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| author | Lee Jones <lee.jones@linaro.org> | 2019-10-21 11:16:34 +0200 |
|---|---|---|
| committer | Lee Jones <lee.jones@linaro.org> | 2019-11-11 09:45:03 +0100 |
| commit | b195e101580db390f50b0d587b7f66f241d2bc88 (patch) | |
| tree | 35f5a044a7379036a0bd9dce890bad2125176620 /drivers/mfd | |
| parent | mfd: cs5535-mfd: Register clients using their own dedicated MFD cell entries (diff) | |
| download | linux-b195e101580db390f50b0d587b7f66f241d2bc88.tar.xz linux-b195e101580db390f50b0d587b7f66f241d2bc88.zip | |
mfd: mfd-core: Protect against NULL call-back function pointer
If a child device calls mfd_cell_{en,dis}able() without an appropriate
call-back being set, we are likely to encounter a panic. Avoid this
by adding suitable checking.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/mfd')
| -rw-r--r-- | drivers/mfd/mfd-core.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 23276a80e3b4..96d02b6f06fd 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -28,6 +28,11 @@ int mfd_cell_enable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->enable) { + dev_dbg(&pdev->dev, "No .enable() call-back registered\n"); + return 0; + } + /* only call enable hook if the cell wasn't previously enabled */ if (atomic_inc_return(cell->usage_count) == 1) err = cell->enable(pdev); @@ -45,6 +50,11 @@ int mfd_cell_disable(struct platform_device *pdev) const struct mfd_cell *cell = mfd_get_cell(pdev); int err = 0; + if (!cell->disable) { + dev_dbg(&pdev->dev, "No .disable() call-back registered\n"); + return 0; + } + /* only disable if no other clients are using it */ if (atomic_dec_return(cell->usage_count) == 0) err = cell->disable(pdev); |