Messages in this thread | | | Date | Sat, 6 Aug 2022 13:46:16 -0700 | From | Jack Rosenthal <> | Subject | Re: [PATCH v7] firmware: google: Implement cbmem in sysfs driver |
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On 2022-08-04 at 15:59 -0500, Stephen Boyd wrote: > I suspect this won't work because the driver can be unbound, and thus > the mapping can be destroyed by devm, but then the kobject and sysfs > file like 'mem' can be held by userspace after the driver is unbound. > Userspace access after that time will try to read/write unmapped memory.
When the driver is unbound, read()/write() will return -ENODEV, and mmap() isn't supported.
> Why not make this in the bus driver (coreboot-table.c)? In fact, most > things could probably be created there instead of in a 'driver' that > really isn't doing much 'driving' at all.
In v8, I moved the coreboot_kobj to coreboot-table.c. I imagine in the future we could move some of the other things (e.g., "vpd") under this object for consistency. So now the structure is:
/sys/firmware/coreboot/cbmem/<id>/...
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