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2006-08-06[PATCH] vt: printk: Fix framebuffer console triggering might_sleep assertionAntonino A. Daplas
Reported by: Dave Jones Whilst printk'ing to both console and serial console, I got this... (2.6.18rc1) BUG: sleeping function called from invalid context at kernel/sched.c:4438 in_atomic():0, irqs_disabled():1 Call Trace: [<ffffffff80271db8>] show_trace+0xaa/0x23d [<ffffffff80271f60>] dump_stack+0x15/0x17 [<ffffffff8020b9f8>] __might_sleep+0xb2/0xb4 [<ffffffff8029232e>] __cond_resched+0x15/0x55 [<ffffffff80267eb8>] cond_resched+0x3b/0x42 [<ffffffff80268c64>] console_conditional_schedule+0x12/0x14 [<ffffffff80368159>] fbcon_redraw+0xf6/0x160 [<ffffffff80369c58>] fbcon_scroll+0x5d9/0xb52 [<ffffffff803a43c4>] scrup+0x6b/0xd6 [<ffffffff803a4453>] lf+0x24/0x44 [<ffffffff803a7ff8>] vt_console_print+0x166/0x23d [<ffffffff80295528>] __call_console_drivers+0x65/0x76 [<ffffffff80295597>] _call_console_drivers+0x5e/0x62 [<ffffffff80217e3f>] release_console_sem+0x14b/0x232 [<ffffffff8036acd6>] fb_flashcursor+0x279/0x2a6 [<ffffffff80251e3f>] run_workqueue+0xa8/0xfb [<ffffffff8024e5e0>] worker_thread+0xef/0x122 [<ffffffff8023660f>] kthread+0x100/0x136 [<ffffffff8026419e>] child_rip+0x8/0x12 This can occur when release_console_sem() is called but the log buffer still has contents that need to be flushed. The console drivers are called while the console_may_schedule flag is still true. The might_sleep() is triggered when fbcon calls console_conditional_schedule(). Fix by setting console_may_schedule to zero earlier, before the call to the console drivers. Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] kernel/printk.c: EXPORT_SYMBOL_UNUSEDAdrian Bunk
This patch marks unused exports as EXPORT_SYMBOL_UNUSED. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: do not recurse in printkIngo Molnar
Make printk()-ing from within the lock validation code safer by using the lockdep-recursion counter. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-25[PATCH] printk time parameterJan Engelhardt
Currently, enabling/disabling printk timestamps is only possible through reboot (bootparam) or recompile. I normally do not run with timestamps (since syslog handles that in a good manner), but for measuring small kernel delays (e.g. irq probing - see parport thread) I needed subsecond precision, but then again, just for some minutes rather than all kernel messages to come. The following patch adds a module_param() with which the timestamps can be en-/disabled in a live system through /sys/modules/printk/parameters/printk_time. Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] Make printk work for really early debuggingMichael Ellerman
Currently printk is no use for early debugging because it refuses to actually print anything to the console unless cpu_online(smp_processor_id()) is true. The stated explanation is that console drivers may require per-cpu resources, or otherwise barf, because the system is not yet setup correctly. Fair enough. However some console drivers might be quite happy running early during boot, in fact we have one, and so it'd be nice if printk understood that. So I added a flag (which I would have called CON_BOOT, but that's taken) called CON_ANYTIME, which indicates that a console is happy to be called anytime, even if the cpu is not yet online. Tested on a Power 5 machine, with both a CON_ANYTIME driver and a bogus console driver that BUG()s if called while offline. No problems AFAICT. Built for i386 UP & SMP. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-19Add support for suspending and resuming the whole console subsystemLinus Torvalds
Trying to suspend/resume with console messages flying all around is doomed to failure, when the devices that the messages are trying to go to are being shut down. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-01BUG_ON() Conversion in kernel/printk.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-24[PATCH] console_setup() depends (wrongly?) on CONFIG_PRINTKJohn Z. Bohach
It appears that console_setup() code only gets compiled into the kernel if CONFIG_PRINTK is enabled. One detrimental side-effect of this is that serial8250_console_setup() never gets invoked when CONFIG_PRINTK is not set, resulting in baud rate not being read/parsed from command line (i.e. console=ttyS0,115200n8 is ignored, at least the baud rate part...) Attached patch moves console_setup() code from inside #ifdef CONFIG_PRINTK to outside (in printk.c), removing dependence on said config. option. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-15correct email address of Manfred SpraulChristian Kujau
I tried to send the forcedeth maintainer an email, but it came back with: "The mail address manfreds@colorfullife.com is not read anymore. Please resent your mail to manfred@ instead of manfreds@." This patch fixes this. Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-08[PATCH] printk return value: fix itGuillaume Chazarain
