binutils-gdb/ld/testsuite/ld-mips-elf/binary.ld

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MIPS/LD: Fix a segfault from ELF `e_flags' access with non-ELF output BFD Fix a commit 861fb55ab50a ("Defer allocation of R_MIPS_REL32 GOT slots"), <https://sourceware.org/ml/binutils/2008-08/msg00096.html>, regression and a more recent: FAIL: ld-unique/pr21529 new LD test case failure, observed with all the relevant MIPS targets whenever the linker is invoked with one or more ELF inputs and the output format set to `binary'. The culprit is a segmentation fault caused in `mips_before_allocation' by a null pointer dereference, where an attempt is made to access the ELF file header's `e_flags' member, for the purpose of determining whether to produce a PLT and copy relocations, without first checking that the output BFD is ELF. The `e_flags' member is stored in BFD's private data pointed to by `tdep', which in the case of the `binary' BFD is null, causing the segmentation fault. With other non-ELF BFDs such as SREC `tdep' is not null and consequently no crash may happen and in that case random data will be interpreted as it was `e_flags'. Disable the access to `e_flags' then and all the associated checks and consequently never produce a PLT and copy relocations if output is not a MIPS ELF BFD, matching `_bfd_mips_elf_merge_private_bfd_data' that does not process `e_flags' in that case either and therefore does not let us decide here anyway if all the input objects included in the link are suitable for use with a PLT and copy relocations. ld/ * emultempl/mipself.em (mips_before_allocation): Avoid ELF processing if not MIPS ELF. * testsuite/ld-mips-elf/binary.d: New test. * testsuite/ld-mips-elf/binary.ld: New test linker script. * testsuite/ld-mips-elf/binary.s: New test source. * testsuite/ld-mips-elf/mips-elf.exp: Run the new test. 2017-07-07 18:58:03 +02:00			`SECTIONS`
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