From e112b032a72c78f15d0c803c5dc6be444c2e6c66 Mon Sep 17 00:00:00 2001 From: Hsin-Yi Wang Date: Fri, 23 Aug 2019 14:24:50 +0800 Subject: [PATCH] arm64: map FDT as RW for early_init_dt_scan() Currently in arm64, FDT is mapped to RO before it's passed to early_init_dt_scan(). However, there might be some codes (eg. commit "fdt: add support for rng-seed") that need to modify FDT during init. Map FDT to RO after early fixups are done. Signed-off-by: Hsin-Yi Wang Reviewed-by: Stephen Boyd Reviewed-by: Mike Rapoport Signed-off-by: Will Deacon --- arch/arm64/include/asm/mmu.h | 2 +- arch/arm64/kernel/kaslr.c | 5 +---- arch/arm64/kernel/setup.c | 9 ++++++++- arch/arm64/mm/mmu.c | 15 +-------------- 4 files changed, 11 insertions(+), 20 deletions(-) diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index fd61613..f217e32 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -126,7 +126,7 @@ extern void init_mem_pgprot(void); extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, unsigned long virt, phys_addr_t size, pgprot_t prot, bool page_mappings_only); -extern void *fixmap_remap_fdt(phys_addr_t dt_phys); +extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot); extern void mark_linear_text_alias_ro(void); #define INIT_MM_CONTEXT(name) \ diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c index 7080516..d94a3e4 100644 --- a/arch/arm64/kernel/kaslr.c +++ b/arch/arm64/kernel/kaslr.c @@ -62,9 +62,6 @@ out: return default_cmdline; } -extern void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, - pgprot_t prot); - /* * This routine will be executed with the kernel mapped at its default virtual * address, and if it returns successfully, the kernel will be remapped, and @@ -93,7 +90,7 @@ u64 __init kaslr_early_init(u64 dt_phys) * attempt at mapping the FDT in setup_machine() */ early_fixmap_init(); - fdt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL); + fdt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL); if (!fdt) return 0; diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 9c4bad7..25f5127 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -170,9 +170,13 @@ static void __init smp_build_mpidr_hash(void) static void __init setup_machine_fdt(phys_addr_t dt_phys) { - void *dt_virt = fixmap_remap_fdt(dt_phys); + int size; + void *dt_virt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL); const char *name; + if (dt_virt) + memblock_reserve(dt_phys, size); + if (!dt_virt || !early_init_dt_scan(dt_virt)) { pr_crit("\n" "Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n" @@ -184,6 +188,9 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys) cpu_relax(); } + /* Early fixups are done, map the FDT as read-only now */ + fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); + name = of_flat_dt_get_machine_name(); if (!name) return; diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 750a69d..54e9358 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -876,7 +876,7 @@ void __set_fixmap(enum fixed_addresses idx, } } -void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) +void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) { const u64 dt_virt_base = __fix_to_virt(FIX_FDT); int offset; @@ -929,19 +929,6 @@ void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) return dt_virt; } -void *__init fixmap_remap_fdt(phys_addr_t dt_phys) -{ - void *dt_virt; - int size; - - dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); - if (!dt_virt) - return NULL; - - memblock_reserve(dt_phys, size); - return dt_virt; -} - int __init arch_ioremap_p4d_supported(void) { return 0; -- 2.7.4