summaryrefslogtreecommitdiff
path: root/kernel/printk.c
AgeCommit message (Collapse)AuthorFilesLines
2010-01-24Merge git://git.infradead.org/~dwmw2/mtd-2.6.33Linus Torvalds1-0/+1
* git://git.infradead.org/~dwmw2/mtd-2.6.33: mtd: tests: fix read, speed and stress tests on NOR flash mtd: Really add ARM pismo support kmsg_dump: Dump on crash_kexec as well
2009-12-31kmsg_dump: Dump on crash_kexec as wellKOSAKI Motohiro1-0/+1
crash_kexec gets called before kmsg_dump(KMSG_DUMP_OOPS) if panic_on_oops is set, so the kernel log buffer is not stored for this case. This patch adds a KMSG_DUMP_KEXEC dump type which gets called when crash_kexec() is invoked. To avoid getting double dumps, the old KMSG_DUMP_PANIC is moved below crash_kexec(). The mtdoops driver is modified to handle KMSG_DUMP_KEXEC in the same way as a panic. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-12-18printk: fix new kernel-doc warningsRandy Dunlap1-2/+2
Fix kernel-doc warnings in printk.c: Warning(kernel/printk.c:1422): No description found for parameter 'dumper' Warning(kernel/printk.c:1422): Excess function parameter 'dump' description in 'kmsg_dump_register' Warning(kernel/printk.c:1451): No description found for parameter 'dumper' Warning(kernel/printk.c:1451): Excess function parameter 'dump' description in 'kmsg_dump_unregister' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16Merge git://git.infradead.org/mtd-2.6Linus Torvalds1-0/+119
* git://git.infradead.org/mtd-2.6: (90 commits) jffs2: Fix long-standing bug with symlink garbage collection. mtd: OneNAND: Fix test of unsigned in onenand_otp_walk() mtd: cfi_cmdset_0002, fix lock imbalance Revert "mtd: move mxcnd_remove to .exit.text" mtd: m25p80: add support for Macronix MX25L4005A kmsg_dump: fix build for CONFIG_PRINTK=n mtd: nandsim: add support for 4KiB pages mtd: mtdoops: refactor as a kmsg_dumper mtd: mtdoops: make record size configurable mtd: mtdoops: limit the maximum mtd partition size mtd: mtdoops: keep track of used/unused pages in an array mtd: mtdoops: several minor cleanups core: Add kernel message dumper to call on oopses and panics mtd: add ARM pismo support mtd: pxa3xx_nand: Fix PIO data transfer mtd: nand: fix multi-chip suspend problem mtd: add support for switching old SST chips into QRY mode mtd: fix M29W800D dev_id and uaddr mtd: don't use PF_MEMALLOC mtd: Add bad block table overrides to Davinci NAND driver ... Fixed up conflicts (mostly trivial) in drivers/mtd/devices/m25p80.c drivers/mtd/maps/pcmciamtd.c drivers/mtd/nand/pxa3xx_nand.c kernel/printk.c
2009-12-05Merge branch 'core-printk-for-linus' of ↵Linus Torvalds1-3/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ratelimit: Make suppressed output messages more useful printk: Remove ratelimit.h from kernel.h ratelimit: Fix/allow use in atomic contexts ratelimit: Use per ratelimit context locking
2009-12-02kmsg_dump: fix build for CONFIG_PRINTK=nRandy Dunlap1-1/+1
kmsg_dump() fails to build when CONFIG_PRINTK=n; provide stubs for the kmsg_dump*() functions when CONFIG_PRINTK=n. kernel/printk.c: In function 'kmsg_dump': kernel/printk.c:1501: error: 'log_buf_len' undeclared (first use in this function) kernel/printk.c:1502: error: 'logged_chars' undeclared (first use in this function) kernel/printk.c:1506: error: 'log_buf' undeclared (first use in this function) Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-11-30core: Add kernel message dumper to call on oopses and panicsSimon Kagstrom1-0/+119
The core functionality is implemented as per Linus suggestion from http://lists.infradead.org/pipermail/linux-mtd/2009-October/027620.html (with the kmsg_dump implementation by Linus). A struct kmsg_dumper has been added which contains a callback to dump the kernel log buffers on crashes. The kmsg_dump function gets called from oops_exit() and panic() and invokes this callbacks with the crash reason. [dwmw2: Fix log_end handling] Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net> Reviewed-by: Anders Grafstrom <anders.grafstrom@netinsight.net> Reviewed-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-23ratelimit: Make suppressed output messages more usefulChristian Borntraeger1-3/+3
Today I got: [39648.224782] Registered led device: iwl-phy0::TX [40676.545099] __ratelimit: 246 callbacks suppressed [40676.545103] abcdef[23675]: segfault at 0 ... as you can see the ratelimit message contains a function prefix. Since this is always __ratelimit, this wont help much. This patch changes __ratelimit and printk_ratelimit to print the function name that calls ratelimit. This will pinpoint the responsible function, as long as not several different places call ratelimit with the same ratelimit state at the same time. In that case we catch only one random function that calls ratelimit after the wait period. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> CC: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <200910231458.11832.borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-23printk: add printk_delay to make messages readable for some scenariosDave Young1-0/+15
