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llvm-project/lld/test/ELF/linkerscript/out-of-order.s

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Diagnose another case of the location counter moving backwards. This case should be possible to handle, but it is hard: * In order to create program headers correctly, we have to scan the sections in the order they are in the file. * To find that order, we have to "execute" the linker script. * The linker script can contain SIZEOF_HEADERS. So to support this we have to start with a guess of how many headers we need (3), run the linker script and try to create the program headers. If it turns out we need more headers, we run the script again with a larger SIZEOF_HEADERS. Also, running the linker script depends on knowing the size of the sections, so we have to finalize them. But creating the program headers can change the value stored in some sections, so we have to split size finalization and content finalization. Looks like the last part is also needed for range extension thunks, so we might support this at some point. For now just report an error instead of producing broken files. llvm-svn: 295458
2017-02-18 00:26:13 +08:00
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-linux %s -o %t.o
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00
# RUN: echo "SECTIONS { .data 0x4000 : {*(.data)} .dynsym 0x2000 : {*(.dynsym)} .dynstr : {*(.dynstr)} }" > %t.script
[ELF] - Do --hash-style=both by default. Its PR34712, GNU linkers recently changed default values to "both" of "sysv". Patch do the same for all targets except MIPS, where .gnu.hash section is not yet supported. Code suggested by Rui Ueyama. Differential revision: https://reviews.llvm.org/D38407 llvm-svn: 315051
2017-10-06 17:37:44 +08:00
# RUN: ld.lld --hash-style=sysv -o %t.so --script %t.script %t.o -shared
[ELF] - Allow moving location counter backward in some cases. Patch removes restriction about moving location counter backwards outside of output sections declarations. That may be useful for some apps relying on such scripts, known example is linux kernel. Differential revision: https://reviews.llvm.org/D34977 llvm-svn: 307794
2017-07-12 22:50:25 +08:00
# RUN: llvm-objdump -section-headers %t.so | FileCheck %s
Diagnose another case of the location counter moving backwards. This case should be possible to handle, but it is hard: * In order to create program headers correctly, we have to scan the sections in the order they are in the file. * To find that order, we have to "execute" the linker script. * The linker script can contain SIZEOF_HEADERS. So to support this we have to start with a guess of how many headers we need (3), run the linker script and try to create the program headers. If it turns out we need more headers, we run the script again with a larger SIZEOF_HEADERS. Also, running the linker script depends on knowing the size of the sections, so we have to finalize them. But creating the program headers can change the value stored in some sections, so we have to split size finalization and content finalization. Looks like the last part is also needed for range extension thunks, so we might support this at some point. For now just report an error instead of producing broken files. llvm-svn: 295458
2017-02-18 00:26:13 +08:00
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00
# Note: how the layout is done:
# we need to layout 2 segments, each contains sections:
# seg1: .data .dynamic
# seg2: .dynsym .dynstr .text .hash
# for each segment, we start from the first section, regardless
# whether it is an orphan or not (sections that are not listed in the
# linkerscript are orphans):
# for seg1, we assign address: .data(0x4000), .dynamic(0x4008)
# for seg2, we assign address: .dynsym(0x2000), .dynstr(0x2018) ...
# .dynsym is not an orphan, so we take address from script, we assign
# .dynstr current address cursor, which is the end # of .dynsym and so
# on for later sections.
# Also note, it is absolutely *illegal* to have section addresses of
# the same segment in none-increasing order, authors of linker scripts
# must take responsibility to make sure this does not happen.
[ELF] - Allow moving location counter backward in some cases. Patch removes restriction about moving location counter backwards outside of output sections declarations. That may be useful for some apps relying on such scripts, known example is linux kernel. Differential revision: https://reviews.llvm.org/D34977 llvm-svn: 307794
2017-07-12 22:50:25 +08:00
# CHECK: Sections:
# CHECK-NEXT: Idx Name Size Address Type
# CHECK-NEXT: 0 00000000 0000000000000000
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00
# CHECK-NEXT: 1 .data 00000008 0000000000004000
[ELF] - Allow moving location counter backward in some cases. Patch removes restriction about moving location counter backwards outside of output sections declarations. That may be useful for some apps relying on such scripts, known example is linux kernel. Differential revision: https://reviews.llvm.org/D34977 llvm-svn: 307794
2017-07-12 22:50:25 +08:00
# CHECK-NEXT: 2 .dynamic 00000060 0000000000004008
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00
# CHECK-NEXT: 3 .dynsym 00000018 0000000000002000
# CHECK-NEXT: 4 .dynstr 00000001 0000000000002018
# CHECK-NEXT: 5 .text 00000008 000000000000201c
# CHECK-NEXT: 6 .hash 00000010 0000000000002024
Diagnose another case of the location counter moving backwards. This case should be possible to handle, but it is hard: * In order to create program headers correctly, we have to scan the sections in the order they are in the file. * To find that order, we have to "execute" the linker script. * The linker script can contain SIZEOF_HEADERS. So to support this we have to start with a guess of how many headers we need (3), run the linker script and try to create the program headers. If it turns out we need more headers, we run the script again with a larger SIZEOF_HEADERS. Also, running the linker script depends on knowing the size of the sections, so we have to finalize them. But creating the program headers can change the value stored in some sections, so we have to split size finalization and content finalization. Looks like the last part is also needed for range extension thunks, so we might support this at some point. For now just report an error instead of producing broken files. llvm-svn: 295458
2017-02-18 00:26:13 +08:00
.quad 0
.data
.quad 0
[lld] Mitigate relocation overflow [part 1 of 2]. This CL places .dynsym and .dynstr at the beginning of SHF_ALLOC sections. We do this to mitigate the possibility that huge .dynsym and .dynstr sections placed between ro-data and text sections cause relocation overflow. Differential Revision: https://reviews.llvm.org/D45788 llvm-svn: 332374
2018-05-16 01:02:35 +08:00