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| author | Peter Zijlstra <peterz@infradead.org> | 2020-04-14 12:36:16 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-04-30 20:14:34 +0200 |
| commit | 089dd8e53126ebaf506e2dc0bf89d652c36bfc12 (patch) | |
| tree | 7a3823e8af26ae775f76352b555eb7907ee09a0d /arch/x86/lib/retpoline.S | |
| parent | objtool: Add support for intra-function calls (diff) | |
| download | linux-089dd8e53126ebaf506e2dc0bf89d652c36bfc12.tar.xz linux-089dd8e53126ebaf506e2dc0bf89d652c36bfc12.zip | |
x86/speculation: Change FILL_RETURN_BUFFER to work with objtool
Change FILL_RETURN_BUFFER so that objtool groks it and can generate
correct ORC unwind information.
- Since ORC is alternative invariant; that is, all alternatives
should have the same ORC entries, the __FILL_RETURN_BUFFER body
can not be part of an alternative.
Therefore, move it out of the alternative and keep the alternative
as a sort of jump_label around it.
- Use the ANNOTATE_INTRA_FUNCTION_CALL annotation to white-list
these 'funny' call instructions to nowhere.
- Use UNWIND_HINT_EMPTY to 'fill' the speculation traps, otherwise
objtool will consider them unreachable.
- Move the RSP adjustment into the loop, such that the loop has a
deterministic stack layout.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200428191700.032079304@infradead.org
Diffstat (limited to 'arch/x86/lib/retpoline.S')
0 files changed, 0 insertions, 0 deletions