Messages in this thread Patch in this message | | | From | Zhen Lei <> | Subject | [PATCH] ARM: 9220/1: amba: Add sanity check for dev->periphid in amba_probe() | Date | Sat, 27 Aug 2022 18:18:53 +0800 |
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Commit f2d3b9a46e0e ("ARM: 9220/1: amba: Remove deferred device addition") forcibly invokes device_add() even if dev->periphid is not ready. Although it will be remedied in amba_match(): dev->periphid will be initialized if everything is in place; Otherwise, return -EPROBE_DEFER to block __driver_attach() from further execution. But not all drivers have .match hook, such as pl031, the dev->bus->probe will be called directly in __driver_attach(). Unfortunately, if dev->periphid is still not initialized, the following exception will be triggered.
8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000008 [00000008] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc2+ #7 Hardware name: ARM-Versatile Express PC is at pl031_probe+0x8/0x208 LR is at amba_probe+0xf0/0x160 pc : 80698df8 lr : 8050eb54 psr: 80000013 sp : c0825df8 ip : 00000000 fp : 811fda38 r10: 00000000 r9 : 80d72470 r8 : fffffdfb r7 : 811fd800 r6 : be7eb330 r5 : 00000000 r4 : 811fd900 r3 : 80698df0 r2 : 37000000 r1 : 00000000 r0 : 811fd800 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 6000406a DAC: 00000051 ... ... pl031_probe from amba_probe+0xf0/0x160 amba_probe from really_probe+0x118/0x290 really_probe from __driver_probe_device+0x84/0xe4 __driver_probe_device from driver_probe_device+0x30/0xd0 driver_probe_device from __driver_attach+0x8c/0xfc __driver_attach from bus_for_each_dev+0x70/0xb0 bus_for_each_dev from bus_add_driver+0x168/0x1f4 bus_add_driver from driver_register+0x7c/0x118 driver_register from do_one_initcall+0x44/0x1ec do_one_initcall from kernel_init_freeable+0x238/0x288 kernel_init_freeable from kernel_init+0x18/0x12c kernel_init from ret_from_fork+0x14/0x2c ... ... ---[ end trace 0000000000000000 ]---
Therefore, take the same action as in amba_match(): return -EPROBE_DEFER if dev->periphid is not ready in amba_probe().
Fixes: f2d3b9a46e0e ("ARM: 9220/1: amba: Remove deferred device addition") Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- KernelVersion: v6.0-rc2 drivers/amba/bus.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 32b0e0b930c1068..2e5572f60692a33 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -274,9 +274,17 @@ static int amba_probe(struct device *dev) { struct amba_device *pcdev = to_amba_device(dev); struct amba_driver *pcdrv = to_amba_driver(dev->driver); - const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev); + const struct amba_id *id; int ret; + if (!pcdev->periphid) { + ret = amba_read_periphid(pcdev); + if (ret) + return -EPROBE_DEFER; + } + + id = amba_lookup(pcdrv->id_table, pcdev); + do { ret = of_amba_device_decode_irq(pcdev); if (ret) -- 2.25.1
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