On Fri, 9 Mar 2007 12:52:41 -0500 Mike Frysinger wrote:
> On 3/9/07, Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote:
> > If you want to only disable one sysrq key, that will require a
> > kernel patch and recompile.
>
> sysrq doc implies different ... it says you can echo a bitmask to
> control some of the functions
> in /proc/sys/kernel/sysrq:
> 0 - disable sysrq completely
> 1 - enable all functions of sysrq
> >1 - bitmask of allowed sysrq functions (see below for detailed
> function description):
Oops. Thanks for that.
OK, so to disable 'p', it's like this:
look up 'p' in the sysrq table:
&sysrq_showregs_op, /* p */
look at that data structure:
static struct sysrq_key_op sysrq_showregs_op = {
.handler = sysrq_handle_showregs,
.help_msg = "showPc",
.action_msg = "Show Regs",
.enable_mask = SYSRQ_ENABLE_DUMP,
};
OK, use SYSRQ_ENABLE_DUMP as the mask to enable or disable sysrq 'p'.
/* Possible values of bitmask for enabling sysrq functions */
/* 0x0001 is reserved for enable everything */
#define SYSRQ_ENABLE_LOG 0x0002
#define SYSRQ_ENABLE_KEYBOARD 0x0004
#define SYSRQ_ENABLE_DUMP 0x0008
#define SYSRQ_ENABLE_SYNC 0x0010
#define SYSRQ_ENABLE_REMOUNT 0x0020
#define SYSRQ_ENABLE_SIGNAL 0x0040
#define SYSRQ_ENABLE_BOOT 0x0080
#define SYSRQ_ENABLE_RTNICE 0x0100
so echo 0xfff7 > /proc/sys/kernel/sysrq
to disable all DUMP commands (crashdump, p, t, w, m).
Does that sound correct?
Thanks again, Mike.
---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
--
To unsubscribe from this list: send an email with
"unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx
Please read the FAQ at http://kernelnewbies.org/FAQ
