Sorry i was supposed to reply for another mail. Did it here by mistake.
On Fri, Nov 15, 2013 at 10:29 AM, manty kuma <[email protected]> wrote: > Ideally, it depends on the platform you are working. You need to discuss > with them for the correct approach. For Qualcomm they have some hardware > caled as RPU(Register protection unit). They have systems calls exposed for > using them. You can associtate it to the register you want protection. I > dont know if there is any way you could do it in Linux itself? > > Regards, > Sandeep > > > On Fri, Nov 15, 2013 at 6:03 AM, <[email protected]> wrote: > >> On Thu, 14 Nov 2013 18:32:05 +0900, manty kuma said: >> >> > I see that when we declare a variable as module_param from a driver, i >> can >> > see it listed in "/sys/module/xxx/parameters/...". >> > >> > Ex : /sys/module/usbcore/parameters/autosuspend >> > >> > we can modify and read it with echo and cat commands from terminal. >> > >> > But is there a way i can read this value from other drivers? Common >> sense >> > says it should be there because if we are able to access them from user >> > space, from kernel space we should definitely be able to do. Is it so? >> If >> > yes, what are the API's? >> >> It's just a variable. Read the source and find out what it's name is. >> You may need an EXPORT_SYMBOL() to make it available if it isn't already. >> And depending on the variable and its use, you may need locking and/or >> atomic operations to read it. >> >> And *modifying* another module's variables is just asking for trouble, >> mostly because very little code is written assuming that its variables may >> be maliciously modified out from under it. So consider code like: >> >> int foo_size, i; >> struct bar *stuff; >> >> stuff = malloc(foo_size* sizeof(struct bar)); >> >> /* somebody raises the value of foo_size from outside */ >> >> for (i=0; i < foo_size; i++) do_something(stuff[i]); >> >> You can see where that sort of stuff is heading.... >> > >
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