[PATCH AUTOSEL 4.19 12/36] rtc: cmos: Do not export alarm rtc_ops when we do not support alarms

[PATCH AUTOSEL 4.19 12/36] rtc: cmos: Do not export alarm rtc_ops when we do not support alarms

[Sasha Levin]

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit fbb974ba693bbfb4e24a62181ef16d4e45febc37 ]

When there is no IRQ configured for the RTC, the rtc-cmos code does not
support alarms, all alarm rtc_ops fail with -EIO / -EINVAL.

The rtc-core expects a rtc driver which does not support rtc alarms to
not have alarm ops at all. Otherwise the wakealarm sysfs attr will read
as empty rather then returning an error, making it impossible for
userspace to find out beforehand if alarms are supported.

A system without an IRQ for the RTC before this patch:
[root@localhost ~]# cat /sys/class/rtc/rtc0/wakealarm
[root@localhost ~]#

After this patch:
[root@localhost ~]# cat /sys/class/rtc/rtc0/wakealarm
cat: /sys/class/rtc/rtc0/wakealarm: No such file or directory
[root@localhost ~]#

This fixes gnome-session + systemd trying to use suspend-then-hibernate,
which causes systemd to abort the suspend when writing the RTC alarm fails.

BugLink: https://github.com/systemd/systemd/issues/9988
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/rtc/rtc-cmos.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index df0c5776d49b..a5a19ff10535 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -257,6 +257,7 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned char	rtc_control;
 
+	/* This not only a rtc_op, but also called directly */
 	if (!is_valid_irq(cmos->irq))
 		return -EIO;
 
@@ -452,6 +453,7 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 	unsigned char mon, mday, hrs, min, sec, rtc_control;
 	int ret;
 
+	/* This not only a rtc_op, but also called directly */
 	if (!is_valid_irq(cmos->irq))
 		return -EIO;
 
@@ -516,9 +518,6 @@ static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);
 	unsigned long	flags;
 
-	if (!is_valid_irq(cmos->irq))
-		return -EINVAL;
-
 	spin_lock_irqsave(&rtc_lock, flags);
 
 	if (enabled)
@@ -579,6 +578,12 @@ static const struct rtc_class_ops cmos_rtc_ops = {
 	.alarm_irq_enable	= cmos_alarm_irq_enable,
 };
 
+static const struct rtc_class_ops cmos_rtc_ops_no_alarm = {
+	.read_time		= cmos_read_time,
+	.set_time		= cmos_set_time,
+	.proc			= cmos_procfs,
+};
+
 /*----------------------------------------------------------------*/
 
 /*
@@ -855,9 +860,12 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 			dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 			goto cleanup1;
 		}
+
+		cmos_rtc.rtc->ops = &cmos_rtc_ops;
+	} else {
+		cmos_rtc.rtc->ops = &cmos_rtc_ops_no_alarm;
 	}
 
-	cmos_rtc.rtc->ops = &cmos_rtc_ops;
 	cmos_rtc.rtc->nvram_old_abi = true;
 	retval = rtc_register_device(cmos_rtc.rtc);
 	if (retval)
-- 
2.17.1

[PATCH AUTOSEL 4.19 13/36] rtc: pcf2127: fix a kmemleak caused in pcf2127_i2c_gather_write

[Sasha Levin]

From: Xulin Sun <xulin.sun@windriver.com>

[ Upstream commit 9bde0afb7a906f1dabdba37162551565740b862d ]

pcf2127_i2c_gather_write() allocates memory as local variable
for i2c_master_send(), after finishing the master transfer,
the allocated memory should be freed. The kmemleak is reported:

unreferenced object 0xffff80231e7dba80 (size 64):
  comm "hwclock", pid 27762, jiffies 4296880075 (age 356.944s)
  hex dump (first 32 bytes):
    03 00 12 03 19 02 11 13 00 80 98 18 00 00 ff ff ................
    00 50 00 00 00 00 00 00 02 00 00 00 00 00 00 00 .P..............
  backtrace:
    [<ffff000008221398>] create_object+0xf8/0x278
    [<ffff000008a96264>] kmemleak_alloc+0x74/0xa0
    [<ffff00000821070c>] __kmalloc+0x1ac/0x348
    [<ffff0000087ed1dc>] pcf2127_i2c_gather_write+0x54/0xf8
    [<ffff0000085fd9d4>] _regmap_raw_write+0x464/0x850
    [<ffff0000085fe3f4>] regmap_bulk_write+0x1a4/0x348
    [<ffff0000087ed32c>] pcf2127_rtc_set_time+0xac/0xe8
    [<ffff0000087eaad8>] rtc_set_time+0x80/0x138
    [<ffff0000087ebfb0>] rtc_dev_ioctl+0x398/0x610
    [<ffff00000823f2c0>] do_vfs_ioctl+0xb0/0x848
    [<ffff00000823fae4>] SyS_ioctl+0x8c/0xa8
    [<ffff000008083ac0>] el0_svc_naked+0x34/0x38
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Xulin Sun <xulin.sun@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/rtc/rtc-pcf2127.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 9f99a0966550..7cb786d76e3c 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -303,6 +303,9 @@ static int pcf2127_i2c_gather_write(void *context,
 	memcpy(buf + 1, val, val_size);
 
 	ret = i2c_master_send(client, buf, val_size + 1);
+
+	kfree(buf);
+
 	if (ret != val_size + 1)
 		return ret < 0 ? ret : -EIO;
 
-- 
2.17.1