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objtool: Skip magical retpoline .altinstr_replacement

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commit 50e7b4a1a1b264fc7df0698f2defb93cadf19a7b upstream.

When the .altinstr_replacement is a retpoline, skip the alternative.
We already special case retpolines anyway.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151300.259429287@infradead.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Zijlstra 2021-03-26 16:12:14 +01:00 committed by Greg Kroah-Hartman
parent e87c18c4a9
commit ed7783dca5
1 changed files with 11 additions and 1 deletions
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12
tools/objtool/special.c
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@ -104,6 +104,14 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
return -1;
}
/*
* Skip retpoline .altinstr_replacement... we already rewrite the
* instructions for retpolines anyway, see arch_is_retpoline()
* usage in add_{call,jump}_destinations().
*/
if (arch_is_retpoline(new_reloc->sym))
return 1;
alt->new_sec = new_reloc->sym->sec;
alt->new_off = (unsigned int)new_reloc->addend;
@ -152,7 +160,9 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
memset(alt, 0, sizeof(*alt));
ret = get_alt_entry(elf, entry, sec, idx, alt);
if (ret)
if (ret > 0)
continue;
if (ret < 0)
return ret;
list_add_tail(&alt->list, alts);