summaryrefslogtreecommitdiff
path: root/drivers/tty/serial/kgdb_nmi.c
AgeCommit message (Collapse)Author
2015-05-06serial: kgdb_nmi: Use bool function return values of true/false not 1/0Joe Perches
Use the normal return values for bool functions Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08serial: kgdb_nmi: No CON_ENABLED by defaultDaniel Thompson
At present this console is optionally registered by NULL checking arch_kgdb_ops.enable_nmi. In practice this requires the architecture dependant code to implement some kind of control (e.g. module arguments) to enable/disable this feature. The kernel already provides us the perfectly adequate console= argument to enable/disable consoles. Let's use that instead! Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17tty: kgdb_nmi: Automatically manage tty enableDaniel Thompson
At present it is not possible to boot with the ttyNMI0 console treating character input normally, instead character input triggers a prompt telling the user how to trigger the knock detector and enter the debugger. To use the console normally requires that kdb be entered and the nmi_console command be used to enable the console (or if only kgdb is present then gdb must directly manipulate the value of kgdb_nmi_tty_enabled). This patch automates the management of kgdb_nmi_tty_enabled by keeping track of the number of file handles that are open for reading and using that to determine how to tty should operate. The approach means that: 1. Behaviour before init starts is unchanged. 2. If the userspace runs a getty or some other interactive process on /dev/console (or explicitly on /dev/ttyNMI0) the tty will treat character input like any other tty. 3. If the userspace doesn't use /dev/console or if it uses /dev/console only to log messages (O_WRONLY) then the user prompt is retained. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-serial@vger.kernel.org Cc: Jason Wessel <jason.wessel@windriver.com> Cc: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-29serial: kgdb_nmi: Improve console integration with KDB I/ODaniel Thompson
kgdb_nmi_tty_enabled is used for two unrelated purposes, namely to suppress normal TTY input handling and to suppress console output (although it has no effect at all on TTY output). A much better way to handle muting the console is to not have to mute it in the first place! That's what this patch does. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-29serial: kgdb_nmi: Switch from tasklets to real timersDaniel Thompson
kgdb_nmi uses tasklets on the assumption they will not be scheduled until the next timer tick. This assumption is invalid and can lead to live lock, continually servicing the kgdb_nmi tasklet. This is fixed by using the timer API instead. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-29serial: kgdb_nmi: Use container_of() to locate private dataDaniel Thompson
This corrects a crash in kgdb_nmi_tty_shutdown() which occurs when the function is called with port->tty set to NULL. All conversions between struct tty_port and struct kgdb_nmi_tty_priv have been switched to direct calls to container_of() to improve code clarity and consistancy. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07tty: delete non-required instances of include <linux/init.h>Paul Gortmaker
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-04kgdb: remove #include <linux/serial_8250.h> from kgdb.hGreg Kroah-Hartman
There's no reason kgdb.h itself needs to include the 8250 serial port header file. So push it down to the _very_ limited number of individual drivers that need the values in that file, and fix up the places where people really wanted serial_core.h and platform_device.h. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_flip_buffer_pushJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_charJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15TTY: call tty_port_destroy in the rest of driversJiri Slaby
After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. To be sure, the TTY buffers (and later some stuff) are gone along with the tty_port, we have to call tty_port_destroy at tear-down places. This is mostly where the structure containing a tty_port is freed. This patch does exactly that -- put tty_port_destroy at those places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26tty/serial: Add kgdb_nmi driverAnton Vorontsov
This special driver makes it possible to temporary use NMI debugger port as a normal console by issuing 'nmi_console' command (assuming that the port is attached to KGDB). Unlike KDB's disable_nmi command, with this driver you are always able to go back to the debugger using KGDB escape sequence ($3#33). This is because this console driver processes the input in NMI context, and thus is able to intercept the magic sequence. Note that since the console interprets input and uses polling communication methods, for things like PPP it is still better to fully detach debugger port from the KGDB NMI (i.e. disable_nmi), and use raw console. Usually, to enter the debugger one have to type the magic sequence, so initially the kernel will print the following prompt on the NMI debugger console: Type $3#33 to enter the debugger> For convenience, there is a kgdb_fiq.knock kernel command line option, when set to 0, this turns the special command to just a return key press, so the kernel will be printing this: Hit <return> to enter the debugger> This is more convenient for long debugging sessions, although it makes nmi_console feature somewhat useless. And for the cases when NMI connected to a dedicated button, the knocking can be disabled altogether by setting kgdb_fiq.knock to -1. Suggested-by: Colin Cross <ccross@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Alan Cox <alan@linux.intel.com> Acked-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>