diff options
| author | Chengfeng Ye <dg573847474@gmail.com> | 2023-07-20 07:13:30 +0000 |
|---|---|---|
| committer | Lee Jones <lee@kernel.org> | 2023-08-18 21:48:03 +0100 |
| commit | f1a63db65e456263fa10d8a52aed652f392f22ce (patch) | |
| tree | f7bc240617320e27057cebd61492c2df68ec672e /drivers/mfd | |
| parent | 506fbc6b37805c95617777ff7aa05476bbf9313d (diff) | |
| download | linux-f1a63db65e456263fa10d8a52aed652f392f22ce.tar.gz | |
mfd: qcom-pm8xxx: Fix potential deadlock on &chip->pm_irq_lock
As &chip->pm_irq_lock is acquired by pm8xxx_irq_handler() under irq
context, other process context code should disable irq before acquiring
the lock.
Since .irq_set_type and .irq_get_irqchip_state callbacks are generally
executed from process context without irq disabled by default, the same
lock acquision should disable irq.
Possible deadlock scenario
pm8xxx_irq_set_type()
-> pm8xxx_config_irq()
-> spin_lock(&chip->pm_irq_lock)
<irq interrupt>
-> pm8xxx_irq_handler()
-> pm8xxx_irq_master_handler()
-> pm8xxx_irq_block_handler()
-> pm8xxx_read_block_irq()
-> spin_lock(&chip->pm_irq_lock) (deadlock here)
This flaw was found using an experimental static analysis tool we are
developing for irq-related deadlock.
Fix the potential deadlock by spin_lock_irqsave().
Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Link: https://lore.kernel.org/r/20230720071330.50382-1-dg573847474@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
Diffstat (limited to 'drivers/mfd')
| -rw-r--r-- | drivers/mfd/qcom-pm8xxx.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/mfd/qcom-pm8xxx.c b/drivers/mfd/qcom-pm8xxx.c index 9a948df8c28dcf..07c531bd1236e5 100644 --- a/drivers/mfd/qcom-pm8xxx.c +++ b/drivers/mfd/qcom-pm8xxx.c @@ -103,8 +103,9 @@ static int pm8xxx_config_irq(struct pm_irq_chip *chip, unsigned int bp, unsigned int cp) { int rc; + unsigned long flags; - spin_lock(&chip->pm_irq_lock); + spin_lock_irqsave(&chip->pm_irq_lock, flags); rc = regmap_write(chip->regmap, SSBI_REG_ADDR_IRQ_BLK_SEL, bp); if (rc) { pr_err("Failed Selecting Block %d rc=%d\n", bp, rc); @@ -116,7 +117,7 @@ pm8xxx_config_irq(struct pm_irq_chip *chip, unsigned int bp, unsigned int cp) if (rc) pr_err("Failed Configuring IRQ rc=%d\n", rc); bail: - spin_unlock(&chip->pm_irq_lock); + spin_unlock_irqrestore(&chip->pm_irq_lock, flags); return rc; } @@ -321,6 +322,7 @@ static int pm8xxx_irq_get_irqchip_state(struct irq_data *d, struct pm_irq_chip *chip = irq_data_get_irq_chip_data(d); unsigned int pmirq = irqd_to_hwirq(d); unsigned int bits; + unsigned long flags; int irq_bit; u8 block; int rc; @@ -331,7 +333,7 @@ static int pm8xxx_irq_get_irqchip_state(struct irq_data *d, block = pmirq / 8; irq_bit = pmirq % 8; - spin_lock(&chip->pm_irq_lock); + spin_lock_irqsave(&chip->pm_irq_lock, flags); rc = regmap_write(chip->regmap, SSBI_REG_ADDR_IRQ_BLK_SEL, block); if (rc) { pr_err("Failed Selecting Block %d rc=%d\n", block, rc); @@ -346,7 +348,7 @@ static int pm8xxx_irq_get_irqchip_state(struct irq_data *d, *state = !!(bits & BIT(irq_bit)); bail: - spin_unlock(&chip->pm_irq_lock); + spin_unlock_irqrestore(&chip->pm_irq_lock, flags); return rc; } |