Capabilities pointing to symbols in SEC_CODE sections are given the bounds of the entire PCC. We ensure that the PCC bounds are padded and aligned as needed in the linker.
Capabilities pointing to other symbols (e.g. in data sections) are given the bounds of the symbol that they point to. It is the responsibility of the assembly generator (i.e. usually the compiler) to ensure these bounds are correctly aligned and padded as necessary.
We emit a warning for imprecise bounds in the second case, until this patch that warning also looked at the first case. This was a mistake and is rectified in this commit.
############### Attachment also inlined for ease of reply ###############
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c index 3e0562b72bc69a9c43f01c80c604b85c582f4f7b..da3c629fcdbfbceed633d9af7c5751dd358492fc 100644 --- a/bfd/elfnn-aarch64.c +++ b/bfd/elfnn-aarch64.c @@ -6965,17 +6965,6 @@ c64_fixup_frag (bfd *input_bfd, struct bfd_link_info *info, bfd_vma base = value, limit = value + size; unsigned align = 0;
- if (!bounds_ok && !c64_valid_cap_range (&base, &limit, &align)) - { - /* Just warn about this. It's not a requirement that bounds on - objects should be precise, so there's no reason to error out on - such an object. */ - /* xgettext:c-format */ - _bfd_error_handler - (_("%pB: capability range for '%s' may exceed object bounds"), - input_bfd, sym_name); - } - if (perm_sec && perm_sec->flags & SEC_CODE) { /* Any symbol pointing into an executable section gets bounds according @@ -6994,6 +6983,16 @@ c64_fixup_frag (bfd *input_bfd, struct bfd_link_info *info, data or jump to other functions. */ size = pcc_high - pcc_low; } + else if (!bounds_ok && !c64_valid_cap_range (&base, &limit, &align)) + { + /* Just warn about this. It's not a requirement that bounds on + objects should be precise, so there's no reason to error out on + such an object. */ + /* xgettext:c-format */ + _bfd_error_handler + (_("%pB: capability range for '%s' may exceed object bounds"), + input_bfd, sym_name); + }
if (perm_sec != NULL) { diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp index 4200c1d17e97ac9b54f2a0a051f15f0d51d47c06..a07a6c50bb8b601761cf38607afbc0a4dcc9ef0c 100644 --- a/ld/testsuite/ld-aarch64/aarch64-elf.exp +++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp @@ -390,6 +390,8 @@ run_dump_test_lp64 "morello-illegal-tls" run_dump_test_lp64 "morello-illegal-tls-pie" run_dump_test_lp64 "morello-illegal-tls-shared"
+run_dump_test_lp64 "morello-large-function" + run_dump_test "no-morello-syms-static"
run_dump_test "reloc-overflow-bad" diff --git a/ld/testsuite/ld-aarch64/morello-large-function.d b/ld/testsuite/ld-aarch64/morello-large-function.d new file mode 100644 index 0000000000000000000000000000000000000000..dc0af92e12f9ab7203a400997ded14c8bdf4172c --- /dev/null +++ b/ld/testsuite/ld-aarch64/morello-large-function.d @@ -0,0 +1,23 @@ +# Mainly here to check that this actually links. +# This testcase used to complain that the function capability may have +# imprecise bounds, but since such capabilities are given PCC bounds that error +# was invalid. +# +# Even though the only point is to check that the testcase links, we still +# ensure that the dump of the .data section contains a relocation with the +# correct permissions. +#as: -march=morello+c64 +#ld: -pie -static +#objdump: -DR -j .data + +.*: file format .* + + +Disassembly of section .data: + +[0-9a-f]+ <__data_start>: + *[0-9a-f]+: .* + .*: R_MORELLO_RELATIVE *ABS*+.* + *[0-9a-f]+: .* udf #0 + *[0-9a-f]+: .* + *[0-9a-f]+: 04000000 .* diff --git a/ld/testsuite/ld-aarch64/morello-large-function.s b/ld/testsuite/ld-aarch64/morello-large-function.s new file mode 100644 index 0000000000000000000000000000000000000000..46cb51e0c68cba982e8bf2b83b696399a6225f21 --- /dev/null +++ b/ld/testsuite/ld-aarch64/morello-large-function.s @@ -0,0 +1,9 @@ +.data + .chericap _start +.text + .globl _start + .type _start,@function +_start: + ret + .zero 0x8000 + .size _start, .-_start