[Bug binutils/22782] New: ld.bfd large static binaries

[felix-glibc at fefe dot de]

https://sourceware.org/bugzilla/show_bug.cgi?id=22782

            Bug ID: 22782
           Summary: ld.bfd large static binaries
           Product: binutils
           Version: 2.30
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: binutils
          Assignee: unassigned at sourceware dot org
          Reporter: felix-glibc at fefe dot de
  Target Milestone: ---

Created attachment 10782
  --> https://sourceware.org/bugzilla/attachment.cgi?id=10782&action=edit
test case (object files and shell script that calls ld)

I wrote a small libc for Linux (www.fefe.de/dietlibc/) and a collection of
small utils to go with it (www.fefe.de/embutils/). With ld.bfd from binutils
2.30 the binary for /bin/true is >4k large. With ld.bfd from earlier binutils
and ld.gold from 2.30 the binary is much smaller.

size true says: text 783 data 24 bss 92.

The thing is: there is no data. true is literally "return true", and my libc
puts errno into TLS not .data and environ into .bss.

If I link with -Wl,-Map,mapfile I can see this:

.got            0x0000000000601000        0x0
 *(.got)
 .got           0x0000000000601000        0x0 /opt/diet/lib-x86_64/start.o
 *(.igot)
                0x0000000000601fe8                . = DATA_SEGMENT_RELRO_END
(., (SIZEOF (.got.plt) >= 0x18)?0x18:0x0)

.got.plt        0x0000000000601000       0x18
 *(.got.plt)
 .got.plt       0x0000000000601000       0x18 /opt/diet/lib-x86_64/start.o
                0x0000000000601000                _GLOBAL_OFFSET_TABLE_

Wait, what? a PLT for a static binary? How did this happen?
It appears to me like this and the 4k page alignment are what is responsible
for the larger binaries.

I'll attach a tarball with the object files and a shell script to link them to
this bug.

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