate implicit fall throughs omapfb: fix typo fbdev: Use of_node_name_eq for node name comparisons fbcon: use kvmalloc() for scrollback buffer fbdev: chipsfb: remove set but not used variable 'size' fbdev/via: fix spelling mistake "Expandsion" -> "Expansion"
| * printk: Export console_printkPrarit Bhargava2019-02-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | The fbcon can be built as a module and requires console_printk. Export console_printk. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
* | memblock: drop memblock_alloc_*_nopanic() variantsMike Rapoport2019-03-121-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As all the memblock allocation functions return NULL in case of error rather than panic(), the duplicates with _nopanic suffix can be removed. Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [printk] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> [c-sky] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Juergen Gross <jgross@suse.com> [Xen] Cc: Mark Salter <msalter@redhat.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: Paul Burton <paul.burton@mips.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'printk-for-5.1' of ↵Linus Torvalds2019-03-091-20/+70
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow to sort mixed lines by an extra information about the caller - Remove no longer used LOG_PREFIX. - Some clean up and documentation update. * tag 'printk-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk/docs: Add extra integer types to printk-formats printk: Remove no longer used LOG_PREFIX. lib/vsprintf: Remove %pCr remnant in comment printk: Pass caller information to log_store(). printk: Add caller information to printk() output.
| * printk: Remove no longer used LOG_PREFIX.Tetsuo Handa2019-03-041-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When commit 5becfb1df5ac8e49 ("kmsg: merge continuation records while printing") introduced LOG_PREFIX, we used KERN_DEFAULT etc. as a flag for setting LOG_PREFIX in order to tell whether to call cont_add() (i.e. whether to append the message to "struct cont"). But since commit 4bcc595ccd80decb ("printk: reinstate KERN_CONT for printing continuation lines") inverted the behavior (i.e. don't append the message to "struct cont" unless KERN_CONT is specified) and commit 5aa068ea4082b39e ("printk: remove games with previous record flags") removed the last LOG_PREFIX check, setting LOG_PREFIX via KERN_DEFAULT etc. is no longer meaningful. Therefore, we can remove LOG_PREFIX and make KERN_DEFAULT empty string. Link: http://lkml.kernel.org/r/1550829580-9189-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp To: Steven Rostedt <rostedt@goodmis.org> To: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
| * printk: Pass caller information to log_store().Tetsuo Handa2019-02-211-15/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When thread1 called printk() which did not end with '\n', and then thread2 called printk() which ends with '\n' before thread1 calls pr_cont(), the partial content saved into "struct cont" is flushed by thread2 despite the partial content was generated by thread1. This leads to confusing output as if the partial content was generated by thread2. Fix this problem by passing correct caller information to log_store(). Before: [ T8533] abcdefghijklm [ T8533] ABCDEFGHIJKLMNOPQRSTUVWXYZ [ T8532] nopqrstuvwxyz [ T8532] abcdefghijklmnopqrstuvwxyz [ T8533] abcdefghijklm [ T8533] ABCDEFGHIJKLMNOPQRSTUVWXYZ [ T8532] nopqrstuvwxyz After: [ T8507] abcdefghijklm [ T8508] ABCDEFGHIJKLMNOPQRSTUVWXYZ [ T8507] nopqrstuvwxyz [ T8507] abcdefghijklmnopqrstuvwxyz [ T8507] abcdefghijklm [ T8508] ABCDEFGHIJKLMNOPQRSTUVWXYZ [ T8507] nopqrstuvwxyz Link: http://lkml.kernel.org/r/1550314773-8607-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp To: Dmitry Vyukov <dvyukov@google.com> To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> To: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek: broke 80-column rule where it made more harm than good] Signed-off-by: Petr Mladek <pmladek@suse.com>
