Re: done digging around test-dprintf-posix2

[Bruno Haible]

Bruce Korb wrote:
> SYS_brk(NULL)                                    = 0x00606000
> SYS_brk(0x00627000)                              = 0x00606000
> SYS_mmap(0, 0x100000, 3, 34, 0xffffffff)         = -12

I don't understand this. The brk area contains 132 KiB,
and an attempt to mmap 1 MB fails. Where are the remaining 8.9 MB
allocated?

> test-fprintf-posix3
>         linux-vdso.so.1 =>  (0x00007fffa6fff000)
>         librt.so.1 => /lib64/librt.so.1 (0x00007f41de2b7000)
>         libm.so.6 => /lib64/libm.so.6 (0x00007f41de060000)
>         libc.so.6 => /lib64/libc.so.6 (0x00007f41ddd00000)
>         libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f41ddae3000)
>         /lib64/ld-linux-x86-64.so.2 (0x00007f41de4c0000)
> test-dprintf-posix2
>         linux-vdso.so.1 =>  (0x00007fff995f9000)
>         librt.so.1 => /lib64/librt.so.1 (0x00007f9b1dc99000)
>         libm.so.6 => /lib64/libm.so.6 (0x00007f9b1da42000)
>         libc.so.6 => /lib64/libc.so.6 (0x00007f9b1d6e2000)
>         libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f9b1d4c5000)
>         /lib64/ld-linux-x86-64.so.2 (0x00007f9b1dea2000)
> $ size test-fprintf-posix3 test-dprintf-posix2
>    text    data     bss     dec     hex filename
>   15338     648      24   16010    3e8a test-fprintf-posix3
>   15540     648      16   16204    3f4c test-dprintf-posix2

OK, and what about
  $ size linux-vdso.so.1
  $ size /lib64/librt.so.1
  $ size /lib64/libm.so.6
  $ size /lib64/libpthread.so.0
  $ size /lib64/ld-linux-x86-64.so.2

Even more useful would be to put a breakpoint at the malloc(0x88),
and while gdb is halting the process, do $ cat /proc/pid/maps

Have you by chance enabled 4 MB pages on your system?

Bruno