Re: RPM strip scripts and executables as shared objects
On 29/03/2019 16:17, Robert Marcano wrote:
I have been working on a private RPM for a Rust based program and
noticed that the RPM strip scripts are not reducing the binaries files
like when I execute strip directly on those binaries.
The first thing I checked is the brp-strip script. This one is filtering
executables where "file" reports it is a "shared object", Rust
binaries
are marked as "ELF 64-bit LSB shared object" instead of "ELF 64-bit LSB
executable". My understating of this after a few web searches is that
this is for security features like PIE and ASLR.
brp-strip-shared runs "strip --strip-unneeded" but brp-strip run
"strip"
(no arguments). Is there a reason why binaries marked as "ELF 64-bit LSB
shared object" should not be fully stripped?
Yes - read the manual page definition of --strip-unneeded and you
will see:
"Remove all symbols that are not needed for relocation processing."
So the extra bits it leaves (which --strip removes) are the symbols
needed to be able to relocate it, and shared libraries and position
independent executables need to be relocated when they are loaded.
In short if you use --strip you will find that you are no longer
able to actually load the program or shared library.
Tom
--
Tom Hughes (tom(a)compton.nu)
http://compton.nu/