On Sat, May 23, 2009 at 1:02 PM, SandeepKsinha <sandeepksinha@xxxxxxxxx> wrote: > IMO, binutils members can answer this better. > copying binutils list.... > > On Sat, May 23, 2009 at 12:06 AM, seshikanth varma > <seshikanthvarma@xxxxxxxxx> wrote: >> Hi >> I googled out but i could not find these things: >>> .section .fixup >>> .previous >>> .align 4 >> Can u please help me in finding the meaning of these things? Any document >> which gives elaborate explanation would be really helpful for me for >> future reference, I have seen some more things in linux source code like >> __extable .... >> >> >> >> On Sun, May 17, 2009 at 4:16 PM, SandeepKsinha <sandeepksinha@xxxxxxxxx> >> wrote: >>> >>> On Sun, May 17, 2009 at 3:18 PM, seshikanth varma >>> <seshikanthvarma@xxxxxxxxx> wrote: >>> > Hi All, >>> > I am trying to understand the implementation of copy_from_user() and >>> > copy_to_user() implementation in linux. I know the basics of asm format. >>> > But >>> > i don't know what is >>> > .section .fixup >>> > .previous >>> > .align 4 >>> > Can u please point me to a detailed documentation of asm details >>> > involving >>> > the above? >>> >>> Google for "inline assembly" and "assembly in C". >>> >>> > Thanks, >>> > Seshikanth >>> > >>> > 320 * Tell gcc we read from memory instead of writing: this is because >>> > 321 * we do not write to any memory gcc knows about, so there are no >>> > 322 * aliasing issues. >>> > 323 */ >>> > 324#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) >>> > \ >>> > 325 __asm__ __volatile__( >>> > \ >>> > 326 "1: mov"itype" %"rtype"1,%2\n" >>> > \ >>> > 327 "2:\n" >>> > \ >>> > 328 ".section .fixup,\"ax\"\n" >>> > \ >>> > 329 "3: movl %3,%0\n" >>> > \ >>> > 330 " jmp 2b\n" >>> > \ >>> > 331 ".previous\n" >>> > \ >>> > 332 ".section __ex_table,\"a\"\n" >>> > \ >>> > 333 " .align 4\n" >>> > \ >>> > 334 " .long 1b,3b\n" >>> > \ >>> > 335 ".previous" >>> > \ >>> > 336 : "=r"(err) >>> > \ >>> > 337 : ltype (x), "m"(__m(addr)), "i"(errret), "0"(err)) >>> > 338 >>> > 339 >>> > >>> > -- >>> > Regards, >>> > Seshikanth >>> > >>> >>> >>> >>> -- >>> Regards, >>> Sandeep. >>> >>> >>> >>> >>> >>> >>> “To learn is to change. Education is a process that changes the learner.” >> >> >> >> -- >> Regards, >> Seshikanth >> > > > > -- > Regards, > Sandeep. > > > > > > > “To learn is to change. Education is a process that changes the learner.” > -- Regards, Sandeep. “To learn is to change. Education is a process that changes the learner.” -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
