summaryrefslogtreecommitdiffstats
path: root/kernel/printk
AgeCommit message (Collapse)AuthorFilesLines
2020-06-21Revert "kernel/printk: add kmsg SEEK_CUR handling"Jason A. Donenfeld1-10/+0
This reverts commit 8ece3b3eb576a78d2e67ad4c3a80a39fa6708809. This commit broke userspace. Bash uses ESPIPE to determine whether or not the file should be read using "unbuffered I/O", which means reading 1 byte at a time instead of 128 bytes at a time. I used to use bash to read through kmsg in a really quite nasty way: while read -t 0.1 -r line 2>/dev/null || [[ $? -ne 142 ]]; do echo "SARU $line" done < /dev/kmsg This will show all lines that can fit into the 128 byte buffer, and skip lines that don't. That's pretty awful, but at least it worked. With this change, bash now tries to do 1-byte reads, which means it skips all the lines, which is worse than before. Now, I don't really care very much about this, and I'm already look for a workaround. But I did just spend an hour trying to figure out why my scripts were broken. Either way, it makes no difference to me personally whether this is reverted, but it might be something to consider. If you declare that "trying to read /dev/kmsg with bash is terminally stupid anyway," I might be inclined to agree with you. But do note that bash uses lseek(fd, 0, SEEK_CUR)==>ESPIPE to determine whether or not it's reading from a pipe. Cc: Bruno Meneguele <bmeneg@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-12Merge tag 'printk-for-5.8-kdb-nmi' of ↵Linus Torvalds2-13/+8
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk fix from Petr Mladek: "One more printk change for 5.8: make sure that messages printed from KDB context are redirected to KDB console handlers. It did not work when KDB interrupted NMI or printk_safe contexts. Arm people started hitting this problem more often recently. I forgot to add the fix into the previous pull request by mistake" * tag 'printk-for-5.8-kdb-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk/kdb: Redirect printk messages into kdb in any context
2020-06-11printk/kdb: Redirect printk messages into kdb in any contextPetr Mladek2-13/+8
kdb has to get messages on consoles even when the system is stopped. It uses kdb_printf() internally and calls console drivers on its own. It uses a hack to reuse an existing code. It sets "kdb_trap_printk" global variable to redirect even the normal printk() into the kdb_printf() variant. The variable "kdb_trap_printk" is checked in printk_default() and it is ignored when printk is redirected to printk_safe in NMI context. Solve this by moving the check into printk_func(). It is obvious that it is not fully safe. But it does not make things worse. The console drivers are already called in this context by db_printf() direct calls. Reported-by: Sumit Garg <sumit.garg@linaro.org> Tested-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20200520102233.GC3464@linux-b0ei
2020-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-1/+1
Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
2020-06-01Merge tag 'core-rcu-2020-06-01' of ↵Linus Torvalds2-7/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The RCU updates for this cycle were: - RCU-tasks update, including addition of RCU Tasks Trace for BPF use and TASKS_RUDE_RCU - kfree_rcu() updates. - Remove scheduler locking restriction - RCU CPU stall warning updates. - Torture-test updates. - Miscellaneous fixes and other updates" * tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits) rcu: Allow for smp_call_function() running callbacks from idle rcu: Provide rcu_irq_exit_check_preempt() rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter() rcu: Provide __rcu_is_watching() rcu: Provide rcu_irq_exit_preempt() rcu: Make RCU IRQ enter/exit functions rely on in_nmi() rcu/tree: Mark the idle relevant functions noinstr x86: Replace ist_enter() with nmi_enter() x86/mce: Send #MC singal from task work x86/entry: Get rid of ist_begin/end_non_atomic() sched,rcu,tracing: Avoid tracing before in_nmi() is correct sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception lockdep: Always inline lockdep_{off,on}() hardirq/nmi: Allow nested nmi_enter() arm64: Prepare arch_nmi_enter() for recursion printk: Disallow instrumenting print_nmi_enter() printk: Prepare for nested printk_nmi_enter() rcutorture: Convert ULONG_CMP_LT() to time_before() torture: Add a --kasan argument torture: Save a few lines by using config_override_param initially ...
