From 79e741920446582bd0e09f3e2b9f899c258efa56 Mon Sep 17 00:00:00 2001 From: Renlin Li Date: Wed, 13 Dec 2017 12:11:25 +0000 Subject: [PATCH] [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. --- bfd/ChangeLog | 6 ++++++ bfd/elfnn-aarch64.c | 21 +++++++++++++++++++++ ld/ChangeLog | 10 ++++++++++ ld/testsuite/ld-aarch64/aarch64-elf.exp | 2 ++ ld/testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d | 4 ++++ ld/testsuite/ld-aarch64/emit-relocs-258.s | 6 ++++++ ld/testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d | 4 ++++ ld/testsuite/ld-aarch64/emit-relocs-259.s | 6 ++++++ ld/testsuite/ld-aarch64/gc-relocs-257.s | 8 +++++--- 9 files changed, 64 insertions(+), 3 deletions(-) create mode 100644 ld/testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d create mode 100644 ld/testsuite/ld-aarch64/emit-relocs-258.s create mode 100644 ld/testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d create mode 100644 ld/testsuite/ld-aarch64/emit-relocs-259.s diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 8b315fa..ff8feab 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2017-12-13 Renlin Li + + * elfnn-aarch64.c (elfNN_aarch64_check_relocs): Disallow + BFD_RELOC_AARCH64_16 in shared object const section. Disallow + BFD_RELOC_AARCH64_32 in shared object const section under LP64. + 2017-12-11 Sangamesh Mallayya * bfd.c (bfd_get_sign_extend_vma): Correct typo. 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: diff --git a/ld/ChangeLog b/ld/ChangeLog index db025ee..d0b80d1 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,13 @@ +2017-12-13 Renlin Li + + * testsuite/ld-aarch64/aarch64-elf.exp: Run new test cases. + * testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d: New. + * testsuite/ld-aarch64/emit-relocs-258.s: New. + * testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d: New. + * testsuite/ld-aarch64/emit-relocs-259.s: New. + * testsuite/ld-aarch64/gc-relocs-257.s: Put R_AARCH64_ABS32, + R_AARCH64_ABS16 data into data section. + 2017-12-07 Alan Modra PR 22465 diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp index b9c9885..fffc60e 100644 --- a/ld/testsuite/ld-aarch64/aarch64-elf.exp +++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp @@ -103,6 +103,8 @@ run_dump_test_lp64 "emit-relocs-257" run_dump_test_lp64 "emit-relocs-257-be" # 258 is tested in 257 # 259 is tested in 257 +run_dump_test_lp64 "emit-relocs-258-dyn-bad" +run_dump_test_lp64 "emit-relocs-259-dyn-bad" run_dump_test_lp64 "emit-relocs-260" run_dump_test_lp64 "emit-relocs-260-be" # 261 is tested by 260 diff --git a/ld/testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d b/ld/testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d new file mode 100644 index 0000000..4de6e55 --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-258-dyn-bad.d @@ -0,0 +1,4 @@ +#name: LP64 R_AARCH64_ABS32 shared library test +#source: emit-relocs-258.s +#ld: -shared +#error: .*: relocation R_AARCH64_ABS32 against `dummy' can not be used when making a shared object diff --git a/ld/testsuite/ld-aarch64/emit-relocs-258.s b/ld/testsuite/ld-aarch64/emit-relocs-258.s new file mode 100644 index 0000000..f724776 --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-258.s @@ -0,0 +1,6 @@ +.text + + ldr x0, .L1 + +.L1: + .word dummy diff --git a/ld/testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d b/ld/testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d new file mode 100644 index 0000000..f133e89 --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-259-dyn-bad.d @@ -0,0 +1,4 @@ +#name: R_AARCH64_ABS16 shared library test +#source: emit-relocs-259.s +#ld: -shared +#error: .*: relocation R_AARCH64_ABS16 against `dummy' can not be used when making a shared object diff --git a/ld/testsuite/ld-aarch64/emit-relocs-259.s b/ld/testsuite/ld-aarch64/emit-relocs-259.s new file mode 100644 index 0000000..7e1ba3c --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-259.s @@ -0,0 +1,6 @@ +.text + + ldr x0, .L1 + +.L1: + .hword dummy diff --git a/ld/testsuite/ld-aarch64/gc-relocs-257.s b/ld/testsuite/ld-aarch64/gc-relocs-257.s index dcc9db1..f57f9c6 100644 --- a/ld/testsuite/ld-aarch64/gc-relocs-257.s +++ b/ld/testsuite/ld-aarch64/gc-relocs-257.s @@ -1,8 +1,10 @@ .text - .word tempy + and x0, x0, x0 + and x0, x0, #0x1 .xword tempy2 + + .data + .word tempy .hword tempy3 .hword tempy3+8 - and x0, x0, x0 - and x0, x0, #0x1 -- 2.7.4