Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] objtool: fix objtool regression on x32 systems | Date | Tue, 17 May 2022 08:26:42 +0000 |
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From: Peter Zijlstra > Sent: 16 May 2022 22:25 ... > A quick look seems to suggest at least all the 'offset' fields should be > u64 or something. The only reason that works is because -mcmodel=kernel > keeps everything in the 2G range to make s32 immediates work. But it > isn't right.
Offsets in instructions are only 8bit or 32bit. The mod/reg/rm and SiB encodings don't support anything else. If offsets might be large then they have to be loaded into registers - which will slow things down.
Immediates can be 64bit (but not if the addressing mode includes an offset).
David
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