[patch] validate binary before use

[Jan Kratochvil]

On Thu, 27 Dec 2012 21:06:52 +0100, Aleksandar Ristovski wrote:
> build-id would be great if it was required by the standard

GDB can check if it exists and do something as a fallback if it does not exist.
Such as printing a warning and possibly also verifying the program headers, if
compatibility with binaries from old toolchain and/or toolchain without
configured ld --build-id is required in some situations (which I doubt).


> and mapped into loadable segments.

It is mapped, because one of its purposes is to get dumped into a core file.
In fact there is a special care to make it always present in the first page.

Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
  [ 3] .note.gnu.build-id NOTE            00000000004002ac 0002ac 000024 00   A  0   0  4
Program Headers:
  Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
  LOAD           0x000000 0x0000000000400000 0x0000000000400000 0x0d9db0 0x0d9db0 R E 0x200000


Thanks,
Jan