user/sven/linux.git/kernel/printk, branch v5.4.70

printk: handle blank console arguments passed in.

2020-10-01T11:18:04Z

[ Upstream commit 48021f98130880dd74286459a1ef48b5e9bc374f ] If uboot passes a blank string to console_setup then it results in a trashed memory. Ultimately, the kernel crashes during freeing up the memory. This fix checks if there is a blank parameter being passed to console_setup from uboot. In case it detects that the console parameter is blank then it doesn't setup the serial device and it gracefully exits. Link: https://lore.kernel.org/r/20200522065306.83-1-shreyas.joshi@biamp.com Signed-off-by: Shreyas Joshi Acked-by: Sergey Senozhatsky [pmladek@suse.com: Better format the commit message and code, remove unnecessary brackets.] Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin

printk: queue wake_up_klogd irq_work only if per-CPU areas are ready

2020-05-02T06:48:42Z

commit ab6f762f0f53162d41497708b33c9a3236d3609e upstream. printk_deferred(), similarly to printk_safe/printk_nmi, does not immediately attempt to print a new message on the consoles, avoiding calls into non-reentrant kernel paths, e.g. scheduler or timekeeping, which potentially can deadlock the system. Those printk() flavors, instead, rely on per-CPU flush irq_work to print messages from safer contexts. For same reasons (recursive scheduler or timekeeping calls) printk() uses per-CPU irq_work in order to wake up user space syslog/kmsg readers. However, only printk_safe/printk_nmi do make sure that per-CPU areas have been initialised and that it's safe to modify per-CPU irq_work. This means that, for instance, should printk_deferred() be invoked "too early", that is before per-CPU areas are initialised, printk_deferred() will perform illegal per-CPU access. Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random: silence a lockdep splat with printk()") user-space syslog/kmsg readers are not able to read new kernel messages. The reason is printk_deferred() being called too early (as was pointed out by Petr and John). Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU areas are initialized. Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/ Reported-by: Lech Perczak Signed-off-by: Sergey Senozhatsky Tested-by: Jann Horn Reviewed-by: Petr Mladek Cc: Greg Kroah-Hartman Cc: Theodore Ts'o Cc: John Ogness Signed-off-by: Linus Torvalds Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

printk: fix exclusive_console replaying

2020-02-24T07:36:24Z

[ Upstream commit def97da136515cb289a14729292c193e0a93bc64 ] 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 Cc: linux-kernel@vger.kernel.org Signed-off-by: John Ogness Acked-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Sasha Levin

Merge branch 'for-5.4' into for-linus

2019-09-16T10:54:25Z

printk: Replace strncmp() with str_has_prefix()

2019-08-16T07:54:08Z

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" Cc: linux-kernel@vger.kernel.org Signed-off-by: Chuhong Yuan Reviewed-by: Sergey Senozhatsky [pmladek@suse.com: Slightly updated and reformatted the commit message.] Signed-off-by: Petr Mladek

printk: Do not lose last line in kmsg buffer dump

2019-07-12T12:10:58Z

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: # v3.5+ Signed-off-by: Vincent Whitchurch Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13

2019-05-21T09:28:45Z

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 Reviewed-by: Kate Stewart Reviewed-by: Jilayne Lovejoy Reviewed-by: Steve Winslow Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46Z

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 Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45Z

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 Signed-off-by: Greg Kroah-Hartman

panic: add an option to replay all the printk message in buffer

2019-05-18T22:52:26Z

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 Reviewed-by: Petr Mladek Cc: Aaro Koskinen Cc: Petr Mladek Cc: Steven Rostedt Cc: Sergey Senozhatsky Cc: Kees Cook Cc: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds