From: Christophe Leroy <christophe.leroy@csgroup.eu>
Date: Mon, 29 Jun 2020 11:15:22 +0000 (+0000)
Subject: powerpc/32s: Only leave NX unset on segments used for modules
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c496433197154144c310a17939736bc5c155914d;p=linux.git

powerpc/32s: Only leave NX unset on segments used for modules

Instead of leaving NX unset on all segments above the start
of vmalloc space, only leave NX unset on segments used for
modules.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7172c0f5253419315e434a1816ee3d6ed6505bc0.1593428200.git.christophe.leroy@csgroup.eu
---

diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 03b6ba54460e2..c0162911f6cbd 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -187,6 +187,17 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
 	return __mmu_mapin_ram(border, top);
 }
 
+static bool is_module_segment(unsigned long addr)
+{
+	if (!IS_ENABLED(CONFIG_MODULES))
+		return false;
+	if (addr < ALIGN_DOWN(VMALLOC_START, SZ_256M))
+		return false;
+	if (addr >= ALIGN(VMALLOC_END, SZ_256M))
+		return false;
+	return true;
+}
+
 void mmu_mark_initmem_nx(void)
 {
 	int nb = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4;
@@ -223,9 +234,9 @@ void mmu_mark_initmem_nx(void)
 
 	for (i = TASK_SIZE >> 28; i < 16; i++) {
 		/* Do not set NX on VM space for modules */
-		if (IS_ENABLED(CONFIG_MODULES) &&
-		    (VMALLOC_START & 0xf0000000) == i << 28)
-			break;
+		if (is_module_segment(i << 28))
+			continue;
+
 		mtsrin(mfsrin(i << 28) | 0x10000000, i << 28);
 	}
 }