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| author | Renlin Li <renlin.li@arm.com> | 2017-12-13 12:11:25 +0000 |
|---|---|---|
| committer | Renlin Li <renlin.li@arm.com> | 2017-12-13 15:15:50 +0000 |
| commit | 79e741920446582bd0e09f3e2b9f899c258efa56 (patch) | |
| tree | 1263cda68772ac90612d09e1ab2747c046a554d3 /bfd/elfnn-aarch64.c | |
| parent | 9664701462aec634d304923df8dc9c52c5a92caf (diff) | |
| download | gdb-79e741920446582bd0e09f3e2b9f899c258efa56.zip gdb-79e741920446582bd0e09f3e2b9f899c258efa56.tar.gz gdb-79e741920446582bd0e09f3e2b9f899c258efa56.tar.bz2 | |
[BFD][AARCH64]Disallow R_AARCH64_ABS32(LP64) & R_AARCH64_ABS16 in const section of shared object.
R_AARCH64_ABS64, R_AARCH64_ABS32 and R_AARCH64_ABS16 are data relocations
supported in AArch64 elf ABI.
R_AARCH64_ABS64 under LP64 is allowed in shared object and a dynamic relocation entry
will be generated. This allows the dynamic linker to do further symbol resolution.
R_AARCH64_ABS32 likewise is allowed in shared object, however under ILP32 abi.
The original behavior for R_AARCH64_ABS32 under LP64 is that, it's allowed
in shared object and silently resolved at static linking time.
No dynamic relocation entry is generate for it.
R_AARCH64_ABS16 is allowed in shared object under both L64 and ILP32.
It's resolved at static linking time as well.
Under LP64, the address should be 64-bit. R_AARCH64_ABS32 relocation indicates
an address that is only sized 32 bits which is meaningless in LP64 shared object.
It's useful to error out.
I have checked glibc dynamic linker code, R_AARCH64_ABS16 is not supported at all. So
R_AARCH64_ABS16 should be reject in shared object completely.
In this patch, R_AARCH64_ABS32 is rejected under LP64 in constant section of shared object.
R_AARCH64_ABS16 is rejected in constant section of shared object in both ABI.
This will sometimes provide useful information for buggy code.
Diffstat (limited to 'bfd/elfnn-aarch64.c')
| -rw-r--r-- | bfd/elfnn-aarch64.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c index 212d335..52da856 100644 --- a/bfd/elfnn-aarch64.c +++ b/bfd/elfnn-aarch64.c @@ -7070,6 +7070,27 @@ elfNN_aarch64_check_relocs (bfd *abfd, struct bfd_link_info *info, switch (bfd_r_type) { + case BFD_RELOC_AARCH64_16: +#if ARCH_SIZE == 64 + case BFD_RELOC_AARCH64_32: +#endif + if (bfd_link_pic (info) + && (sec->flags & SEC_ALLOC) != 0 + && (sec->flags & SEC_READONLY) != 0) + { + int howto_index = bfd_r_type - BFD_RELOC_AARCH64_RELOC_START; + _bfd_error_handler + /* xgettext:c-format */ + (_("%B: relocation %s against `%s' can not be used when making " + "a shared object"), + abfd, elfNN_aarch64_howto_table[howto_index].name, + (h) ? h->root.root.string : "a local symbol"); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + else + break; + case BFD_RELOC_AARCH64_MOVW_G0_NC: case BFD_RELOC_AARCH64_MOVW_G1_NC: case BFD_RELOC_AARCH64_MOVW_G2_NC: |