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 <sandeepksi...@gmail.com>wrote: > On Sun, May 17, 2009 at 3:18 PM, seshikanth varma > <seshikanthva...@gmail.com> 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
