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[76.210.143.223]) by smtp.gmail.com with ESMTPSA id w13sm730131pfn.219.2021.04.14.21.20.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Apr 2021 21:20:02 -0700 (PDT) Date: Wed, 14 Apr 2021 21:20:02 -0700 (PDT) X-Google-Original-Date: Wed, 14 Apr 2021 21:20:01 PDT (-0700) Subject: Re: [PATCH v5 1/3] riscv: Move kernel mapping outside of linear mapping In-Reply-To: <20210411164146.20232-2-alex@ghiti.fr> CC: corbet@lwn.net, Paul Walmsley , aou@eecs.berkeley.edu, Arnd Bergmann , aryabinin@virtuozzo.com, glider@google.com, dvyukov@google.com, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arch@vger.kernel.org, linux-mm@kvack.org, alex@ghiti.fr From: Palmer Dabbelt To: alex@ghiti.fr Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed X-Rspamd-Queue-Id: EB1CEC0001FA X-Stat-Signature: kssejx9ur9bcbpfg1fwcuhry7qwjzej3 X-Rspamd-Server: rspam02 Received-SPF: none (dabbelt.com>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=mail-pf1-f177.google.com; client-ip=209.85.210.177 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1618460406-303356 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, 11 Apr 2021 09:41:44 PDT (-0700), alex@ghiti.fr wrote: > This is a preparatory patch for relocatable kernel and sv48 support. > > The kernel used to be linked at PAGE_OFFSET address therefore we could = use > the linear mapping for the kernel mapping. But the relocated kernel bas= e > address will be different from PAGE_OFFSET and since in the linear mapp= ing, > two different virtual addresses cannot point to the same physical addre= ss, > the kernel mapping needs to lie outside the linear mapping so that we d= on't > have to copy it at the same physical offset. > > The kernel mapping is moved to the last 2GB of the address space, BPF > is now always after the kernel and modules use the 2GB memory range rig= ht > before the kernel, so BPF and modules regions do not overlap. KASLR > implementation will simply have to move the kernel in the last 2GB rang= e > and just take care of leaving enough space for BPF. > > In addition, by moving the kernel to the end of the address space, both > sv39 and sv48 kernels will be exactly the same without needing to be > relocated at runtime. > > Suggested-by: Arnd Bergmann > Signed-off-by: Alexandre Ghiti > --- > arch/riscv/boot/loader.lds.S | 3 +- > arch/riscv/include/asm/page.h | 17 +++++- > arch/riscv/include/asm/pgtable.h | 37 ++++++++---- > arch/riscv/include/asm/set_memory.h | 1 + > arch/riscv/kernel/head.S | 3 +- > arch/riscv/kernel/module.c | 6 +- > arch/riscv/kernel/setup.c | 5 ++ > arch/riscv/kernel/vmlinux.lds.S | 3 +- > arch/riscv/mm/fault.c | 13 +++++ > arch/riscv/mm/init.c | 87 ++++++++++++++++++++++------- > arch/riscv/mm/kasan_init.c | 9 +++ > arch/riscv/mm/physaddr.c | 2 +- > 12 files changed, 146 insertions(+), 40 deletions(-) > > diff --git a/arch/riscv/boot/loader.lds.S b/arch/riscv/boot/loader.lds.= S > index 47a5003c2e28..62d94696a19c 100644 > --- a/arch/riscv/boot/loader.lds.S > +++ b/arch/riscv/boot/loader.lds.S > @@ -1,13 +1,14 @@ > /* SPDX-License-Identifier: GPL-2.0 */ > > #include > +#include > > OUTPUT_ARCH(riscv) > ENTRY(_start) > > SECTIONS > { > - . =3D PAGE_OFFSET; > + . =3D KERNEL_LINK_ADDR; > > .payload : { > *(.payload) > diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/pag= e.h > index adc9d26f3d75..22cfb2be60dc 100644 > --- a/arch/riscv/include/asm/page.h > +++ b/arch/riscv/include/asm/page.h > @@ -90,15 +90,28 @@ typedef struct page *pgtable_t; > > #ifdef CONFIG_MMU > extern unsigned long va_pa_offset; > +extern unsigned long va_kernel_pa_offset; > extern unsigned long pfn_base; > #define ARCH_PFN_OFFSET (pfn_base) > #else > #define va_pa_offset 0 > +#define va_kernel_pa_offset 0 > #define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) > #endif /* CONFIG_MMU */ > > -#define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_of= fset)) > -#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset) > +extern unsigned long kernel_virt_addr; > + > +#define linear_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_p= a_offset)) > +#define kernel_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_k= ernel_pa_offset)) > +#define __pa_to_va_nodebug(x) linear_mapping_pa_to_va(x) > + > +#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - va_pa_offset) > +#define kernel_mapping_va_to_pa(x) ((unsigned long)(x) - va_kernel_pa_= offset) > +#define __va_to_pa_nodebug(x) ({ \ > + unsigned long _x =3D x; \ > + (_x < kernel_virt_addr) ? \ > + linear_mapping_va_to_pa(_x) : kernel_mapping_va_to_pa(_x); \ > + }) > > #ifdef CONFIG_DEBUG_VIRTUAL > extern phys_addr_t __virt_to_phys(unsigned long x); > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/= pgtable.h > index ebf817c1bdf4..80e63a93e903 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -11,23 +11,30 @@ > > #include > > -#ifndef __ASSEMBLY__ > - > -/* Page Upper Directory not used in RISC-V */ > -#include > -#include > -#include > -#include > +#ifndef CONFIG_MMU > +#define KERNEL_LINK_ADDR PAGE_OFFSET > +#else > > -#ifdef CONFIG_MMU > +#define ADDRESS_SPACE_END (UL(-1)) > +/* > + * Leave 2GB for kernel and BPF at the end of the address space > + */ > +#define KERNEL_LINK_ADDR (ADDRESS_SPACE_END - SZ_2G + 1) > > #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) > #define VMALLOC_END (PAGE_OFFSET - 1) > #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) > > +/* KASLR should leave at least 128MB for BPF after the kernel */ > #define BPF_JIT_REGION_SIZE (SZ_128M) > -#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) > -#define BPF_JIT_REGION_END (VMALLOC_END) > +#define BPF_JIT_REGION_START PFN_ALIGN((unsigned long)&_end) > +#define BPF_JIT_REGION_END (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE= ) > + > +/* Modules always live before the kernel */ > +#ifdef CONFIG_64BIT > +#define MODULES_VADDR (PFN_ALIGN((unsigned long)&_end) - SZ_2G) > +#define MODULES_END (PFN_ALIGN((unsigned long)&_start)) > +#endif > > /* > * Roughly size the vmemmap space to be large enough to fit enough > @@ -57,9 +64,16 @@ > #define FIXADDR_SIZE PGDIR_SIZE > #endif > #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) > - > #endif > > +#ifndef __ASSEMBLY__ > + > +/* Page Upper Directory not used in RISC-V */ > +#include > +#include > +#include > +#include > + > #ifdef CONFIG_64BIT > #include > #else > @@ -484,6 +498,7 @@ static inline int ptep_clear_flush_young(struct vm_= area_struct *vma, > > #define kern_addr_valid(addr) (1) /* FIXME */ > > +extern char _start[]; > extern void *dtb_early_va; > extern uintptr_t dtb_early_pa; > void setup_bootmem(void); > diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/a= sm/set_memory.h > index 6887b3d9f371..a9c56776fa0e 100644 > --- a/arch/riscv/include/asm/set_memory.h > +++ b/arch/riscv/include/asm/set_memory.h > @@ -17,6 +17,7 @@ int set_memory_x(unsigned long addr, int numpages); > int set_memory_nx(unsigned long addr, int numpages); > int set_memory_rw_nx(unsigned long addr, int numpages); > void protect_kernel_text_data(void); > +void protect_kernel_linear_mapping_text_rodata(void); > #else > static inline int set_memory_ro(unsigned long addr, int numpages) { re= turn 0; } > static inline int set_memory_rw(unsigned long addr, int numpages) { re= turn 0; } > diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S > index f5a9bad86e58..6cb05f22e52a 100644 > --- a/arch/riscv/kernel/head.S > +++ b/arch/riscv/kernel/head.S > @@ -69,7 +69,8 @@ pe_head_start: > #ifdef CONFIG_MMU > relocate: > /* Relocate return address */ > - li a1, PAGE_OFFSET > + la a1, kernel_virt_addr > + REG_L a1, 0(a1) > la a2, _start > sub a1, a1, a2 > add ra, ra, a1 > diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c > index 104fba889cf7..ce153771e5e9 100644 > --- a/arch/riscv/kernel/module.c > +++ b/arch/riscv/kernel/module.c > @@ -408,12 +408,10 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const c= har *strtab, > } > > #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) > -#define VMALLOC_MODULE_START \ > - max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START) > void *module_alloc(unsigned long size) > { > - return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START, > - VMALLOC_END, GFP_KERNEL, > + return __vmalloc_node_range(size, 1, MODULES_VADDR, > + MODULES_END, GFP_KERNEL, > PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, > __builtin_return_address(0)); > } > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index e85bacff1b50..30e4af0fd50c 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -265,6 +265,11 @@ void __init setup_arch(char **cmdline_p) > > if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) > protect_kernel_text_data(); > + > +#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) > + protect_kernel_linear_mapping_text_rodata(); > +#endif > + > #ifdef CONFIG_SWIOTLB > swiotlb_init(1); > #endif > diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinu= x.lds.S > index de03cb22d0e9..0726c05e0336 100644 > --- a/arch/riscv/kernel/vmlinux.lds.S > +++ b/arch/riscv/kernel/vmlinux.lds.S > @@ -4,7 +4,8 @@ > * Copyright (C) 2017 SiFive > */ > > -#define LOAD_OFFSET PAGE_OFFSET > +#include > +#define LOAD_OFFSET KERNEL_LINK_ADDR > #include > #include > #include > diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c > index 8f17519208c7..1b14d523a95c 100644 > --- a/arch/riscv/mm/fault.c > +++ b/arch/riscv/mm/fault.c > @@ -231,6 +231,19 @@ asmlinkage void do_page_fault(struct pt_regs *regs= ) > return; > } > > +#ifdef CONFIG_64BIT > + /* > + * Modules in 64bit kernels lie in their own virtual region which is = not > + * in the vmalloc region, but dealing with page faults in this region > + * or the vmalloc region amounts to doing the same thing: checking th= at > + * the mapping exists in init_mm.pgd and updating user page table, so > + * just use vmalloc_fault. > + */ > + if (unlikely(addr >=3D MODULES_VADDR && addr < MODULES_END)) { > + vmalloc_fault(regs, code, addr); > + return; > + } > +#endif > /* Enable interrupts if they were enabled in the parent context. */ > if (likely(regs->status & SR_PIE)) > local_irq_enable(); > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 7f5036fbee8c..093f3a96ecfc 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -25,6 +25,9 @@ > > #include "../kernel/head.h" > > +unsigned long kernel_virt_addr =3D KERNEL_LINK_ADDR; > +EXPORT_SYMBOL(kernel_virt_addr); > + > unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] > __page_aligned_bss; > EXPORT_SYMBOL(empty_zero_page); > @@ -88,6 +91,8 @@ static void print_vm_layout(void) > (unsigned long)VMALLOC_END); > print_mlm("lowmem", (unsigned long)PAGE_OFFSET, > (unsigned long)high_memory); > + print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR, > + (unsigned long)ADDRESS_SPACE_END); > } > #else > static void print_vm_layout(void) { } > @@ -116,8 +121,13 @@ void __init setup_bootmem(void) > /* The maximal physical memory size is -PAGE_OFFSET. */ > memblock_enforce_memory_limit(-PAGE_OFFSET); > > - /* Reserve from the start of the kernel to the end of the kernel */ > - memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); > + /* > + * Reserve from the start of the kernel to the end of the kernel > + * and make sure we align the reservation on PMD_SIZE since we will > + * map the kernel in the linear mapping as read-only: we do not want > + * any allocation to happen between _end and the next pmd aligned pag= e. > + */ > + memblock_reserve(vmlinux_start, (vmlinux_end - vmlinux_start + PMD_SI= ZE - 