From 4a614a68d9f87b22b4177e5e255a0ab90239b20d Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Sat, 28 Jan 2023 17:35:12 +0100 Subject: [PATCH] s390/vmem: fix empty page tables cleanup under KASAN [ Upstream commit 108303b0a2d27cb14eed565e33e64ad9eefe5d7e ] Commit b9ff81003cf1 ("s390/vmem: cleanup empty page tables") introduced empty page tables cleanup in vmem code, but when the kernel is built with KASAN enabled the code has no effect due to wrong KASAN shadow memory intersection condition, which effectively ignores any memory range below KASAN shadow. Fix intersection condition to make code work as anticipated. Fixes: b9ff81003cf1 ("s390/vmem: cleanup empty page tables") Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/mm/vmem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index b239f2ba93b0..cbfff2460e58 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -296,7 +296,7 @@ static void try_free_pmd_table(pud_t *pud, unsigned long start) if (end > VMALLOC_START) return; #ifdef CONFIG_KASAN - if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end) + if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START) return; #endif pmd = pmd_offset(pud, start); @@ -371,7 +371,7 @@ static void try_free_pud_table(p4d_t *p4d, unsigned long start) if (end > VMALLOC_START) return; #ifdef CONFIG_KASAN - if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end) + if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START) return; #endif @@ -425,7 +425,7 @@ static void try_free_p4d_table(pgd_t *pgd, unsigned long start) if (end > VMALLOC_START) return; #ifdef CONFIG_KASAN - if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end) + if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START) return; #endif