Re: copy_to_user() and copy_from_user(): confusing code

[Bond <jamesbond.2k.g@xxxxxxxxx>]

On Sat, Sep 25, 2010 at 11:06 PM, Chetan Nanda <chetannanda@xxxxxxxxx> wrote:

 

as per my understanding (may be wrong), issue is not with the copy_to/from_user. May be with the return values from  bond_read/write function.
Drivers read/write should return the number of bytes read or written.

Agreed that was a mistake in my code.

On Sat, Sep 25, 2010 at 7:34 PM, Bond <jamesbond.2k.g@xxxxxxxxx> wrote: 

mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f2a2f03b000

write(1, "abcde", 5)                    = 1

write(1, "bcde", 4)                     = 1

write(1, "cde", 3)                      = 1

write(1, "de", 2)                       = 1

write(1, "e", 1)                        = 1

close(1)                                = 0

munmap(0x7f2a2f03b000, 4096)            = 0

close(2)                                = 0

exit_group(0)                           = ?

Can you say any thing about the strace log above as why did I got the above output.