From 1359fd9eae29490c542e17c107cb41cfb8463138 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 23 Oct 2024 13:03:14 +0100 Subject: [PATCH] ARM: 9429/1: ioremap: Sync PGDs for VMALLOC shadow commit d6e6a74d4cea853b5321eeabb69c611148eedefe upstream. When sync:ing the VMALLOC area to other CPUs, make sure to also sync the KASAN shadow memory for the VMALLOC area, so that we don't get stale entries for the shadow memory in the top level PGD. Since we are now copying PGDs in two instances, create a helper function named memcpy_pgd() to do the actual copying, and create a helper to map the addresses of VMALLOC_START and VMALLOC_END into the corresponding shadow memory. Co-developed-by: Melon Liu Cc: stable@vger.kernel.org Fixes: 565cbaad83d8 ("ARM: 9202/1: kasan: support CONFIG_KASAN_VMALLOC") Link: https://lore.kernel.org/linux-arm-kernel/a1a1d062-f3a2-4d05-9836-3b098de9db6d@foss.st.com/ Reported-by: Clement LE GOFFIC Suggested-by: Mark Rutland Suggested-by: Russell King (Oracle) Acked-by: Mark Rutland Signed-off-by: Linus Walleij Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/ioremap.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index 2129070065c3..cd9ef5b6a70f 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -23,6 +23,7 @@ */ #include #include +#include #include #include #include @@ -115,16 +116,40 @@ int ioremap_page(unsigned long virt, unsigned long phys, } EXPORT_SYMBOL(ioremap_page); +#ifdef CONFIG_KASAN +static unsigned long arm_kasan_mem_to_shadow(unsigned long addr) +{ + return (unsigned long)kasan_mem_to_shadow((void *)addr); +} +#else +static unsigned long arm_kasan_mem_to_shadow(unsigned long addr) +{ + return 0; +} +#endif + +static void memcpy_pgd(struct mm_struct *mm, unsigned long start, + unsigned long end) +{ + end = ALIGN(end, PGDIR_SIZE); + memcpy(pgd_offset(mm, start), pgd_offset_k(start), + sizeof(pgd_t) * (pgd_index(end) - pgd_index(start))); +} + void __check_vmalloc_seq(struct mm_struct *mm) { int seq; do { seq = atomic_read(&init_mm.context.vmalloc_seq); - memcpy(pgd_offset(mm, VMALLOC_START), - pgd_offset_k(VMALLOC_START), - sizeof(pgd_t) * (pgd_index(VMALLOC_END) - - pgd_index(VMALLOC_START))); + memcpy_pgd(mm, VMALLOC_START, VMALLOC_END); + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { + unsigned long start = + arm_kasan_mem_to_shadow(VMALLOC_START); + unsigned long end = + arm_kasan_mem_to_shadow(VMALLOC_END); + memcpy_pgd(mm, start, end); + } /* * Use a store-release so that other CPUs that observe the * counter's new value are guaranteed to see the results of the -- 2.39.5