| * printk: Add caller information to printk() output.Tetsuo Handa2018-12-181-4/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes we want to print a series of printk() messages to consoles without being disturbed by concurrent printk() from interrupts and/or other threads. But we can't enforce printk() callers to use their local buffers because we need to ask them to make too much changes. Also, even buffering up to one line inside printk() might cause failing to emit an important clue under critical situation. Therefore, instead of trying to help buffering, let's try to help reconstructing messages by saving caller information as of calling log_store() and adding it as "[T$thread_id]" or "[C$processor_id]" upon printing to consoles. Some examples for console output: [ 1.222773][ T1] x86: Booting SMP configuration: [ 2.779635][ T1] pci 0000:00:01.0: PCI bridge to [bus 01] [ 5.069193][ T268] Fusion MPT base driver 3.04.20 [ 9.316504][ C2] random: fast init done [ 13.413336][ T3355] Initialized host personality Some examples for /dev/kmsg output: 6,496,1222773,-,caller=T1;x86: Booting SMP configuration: 6,968,2779635,-,caller=T1;pci 0000:00:01.0: PCI bridge to [bus 01] SUBSYSTEM=pci DEVICE=+pci:0000:00:01.0 6,1353,5069193,-,caller=T268;Fusion MPT base driver 3.04.20 5,1526,9316504,-,caller=C2;random: fast init done 6,1575,13413336,-,caller=T3355;Initialized host personality Note that this patch changes max length of messages which can be printed by printk() or written to /dev/kmsg interface from 992 bytes to 976 bytes, based on an assumption that userspace won't try to write messages hitting that border line to /dev/kmsg interface. Link: http://lkml.kernel.org/r/93f19e57-5051-c67d-9af4-b17624062d44@i-love.sakura.ne.jp Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* | 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 'printk-for-4.21' of ↵Linus Torvalds2018-12-271-68/+63
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Keep spinlocks busted until the end of panic() - Fix races between calculating number of messages that would fit into user space buffers, filling the buffers, and switching printk.time parameter - Some code clean up * tag 'printk-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk: Remove print_prefix() calls with NULL buffer. printk: fix printk_time race. printk: Make printk_emit() local function. panic: avoid deadlocks in re-entrant console drivers
| * printk: Remove print_prefix() calls with NULL buffer.Tetsuo Handa2018-12-121-25/+14
| | | | | | | | | | | | | | | | | | | | | | | | We can save lines/size by removing print_prefix() with buf == NULL. This patch makes no functional change. Link: http://lkml.kernel.org/r/1544521745-11925-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp To: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
| * printk: fix printk_time race.Tetsuo Handa2018-12-101-31/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since printk_time can be toggled via /sys/module/printk/parameters/time , it is not safe to assume that output length does not change across multiple msg_print_text() calls. If we hit this race, we can observe failures such as SYSLOG_ACTION_READ_ALL writes more bytes than userspace has supplied, SYSLOG_ACTION_SIZE_UNREAD returns -EFAULT when succeeded, SYSLOG_ACTION_READ reads garbage memory or even triggers an kernel oops at _copy_to_user() due to integer overflow. To close this race, get a snapshot value of printk_time and pass it to SYSLOG_ACTION_READ, SYSLOG_ACTION_READ_ALL, SYSLOG_ACTION_SIZE_UNREAD and kmsg_dump_get_buffer(). Link: http://lkml.kernel.org/r/555af37c-b9e0-f940-cb73-a78eba2d4944@i-love.sakura.ne.jp To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
| * printk: Make printk_emit() local function.Tetsuo Handa2018-11-291-16/+14
| | | | | | | | | | | | | | | | | | | | | | printk_emit() is called from only devkmsg_write() in the same file. Save object size by making it a local function. Link: http://lkml.kernel.org/r/5cc99d2c-c408-34f7-d1fc-e1cd2a9e31da@i-love.sakura.ne.jp Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* | mm: remove include/linux/bootmem.hMike Rapoport2018-10-311-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memblock: remove _virt from APIs returning virtual addressMike Rapoport2018-10-311-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The conversion is done using sed -i 's@memblock_virt_alloc@memblock_alloc@g' \ $(git grep -l memblock_virt_alloc) Link: http://lkml.kernel.org/r/1536927045-23536-8-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* printk: fix integer overflow in setup_log_buf()Sergey Senozhatsky2018-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The way we calculate logbuf free space percentage overflows signed integer: int free; free = __LOG_BUF_LEN - log_next_idx; pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); We support LOG_BUF_LEN of up to 1<<25 bytes. Since setup_log_buf() is called during early init, logbuf is mostly empty, so __LOG_BUF_LEN - log_next_idx is close to 1<<25. Thus when we multiply it by 100, we overflow