What's the true meaning of the printk return value? Should it include the priority prefix length of 3? and what about the timing information? In both cases it was broken: strace -e write echo 1 > /dev/kmsg => write(1, "1\n", 2) = 5 strace -e write echo "<1>1" > /dev/kmsg => write(1, "<1>1\n", 5) = 8 The returned length was "length of input string + 3", I made it "length of string output to the log buffer". Note that I couldn't find any printk caller in the kernel interested by its return value besides kmsg_write. Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr> Acked-By: Tim Bird <tim.bird@am.sony.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23[PATCH] Fix crash in unregister_console()Benjamin Herrenschmidt
If unregister_console() is inadvertently called while no consoles are registered, it will crash trying to dereference NULL pointer. It is necessary to fix that because register_console() provides no indication that it actually registered the console passed in. In fact, it may well decide not to register it based on various things... (akpm: It'd be better to make register_console() return something and fix the callers. All 106 of them...) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-13[PATCH] DocBook: include printk documentationMartin Waitz
Add printk documentation to kernel-api. Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] unexport console_unblankAdrian Bunk
I didn't find any possible modular usage of console_unblank in the kernel. This patch was already ACK'ed by Alan Cox. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] cleanup for kernel/printk.cJesper Juhl
- Removes some trailing whitespace - Breaks long lines and make other small changes to conform to CodingStyle - Add explicit printk loglevels in two places. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-21[PATCH] Add printk_clock()Andrew Morton
ia64's sched_clock() accesses per-cpu data which isn't set up at boot time. Hence ia64 cannot use printk timestamping, because printk() will crash in sched_clock(). So make printk() use printk_clock(), defaulting to sched_clock(), overrideable by the architecture via attribute(weak). Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07[PATCH] Provide better printk() support for SMP machinesDavid Howells
The attached patch prevents oopses interleaving with characters from other printks on other CPUs by only breaking the lock if the oops is happening on the machine holding the lock. It might be better if the oops generator got the lock and then called an inner vprintk routine that assumed the caller holds the lock, thus making oops reports "atomic". Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] CPU hotplug printk fixShaohua Li
In the cpu hotplug case, per-cpu data possibly isn't initialized even the system state is 'running'. As the comments say in the original code, some console drivers assume per-cpu resources have been allocated. radeon fb is one such driver, which uses kmalloc. After a CPU is down, the per-cpu data of slab is freed, so the system crashed when printing some info. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23[PATCH] CON_CONSDEV bit not set correctly on last consoleGreg Edwards
According to include/linux/console.h, CON_CONSDEV flag should be set on the last console specified on the boot command line: 86 #define CON_PRINTBUFFER (1) 87 #define CON_CONSDEV (2) /* Last on the command line */ 88 #define CON_ENABLED (4) 89 #define CON_BOOT (8) This does not currently happen if there is more than one console specified on the boot commandline. Instead, it gets set on the first console on the command line. This can cause problems for things like kdb that look for the CON_CONSDEV flag to see if the console is valid. Additionaly, it doesn't look like CON_CONSDEV is reassigned to the next preferred console at unregister time if the console being unregistered currently has that bit set. Example (from sn2 ia64): elilo vmlinuz root=<dev> console=ttyS0 console=ttySG0 in this case, the flags on ttySG console struct will be 0x4 (should be 0x6). Attached patch against bk fixes both issues for the cases I looked at. It uses selected_console (which gets incremented for each console specified on the command line) as the indicator of which console to set CON_CONSDEV on. When adding the console to the list, if the previous one had CON_CONSDEV set, it masks it out. Tested on ia64 and x86. The problem with the current behavior is it breaks overriding the default from the boot line. In the ia64 case, there may be a global append line defining console=a in elilo.conf. Then you want to boot your kernel, and want to override the default by passing console=b on the boot line. elilo constructs the kernel cmdline by starting with the value of the global append line, then tacks on whatever else you specify, which puts console=b last. Signed-off-by: Greg Edwards <edwardsg@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-17[PATCH] add_preferred_console() build fixMatt Mackall
Move add_preferred_console out of CONFIG_PRINTK so serial console does the right thing. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] clean up kernel messagesMatt Mackall
Arrange for all kernel printks to be no-ops. Only available if CONFIG_EMBEDDED. This patch saves about 375k on my laptop config and nearly 100k on minimal configs. Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!