[PATCH v2 1/5] x86: Put trampoline in .init.data section

Frediano Ziglio posted 5 patches 3 months, 1 week ago
[PATCH v2 1/5] x86: Put trampoline in .init.data section
Posted by Frediano Ziglio 3 months, 1 week ago
This change allows to put the trampoline in a separate, not executable
section. The trampoline contains a mix of code and data (data which
is modified from C code during early start so must be writable).
This is in preparation for W^X patch in order to satisfy UEFI CA
memory mitigation requirements.
At the moment .init.text and .init.data in EFI mode are put together
so they will be in the same final section as before this patch.

Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
---
 xen/arch/x86/boot/head.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index d8ac0f0494..16830f636f 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -870,6 +870,8 @@ cmdline_parse_early:
 reloc:
         .incbin "reloc.bin"
 
+        .section .init.data, "aw", @progbits
+
 ENTRY(trampoline_start)
 #include "trampoline.S"
 ENTRY(trampoline_end)
-- 
2.45.2