signed integer value range: 100 is 2^6 + 2^5 + 2^2. Example, booting with LOG_BUF_LEN 1<<25 and log_buf_len=2G boot param: [ 0.075317] log_buf_len: -2147483648 bytes [ 0.075319] early log buf free: 33549896(-28%) Make "free" unsigned integer and use appropriate printk() specifier. Link: http://lkml.kernel.org/r/20181010113308.9337-1-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: do not preliminary split up cont bufferSergey Senozhatsky2018-10-121-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have a proper 'overflow' check which tells us that we need to split up existing cont buffer in separate records: if (cont.len + len > sizeof(cont.buf)) cont_flush(); At the same time we also have one extra flush: "if cont buffer is 80% full then split it up" in cont_add(): if (cont.len > (sizeof(cont.buf) * 80) / 100) cont_flush(); This looks to be redundant, since the existing "overflow" check should work just fine, so remove this 80% check and wait for either a normal cont termination \n, for preliminary flush due to possible buffer overflow or for preliminary flush due to cont race. Link: http://lkml.kernel.org/r/20181002023836.4487-4-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: lock/unlock console only for new logbuf entriesSergey Senozhatsky2018-10-121-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to commit 5c2992ee7fd8a29 ("printk: remove console flushing special cases for partial buffered lines") we would do console_cont_flush() for each pr_cont() to print cont fragments, so console_unlock() would actually print data: pr_cont(); console_lock(); console_unlock() console_cont_flush(); // print cont fragment ... pr_cont(); console_lock(); console_unlock() console_cont_flush(); // print cont fragment We don't do console_cont_flush() anymore, so when we do pr_cont() console_unlock() does nothing (unless we flushed the cont buffer): pr_cont(); console_lock(); console_unlock(); // noop ... pr_cont(); console_lock(); console_unlock(); // noop ... pr_cont(); cont_flush(); console_lock(); console_unlock(); // print data We also wakeup klogd purposelessly for pr_cont() output - un-flushed cont buffer is not stored in log_buf; there is nothing to pull. Thus we can console_lock()/console_unlock()/wake_up_klogd() only when we know that we log_store()-ed a message and there is something to print to the consoles/syslog. Link: http://lkml.kernel.org/r/20181002023836.4487-3-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: keep kernel cont support always enabledSergey Senozhatsky2018-10-121-18/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 5c2992ee7fd8a29 ("printk: remove console flushing special cases for partial buffered lines") we don't print cont fragments to the consoles; cont lines are now proper log_buf entries and there is no "consecutive continuation flag" anymore: we either have 'c' entries that mark continuation lines without fragments; or '-' entries that mark normal logbuf entries. There are no '+' entries anymore. However, we still have a small leftover - presence of ext_console drivers disables kernel cont support and we flush each pr_cont() and store it as a separate log_buf entry. Previously, it worked because msg_print_ext_header() had that "an optional external merge of the records" functionality: if (msg->flags & LOG_CONT) cont = (prev_flags & LOG_CONT) ? '+' : 'c'; We don't do this as of now, so keep kernel cont always enabled. Note from pmladek: The original purpose was to get full information including the metadata and dictionary via extended console drivers, see commit 6fe29354befe4c46e ("printk: implement support for extended console drivers"). The dictionary probably was the most important part but it was actually lost: static void cont_flush(void) { [...] log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, NULL, 0, cont.buf, cont.len); Nobody noticed because the only dictionary user is dev_printk() and dev_cont() is _not_ defined. Link: http://lkml.kernel.org/r/20181002023836.4487-2-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: LKML <linux-kernel@vger.kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: Updated commit message] Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Give error on attempt to set log buffer length to over 2GHe Zhe2018-10-091-6/+12
| | | | | | | | | | | | | | | | The current printk() is ready to handle log buffer size up to 2G. Give an explicit error for users who want to use larger log buffer. Also fix printk formatting to show the 2G as a positive number. Link: http://lkml.kernel.org/r/20181008135916.gg4kkmoki5bgtco5@pathway.suse.cz Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek: Fixed to the really safe limit 2GB.] Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Add KBUILD_MODNAME and remove a redundant print prefixHe Zhe2018-10-051-1/+3
