diff mbox series

[v6,kspp-next,08/22] Make sure ORC lookup covers the entire _etext - _stext

Message ID 20210831144114.154-9-alexandr.lobakin@intel.com (mailing list archive)
State New, archived
Headers show
Series Function Granular KASLR | expand

Commit Message

Alexander Lobakin Aug. 31, 2021, 2:41 p.m. UTC 
From: Kristen Carlson Accardi <kristen@linux.intel.com>

When using -ffunction-sections to place each function in
it's own text section so it can be randomized at load time, 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, the total text size must be calculated to
include .text AND all .text.*.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[ alobakin: move it to vmlinux.lds.h and make arch-indep ]
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
 include/asm-generic/vmlinux.lds.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 5d6da19b02bc..01fdeb5dd216 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -887,10 +887,11 @@ 
 		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 = .;					\
 	}