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| author | Peter Zijlstra <peterz@infradead.org> | 2021-10-26 14:01:36 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-10-28 23:25:25 +0200 |
| commit | 134ab5bd1883312d7a4b3033b05c6b5a1bb8889b (patch) | |
| tree | 39d11f68c60a068c6d5ed56688e89a3907fe0ad4 /arch | |
| parent | c509331b41b7365e17396c246e8c5797bccc8074 (diff) | |
| download | linux-stable-134ab5bd1883312d7a4b3033b05c6b5a1bb8889b.tar.gz linux-stable-134ab5bd1883312d7a4b3033b05c6b5a1bb8889b.tar.bz2 linux-stable-134ab5bd1883312d7a4b3033b05c6b5a1bb8889b.zip | |
objtool,x86: Replace alternatives with .retpoline_sites
Instead of writing complete alternatives, simply provide a list of all
the retpoline thunk calls. Then the kernel is free to do with them as
it pleases. Simpler code all-round.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.850007165@infradead.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index efd9e9ea17f2..3d6dc12d198f 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -272,6 +272,20 @@ SECTIONS __parainstructions_end = .; } +#ifdef CONFIG_RETPOLINE + /* + * List of instructions that call/jmp/jcc to retpoline thunks + * __x86_indirect_thunk_*(). These instructions can be patched along + * with alternatives, after which the section can be freed. + */ + . = ALIGN(8); + .retpoline_sites : AT(ADDR(.retpoline_sites) - LOAD_OFFSET) { + __retpoline_sites = .; + *(.retpoline_sites) + __retpoline_sites_end = .; + } +#endif + /* * struct alt_inst entries. From the header (alternative.h): * "Alternative instructions for different CPU types or capabilities" |