Re: Handling pgoff in perf elf mmap/mmap2 elf info

[Milian Wolff <mail at milianw dot de>]

On Montag, 15. Oktober 2018 23:04:52 CEST Mark Wielaard wrote:
> Hi Milian,
> 
> On Mon, 2018-10-15 at 22:38 +0200, Milian Wolff wrote:
> > here's one example of mmap events recorded by perf:
> > 
> > 0x7fac5ec0b000 to 0x7fac5ed9a000, len =   0x18f000, offset
> > =                0    r--p    /usr/lib/libstdc++.so.6.0.25
> > 0x7fac5ec94000 to 0x7fac5ed8a000, len =    0xf6000, offset
> > =          0x89000    ---p    /usr/lib/libstdc++.so.6.0.25
> > 0x7fac5ec94000 to 0x7fac5ed4c000, len =    0xb8000, offset
> > =          0x89000    r-xp    /usr/lib/libstdc++.so.6.0.25
> > 0x7fac5ed4c000 to 0x7fac5ed89000, len =    0x3d000, offset
> > =         0x141000    r--p    /usr/lib/libstdc++.so.6.0.25
> > 0x7fac5ed8a000 to 0x7fac5ed97000, len =     0xd000, offset
> > =         0x17e000    rw-p    /usr/lib/libstdc++.so.6.0.25
> 
> Could you also post the matching phdr output for the file?
> eu-readelf -l /usr/lib/libstdc++.so.6.0.25 should show it.
> That way we can see how the PT_LOAD segments map to the mmap events.

Sure:

$ eu-readelf -l /usr/lib/libstdc++.so.6.0.25
Program Headers:
  Type           Offset   VirtAddr           PhysAddr           FileSiz  
MemSiz   Flg Align
  LOAD           0x000000 0x0000000000000000 0x0000000000000000 0x088fa8 
0x088fa8 R   0x1000
  LOAD           0x089000 0x0000000000089000 0x0000000000089000 0x0b7ae1 
0x0b7ae1 R E 0x1000
  LOAD           0x141000 0x0000000000141000 0x0000000000141000 0x03cfe0 
0x03cfe0 R   0x1000
  LOAD           0x17e8e0 0x000000000017f8e0 0x000000000017f8e0 0x00b8b8 
0x00ed60 RW  0x1000
  DYNAMIC        0x1873a8 0x00000000001883a8 0x00000000001883a8 0x0001e0 
0x0001e0 RW  0x8
  NOTE           0x0002a8 0x00000000000002a8 0x00000000000002a8 0x000024 
0x000024 R   0x4
  NOTE           0x17dfc0 0x000000000017dfc0 0x000000000017dfc0 0x000020 
0x000020 R   0x8
  TLS            0x17e8e0 0x000000000017f8e0 0x000000000017f8e0 0x000000 
0x000020 R   0x8
  GNU_EH_FRAME   0x149558 0x0000000000149558 0x0000000000149558 0x007f04 
0x007f04 R   0x4
  GNU_STACK      0x000000 0x0000000000000000 0x0000000000000000 0x000000 
0x000000 RW  0x10
  GNU_RELRO      0x17e8e0 0x000000000017f8e0 0x000000000017f8e0 0x00b720 
0x00b720 R   0x1

 Section to Segment mapping:
  Segment Sections...
   00      [RO: .note.gnu.build-id .gnu.hash .dynsym .dynstr .gnu.version 
.gnu.version_d .gnu.version_r .rela.dyn]
   01      [RO: .init .text .fini]
   02      [RO: .rodata .eh_frame_hdr .eh_frame .gcc_except_table 
.note.gnu.property]
   03      [RELRO: .tbss .init_array .fini_array .data.rel.ro .dynamic .got] 
.got.plt .data .bss
   04      [RELRO: .dynamic]
   05      [RO: .note.gnu.build-id]
   06      [RO: .note.gnu.property]
   07      [RELRO: .tbss]
   08      [RO: .eh_frame_hdr]
   09     
   10      [RELRO: .tbss .init_array .fini_array .data.rel.ro .dynamic .got]

-- 
Milian Wolff
mail@milianw.de
http://milianw.de

Attachment: signature.asc
Description: This is a digitally signed message part.