input_event for 64-bit kernel and 32-bit userland.
Hi all,
I stuck in simple situation:
USB mouse (or keyboard). n64 kernel (2.4.20), n32 userland.
Userspace application tries to read "input_event" (16 bytes) from "/dev/input/event0" [ read(fd,&key_ev, sizeof(key_ev)) ],
input core driver treats "input_event" as 24 bytes structure. It is due to different size of "timeval" (and finally "long") in n64 kernel and n32 userland.
Application gets some garbage as mouse events . No solutions like "ioctl wrappers" applicable in this case.
I don't want to change any arch independent files, but can not find any
acceptable solution. It looks like headers "/usr/include/linux/input.h" in root file system and "/include/linux/input.h" in kernel should be the same, (All works fine as soon as I declare a new "input_event" structure in user application that corresponds in size to kernel structure - but this is not acceptable).
Can anybody advice me what to do with the difference in "input_event"
structure sizes in o32/n32 userland and n64 kernel? Just a general approach that can be used when driver's read/write operation treat some values as 64 bit while user application tries to read/write 32-bit values (based on the same headers).
Please, don't kick me if solution is simple and obvious.
---
Thanks,
Pavel Kiryukhin.
On Wed, 2004-06-02 14:06:10 +0400, Pavel Kiryukhin <[email protected]> wrote in message <[email protected]>:
Quoted 5 lines
Userspace application tries to read "
input_event" (16 bytes) from "/dev/input/event0" [read(fd,&key_ev, sizeof(key_ev))], input core driver treats "input_event" as 24 bytes structure. It is due to different size of "timeval" (and finally "long") in n64 kernel and n32 userland.
You'd probably Cc: that to LKML, too. That's an issue for all systems running 64bit kernel with 32bit userland (eg. Ultra-Sparc, PPC64, IA64, x86_64, ...).
MfG, JBG
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