From c1556ecd7843912269aba283a0fd307729fa0c3a Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Thu, 23 Feb 2017 19:26:53 +0000 Subject: MIPS/BFD: Discard ineligible JALR relocations right away Discard R_MIPS_JALR and R_MICROMIPS_JALR relocations associated with jumps that cannot be converted to an equivalent branch right away in `mips_elf_calculate_relocation' rather than letting them through to `mips_elf_perform_relocation'. This includes cross-mode jumps which need to flip the ISA bit or jumps to a misaligned location that cannot be encoded with a branch, in addition to preemptible symbol references already handled. Cross-mode jumps are actually already rejected as the conversion is made in `mips_elf_perform_relocation', so in this case this change only saves some processing. Jumps to a misaligned location are however converted, with bits causing misalignment lost, making resulting code functionally different even if the lone effect is avoiding an address error exception with an instruction fetch at the jump destination requested. Add test cases suitable, also including GAS verification to confirm that the JALR relocations explicitly requested have indeed been output in the intermediate objects used. bfd/ * elfxx-mips.c (mips_elf_calculate_relocation) : Discard relocation if `cross_mode_jump_p' or misaligned. gas/ * testsuite/gas/mips/jalr4.d: New test. * testsuite/gas/mips/jalr4-n32.d: New test. * testsuite/gas/mips/jalr4-n64.d: New test. * testsuite/gas/mips/jalr4.s: New test source. * testsuite/gas/mips/mips.exp: Run the new tests. ld/ * testsuite/ld-mips-elf/jalr4.dd: New test. * testsuite/ld-mips-elf/mips-elf.exp: Run the new test. --- ld/testsuite/ld-mips-elf/jalr4.dd | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 ld/testsuite/ld-mips-elf/jalr4.dd (limited to 'ld/testsuite/ld-mips-elf/jalr4.dd') diff --git a/ld/testsuite/ld-mips-elf/jalr4.dd b/ld/testsuite/ld-mips-elf/jalr4.dd new file mode 100644 index 0000000..8e41756 --- /dev/null +++ b/ld/testsuite/ld-mips-elf/jalr4.dd @@ -0,0 +1,19 @@ +.*: +file format .*mips.* + +Disassembly of section \.text: +[0-9a-f]+ <[^>]*> 0411000f bal 0+000040 +[0-9a-f]+ <[^>]*> 00000000 nop +[0-9a-f]+ <[^>]*> 1000000d b 0+000040 +[0-9a-f]+ <[^>]*> 00000000 nop +[0-9a-f]+ <[^>]*> 0320f809 jalr t9 +[0-9a-f]+ <[^>]*> 00000000 nop +[0-9a-f]+ <[^>]*> 03200008 jr t9 +[0-9a-f]+ <[^>]*> 00000000 nop +[0-9a-f]+ <[^>]*> 0320f809 jalr t9 +[0-9a-f]+ <[^>]*> 00000000 nop +[0-9a-f]+ <[^>]*> 03200008 jr t9 +[0-9a-f]+ <[^>]*> 00000000 nop + \.\.\. + \.\.\. + \.\.\. + \.\.\. -- cgit v1.1