mirror/binutils-gdb
2
0
Fork 0
mirror of https://sourceware.org/git/binutils-gdb.git synced 2024-12-27 04:52:05 +08:00
Code Issues Packages Projects Releases Wiki Activity
783a7b12d3
binutils-gdb/ld/testsuite/ld-aarch64/erratum843419-adrp.d

23 lines
629 B
D
Raw Normal View History

AArch64: Implement choice between Cortex-A53 erratum workarounds. (PR ld/24373) The Cortex-A53 erratum currently has two ways it can resolve the erratum when using the flag --fix-cortex-a53-843419: 1) If the address is within the range of an ADR instruction it rewrites the ADRP into an ADR, and those doesn't need the use of a veneer. 2) If the address is not within range, it adds a branch to a veneer which will execute the final bit of the erratum workaround and branch back to the call site. When we do this we always generate the veneers and we always align the size of the text section to 4KB. This is because we only know which workaround we can use after all linking has finished and all addresses are known. This means even though the veneers are not used, we still generate the section and we still change the size of the input section. This is problematic for small memory devices as this would require the user to take about a ~4KB hit in memory even though it's not even used. Since there's no real way to restart the linking process from the final write phase this patch solves the issue by allowing the user more control over which erratum workaround gets used. Concretely this changes the option --fix-cortex-a53-843419 to take optional arguments --fix-cortex-a53-843419[=full|adr|adrp] - full (default): Use both ADRP and ADR workaround. This is equivalent to not specifying any options and is the default behavior before this patch. - adr: Only use the ADR workaround, this will not cause any increase in binary size but linking will fail if the referenced address is out of range of an ADR instruction. - adrp: Use only the ADRP workaround, this will never rewrite your ADRP. In the cases where the user knows how big their binaries are the `adr` option would prevent the unneeded overhead. bfd/ChangeLog: PR ld/24373 * bfd-in.h (enum erratum_84319_opts): New (bfd_elf64_aarch64_set_options, bfd_elf32_aarch64_set_options): Change int to enum erratum_84319_opts. * bfd-in2.h: Regenerate. * elfnn-aarch64.c (struct elf_aarch64_link_hash_table): Change fix_erratum_843419 to use new enum, remove fix_erratum_843419_adr. (_bfd_aarch64_add_stub_entry_after): Conditionally create erratum stub. (aarch64_size_one_stub): Conditionally size erratum 843419 stubs. (_bfd_aarch64_resize_stubs): Amend comment. (elfNN_aarch64_size_stubs): Don't generate stubs when no workaround requested. (bfd_elfNN_aarch64_set_options): Use new fix_erratum_843419 enum. (_bfd_aarch64_erratum_843419_branch_to_stub): Implement selection of erratum workaround. (clear_erratum_843419_entry): Update erratum conditional. ld/ChangeLog: PR ld/24373 * emultempl/aarch64elf.em (PARSE_AND_LIST_LONGOPTS): Add optional args to flags. * NEWS: Add changes to flag. (PARSE_AND_LIST_OPTIONS): Update help descriptions. (PARSE_AND_LIST_ARGS_CASES): Add new options to parser. * testsuite/ld-aarch64/aarch64-elf.exp: Add new run_dump_tests. * testsuite/ld-aarch64/erratum843419-adr.d: New test. * testsuite/ld-aarch64/erratum843419-adrp.d: New test. * testsuite/ld-aarch64/erratum843419-far-adr.d: New test. * testsuite/ld-aarch64/erratum843419-far-full.d: New test. * testsuite/ld-aarch64/erratum843419-far.s: New test. * testsuite/ld-aarch64/erratum843419-full.d: New test. * testsuite/ld-aarch64/erratum843419-near.s: New test. * testsuite/ld-aarch64/erratum843419-no-args.d: New test.
2019-05-21 20:04:08 +08:00
#source: erratum843419-near.s
#as:
#ld: -Ttext=0x400000 --fix-cortex-a53-843419=adrp
#objdump: -dr
#...
Disassembly of section \.text:
0*400000 <_start>:
...
400ffc: 90000040 adrp x0, 408000 <e843419@0002_00000010_1008\+0x6fe8>
401000: f9000042 str x2, \[x2\]
401004: d2800002 mov x2, #0x0 // #0
401008: 14000004 b 401018 <e843419@0002_00000010_1008>
40100c: d503201f nop
401010: 14000400 b 402010 <e843419@0002_00000010_1008\+0xff8>
401014: d503201f nop
0*401018 <e843419@0002_00000010_1008>:
401018: f9402001 ldr x1, \[x0, #64\]
40101c: 17fffffc b 40100c <_start\+0x100c>
...
Reference in New Issue Copy Permalink