[PATCH v5 24/27] x86/mm: Make the x86 GOT read-only
From: Thomas Garnier <hidden>
Date: 2018-06-25 22:43:39
Also in:
lkml
Subsystem:
generic include/asm header files, the rest · Maintainers:
Arnd Bergmann, Linus Torvalds
The GOT is changed during early boot when relocations are applied. Make it read-only directly. This table exists only for PIE binary. Position Independent Executable (PIE) support will allow to extend the KASLR randomization range 0xffffffff80000000. Signed-off-by: Thomas Garnier <redacted> --- include/asm-generic/vmlinux.lds.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index e373e2e10f6a..e5b0710fe693 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h@@ -314,6 +314,17 @@ __end_ro_after_init = .; #endif +#ifdef CONFIG_X86_PIE +#define RO_GOT_X86 \ + .got : AT(ADDR(.got) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start_got) = .; \ + *(.got); \ + VMLINUX_SYMBOL(__end_got) = .; \ + } +#else +#define RO_GOT_X86 +#endif + /* * Read only Data */
@@ -370,6 +381,7 @@ __end_builtin_fw = .; \ } \ \ + RO_GOT_X86 \ TRACEDATA \ \ /* Kernel symbol table: Normal symbols */ \
--
2.18.0.rc2.346.g013aa6912e-goog