[llvm-bugs] [Bug 38875] New: lld always emits .relr.dyn section even when that section is empty

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=38875

            Bug ID: 38875
           Summary: lld always emits .relr.dyn section even when that
                    section is empty
           Product: lld
           Version: unspecified
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: ELF
          Assignee: unassignedbugs at nondot.org
          Reporter: phosek at chromium.org
                CC: llvm-bugs at lists.llvm.org

We're seeing this in our kernel, there should be no need for lld to emit that
section.

./prebuilt/downloads/clang/bin/llvm-readelf -S build-x64-clang/zircon.elf      
                                                                               
                                                                               
                                                                               
                                                                 
~/fuchsia/zircon
There are 40 section headers, starting at offset 0xc83088:
Section Headers:
  [Nr] Name              Type            Address          Off    Size   ES Flg
Lk Inf Al
  [ 0]                   NULL            0000000000000000 000000 000000 00     
0   0  0
  [ 1] .text.boot0       PROGBITS        ffffffff80100000 001000 000070 00   A 
0   0  1
  [ 2] .buildsig         PROGBITS        ffffffff80100070 001070 000028 00   A 
0   0  1
  [ 3] .text.boot        PROGBITS        ffffffff80100098 001098 0002d8 00  AX 
0   0  8
  [ 4] .text.bootstrap16 PROGBITS        ffffffff80101000 002000 000166 00  AX 
0   0 4096
  [ 5] .text             PROGBITS        ffffffff80101170 002170 0f6325 00  AX 
0   0 16
  [ 6] .rodata.rodso_image PROGBITS      ffffffff801f8000 0f9000 00e000 00   A 
0   0 4096
  [ 7] code_patch_table  PROGBITS        ffffffff80206000 107000 000060 00   A 
0   0  8
  [ 8] .relr.dyn         RELR            ffffffff80206060 107060 000000 08   A 
0   0  8
  [ 9] .note.gnu.build-id NOTE           ffffffff80206060 107060 000018 00   A 
0   0  4
  [10] .kcounter.desc    PROGBITS        ffffffff80206078 107078 0001a0 00  WA 
0   0  8
  [11] .rodata           PROGBITS        ffffffff80206220 107220 024bd0 00 AMS 
0   0 32
  [12] .data.rel.ro      PROGBITS        ffffffff8022adf0 12bdf0 0062d8 00  WA 
0   0 16
  [13] .init_array       INIT_ARRAY      ffffffff802310c8 1320c8 0000c0 00  WA 
0   0  8
  [14] .data             PROGBITS        ffffffff80232000 133000 00f0e8 00  WA 
0   0 4096
  [15] .bss              NOBITS          ffffffff80242000 1420e8 083970 00  WA 
0   0 4096
  [16] .comment          PROGBITS        0000000000000000 1420e8 000107 01  MS 
0   0  1
  [17] .rela.text        RELA            0000000000000000 1421f0 0e7048 18   I
37   5  8
  [18] .rela.data.rel.ro RELA            0000000000000000 229238 00e178 18   I
37  12  8
  [19] .debug_str        PROGBITS        0000000000000000 2373b0 0fb516 01  MS 
0   0  1
  [20] .debug_loc        PROGBITS        0000000000000000 3328c6 220c96 00     
0   0  1
  [21] .debug_abbrev     PROGBITS        0000000000000000 55355c 044085 00     
0   0  1
  [22] .debug_info       PROGBITS        0000000000000000 5975e1 3faedc 00     
0   0  1
  [23] .debug_ranges     PROGBITS        0000000000000000 9924bd 06a9c0 00     
0   0  1
  [24] .debug_macinfo    PROGBITS        0000000000000000 9fce7d 00013b 00     
0   0  1
  [25] .debug_pubnames   PROGBITS        0000000000000000 9fcfb8 0be92b 00     
0   0  1
  [26] .debug_pubtypes   PROGBITS        0000000000000000 abb8e3 070e6b 00     
0   0  1
  [27] .debug_frame      PROGBITS        0000000000000000 b2c750 033b88 00     
0   0  8
  [28] .debug_line       PROGBITS        0000000000000000 b602d8 0cdaf2 00     
0   0  1
  [29] .rela.rodata      RELA            0000000000000000 c2ddd0 0113d0 18   I
37  11  8
  [30] .rela.data        RELA            0000000000000000 c3f1a0 000588 18   I
37  14  8
  [31] .rela.init_array  RELA            0000000000000000 c3f728 000240 18   I
37  13  8
  [32] .rela.kcounter.desc RELA          0000000000000000 c3f968 0004e0 18   I
37  10  8
  [33] .debug_aranges    PROGBITS        0000000000000000 c3fe48 000290 00     
0   0  1
  [34] .rela.text.boot   RELA            0000000000000000 c400d8 000540 18   I
37   3  8
  [35] .relacode_patch_table RELA        0000000000000000 c40618 0000c0 18   I
37   7  8
  [36] .rela.text.bootstrap16 RELA       0000000000000000 c406d8 0000c0 18   I
37   4  8
  [37] .symtab           SYMTAB          0000000000000000 c40798 01a9d0 18    
39 4534  8
  [38] .shstrtab         STRTAB          0000000000000000 c5b168 000206 00     
0   0  1
  [39] .strtab           STRTAB          0000000000000000 c5b36e 027d17 00     
0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), l (large)
  I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20180907/476c4b7c/attachment.html>