lkml.org 
[lkml]   [2021]   [Jul]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.13 348/800] objtool: Dont make .altinstructions writable
Date
From: Josh Poimboeuf <jpoimboe@redhat.com>

[ Upstream commit e31694e0a7a709293319475d8001e05e31f2178c ]

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/6c284ae89717889ea136f9f0064d914cd8329d31.1624462939.git.jpoimboe@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/objtool/arch/x86/decode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 523aa4157f80..bc821056aba9 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -684,7 +684,7 @@ static int elf_add_alternative(struct elf *elf,
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");
--
2.30.2


\
 
 \ /
  Last update: 2021-07-12 10:41    [W:2.218 / U:1.700 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site