[PATCH v2 3/4] tpm: Hold the kref during tpm_chip_find_get

[Jarkko Sakkinen]

From: Jason Gunthorpe <jguntho...@obsidianresearch.com>

This was missed during the struct device conversion, we
need to hold a kref on the chip to make sure it isn't freed.

Signed-off-by: Jason Gunthorpe <jguntho...@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.cm>
Fixes: afb5abc262e9 ("tpm: two-phase chip management functions")
cc: sta...@vger.kernel.org
---
 drivers/char/tpm/tpm-chip.c | 2 ++
 drivers/char/tpm/tpm.h      | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 274dd01..84a54a2 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -53,6 +53,8 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
                        chip = pos;
                        break;
                }
+
+               get_device(&chip->dev);
        }
        rcu_read_unlock();
        return chip;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 28b477e..f6bc0b3 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -200,6 +200,7 @@ struct tpm_chip {
 static inline void tpm_chip_put(struct tpm_chip *chip)
 {
        module_put(chip->pdev->driver->owner);
+       put_device(&chip->dev);
 }
 
 static inline int tpm_read_index(int base, int index)
-- 
2.7.0