linux-kernel - [PATCH v3 11/21] x86/kaslr: Short-circuit gb_huge

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Date:   Tue, 28 Jul 2020 18:57:12 -0400
From:   Arvind Sankar <nivedita@...m.mit.edu>
To:     Kees Cook <keescook@...omium.org>, x86@...nel.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH v3 11/21] x86/kaslr: Short-circuit gb_huge_pages on x86-32

32-bit does not have GB pages, so don't bother checking for them. Using
the IS_ENABLED allows the compiler to completely remove the
gb_huge_pages code.

Signed-off-by: Arvind Sankar <nivedita@...m.mit.edu>
---
 arch/x86/boot/compressed/kaslr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 0df513e3e2ce..3727e9708690 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -303,7 +303,7 @@ static void handle_mem_options(void)
 
 		if (!strcmp(param, "memmap")) {
 			mem_avoid_memmap(PARSE_MEMMAP, val);
-		} else if (strstr(param, "hugepages")) {
+		} else if (IS_ENABLED(CONFIG_X86_64) && strstr(param, "hugepages")) {
 			parse_gb_huge_pages(param, val);
 		} else if (!strcmp(param, "mem")) {
 			char *p = val;
@@ -551,7 +551,7 @@ process_gb_huge_pages(struct mem_vector *region, unsigned long image_size)
 	struct mem_vector tmp;
 	int i = 0;
 
-	if (!max_gb_huge_pages) {
+	if (!IS_ENABLED(CONFIG_X86_64) || !max_gb_huge_pages) {
 		store_slot_info(region, image_size);
 		return;
 	}
-- 
2.26.2