From: Josh Poimboeuf jpoimboe@redhat.com
commit e31694e0a7a709293319475d8001e05e31f2178c upstream.
When objtool creates the .altinstructions section, it sets the SHF_WRITE flag to make the section writable -- unless the section had already been previously created by the kernel. The mismatch between kernel-created and objtool-created section flags can cause failures with external tooling (kpatch-build). And the section doesn't need to be writable anyway.
Make the section flags consistent with the kernel's.
Fixes: 9bc0bb50727c ("objtool/x86: Rewrite retpoline thunk calls") Reported-by: Joe Lawrence joe.lawrence@redhat.com Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/6c284ae89717889ea136f9f0064d914cd8329d31.162446293... Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/arch/x86/decode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -611,7 +611,7 @@ static int elf_add_alternative(struct el sec = find_section_by_name(elf, ".altinstructions"); if (!sec) { sec = elf_create_section(elf, ".altinstructions", - SHF_WRITE, size, 0); + SHF_ALLOC, size, 0);
if (!sec) { WARN_ELF("elf_create_section");