[PATCH 5.10 043/148] objtool: Remove reloc symbol type checks in get_alt_entry()

Greg Kroah-Hartman
2022-07-23T10:02:05Z

From: Josh Poimboeuf <jpoimboe@redhat.com>

commit 4d8b35968bbf9e42b6b202eedb510e2c82ad8b38 upstream.

Converting a special section's relocation reference to a symbol is
straightforward. No need for objtool to complain that it doesn't know
how to handle it. Just handle it.

This fixes the following warning:

arch/x86/kvm/emulate.o: warning: objtool: __ex_table+0x4: don't know how to handle reloc symbol type: kvm_fastop_exception

Fixes: 24ff65257375 ("objtool: Teach get_alt_entry() about more relocation types")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/feadbc3dfb3440d973580fad8d3db873cbfe1694.1633367242.git.jpoimboe@redhat.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/objtool/special.c | 36 +++++++-----------------------------
1 file changed, 7 insertions(+), 29 deletions(-)

--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -55,22 +55,11 @@ void __weak arch_handle_alternative(unsi
{
}

-static bool reloc2sec_off(struct reloc *reloc, struct section **sec, unsigned long *off)
+static void reloc_to_sec_off(struct reloc *reloc, struct section **sec,
+ unsigned long *off)
{
- switch (reloc->sym->type) {
- case STT_FUNC:
- *sec = reloc->sym->sec;
- *off = reloc->sym->offset + reloc->addend;
- return true;
-
- case STT_SECTION:
- *sec = reloc->sym->sec;
- *off = reloc->addend;
- return true;
-
- default:
- return false;
- }
+ *sec = reloc->sym->sec;
+ *off = reloc->sym->offset + reloc->addend;
}

static int get_alt_entry(struct elf *elf, struct special_entry *entry,
@@ -105,13 +94,8 @@ static int get_alt_entry(struct elf *elf
WARN_FUNC("can't find orig reloc", sec, offset + entry->orig);
return -1;
}
- if (!reloc2sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off)) {
- WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
- sec, offset + entry->orig,
- orig_reloc->sym->type,
- orig_reloc->sym->name);
- return -1;
- }
+
+ reloc_to_sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off);

if (!entry->group || alt->new_len) {
new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
@@ -129,13 +113,7 @@ static int get_alt_entry(struct elf *elf
if (arch_is_retpoline(new_reloc->sym))
return 1;

- if (!reloc2sec_off(new_reloc, &alt->new_sec, &alt->new_off)) {
- WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
- sec, offset + entry->new,
- new_reloc->sym->type,
- new_reloc->sym->name);
- return -1;
- }
+ reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off);

/* _ASM_EXTABLE_EX hack */
if (alt->new_off >= 0x7ffffff0)