linux-kernel - [tip: x86/kaslr] x86/kaslr: Short-circuit gb_huge

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Date:   Thu, 06 Aug 2020 23:38:56 -0000
From:   "tip-bot2 for Arvind Sankar" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Arvind Sankar <nivedita@...m.mit.edu>,
        Ingo Molnar <mingo@...nel.org>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [tip: x86/kaslr] x86/kaslr: Short-circuit gb_huge_pages on x86-32

The following commit has been merged into the x86/kaslr branch of tip:

Commit-ID:     50def2693a900dfb1d91872056dc8164245820fc
Gitweb:        https://git.kernel.org/tip/50def2693a900dfb1d91872056dc8164245820fc
Author:        Arvind Sankar <nivedita@...m.mit.edu>
AuthorDate:    Tue, 28 Jul 2020 18:57:12 -04:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Fri, 31 Jul 2020 11:08:17 +02:00

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() macro allows the compiler to completely remove the
gb_huge_pages code.

Signed-off-by: Arvind Sankar <nivedita@...m.mit.edu>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Link: https://lore.kernel.org/r/20200728225722.67457-12-nivedita@alum.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 0df513e..3727e97 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;
 	}