On 29/01/2024 12:01, Jon Hunter wrote:
Commit c5b2d43e67bb ("soc/tegra: fuse: Add ACPI support for Tegra194 and
Tegra234") updated the Tegra fuse driver to add ACPI support and added a
test to the tegra_fuse_readl() function to check if the device is
booting with device-tree. This test passes 'fuse->dev' variable to
dev_fwnode() but does not check first is 'fuse->dev' is valid. This is
causing a crash to occur in Tegra XUSB PHY driver that calls the
tegra_fuse_readl() function before 'fuse->dev' variable has been
initialised ...
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000290
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[0000000000000290] user address but active_mm is swapper
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 7 PID: 70 Comm: kworker/u16:4 Not tainted 6.8.0-rc1-next-20240129-02825-g596764183be8 #1
Hardware name: NVIDIA Jetson AGX Xavier Developer Kit (DT)
Workqueue: events_unbound deferred_probe_work_func
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __dev_fwnode+0x0/0x18
lr : tegra_fuse_readl+0x24/0x98
sp : ffff80008393ba10
x29: ffff80008393ba10 x28: 0000000000000000 x27: ffff800081233c10
x26: 00000000000001c8 x25: ffff000080b7bc10 x24: ffff000082df3b00
x23: fffffffffffffff4 x22: 0000000000000004 x21: ffff80008393ba84
x20: 00000000000000f0 x19: ffff800082f1e000 x18: ffff800081d72000
x17: 0000000000000001 x16: 0000000000000001 x15: ffff800082fcdfff
x14: 0000000000000000 x13: 0000000003541000 x12: 0000000000000020
x11: 0140000000000000 x10: ffff800080000000 x9 : 0000000000000000
x8 : ffff000082df3b40 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 00000000ffffffff x4 : 0000000000000dc0 x3 : 00000000000000c0
x2 : 0000000000000001 x1 : ffff80008393ba84 x0 : 0000000000000000
Call trace:
__dev_fwnode+0x0/0x18
tegra186_xusb_padctl_probe+0xb0/0x1a8
tegra_xusb_padctl_probe+0x7c/0xebc
platform_probe+0x90/0xd8
really_probe+0x13c/0x29c
__driver_probe_device+0x7c/0x124
driver_probe_device+0x38/0x11c
__device_attach_driver+0x90/0xdc
bus_for_each_drv+0x78/0xdc
__device_attach+0xfc/0x188
device_initial_probe+0x10/0x18
bus_probe_device+0xa4/0xa8
deferred_probe_work_func+0x80/0xb4
process_scheduled_works+0x178/0x3e0
worker_thread+0x164/0x2e8
kthread+0xfc/0x11c
ret_from_fork+0x10/0x20
Code: a8c27bfd d65f03c0 128002a0 d65f03c0 (f9414801)
---[ end trace 0000000000000000 ]---
Fix this by verifying that 'fuse->dev' is valid before passing to
dev_fwnode(). Given that 'fuse->clk' and 'fuse->clk' are initialised in
the same function, test these variables in the same if-statement.
Fixes: c5b2d43e67bb ("soc/tegra: fuse: Add ACPI support for Tegra194 and Tegra234")
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/soc/tegra/fuse/fuse-tegra.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index c34efa5bf44c..efe9853d4a8a 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -348,7 +348,10 @@ int tegra_fuse_readl(unsigned long offset, u32 *value)
/*
* Wait for fuse->clk to be initialized if device-tree boot is used.
*/
- if (is_of_node(dev_fwnode(fuse->dev)) && !fuse->clk)
+ if (!fuse->clk || !fuse->dev)
+ return -EPROBE_DEFER;
+
+ if (is_of_node(dev_fwnode(fuse->dev)))
return -EPROBE_DEFER;
Actually, this is still not correct, because this will now break ACPI
support. I will update and resend.
Jon
--
nvpublic
