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![Michael Ellerman](/assets/img/avatar_default.png)
Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
18 lines
397 B
C
18 lines
397 B
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright 2018, Michael Ellerman, IBM Corporation.
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*/
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#ifndef _ASM_POWERPC_CODE_PATCHING_ASM_H
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#define _ASM_POWERPC_CODE_PATCHING_ASM_H
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/* Define a "site" that can be patched */
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.macro patch_site label name
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.pushsection ".rodata"
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.balign 4
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.global \name
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\name:
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.4byte \label - .
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.popsection
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.endm
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#endif /* _ASM_POWERPC_CODE_PATCHING_ASM_H */
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