wait_event_interruptible_timeout() evaluates its condition after setting
the current task state to TASK_INTERRUPTIBLE.
With CONFIG_DEBUG_ATOMIC_SLEEP this triggers a warning when the IRQ wait
path is used:
tpm_tis_status()
tpm_tis_spi_read_bytes()
tpm_tis_spi_transfer_full()
spi_bus_lock()
mutex_lock()
Address this with the following measures:
1. Call wait_tpm_stat_cond() only while tasking is running.
2. Use wait_woken() to wait for changes.
Cc: [email protected] # v4.19+
Cc: Linus Walleij <[email protected]>
Reported-by: Stefan Wahren <[email protected]>
Closes:
https://lore.kernel.org/linux-integrity/[email protected]/
Fixes: 1a339b658d9d ("tpm_tis_spi: Pass the SPI IRQ down to the driver")
Signed-off-by: Jarkko Sakkinen <[email protected]>
---
Linus' change only unmasked a pre-existing bug but it is the change
realizes it in tpm_tis_spi.
drivers/char/tpm/tpm_tis_core.c | 35 ++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 21d79ad3b164..153a57c79240 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -66,8 +66,8 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
bool check_cancel)
{
struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
unsigned long stop;
- long rc;
u8 status;
bool canceled = false;
u8 sts_mask;
@@ -87,23 +87,30 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
/* process status changes with irq support */
if (sts_mask) {
ret = -ETIME;
+ add_wait_queue(queue, &wait);
again:
+ if (wait_for_tpm_stat_cond(chip, sts_mask, check_cancel,
+ &canceled)) {
+ ret = canceled ? -ECANCELED : 0;
+ goto out;
+ }
+
timeout = stop - jiffies;
if ((long)timeout <= 0)
- return -ETIME;
- rc = wait_event_interruptible_timeout(*queue,
- wait_for_tpm_stat_cond(chip, sts_mask, check_cancel,
- &canceled),
- timeout);
- if (rc > 0) {
- if (canceled)
- return -ECANCELED;
- ret = 0;
- }
- if (rc == -ERESTARTSYS && freezing(current)) {
- clear_thread_flag(TIF_SIGPENDING);
- goto again;
+ goto out;
+
+ if (signal_pending(current)) {
+ if (freezing(current)) {
+ clear_thread_flag(TIF_SIGPENDING);
+ goto again;
+ }
+ goto out;
}
+
+ wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
+ goto again;
+out:
+ remove_wait_queue(queue, &wait);
}
if (ret)
--
2.47.3
