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 03b6ba54460e2e67afc91fe66c2cdb65ccce5c99..c0162911f6cbdce7b3677795dd8176932669855f 100644 (file)
--- 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);
        }
 }