| Message ID | 20240911095048.25555-1-frediano.ziglio@cloud.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86: Put trampoline in separate .init.trampoline section | expand |
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index 12bbb97f33..61b7b8894c 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -882,8 +882,10 @@ cmdline_parse_early: reloc: .incbin "reloc.bin" +#include "x86_64.S" + + .section .init.trampoline, "aw", @progbits + .align 4 ENTRY(trampoline_start) #include "trampoline.S" ENTRY(trampoline_end) - -#include "x86_64.S" diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index d48de67cfd..390870e463 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -269,6 +269,11 @@ SECTIONS __ctors_end = .; } PHDR(text) + . = ALIGN(PAGE_SIZE); + DECL_SECTION(.init.trampoline) { + *(.init.trampoline) + } PHDR(text) + #ifndef EFI /* * With --orphan-sections=warn (or =error) we need to handle certain linker
This change 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. Putting in a separate section (even in final executables) allows to easily disassembly that section. Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com> --- Changes since last version: - use completely separate section even on final executables (suggested by Jan Beulich). --- xen/arch/x86/boot/head.S | 6 ++++-- xen/arch/x86/xen.lds.S | 5 +++++ 2 files changed, 9 insertions(+), 2 deletions(-)