From: Kristen Carlson Accardi <kristen@linux.intel.com>
Date: Wed, 13 Oct 2021 17:57:42 +0000 (-0700)
Subject: vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ca136cac37eb51649d52d5bc4271c55e30ed354c;p=linux.git

vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext

When using -ffunction-sections to place each function in its own text
section (so it can be randomized at load time in the future FGKASLR
series), the linker will place most of the functions into separate .text.*
sections. SIZEOF(.text) won't work here for calculating the ORC lookup
table size, so the total text size must be calculated to include .text
AND all .text.* sections.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
[ alobakin: move it to vmlinux.lds.h and make arch-indep ]
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20211013175742.1197608-5-keescook@chromium.org
---

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f2984af2b85bd..e8234911dc18b 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -869,10 +869,11 @@
 		KEEP(*(.orc_unwind))					\
 		__stop_orc_unwind = .;					\
 	}								\
+	text_size = _etext - _stext;					\
 	. = ALIGN(4);							\
 	.orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) {		\
 		orc_lookup = .;						\
-		. += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) /	\
+		. += (((text_size + LOOKUP_BLOCK_SIZE - 1) /		\
 			LOOKUP_BLOCK_SIZE) + 1) * 4;			\
 		orc_lookup_end = .;					\
 	}