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| author | Marc Zyngier <maz@kernel.org> | 2023-01-05 12:08:34 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-18 13:58:16 +0300 |
| commit | d0f52562b89155bde80d640ff4ef63bc713fac53 (patch) | |
| tree | 721c9f8203e694085cef5ecf073e35e36be119f1 | |
| parent | a30aafcfba8f9ec2a9f58769c5cdc9a2f3816008 (diff) | |
| download | linux-d0f52562b89155bde80d640ff4ef63bc713fac53.tar.xz | |
firmware/psci: Don't register with debugfs if PSCI isn't available
commit cef139299fd86098c6e3dbd389d1d0b2462d7710 upstream.
Contrary to popular belief, PSCI is not a universal property of an
ARM/arm64 system. There is a garden variety of systems out there
that don't (or even cannot) implement it.
I'm the first one deplore such a situation, but hey...
On such systems, a "cat /sys/kernel/debug/psci" results in
fireworks, as no invocation callback is registered.
Check for the invoke_psci_fn and psci_ops.get_version pointers
before registering with the debugfs subsystem, avoiding the
issue altogether.
Fixes: 3137f2e60098 ("firmware/psci: Add debugfs support to ease debugging")
Reported-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Hector Martin <marcan@marcan.st>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230105090834.630238-1-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/firmware/psci/psci.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index e7bcfca4159f..447ee4ea5c90 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -440,6 +440,9 @@ static const struct file_operations psci_debugfs_ops = { static int __init psci_debugfs_init(void) { + if (!invoke_psci_fn || !psci_ops.get_version) + return 0; + return PTR_ERR_OR_ZERO(debugfs_create_file("psci", 0444, NULL, NULL, &psci_debugfs_ops)); } |