kprobes/arm64: Blacklist sdei watchdog callback functions

euler inclusion
category: bugfix
Bugzilla: 5515
CVE: N/A

----------------------------------------

Functions called in sdei_handler are not allowed to be kprobed, so
marked them as NOKPROBE_SYMBOL. There are so many functions in
'watchdog_check_timestamp()'. Luckily, we don't need
'CONFIG_HARDLOCKUP_CHECK_TIMESTAMP' now. So just make
CONFIG_SDEI_WATCHDOG depends on !CONFIG_HARDLOCKUP_CHECK_TIMESTAMP
in case someone add 'CONFIG_HARDLOCKUP_CHECK_TIMESTAMP' in the future.
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/kernel/watchdog_sdei.c

@@ -14,6 +14,7 @@
 #include <asm/sdei.h>
 #include <asm/virt.h>
 #include <linux/arm_sdei.h>
+#include <linux/kprobes.h>
 #include <linux/nmi.h>
 
 /* We use the secure physical timer as SDEI NMI watchdog timer */
@@ -66,6 +67,7 @@ static int sdei_watchdog_callback(u32 event,
 
 	return 0;
 }
+NOKPROBE_SYMBOL(sdei_watchdog_callback);
 
 static void sdei_nmi_watchdog_bind(void *data)
 {

kernel/watchdog.c

@@ -16,6 +16,7 @@
 #include <linux/cpu.h>
 #include <linux/nmi.h>
 #include <linux/init.h>
+#include <linux/kprobes.h>
 #include <linux/module.h>
 #include <linux/sysctl.h>
 #include <linux/tick.h>
@@ -324,6 +325,7 @@ bool is_hardlockup(void)
 	__this_cpu_write(hrtimer_interrupts_saved, hrint);
 	return false;
 }
+NOKPROBE_SYMBOL(is_hardlockup);
 
 static void watchdog_interrupt_count(void)
 {

kernel/watchdog_hld.c

@@ -14,6 +14,7 @@
 
 #include <linux/nmi.h>
 #include <linux/atomic.h>
+#include <linux/kprobes.h>
 #include <linux/module.h>
 #include <linux/sched/debug.h>
 
@@ -152,6 +153,7 @@ void watchdog_hardlockup_check(struct pt_regs *regs)
 	__this_cpu_write(hard_watchdog_warn, false);
 	return;
 }
+NOKPROBE_SYMBOL(watchdog_hardlockup_check);
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);

lib/Kconfig.debug

@@ -843,7 +843,7 @@ choice
 
 config SDEI_WATCHDOG
 	bool "SDEI NMI Watchdog support"
-	depends on ARM_SDE_INTERFACE
+	depends on ARM_SDE_INTERFACE && !HARDLOCKUP_CHECK_TIMESTAMP
 	select HAVE_HARDLOCKUP_DETECTOR_ARCH
 
 config PMU_WATCHDOG