| | | | | | | | | | | Add KBUILD_MODNAME to make prints more clear. Link: http://lkml.kernel.org/r/1538239553-81805-3-git-send-email-zhe.he@windriver.com Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Correct wrong castingHe Zhe2018-10-051-2/+3
| | | | | | | | | | | | | log_first_seq and console_seq are 64-bit unsigned integers. Correct a wrong casting that might cut off the output. Link: http://lkml.kernel.org/r/1538239553-81805-2-git-send-email-zhe.he@windriver.com Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe <zhe.he@windriver.com> [sergey.senozhatsky@gmail.com: More descriptive commit message] Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Fix panic caused by passing log_buf_len to command lineHe Zhe2018-10-051-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | log_buf_len_setup does not check input argument before passing it to simple_strtoull. The argument would be a NULL pointer if "log_buf_len", without its value, is set in command line and thus causes the following panic. PANIC: early exception 0xe3 IP 10:ffffffffaaeacd0d error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc4-yocto-standard+ #1 [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 ... [ 0.000000] Call Trace: [ 0.000000] simple_strtoull+0x29/0x70 [ 0.000000] memparse+0x26/0x90 [ 0.000000] log_buf_len_setup+0x17/0x22 [ 0.000000] do_early_param+0x57/0x8e [ 0.000000] parse_args+0x208/0x320 [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_options+0x29/0x2d [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_param+0x36/0x4d [ 0.000000] setup_arch+0x336/0x99e [ 0.000000] start_kernel+0x6f/0x4ee [ 0.000000] x86_64_start_reservations+0x24/0x26 [ 0.000000] x86_64_start_kernel+0x6f/0x72 [ 0.000000] secondary_startup_64+0xa4/0xb0 This patch adds a check to prevent the panic. Link: http://lkml.kernel.org/r/1538239553-81805-1-git-send-email-zhe.he@windriver.com Cc: stable@vger.kernel.org Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: CON_PRINTBUFFER console registration is a bit racySergey Senozhatsky2018-10-021-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CON_PRINTBUFFER console registration requires us to do several preparation steps: - Rollback console_seq to replay logbuf messages which were already seen on other consoles; - Set exclusive_console flag so console_unlock() will ->write() logbuf messages only to the exclusive_console driver. The way we do it, however, is a bit racy logbuf_lock_irqsave(flags); console_seq = syslog_seq; console_idx = syslog_idx; logbuf_unlock_irqrestore(flags); << preemption enabled << irqs enabled exclusive_console = newcon; console_unlock(); We rollback console_seq under logbuf_lock with IRQs disabled, but we set exclusive_console with local IRQs enabled and logbuf unlocked. If the system oops-es or panic-s before we set exclusive_console - and given that we have IRQs and preemption enabled there is such a possibility - we will re-play all logbuf messages to every registered console, which may be a bit annoying and time consuming. Move exclusive_console assignment to the same IRQs-disabled and logbuf_lock-protected section where we rollback console_seq. Link: http://lkml.kernel.org/r/20180928095304.9972-1-sergey.senozhatsky@gmail.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Do not miss new messages when replaying the logPetr Mladek2018-10-021-4/+9
| | | | | | | | | | | | | | | | | | | | The variable "exclusive_console" is used to reply all existing messages on a newly registered console. It is cleared when all messages are out. The problem is that new messages might appear in the meantime. These are then visible only on the exclusive console. The obvious solution is to clear "exclusive_console" after we replay all messages that were already proceed before we started the reply. Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: http://lkml.kernel.org/r/20180913123406.14378-1-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* Merge tag 'printk-for-4.19-rc4' of ↵Linus Torvalds2018-09-141-7/+5
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk fix from Petr Mladek: "Revert a commit that caused "quiet", "debug", and "loglevel" early parameters to be ignored for early boot messages" * tag 'printk-for-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: Revert "printk: make sure to print log on console."
