Export a pointer to the sysrq_get_key_op(). This way we can cleanly unregister it, instead of the current solutions of modifuing it inplace.
Since __sysrq_get_key_op() is no longer used externally, let's make it a static function.
This patch will allow us to limit access to each and every sysrq op and constify the sysrq handling.
Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.com Cc: linux-kernel@vger.kernel.org Cc: Richard Henderson rth@twiddle.net Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Matt Turner mattst88@gmail.com Cc: linux-alpha@vger.kernel.org Signed-off-by: Emil Velikov emil.l.velikov@gmail.com --- Please keep me in the CC list, as I'm not subscribed to the list.
IMHO it would be better if this gets merged this via the tty tree. --- arch/alpha/kernel/setup.c | 13 +++++++++++-- drivers/tty/sysrq.c | 4 +++- include/linux/sysrq.h | 2 +- 3 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c index f19aa577354b..dd7f770f23cf 100644 --- a/arch/alpha/kernel/setup.c +++ b/arch/alpha/kernel/setup.c @@ -430,6 +430,15 @@ register_cpus(void)
arch_initcall(register_cpus);
+#ifdef CONFIG_MAGIC_SYSRQ +static struct sysrq_key_op srm_sysrq_reboot_op = { + .handler = machine_halt, + .help_msg = "reboot(b)", + .action_msg = "Resetting", + .enable_mask = SYSRQ_ENABLE_BOOT, +}; +#endif + void __init setup_arch(char **cmdline_p) { @@ -550,8 +559,8 @@ setup_arch(char **cmdline_p) /* If we're using SRM, make sysrq-b halt back to the prom, not auto-reboot. */ if (alpha_using_srm) { - struct sysrq_key_op *op = __sysrq_get_key_op('b'); - op->handler = (void *) machine_halt; + unregister_sysrq_key('b', __sysrq_reboot_op); + register_sysrq_key('b', &srm_sysrq_reboot_op); } #endif
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index 0dc3878794fd..1741134cabca 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -172,6 +172,8 @@ static struct sysrq_key_op sysrq_reboot_op = { .enable_mask = SYSRQ_ENABLE_BOOT, };
+struct sysrq_key_op *__sysrq_reboot_op = &sysrq_reboot_op; + static void sysrq_handle_sync(int key) { emergency_sync(); @@ -516,7 +518,7 @@ static int sysrq_key_table_key2index(int key) /* * get and put functions for the table, exposed to modules. */ -struct sysrq_key_op *__sysrq_get_key_op(int key) +static struct sysrq_key_op *__sysrq_get_key_op(int key) { struct sysrq_key_op *op_p = NULL; int i; diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h index 8e159e16850f..9b51f98e5f60 100644 --- a/include/linux/sysrq.h +++ b/include/linux/sysrq.h @@ -47,7 +47,7 @@ void handle_sysrq(int key); void __handle_sysrq(int key, bool check_mask); int register_sysrq_key(int key, struct sysrq_key_op *op); int unregister_sysrq_key(int key, struct sysrq_key_op *op); -struct sysrq_key_op *__sysrq_get_key_op(int key); +extern struct sysrq_key_op *__sysrq_reboot_op;
int sysrq_toggle_support(int enable_mask); int sysrq_mask(void);