2020-06-01Merge tag 'printk-for-5.8' of ↵Linus Torvalds2-49/+97
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Benjamin Herrenschmidt solved a problem with non-matched console aliases by first checking consoles defined on the command line. It is a more conservative approach than the previous attempts. - Benjamin also made sure that the console accessible via /dev/console always has CON_CONSDEV flag. - Andy Shevchenko added the %ptT modifier for printing struct time64_t. It extends the existing %ptR handling for struct rtc_time. - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported SEEK_CUR. - Tetsuo Handa removed unused pr_cont_once(). ... and a few small fixes. * tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Remove pr_cont_once() printk: handle blank console arguments passed in. kernel/printk: add kmsg SEEK_CUR handling printk: Fix a typo in comment "interator"->"iterator" usb: pulse8-cec: Switch to use %ptT ARM: bcm2835: Switch to use %ptT lib/vsprintf: Print time64_t in human readable format lib/vsprintf: update comment about simple_strto<foo>() functions printk: Correctly set CON_CONSDEV even when preferred console was not registered printk: Fix preferred console selection with multiple matches printk: Move console matching logic into a separate function printk: Convert a use of sprintf to snprintf in console_unlock
2020-06-01Merge branch 'for-5.8' into for-linusPetr Mladek3-32/+84
2020-06-01Merge branch 'for-5.7-preferred-console' into for-linusPetr Mladek2-44/+79
2020-05-30printk: Introduce kmsg_dump_reason_str()Kees Cook1-0/+17
The pstore subsystem already had a private version of this function. With the coming addition of the pstore/zone driver, this needs to be shared. As it really should live with printk, move it there instead. Link: https://lore.kernel.org/lkml/20200515184434.8470-4-keescook@chromium.org/ Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-30printk: honor the max_reason field in kmsg_dumperPavel Tatashin1-4/+11
kmsg_dump() allows to dump kmesg buffer for various system events: oops, panic, reboot, etc. It provides an interface to register a callback call for clients, and in that callback interface there is a field "max_reason", but it was getting ignored when set to any "reason" higher than KMSG_DUMP_OOPS unless "always_kmsg_dump" was passed as kernel parameter. Allow clients to actually control their "max_reason", and keep the current behavior when "max_reason" is not set. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/lkml/20200515184434.8470-3-keescook@chromium.org/ Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-05-22printk: handle blank console arguments passed in.Shreyas Joshi1-0/+3
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 <shreyas.joshi@biamp.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: Better format the commit message and code, remove unnecessary brackets.] Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-05-21kernel/printk: add kmsg SEEK_CUR handlingBruno Meneguele1-0/+10
Userspace libraries, e.g. glibc's dprintf(), perform a SEEK_CUR operation over any file descriptor requested to make sure the current position isn't pointing to junk due to previous manipulation of that same fd. And whenever that fd doesn't have support for such operation, the userspace code expects -ESPIPE to be returned. However, when the fd in question references the /dev/kmsg interface, the current kernel code state returns -EINVAL instead, causing an unexpected behavior in userspace: in the case of glibc, when -ESPIPE is returned it gets ignored and the call completes successfully, while returning -EINVAL forces dprintf to fail without performing any action over that fd: if (_IO_SEEKOFF (fp, (off64_t)0, _IO_seek_cur, _IOS_INPUT|_IOS_OUTPUT) == _IO_pos_BAD && errno != ESPIPE) return NULL; With this patch we make sure to return the correct value when SEEK_CUR is requested over kmsg and also add some kernel doc information to formalize this behavior. Link: https://lore.kernel.org/r/20200317103344.574277-1-bmeneg@redhat.com Cc: linux-kernel@vger.kernel.org Cc: rostedt@goodmis.org, Cc: David.Laight@ACULAB.COM Signed-off-by: Bruno Meneguele <bmeneg@redhat.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-05-21printk: Fix a typo in comment "interator"->"iterator"Ethon Paul1-2/+2
There is a typo in comment, fix it. Signed-off-by: Ethon Paul <ethp@qq.com> Cc: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-05-19printk: Disallow instrumenting print_nmi_enter()Peter Zijlstra1-2/+3
It happens early in nmi_enter(), no tracing, probing or other funnies allowed. Specifically as nmi_enter() will be used in do_debug(), which would cause recursive exceptions when kprobed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200505134101.139720912@linutronix.de
2020-05-19printk: Prepare for nested printk_nmi_enter()Petr Mladek2-5/+7
There is plenty of space in the printk_context variable. Reserve one byte there for the NMI context to be on the safe side. It should never overflow. The BUG_ON(in_nmi() == NMI_MASK) in nmi_enter() will trigger much earlier. Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200505134100.681374113@linutronix.de
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig1-1/+1
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-10printk: queue wake_up_klogd irq_work only if per-CPU areas are readySergey Senozhatsky3-10/+40
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 <l.perczak@camlintechnologies.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Jann Horn <jannh@google.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: John Ogness <john.ogness@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-18printk: Correctly set CON_CONSDEV even when preferred console was not registeredBenjamin Herrenschmidt1-0/+2
CON_CONSDEV flag was historically used to put/keep the preferred console first in console_drivers list. Where the preferred console is the last on the command line. The ordering is important only when opening /dev/console: + tty_kopen() + tty_lookup_driver() + console_device() The flag was originally an implementation detail. But it was later made accessible from userspace via /proc/consoles. It was used, for example, by the tool "showconsole" to show the real tty accessible via /dev/console, see https://github.com/bitstreamout/showconsole Now, the current code sets CON_CONSDEV only for the preferred console or when a fallback console is added. The flag is not set when the preferred console is defined on the command line but it is not registered from some reasons. Simple solution is to set CON_CONSDEV flag for the first registered console. It will work most of the time because: + Most real consoles have console->device defined. + Boot consoles are removed in printk_late_init(). + unregister_console() moves CON_CONSDEV flag to the next console. Clean solution would require checking con->device when the preferred console is registered and in unregister_console(). Conclusion: Use the simple solution for now. It is better than the current state and good enough. The clean solution is not worth it. It would complicate the already complicated code without too much gain. Instead the code would deserve a complete rewrite. Link: https://lore.kernel.org/r/20200213095133.23176-4-pmladek@suse.com Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [pmladek@suse.com: Correct reasoning in the commit message, comment update.] Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-18printk: Fix preferred console selection with multiple matchesBenjamin Herrenschmidt2-11/+19
In the following circumstances, the rule of selecting the console corresponding to the last "console=" entry on the command line as the preferred console (CON_CONSDEV, ie, /dev/console) fails. This is a specific example, but it could happen with different consoles that have a similar name aliasing mechanism. - The kernel command line has both console=tty0 and console=ttyS0 in that order (the latter with speed etc... arguments). This is common with some cloud setups such as Amazon Linux. - add_preferred_console is called early to register "uart0". In our case that happens from acpi_parse_spcr() on arm64 since the "enable_console" argument is true on that architecture. This causes "uart0" to become entry 0 of the console_cmdline array. Now, because of the above, what happens is: - add_preferred_console is called by the cmdline parsing for tty0 and ttyS0 respectively, thus occupying entries 1 and 2 of the console_cmdline array (since this happens after ACPI SPCR parsing). At that point preferred_console is set to 2 as expected. - When the tty layer kicks in, it will call register_console for tty0. This will match entry 1 in console_cmdline array. It isn't our preferred console but because it's our only console at this point, it will end up "first" in the consoles list. - When 8250 probes the actual serial port later on, it calls register_console for ttyS0. At that point the loop in register_console tries to match it with the entries in the console_cmdline array. Ideally this should match ttyS0 in entry 2, which is preferred, causing it to be inserted first and to replace tty0 as CONSDEV. However, 8250 provides a "match" hook in its struct console, and that hook will match "uart" as an alias to "ttyS". So we match uart0 at entry 0 in the array which is not the preferred console and will not match entry 2 which is since we break out of the loop on the first match. As a result, we don't set CONSDEV and don't insert it first, but second in the console list. As a result, we end up with tty0 remaining first in the array, and thus /dev/console going there instead of the last user specified one which is ttyS0. This tentative fix register_console() to scan first for consoles specified on the command line, and only if none is found, to then scan for consoles specified by the architecture. Link: https://lore.kernel.org/r/20200213095133.23176-3-pmladek@suse.com Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-18printk: Move console matching logic into a separate functionBenjamin Herrenschmidt1-40/+65
This moves the loop that tries to match a newly registered console with the command line or add_preferred_console list into a separate helper, in order to be able to call it multiple times in subsequent patches. Link: https://lore.kernel.org/r/20200213095133.23176-2-pmladek@suse.com Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11printk: Convert a use of sprintf to snprintf in console_unlockNathan Chancellor1-3/+3
When CONFIG_PRINTK is disabled (e.g. when building allnoconfig), clang warns: ../kernel/printk/printk.c:2416:10: warning: 'sprintf' will always overflow; destination buffer has size 0, but format string expands to at least 33 [-Wfortify-source] len = sprintf(text, ^ 1 warning generated. It is not wrong; text has a zero size when CONFIG_PRINTK is disabled because LOG_LINE_MAX and PREFIX_MAX are both zero. Change to snprintf so that this case is explicitly handled without any risk of overflow. Link: https://github.com/ClangBuiltLinux/linux/issues/846 Link: https://github.com/llvm/llvm-project/commit/6d485ff455ea2b37fef9e06e426dae6c1241b231 Link: http://lkml.kernel.org/r/20200130221644.2273-1-natechancellor@gmail.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Introduce ->exit() callbackAndy Shevchenko1-0/+3
Some consoles might require special operations on unregistering. For instance, serial console, when registered in the kernel, keeps power on for entire time, until it gets unregistered. Example of use: ->setup(console): pm_runtime_get(...); ->exit(console): pm_runtime_put(...); For such cases to have a balance we would provide ->exit() callback. Link: http://lkml.kernel.org/r/20200203133130.11591-7-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Don't notify user space when unregister non-listed consoleAndy Shevchenko1-1/+11
If console is not on the list then there is nothing for us to do and sysfs notify is pointless. Note, that nr_ext_console_drivers is being changed only for listed consoles. Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Link: http://lkml.kernel.org/r/20200203133130.11591-6-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Avoid positive return code from unregister_console()Andy Shevchenko1-2/+4
There are only two callers that use the returned code from unregister_console(): - unregister_early_console() in arch/m68k/kernel/early_printk.c - kgdb_unregister_nmi_console() in drivers/tty/serial/kgdb_nmi.c They both expect to get "0" on success and a non-zero value on error. But the current behavior is confusing and buggy: - _braille_unregister_console() returns "1" on success - unregister_console() returns "1" on error Fix and clean up the behavior: - Return success when _braille_unregister_console() succeeded - Return a meaningful error code when the console was not registered before Link: http://lkml.kernel.org/r/20200203133130.11591-5-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Drop misleading commentAndy Shevchenko1-1/+0
/* find the last or real console */ This comment is misleading. The purpose of the loop is to check if we are trying to register boot console after a real one has already been registered. This is already mentioned in a comment above. Link: http://lkml.kernel.org/r/20200203133130.11591-4-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [pmladek@suse.com: Updated commit message.] Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Use for_each_console() helper in unregister_console()Andy Shevchenko1-6/+5
We have rather open coded single linked list manipulations where we may simple use for_each_console() helper with properly set exit conditions. Replace open coded single-linked list handling with for_each_console() helper in use. Link: http://lkml.kernel.org/r/20200203133130.11591-3-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11console: Drop double check for console_drivers being non-NULLAndy Shevchenko1-10/+6
There is no need to explicitly check for console_drivers to be non-NULL since for_each_console() does this. Link: http://lkml.kernel.org/r/20200203133130.11591-2-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-01-02printk: fix exclusive_console replayingJohn Ogness1-2/+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>
2019-12-03Merge branch 'irq-core-for-linus' of ↵Linus Torvalds1-1/+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 ...
2019-11-11irq_work: Convert flags to atomic_tFrederic Weisbecker1-1/+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>
2019-10-09locking/lockdep: Remove unused @nested argument from lock_release()Qian Cai1-5/+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>
2019-09-16Merge branch 'for-5.4' into for-linusPetr Mladek2-10/+27
2019-08-16printk: Replace strncmp() with str_has_prefix()Chuhong Yuan2-10/+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>
2019-07-12printk: Do not lose last line in kmsg buffer dumpVincent Whitchurch1-1/+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>
2019-05-21treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13Thomas Gleixner2-26/+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>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+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>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+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>
2019-05-18panic: add an option to replay all the printk message in bufferFeng Tang1-1/+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>
2019-05-14panic: avoid the extra noise dmesgFeng Tang1-0/+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>
2019-03-15Merge tag 'fbdev-v5.1' of git://github.com/bzolnier/linuxLinus Torvalds1-0/+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"
2019-03-12memblock: drop memblock_alloc_*_nopanic() variantsMike Rapoport1-8/+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>
2019-03-09Merge tag 'printk-for-5.1' of ↵Linus Torvalds1-20/+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.
2019-03-04printk: Remove no longer used LOG_PREFIX.Tetsuo Handa1-5/+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>
2019-02-21printk: Pass caller information to log_store().Tetsuo Handa1-15/+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>
2019-02-08printk: Export console_printkPrarit Bhargava1-0/+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>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-2/+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>
2018-12-27Merge tag 'printk-for-4.21' of ↵Linus Torvalds1-68/+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
2018-12-18printk: Add caller information to printk() output.Tetsuo Handa1-4/+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>
2018-12-12printk: Remove print_prefix() calls with NULL buffer.Tetsuo Handa1-25/+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>
2018-12-10printk: fix printk_time race.Tetsuo Handa1-31/+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>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 15:02:06 +0000