| * Revert "printk: make sure to print log on console."Petr Mladek2018-09-111-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 375899cddcbb26881b03cb3fbdcfd600e4e67f4a. The visibility of early messages did not longer take into account "quiet", "debug", and "loglevel" early parameters. It would be possible to invalidate and recompute LOG_NOCONS flag for the affected messages. But it would be hairy. Instead this patch just reverts the problematic commit. We could come up with a better solution for the original problem. For example, we could simplify the logic and just mark messages that should always be visible or always invisible on the console. Also this patch reverts the related build fix commit ffaa619af1b06 ("printk: Fix warning about unused suppress_message_printing"). Finally, this patch does not put back the unused LOG_NOCONS flag. Link: http://lkml.kernel.org/r/20180910145747.emvfzv4mzlk5dfqk@pathway.suse.cz Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Maninder Singh <maninder1.s@samsung.com> Reported-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* | printk/tracing: Do not trace printk_nmi_enter()Steven Rostedt (VMware)2018-09-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I hit the following splat in my tests: ------------[ cut here ]------------ IRQs not enabled as expected WARNING: CPU: 3 PID: 0 at kernel/time/tick-sched.c:982 tick_nohz_idle_enter+0x44/0x8c Modules linked in: ip6t_REJECT nf_reject_ipv6 ip6table_filter ip6_tables ipv6 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.19.0-rc2-test+ #2 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 EIP: tick_nohz_idle_enter+0x44/0x8c Code: ec 05 00 00 00 75 26 83 b8 c0 05 00 00 00 75 1d 80 3d d0 36 3e c1 00 75 14 68 94 63 12 c1 c6 05 d0 36 3e c1 01 e8 04 ee f8 ff <0f> 0b 58 fa bb a0 e5 66 c1 e8 25 0f 04 00 64 03 1d 28 31 52 c1 8b EAX: 0000001c EBX: f26e7f8c ECX: 00000006 EDX: 00000007 ESI: f26dd1c0 EDI: 00000000 EBP: f26e7f40 ESP: f26e7f38 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010296 CR0: 80050033 CR2: 0813c6b0 CR3: 2f342000 CR4: 001406f0 Call Trace: do_idle+0x33/0x202 cpu_startup_entry+0x61/0x63 start_secondary+0x18e/0x1ed startup_32_smp+0x164/0x168 irq event stamp: 18773830 hardirqs last enabled at (18773829): [<c040150c>] trace_hardirqs_on_thunk+0xc/0x10 hardirqs last disabled at (18773830): [<c040151c>] trace_hardirqs_off_thunk+0xc/0x10 softirqs last enabled at (18773824): [<c0ddaa6f>] __do_softirq+0x25f/0x2bf softirqs last disabled at (18773767): [<c0416bbe>] call_on_stack+0x45/0x4b ---[ end trace b7c64aa79e17954a ]--- After a bit of debugging, I found what was happening. This would trigger when performing "perf" with a high NMI interrupt rate, while enabling and disabling function tracer. Ftrace uses breakpoints to convert the nops at the start of functions to calls to the function trampolines. The breakpoint traps disable interrupts and this makes calls into lockdep via the trace_hardirqs_off_thunk in the entry.S code. What happens is the following: do_idle { [interrupts enabled] <interrupt> [interrupts disabled] TRACE_IRQS_OFF [lockdep says irqs off] [...] TRACE_IRQS_IRET test if pt_regs say return to interrupts enabled [yes] TRACE_IRQS_ON [lockdep says irqs are on] <nmi> nmi_enter() { printk_nmi_enter() [traced by ftrace] [ hit ftrace breakpoint ] <breakpoint exception> TRACE_IRQS_OFF [lockdep says irqs off] [...] TRACE_IRQS_IRET [return from breakpoint] test if pt_regs say interrupts enabled [no] [iret back to interrupt] [iret back to code] tick_nohz_idle_enter() { lockdep_assert_irqs_enabled() [lockdep say no!] Although interrupts are indeed enabled, lockdep thinks it is not, and since we now do asserts via lockdep, it gives a false warning. The issue here is that printk_nmi_enter() is called before lockdep_off(), which disables lockdep (for this reason) in NMIs. By simply not allowing ftrace to see printk_nmi_enter() (via notrace annotation) we keep lockdep from getting confused. Cc: stable@vger.kernel.org Fixes: 42a0bb3f71383 ("printk/nmi: generic solution for safe printk in NMI") Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | notifier: Remove notifier header file wherever not usedMukesh Ojha2018-08-301-1/+0
| | | | | | | | | | | | | | | | | | | | The conversion of the hotplug notifiers to a state machine left the notifier.h includes around in some places. Remove them. Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1535114033-4605-1-git-send-email-mojha@codeaurora.org
* | Merge tag 'fbdev-v4.19' of https://github.com/bzolnier/linuxLinus Torvalds2018-08-241-0/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull fbdev updates from Bartlomiej Zolnierkiewicz: "Mostly small fixes and cleanups for fb drivers (the biggest updates are for udlfb and pxafb drivers). This also adds deferred console takeover support to the console code and efifb driver. Summary: - add support for deferred console takeover, when enabled defers fbcon taking over the console from the dummy console until the first text is displayed on the console - together with the "quiet" kernel commandline option this allows fbcon to still be used together with a smooth graphical bootup (Hans de Goede) - improve console locking debugging code (Thomas Zimmermann) - copy the ACPI BGRT boot graphics to the framebuffer when deferred console takeover support is used in efifb driver (Hans de Goede) - update udlfb driver - fix lost console when the user unplugs a USB adapter, fix the screen corruption issue, fix locking and add some performance optimizations (Mikulas Patocka) - update pxafb driver - fix using uninitialized memory, switch to devm_* API, handle initialization errors and add support for lcd-supply regulator (Daniel Mack) - add support for boards booted with a DeviceTree in pxa3xx_gcu driver (Daniel Mack) - rename omap2 module to omap2fb.ko to avoid conflicts with omap1 driver (Arnd Bergmann) - enable ACPI-based enumeration for goldfishfb driver (Yu Ning) - fix goldfishfb driver to make user space Android code use 60 fps (Christoffer Dall) - print big fat warning when nomodeset kernel parameter is used in vgacon driver (Lyude Paul) - remove VLA usage from fsl-diu-fb driver (Kees Cook) - misc fixes (Julia Lawall, Geert Uytterhoeven, Fredrik Noring, Yisheng Xie, Dan Carpenter, Daniel Vetter, Anton Vasilyev, Randy Dunlap, Gustavo A. R. Silva, Colin Ian King, Fengguang Wu) - misc cleanups (Roman Kiryanov, Yisheng Xie, Colin Ian King)" * tag 'fbdev-v4.19' of https://github.com/bzolnier/linux: (54 commits) Documentation/fb: corrections for fbcon.txt fbcon: Do not takeover the console from atomic context dummycon: Stop exporting dummycon_[un]register_output_notifier fbcon: Only defer console takeover if the current console driver is the dummycon fbcon: Only allow FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER if fbdev is builtin fbdev: omap2: omapfb: fix ifnullfree.cocci warnings fbdev: omap2: omapfb: fix bugon.cocci warnings fbdev: omap2: omapfb: fix boolreturn.cocci warnings fb: amifb: fix build warnings when not builtin fbdev/core: Disable console-lock warnings when fb.lockless_register_fb is set console: Replace #if 0 with atomic var 'ignore_console_lock_warning' udlfb: use spin_lock_irq instead of spin_lock_irqsave udlfb: avoid prefetch udlfb: optimization - test the backing buffer udlfb: allow reallocating the framebuffer udlfb: set line_length in dlfb_ops_set_par udlfb: handle allocation failure udlfb: set optimal write delay udlfb: make a local copy of fb_ops udlfb: don't switch if we are switching to the same videomode ...