When syslog is not possible, at the same time there's no serial/net console available, it will be hard to read the printk messages. For example oops/panic/warning messages in shutdown phase. Add a printk delay feature, we can make each printk message delay some milliseconds. Setting the delay by proc/sysctl interface: /proc/sys/kernel/printk_delay The value range from 0 - 10000, default value is 0 [akpm@linux-foundation.org: fix a few things] Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23printk boot_delay: rename printk_delay_msec to loops_per_msecDave Young1-7/+5
Rename `printk_delay_msec' to `loops_per_msec', because the patch "printk: add printk_delay to make messages readable for some scenarios" wishes to more appropriately use the `printk_delay_msec' identifier. [akpm@linux-foundation.org: add a comment] Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22printk: Remove ratelimit.h from kernel.hIngo Molnar1-0/+1
Decouple kernel.h from ratelimit.h: the global declaration of printk's ratelimit_state is not needed, and it leads to messy circular dependencies due to ratelimit.h's (new) adding of a spinlock_types.h include. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David S. Miller <davem@davemloft.net> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-15cleanup console_print()Anirban Sinha1-6/+0
console_print() is an old legacy interface mostly unused in the entire kernel tree. It's best to clean up its existing use and let developers use their own implementation of it as they feel fit. Signed-off-by: Anirban Sinha <asinha@zeugmasystems.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-08printk: Fix "printk: Enable the use of more than one CON_BOOT (early console)"Sonic Zhang1-1/+1
Don't return when we find the first bootconsole - it can leave other bootconsoles still installed, and they can be used and cause problems later (if they are in the init section, and eventually released), and cause problems. Make sure we remove all of them. Signed-off-by: Sonic Zhang <Sonic.Zhang@analog.com> Signed-off-by: Robin Getz <rgetz@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10printk: Restore previous console_loglevel when re-enabling loggingFrans Pop1-1/+10
When logging to console is disabled from userspace using klogctl() and later re-enabled, console_loglevel gets set to the default log level instead to the previous value. This means that if the kernel was booted with 'quiet', the boot is suddenly no longer quiet after logging to console gets re-enabled. Save the current console_loglevel when logging is disabled and restore to that value. If the log level is set to a specific value while disabled, this is interpreted as an implicit re-enabling of the logging. The problem that prompted this patch is described in: http://lkml.org/lkml/2009/6/28/234 There are two variations possible on the patch below: 1) If klogctl(7) is called while logging is not disabled, then set level to default (partially preserving current functionality): case 7: /* Enable logging to console */ - console_loglevel = default_console_loglevel; + if (saved_console_loglevel == -1) + console_loglevel = default_console_loglevel; + else { + console_loglevel = saved_console_loglevel; + saved_console_loglevel = -1; + } 2) If klogctl(8) is called while logging is disabled, then don't enable logging, but remember the requested value for when logging does get enabled again: case 8: /* Set level of messages printed to console */ [...] - console_loglevel = len; + if (saved_console_loglevel == -1) + console_loglevel = len; + else + saved_console_loglevel = len; Yet another option would be to ignore the request. Signed-off-by: Frans Pop <elendil@planet.nl> Cc: cryptsetup@packages.debian.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <200907061331.49930.elendil@planet.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10printk: Ensure that "console enabled" messages are printed on the consoleRobin Getz1-15/+29
Today, when a console is registered without CON_PRINTBUFFER, end users never see the announcement of it being added, and never know if they missed something, if the console is really at the start or not, and just leads to general confusion. This re-orders existing code, to make sure the console is added, before the "console [%s%d] enabled" is printed out - ensuring that this message is _always_ seen. This has the desired/intended side effect of making sure that "console enabled:" messages are printed on the bootconsole, and the real console. This does cause the same line is printed twice if the bootconsole and real console are the same device, but if they are on different devices, the message is printed to both consoles. Signed-off-by : Robin Getz <rgetz@blackfin.uclinux.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: "Linus Torvalds" <torvalds@linux-foundation.org> LKML-Reference: <200907091308.37370.rgetz@blackfin.uclinux.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-03printk: Enable the use of more than one CON_BOOT (early console)Robin Getz1-54/+92
Today, register_console() assumes the following usage: - The first console to register with a flag set to CON_BOOT is the one and only bootconsole. - If another register_console() is called with an additional CON_BOOT, it is silently rejected. - As soon as a console without the CON_BOOT set calls registers the bootconsole is automatically unregistered. - Once there is a "real" console - register_console() will silently reject any consoles with it's CON_BOOT flag set. In many systems (alpha, blackfin, microblaze, mips, powerpc, sh, & x86), there are early_printk implementations, which use the CON_BOOT which come out serial ports, vga, usb, & memory buffers. In many embedded systems, it would be nice to have two bootconsoles - in case the primary fails, you always have access to a backup memory buffer - but this requires at least two CON_BOOT consoles... This patch enables that functionality. With the change applied, on boot you get (if you try to re-enable a boot console after the "real" console has been registered): root:/> dmesg | grep console bootconsole [early_shadow0] enabled bootconsole [early_BFuart0] enabled Kernel command line: root=/dev/mtdblock0 rw earlyprintk=serial,uart0,57600 console=ttyBF0,57600 nmi_debug=regs console handover:boot [early_BFuart0] boot [early_shadow0] -> real [ttyBF0] Too late to register bootconsole early_shadow0 or: root:/> dmesg | grep console Kernel command line: root=/dev/mtdblock0 rw console=ttyBF0,57600 console [ttyBF0] enabled Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Cc: "Linus Torvalds" <torvalds@linux-foundation.org> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: "Mike Frysinger" <vapier.adi@gmail.com> Cc: "Paul Mundt" <lethal@linux-sh.org> LKML-Reference: <200907012108.38030.rgetz@blackfin.uclinux.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-16printk: Add KERN_DEFAULT printk log-levelLinus Torvalds1-0/+2
This adds a KERN_DEFAULT loglevel marker, for when you cannot decide which loglevel you want, and just want to keep an existing printk with the default loglevel. The difference between having KERN_DEFAULT and having no log-level marker at all is two-fold: - having the log-level marker will now force a new-line if the previous printout had not added one (perhaps because it forgot, but perhaps because it expected a continuation) - having a log-level marker is required if you are printing out a message that otherwise itself could perhaps otherwise be mistaken for a log-level. Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16printk: clean up handling of log-levels and newlinesLinus Torvalds1-9/+22
It used to be that we would only look at the log-level in a printk() after explicit newlines, which can cause annoying problems when the previous printk() did not end with a '\n'. In that case, the log-level marker would be just printed out in the middle of the line, and be seen as just noise rather than change the logging level. This changes things to always look at the log-level in the first bytes of the printout. If a log level marker is found, it is always used as the log-level. Additionally, if no newline existed, one is added (unless the log-level is the explicit KERN_CONT marker, to explicitly show that it's a continuation of a previous line). Acked-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-05Merge branch 'printk-for-linus' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: printk: correct the behavior of printk_timed_ratelimit() vsprintf: unify the format decoding layer for its 3 users, cleanup fix regression from "vsprintf: unify the format decoding layer for its 3 users" vsprintf: fix bug in negative value printing vsprintf: unify the format decoding layer for its 3 users vsprintf: add binary printf printk: introduce printk_once() Fix trivial conflicts (printk_once vs log_buf_kexec_setup() added near each other) in include/linux/kernel.h.
2009-04-03kexec: add dmesg log symbols to /proc/vmcoreinfo listsNeil Horman1-0/+19
It would be nice to be able to extract the dmesg log from a vmcore file without needing to keep the debug symbols for the running kernel handy all the time. We have a facility to do this in /proc/vmcore. This patch adds the log_buf and log_end symbols to the vmcoreinfo area so that tools (like makedumpfile) can easily extract the dmesg logs from a vmcore image. [akpm@linux-foundation.org: several fixes and cleanups] [akpm@linux-foundation.org: fix unused log_buf_kexec_setup()] [akpm@linux-foundation.org: build fix] Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Cc: Simon Horman <horms@verge.net.au> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-17printk: correct the behavior of printk_timed_ratelimit()Guillaume Knispel1-2/+5
Impact: fix jiffies-comparison sign-wrap behavior The behavior provided by printk_timed_ratelimit() is, in some situations, probably not what a caller would reasonably expect: bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msecs) { if (*caller_jiffies == 0 || time_after(jiffies, *caller_jiffies)) { *caller_jiffies = jiffies + msecs_to_jiffies(interval_msecs); return true; } return false; } On a 32 bit computer, if printk_timed_ratelimit() is initially called at time jiffies == Ja, *caller_jiffies is set to Ja + msecs_to_jiffies(interval_msecs): let's say Ja + 42 for this example. If this caller then doesn't call printk_timed_ratelimit() until jiffies == Ja + (1 << 31) + 42 (which can happen as soon as ~ 25 days later on a 1000 HZ system), printk_timed_ratelimit() will then always return false to this caller until jiffies loops completely (1 << 31 more ticks). Ths change makes it only return false if jiffies is in the small time window starting at the previous call when true was returned and ending interval_msecs later. Note that if jiffies loops completely between two calls to printk_timed_ratelimit(), it will obviously still wrongly return false, but this is something with a low probability. If something completely reliable is needed I guess jiffies_64 must be used (which this change does not do). Signed-off-by: Guillaume Knispel <gknispel@proformatique.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@osdl.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20090317161842.0059096b@xilun.lan.proformatique.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-22PM: Fix suspend_console and resume_console to use only one semaphoreArve Hjønnevåg1-6/+9
This fixes a race where a thread acquires the console while the console is suspended, and the console is resumed before this thread releases it. In this case, the secondary console semaphore would be left locked, and the primary semaphore would be released twice. This in turn would cause the console switch on suspend or resume to hang forever. Note that suspend_console does not actually lock the console for clients that use acquire_console_sem, it only locks it for clients that use try_acquire_console_sem. If we change suspend_console to fully lock the console, then the kernel may deadlock on suspend. One client of try_acquire_console_sem is acquire_console_semaphore_for_printk, which uses it to prevent printk from using the console while it is suspended. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14[CVE-2009-0029] System call wrappers part 27Heiko Carstens1-1/+1
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14[CVE-2009-0029] Make sys_syslog a conditional system callHeiko Carstens1-5/+0
Remove the -ENOSYS implementation for !CONFIG_PRINTK and use the cond_syscall infrastructure instead. Acked-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-06trivial: printk: fix indentation of new_text_line declarationJiri Kosina1-1/+1
Remove bogus indentation of new_text_line declaration introduced in commit ac60ad741. Acked-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2008-12-20printk: fix discarding message when recursion_bugHiroshi Shimamoto1-1/+1
Impact: fix truncated recursion bug message printout When recursion_bug is true, kernel discards original message because printk_buf contains recursion_bug_msg with NULL terminator. The sizeof(recursion_bug_msg) makes this, use strlen() to get correct length without NULL terminator. Reported-by: Toshikazu Nakayama <nakayama.ts@ncos.nec.co.jp> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23printk: remove unused code from kernel/printk.croel kluin1-39/+0
both log_buf_copy() and log_buf_len are unused. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-17Merge branch 'core-v28-for-linus' of ↵Linus Torvalds1-5/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: do_generic_file_read: s/EINTR/EIO/ if lock_page_killable() fails softirq, warning fix: correct a format to avoid a warning softirqs, debug: preemption check x86, pci-hotplug, calgary / rio: fix EBDA ioremap() IO resources, x86: ioremap sanity check to catch mapping requests exceeding, fix IO resources, x86: ioremap sanity check to catch mapping requests exceeding the BAR sizes softlockup: Documentation/sysctl/kernel.txt: fix softlockup_thresh description dmi scan: warn about too early calls to dmi_check_system() generic: redefine resource_size_t as phys_addr_t generic: make PFN_PHYS explicitly return phys_addr_t generic: add phys_addr_t for holding physical addresses softirq: allocate less vectors IO resources: fix/remove printk printk: robustify printk, update comment printk: robustify printk, fix #2 printk: robustify printk, fix printk: robustify printk Fixed up conflicts in: arch/powerpc/include/asm/types.h arch/powerpc/platforms/Kconfig.cputype manually.
2008-10-16Add kerneldoc documentation for new printk format extensionsAndi Kleen1-0/+2
Add documentation in kerneldoc for new printk format extensions This patch documents the new %pS/%pF options in printk in kernel doc. Hope I didn't miss any other extension. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16Remove Andrew Morton's old email accountsFrancois Cami1-1/+1
People can use the real name an an index into MAINTAINERS to find the current email address. Signed-off-by: Francois Cami <francois.cami@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-15Merge branches 'core/softlockup', 'core/softirq', 'core/resources', ↵Ingo Molnar1-5/+17
'core/printk' and 'core/misc' into core-v28-for-linus
2008-10-13tty: Move tty_write_message out of kernel/printkAlan Cox1-16/+0
This is pure tty code so put it in the tty layer where it can be with the locking relevant material it uses Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20printk: robustify printk, update commentJiri Kosina1-3/+0
Remove the comment describing the possibility of printk() deadlocking on runqueue lock. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-20printk: robustify printk, fix #2Peter Zijlstra1-1/+1
Dmitry Adamushko reported: > [*] btw., with DEBUG being enabled, pr_debug() generates [1] when > debug_smp_processor_id() is used (CONFIG_DEBUG_PREEMPT). > > the problem seems to be caused by the following commit: > commit b845b517b5e3706a3729f6ea83b88ab85f0725b0 > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Aug 8 21:47:09 2008 +0200 > > printk: robustify printk > > > wake_up_klogd() -> __get_cpu_var() -> smp_processor_id() > > and that's being called from release_console_sem() which is, in turn, > said to be "may be called from any context" [2] > > and in this case, it seems to be called from some non-preemptible > context (although, it can't be printk()... > although, I haven't looked carefully yet). > > Provided [2], __get_cpu_var() is perhaps not the right solution there. > > > [1] > > [ 7697.942005] BUG: using smp_processor_id() in preemptible [00000000] code: syslogd/3542 > [ 7697.942005] caller is wake_up_klogd+0x1b/0x50 > [ 7697.942005] Pid: 3542, comm: syslogd Not tainted 2.6.27-rc3-tip-git #2 > [ 7697.942005] Call Trace: > [ 7697.942005] [<ffffffff8036b398>] debug_smp_processor_id+0xe8/0xf0 > [ 7697.942005] [<ffffffff80239d3b>] wake_up_klogd+0x1b/0x50 > [ 7697.942005] [<ffffffff8023a047>] release_console_sem+0x1e7/0x200 > [ 7697.942005] [<ffffffff803c0f17>] do_con_write+0xb7/0x1f30 > [ 7697.942005] [<ffffffff8020d920>] ? show_trace+0x10/0x20 > [ 7697.942005] [<ffffffff8020dc42>] ? dump_stack+0x72/0x80 > [ 7697.942005] [<ffffffff8036392d>] ? __ratelimit+0xbd/0xe0 > [ 7697.942005] [<ffffffff8036b398>] ? debug_smp_processor_id+0xe8/0xf0 > [ 7697.942005] [<ffffffff80239d3b>] ? wake_up_klogd+0x1b/0x50 > [ 7697.942005] [<ffffffff8023a047>] ? release_console_sem+0x1e7/0x200 > [ 7697.942005] [<ffffffff803c2de9>] con_write+0x19/0x30 > [ 7697.942005] [<ffffffff803b37b6>] write_chan+0x276/0x3c0 > [ 7697.942005] [<ffffffff80232b20>] ? default_wake_function+0x0/0x10 > [ 7697.942005] [<ffffffff804cb872>] ? _spin_lock_irqsave+0x22/0x50 > [ 7697.942005] [<ffffffff803b1334>] tty_write+0x194/0x260 > [ 7697.942005] [<ffffffff803b3540>] ? write_chan+0x0/0x3c0 > [ 7697.942005] [<ffffffff803b14a4>] redirected_tty_write+0xa4/0xb0 > [ 7697.942005] [<ffffffff803b1400>] ? redirected_tty_write+0x0/0xb0 > [ 7697.942005] [<ffffffff802a88c2>] do_loop_readv_writev+0x52/0x80 > [ 7697.942005] [<ffffffff802a939d>] do_readv_writev+0x1bd/0x1d0 > [ 7697.942005] [<ffffffff802a93e9>] vfs_writev+0x39/0x60 > [ 7697.942005] [<ffffffff802a9870>] sys_writev+0x50/0x90 > [ 7697.942005] [<ffffffff8020bb3b>] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11printk: robustify printkPeter Zijlstra1-2/+17
Avoid deadlocks against rq->lock and xtime_lock by deferring the klogd wakeup by polling from the timer tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-30printk: fix comment for printk ratelimitingUwe Kleine-König1-4/+4
The comment assumed the burst to be one and the ratelimit used to be named printk_ratelimit_jiffies. Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25printk ratelimiting rewriteDave Young1-14/+3
All ratelimit user use same jiffies and burst params, so some messages (callbacks) will be lost. For example: a call printk_ratelimit(5 * HZ, 1) b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will will be supressed. - rewrite __ratelimit, and use a ratelimit_state as parameter. Thanks for hints from andrew. - Add WARN_ON_RATELIMIT, update rcupreempt.h - remove __printk_ratelimit - use __ratelimit in net_ratelimit Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24swsusp: provide users with a hint about the no_console_suspend optionPavel Machek1-1/+1
Tell the user about the no_console_suspend option, so that we don't have to tell each bug reporter personally. [akpm@linux-foundation.org: clarify the text a little] Signed-off-by: Pavel Machek <pavel@suse.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-15Merge branch 'core/printk' of ↵Linus Torvalds1-62/+43
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/printk' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, generic: mark early_printk as asmlinkage printk: export console_drivers printk: remember the message level for multi-line output printk: refactor processing of line severity tokens printk: don't prefer unsuited consoles on registration printk: clean up recursion check related static variables namespacecheck: more kernel/printk.c fixes namespacecheck: fix kernel printk.c
2008-07-14Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar1-0/+2
Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-12Merge branch 'linus' into x86/coreIngo Molnar1-1/+1
Conflicts: arch/x86/mm/ioremap.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10Merge branch 'tracing/ftrace' into auto-ftrace-nextIngo Molnar1-0/+2
2008-07-09kernel/printk.c: Made printk_recursion_bug_msg static.Daniel Guilak1-1/+1
Signed-off-by: Daniel Guilak <daniel@danielguilak.com> Acked-by: Josh Triplett <josh@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-08printk: export console_driversIngo Molnar1-0/+2
this symbol is needed by drivers/video/xen-fbfront.ko. [ cherry-picked from tip/core/printk ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-18x86, generic: mark early_printk as asmlinkageJiri Slaby1-1/+1
It's not explicitly marked as asmlinkage, but invoked from x86_32 startup code with parameters on stack. No other architectures define early_printk and none of them are affected by this change, since defines asmlinkage as empty token. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-16printk: export console_driversIngo Molnar1-0/+2
this symbol is needed by drivers/video/xen-fbfront.ko. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-27xen: Enable console tty by default in domU if it's not a dummyMarkus Armbruster1-0/+3
Without console= arguments on the kernel command line, the first console to register becomes enabled and the preferred console (the one behind /dev/console). This is normally tty (assuming CONFIG_VT_CONSOLE is enabled, which it commonly is). This is okay as long tty is a useful console. But unless we have the PV framebuffer, and it is enabled for this domain, tty0 in domU is merely a dummy. In that case, we want the preferred console to be the Xen console hvc0, and we want it without having to fiddle with the kernel command line. Commit b8c2d3dfbc117dff26058fbac316b8acfc2cb5f7 did that for us. Since we now have the PV framebuffer, we want to enable and prefer tty again, but only when PVFB is enabled. But even then we still want to enable the Xen console as well. Problem: when tty registers, we can't yet know whether the PVFB is enabled. By the time we can know (xenstore is up), the console setup game is over. Solution: enable console tty by default, but keep hvc as the preferred console. Change the preferred console to tty when PVFB probes successfully, unless we've been given console kernel parameters. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-25printk: remember the message level for multi-line outputNick Andrew1-1/+1
printk(KERN_ALERT "Danger Will Robinson!\nAlien Approaching!\n"); At present this will result in one message at ALERT level and one at the current default message loglevel (e.g. WARNING). This is non-intuitive. Modify vprintk() to remember the message loglevel each time it is specified and use it for subsequent lines of output which do not specify one, within the same call to printk. Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-25printk: refactor processing of line severity tokensNick Andrew1-34/+27
Restructure the logic of vprintk() so the processing of the leading 3 characters of each input line is in one place, regardless whether printk_time is enabled. This makes the code smaller and easier to understand. size reduction in kernel/printk.o: text data bss dec hex filename 6157 397 1049804 1056358 101e66 printk.o.before 6117 397 1049804 1056318 101e3e printk.o.after and some style uncleanlinesses removed as well as a side-effect: Before: total: 19 errors, 22 warnings, 1340 lines checked After: total: 17 errors, 22 warnings, 1333 lines checked Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-25printk: don't prefer unsuited consoles on registrationJan Kiszka1-2/+5
console election: If some console happens to be registered first which does not provide a tty binding (!console->device), it prevents that more suited consoles which are registered later on can enter the candidate pool for console_device(). This is observable with KGDB's console which may already be registered (and exploited!) during early debugger connections, that is before any regular console registration. This patch fixes the issue by postponing the final, automated preferred_console selection until someone with a non-NULL device handler comes around. Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Gerd Hoffmann <kraxel@suse.de> Cc: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>