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objtool: Support retpoline jump detection for vmlinux.o

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commit 31a7424bc58063a8e0466c3c10f31a52ec2be4f6 upstream.

Objtool converts direct retpoline jumps to type INSN_JUMP_DYNAMIC, since
that's what they are semantically.

That conversion doesn't work in vmlinux.o validation because the
indirect thunk function is present in the object, so the intra-object
jump check succeeds before the retpoline jump check gets a chance.

Rearrange the checks: check for a retpoline jump before checking for an
intra-object jump.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/4302893513770dde68ddc22a9d6a2a04aca491dd.1611263461.git.jpoimboe@redhat.com
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Josh Poimboeuf 2021-01-21 15:29:20 -06:00 committed by Greg Kroah-Hartman
parent 917a4f6348
commit 3e674f2652
1 changed files with 4 additions and 4 deletions
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8
tools/objtool/check.c
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@ -795,10 +795,6 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
arch_dest_reloc_offset(reloc->addend);
} else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
!strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
/*
@ -812,6 +808,10 @@ static int add_jump_destinations(struct objtool_file *file)
insn->retpoline_safe = true;
continue;
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
arch_dest_reloc_offset(reloc->addend);
} else {
/* external sibling call */
insn->call_dest = reloc->sym;