| * | console: Replace #if 0 with atomic var 'ignore_console_lock_warning'Thomas Zimmermann2018-07-311-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The macro WARN_CONSOLE_UNLOCKED prints a warning when a thread enters the console's critical section without having acquired the console lock. The console lock can be ignored when debugging the console using printk, but this makes WARN_CONSOLE_UNLOCKED generate unnecessary warnings. The variable ignore_console_lock_warning temporarily disables WARN_CONSOLE_UNLOCKED. Developers interested in debugging the console's critical sections should increment it before entering the CS and decrement it after leaving the CS. Setting ignore_console_lock_warning is only for debugging. Regular operation should not manipulate it. Acknoledgements: This patch is based on an earlier version by Steven Rostedt. The use of atomic increment/decrement was suggested by Petr Mladek. Link: http://lkml.kernel.org/r/717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> [b.zolnierkie: use <linux/atomic.h>] Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
* | | init: allow initcall tables to be emitted using relative referencesArd Biesheuvel2018-08-221-7/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the initcall tables to be emitted using relative references that are only half the size on 64-bit architectures and don't require fixups at runtime on relocatable kernels. Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.org Acked-by: James Morris <james.morris@microsoft.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drmLinus Torvalds2018-08-161-0/+1
|\| | | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull drm updates from Dave Airlie: "This is the main drm pull request for 4.19. Rob has some new hardware support for new qualcomm hw that I'll send along separately. This has the display part of it, the remaining pull is for the acceleration engine. This also contains a wound-wait/wait-die mutex rework, Peter has acked it for merging via my tree. Otherwise mostly the usual level of activity. Summary: core: - Wound-wait/wait-die mutex rework - Add writeback connector type - Add "content type" property for HDMI - Move GEM bo to drm_framebuffer - Initial gpu scheduler documentation - GPU scheduler fixes for dying processes - Console deferred fbcon takeover support - Displayport support for CEC tunneling over AUX panel: - otm8009a panel driver fixes - Innolux TV123WAM and G070Y2-L01 panel driver - Ilitek ILI9881c panel driver - Rocktech RK070ER9427 LCD - EDT ETM0700G0EDH6 and EDT ETM0700G0BDH6 - DLC DLC0700YZG-1 - BOE HV070WSA-100 - newhaven, nhd-4.3-480272ef-atxl LCD - DataImage SCF0700C48GGU18 - Sharp LQ035Q7DB03 - p079zca: Refactor to support multiple panels tinydrm: - ILI9341 display panel New driver: - vkms - virtual kms driver to testing. i915: - Icelake: Display enablement DSI support IRQ support Powerwell support - GPU reset fixes and improvements - Full ppgtt support refactoring - PSR fixes and improvements - Execlist improvments - GuC related fixes amdgpu: - Initial amdgpu documentation - JPEG engine support on VCN - CIK uses powerplay by default - Move to using core PCIE functionality for gens/lanes - DC/Powerplay interface rework - Stutter mode support for RV - Vega12 Powerplay updates - GFXOFF fixes - GPUVM fault debugging - Vega12 GFXOFF - DC improvements - DC i2c/aux changes - UVD 7.2 fixes - Powerplay fixes for Polaris12, CZ/ST - command submission bo_list fixes amdkfd: - Raven support - Power management fixes udl: - Cleanups and fixes nouveau: - misc fixes and cleanups. msm: - DPU1 support display controller in sdm845 - GPU coredump support. vmwgfx: - Atomic modesetting validation fixes - Support for multisample surfaces armada: - Atomic modesetting support completed. exynos: - IPPv2 fixes - Move g2d to component framework - Suspend/resume support cleanups - Driver cleanups imx: - CSI configuration improvements - Driver cleanups - Use atomic suspend/resume helpers - ipu-v3 V4L2 XRGB32/XBGR32 support pl111: - Add Nomadik LCDC variant v3d: - GPU scheduler jobs management sun4i: - R40 display engine support - TCON TOP driver mediatek: - MT2712 SoC support rockchip: - vop fixes omapdrm: - Workaround for DRA7 errata i932 - Fix mm_list locking mali-dp: - Writeback implementation PM improvements - Internal error reporting debugfs tilcdc: - Single fix for deferred probing hdlcd: - Teardown fixes tda998x: - Converted to a bridge driver. etnaviv: - Misc fixes" * tag 'drm-next-2018-08-15' of git://anongit.freedesktop.org/drm/drm: (1506 commits) drm/amdgpu/sriov: give 8s for recover vram under RUNTIME drm/scheduler: fix param documentation drm/i2c: tda998x: correct PLL divider calculation drm/i2c: tda998x: get rid of private fill_modes function drm/i2c: tda998x: move mode_valid() to bridge drm/i2c: tda998x: register bridge outside of component helper drm/i2c: tda998x: cleanup from previous changes drm/i2c: tda998x: allocate tda998x_priv inside tda998x_create() drm/i2c: tda998x: convert to bridge driver drm/scheduler: fix timeout worker setup for out of order job completions drm/amd/display: display connected to dp-1 does not light up drm/amd/display: update clk for various HDMI color depths drm/amd/display: program display clock on cache match drm/amd/display: Add NULL check for enabling dp ss drm/amd/display: add vbios table check for enabling dp ss drm/amd/display: Don't share clk source between DP and HDMI drm/amd/display: Fix DP HBR2 Eye Diagram Pattern on Carrizo drm/amd/display: Use calculated disp_clk_khz value for dce110 drm/amd/display: Implement custom degamma lut on dcn drm/amd/display: Destroy aux_engines only once ...
| * printk: Export is_console_lockedHans de Goede2018-06-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparation patch for adding a number of WARN_CONSOLE_UNLOCKED() calls to the fbcon code, which may be built as a module (event though usually it is not). Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
* | Merge branch 'for-4.19-nmi' into for-linusPetr Mladek2018-08-143-44/+80
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| * | printk/nmi: Prevent deadlock when accessing the main log buffer in NMIPetr Mladek2018-07-092-22/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") brought back the possible deadlocks in printk() and NMI. The check of logbuf_lock is done only in printk_nmi_enter() to prevent mixed output. But another CPU might take the lock later, enter NMI, and: + Both NMIs might be serialized by yet another lock, for example, the one in nmi_cpu_backtrace(). + The other CPU might get stopped in NMI, see smp_send_stop() in panic(). The only safe solution is to use trylock when storing the message into the main log-buffer. It might cause reordering when some lines go to the main lock buffer directly and others are delayed via the per-CPU buffer. It means that it is not useful in general. This patch replaces the problematic NMI deferred context with NMI direct context. It can be used to mark a code that might produce many messages in NMI and the risk of losing them is more critical than problems with eventual reordering. The context is then used when dumping trace buffers on oops. It was the primary motivation for the original fix. Also the reordering is even smaller issue there because some traces have their own time stamps. Finally, nmi_cpu_backtrace() need not longer be serialized because it will always us the per-CPU buffers again. Fixes: 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI when logbuf_lock is available") Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
| * | printk: Create helper function to queue deferred console handlingPetr Mladek2018-07-091-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is just a preparation step. The patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20180627140817.27764-3-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
| * | printk: Split the code for storing a message into the log bufferPetr Mladek2018-07-091-17/+26
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is just a preparation step. The patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20180627140817.27764-2-pmladek@suse.com To: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
* | printk: Fix warning about unused suppress_message_printingPetr Mladek2018-07-111-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | suppress_message_printing() is not longer called in console_unlock(). Therefore it is not longer needed with disabled CONFIG_PRINTK. This fixes the warning: kernel/printk/printk.c:2033:13: warning: ‘suppress_message_printing’ defined but not used [-Wunused-function] static bool suppress_message_printing(int level) { return false; } Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Maninder Singh <maninder1.s@samsung.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
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