4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jacky Bai <ping.bai@xxxxxxx>
commit 5b8843fcd49827813da80c0f590a17ae4ce93c5d upstream.
In tpm_set_next_event(delta), return -ETIME by wrong cast to int when delta
is larger than INT_MAX.
For example:
tpm_set_next_event(delta = 0xffff_fffe)
{
...
next = tpm_read_counter(); // assume next is 0x10
next += delta; // next will 0xffff_fffe + 0x10 = 0x1_0000_000e
now = tpm_read_counter(); // now is 0x10
...
return (int)(next - now) <= 0 ? -ETIME : 0;
^^^^^^^^^^
0x1_0000_000e - 0x10 = 0xffff_fffe, which is -2 when
cast to int. So return -ETIME.
}
To fix this, introduce a 'prev' variable and check if 'now - prev' is
larger than delta.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 059ab7b82eec ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Jacky Bai <ping.bai@xxxxxxx>
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
Reviewed-by: Ye Li <ye.li@xxxxxxx>
Reviewed-by: Jason Liu <jason.hui.liu@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
Link: https://lore.kernel.org/r/20240725193355.1436005-1-Frank.Li@xxxxxxx
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/clocksource/timer-imx-tpm.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/clocksource/timer-imx-tpm.c
+++ b/drivers/clocksource/timer-imx-tpm.c
@@ -96,10 +96,10 @@ static int __init tpm_clocksource_init(u
static int tpm_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
- unsigned long next, now;
+ unsigned long next, prev, now;
- next = tpm_read_counter();
- next += delta;
+ prev = tpm_read_counter();
+ next = prev + delta;
writel(next, timer_base + TPM_C0V);
now = tpm_read_counter();
@@ -109,7 +109,7 @@ static int tpm_set_next_event(unsigned l
* of writing CNT registers which may cause the min_delta event got
* missed, so we need add a ETIME check here in case it happened.
*/
- return (int)(next - now) <= 0 ? -ETIME : 0;
+ return (now - prev) >= delta ? -ETIME : 0;
}
static int tpm_set_state_oneshot(struct clock_event_device *evt)
