4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jacky Bai ping.bai@nxp.com
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@vger.kernel.org Fixes: 059ab7b82eec ("clocksource/drivers/imx-tpm: Add imx tpm timer support") Signed-off-by: Jacky Bai ping.bai@nxp.com Reviewed-by: Peng Fan peng.fan@nxp.com Reviewed-by: Ye Li ye.li@nxp.com Reviewed-by: Jason Liu jason.hui.liu@nxp.com Signed-off-by: Frank Li Frank.Li@nxp.com Link: https://lore.kernel.org/r/20240725193355.1436005-1-Frank.Li@nxp.com Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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)