1) & PMD_MASK); > > /* > * memblock allocator is not aware of the fact that last 4K bytes of > @@ -152,8 +162,12 @@ void __init setup_bootmem(void) > #ifdef CONFIG_MMU > static struct pt_alloc_ops pt_ops; > > +/* Offset between linear mapping virtual address and kernel load addre= ss */ > unsigned long va_pa_offset; > EXPORT_SYMBOL(va_pa_offset); > +/* Offset between kernel mapping virtual address and kernel load addre= ss */ > +unsigned long va_kernel_pa_offset; > +EXPORT_SYMBOL(va_kernel_pa_offset); > unsigned long pfn_base; > EXPORT_SYMBOL(pfn_base); > > @@ -257,7 +271,7 @@ static pmd_t *get_pmd_virt_late(phys_addr_t pa) > > static phys_addr_t __init alloc_pmd_early(uintptr_t va) > { > - BUG_ON((va - PAGE_OFFSET) >> PGDIR_SHIFT); > + BUG_ON((va - kernel_virt_addr) >> PGDIR_SHIFT); > > return (uintptr_t)early_pmd; > } > @@ -372,17 +386,32 @@ static uintptr_t __init best_map_size(phys_addr_t= base, phys_addr_t size) > #error "setup_vm() is called from head.S before relocate so it should = not use absolute addressing." > #endif > > +uintptr_t load_pa, load_sz; > + > +static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t ma= p_size) > +{ > + uintptr_t va, end_va; > + > + end_va =3D kernel_virt_addr + load_sz; > + for (va =3D kernel_virt_addr; va < end_va; va +=3D map_size) > + create_pgd_mapping(pgdir, va, > + load_pa + (va - kernel_virt_addr), > + map_size, PAGE_KERNEL_EXEC); > +} > + > asmlinkage void __init setup_vm(uintptr_t dtb_pa) > { > - uintptr_t va, pa, end_va; > - uintptr_t load_pa =3D (uintptr_t)(&_start); > - uintptr_t load_sz =3D (uintptr_t)(&_end) - load_pa; > + uintptr_t pa; > uintptr_t map_size; > #ifndef __PAGETABLE_PMD_FOLDED > pmd_t fix_bmap_spmd, fix_bmap_epmd; > #endif > + load_pa =3D (uintptr_t)(&_start); > + load_sz =3D (uintptr_t)(&_end) - load_pa; > > va_pa_offset =3D PAGE_OFFSET - load_pa; > + va_kernel_pa_offset =3D kernel_virt_addr - load_pa; > + > pfn_base =3D PFN_DOWN(load_pa); > > /* > @@ -410,26 +439,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > create_pmd_mapping(fixmap_pmd, FIXADDR_START, > (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); > /* Setup trampoline PGD and PMD */ > - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, > + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, > (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); > - create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, > + create_pmd_mapping(trampoline_pmd, kernel_virt_addr, > load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); > #else > /* Setup trampoline PGD */ > - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, > + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr, > load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); > #endif > > /* > - * Setup early PGD covering entire kernel which will allows > + * Setup early PGD covering entire kernel which will allow > * us to reach paging_init(). We map all memory banks later > * in setup_vm_final() below. > */ > - end_va =3D PAGE_OFFSET + load_sz; > - for (va =3D PAGE_OFFSET; va < end_va; va +=3D map_size) > - create_pgd_mapping(early_pg_dir, va, > - load_pa + (va - PAGE_OFFSET), > - map_size, PAGE_KERNEL_EXEC); > + create_kernel_page_table(early_pg_dir, map_size); > > #ifndef __PAGETABLE_PMD_FOLDED > /* Setup early PMD for DTB */ > @@ -444,7 +469,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); > dtb_early_va =3D (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1)= ); > #else /* CONFIG_BUILTIN_DTB */ > - dtb_early_va =3D __va(dtb_pa); > + /* > + * __va can't be used since it would return a linear mapping address > + * whereas dtb_early_va will be used before setup_vm_final installs > + * the linear mapping. > + */ > + dtb_early_va =3D kernel_mapping_pa_to_va(dtb_pa); > #endif /* CONFIG_BUILTIN_DTB */ > #else > #ifndef CONFIG_BUILTIN_DTB > @@ -456,7 +486,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL); > dtb_early_va =3D (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - = 1)); > #else /* CONFIG_BUILTIN_DTB */ > - dtb_early_va =3D __va(dtb_pa); > + dtb_early_va =3D kernel_mapping_pa_to_va(dtb_pa); > #endif /* CONFIG_BUILTIN_DTB */ > #endif > dtb_early_pa =3D dtb_pa; > @@ -492,6 +522,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > #endif > } > > +#ifdef CONFIG_64BIT > +void protect_kernel_linear_mapping_text_rodata(void) > +{ > + unsigned long text_start =3D (unsigned long)lm_alias(_start); > + unsigned long init_text_start =3D (unsigned long)lm_alias(__init_text= _begin); > + unsigned long rodata_start =3D (unsigned long)lm_alias(__start_rodata= ); > + unsigned long data_start =3D (unsigned long)lm_alias(_data); > + > + set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIF= T); > + set_memory_nx(text_start, (init_text_start - text_start) >> PAGE_SHIF= T); > + > + set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT= ); > + set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT= ); > +} > +#endif > + > static void __init setup_vm_final(void) > { > uintptr_t va, map_size; > @@ -513,7 +559,7 @@ static void __init setup_vm_final(void) > __pa_symbol(fixmap_pgd_next), > PGDIR_SIZE, PAGE_TABLE); > > - /* Map all memory banks */ > + /* Map all memory banks in the linear mapping */ > for_each_mem_range(i, &start, &end) { > if (start >=3D end) > break; > @@ -525,10 +571,13 @@ static void __init setup_vm_final(void) > for (pa =3D start; pa < end; pa +=3D map_size) { > va =3D (uintptr_t)__va(pa); > create_pgd_mapping(swapper_pg_dir, va, pa, > - map_size, PAGE_KERNEL_EXEC); > + map_size, PAGE_KERNEL); > } > } > > + /* Map the kernel */ > + create_kernel_page_table(swapper_pg_dir, PMD_SIZE); > + > /* Clear fixmap PTE and PMD mappings */ > clear_fixmap(FIX_PTE); > clear_fixmap(FIX_PMD); > diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c > index 2c39f0386673..28f4d52cf17e 100644 > --- a/arch/riscv/mm/kasan_init.c > +++ b/arch/riscv/mm/kasan_init.c > @@ -171,6 +171,10 @@ void __init kasan_init(void) > phys_addr_t _start, _end; > u64 i; > > + /* > + * Populate all kernel virtual address space with kasan_early_shadow_= page > + * except for the linear mapping and the modules/kernel/BPF mapping. > + */ > kasan_populate_early_shadow((void *)KASAN_SHADOW_START, > (void *)kasan_mem_to_shadow((void *) > VMEMMAP_END)); > @@ -183,6 +187,7 @@ void __init kasan_init(void) > (void *)kasan_mem_to_shadow((void *)VMALLOC_START), > (void *)kasan_mem_to_shadow((void *)VMALLOC_END)); > > + /* Populate the linear mapping */ > for_each_mem_range(i, &_start, &_end) { > void *start =3D (void *)__va(_start); > void *end =3D (void *)__va(_end); > @@ -193,6 +198,10 @@ void __init kasan_init(void) > kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end))= ; > }; > > + /* Populate kernel, BPF, modules mapping */ > + kasan_populate(kasan_mem_to_shadow((const void *)MODULES_VADDR), > + kasan_mem_to_shadow((const void *)BPF_JIT_REGION_END)); > + > for (i =3D 0; i < PTRS_PER_PTE; i++) > set_pte(&kasan_early_shadow_pte[i], > mk_pte(virt_to_page(kasan_early_shadow_page), > diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c > index e8e4dcd39fed..35703d5ef5fd 100644 > --- a/arch/riscv/mm/physaddr.c > +++ b/arch/riscv/mm/physaddr.c > @@ -23,7 +23,7 @@ EXPORT_SYMBOL(__virt_to_phys); > > phys_addr_t __phys_addr_symbol(unsigned long x) > { > - unsigned long kernel_start =3D (unsigned long)PAGE_OFFSET; > + unsigned long kernel_start =3D (unsigned long)kernel_virt_addr; > unsigned long kernel_end =3D (unsigned long)_end; > > /* This is breaking boot for me with CONFIG_STRICT_KERNEL_RWX=3Dn. I'm not=20 even really convinced that's a useful config to support, but it's=20 currently optional and I'd prefer to avoid breaking it if possible. I can't quite figure out what's going on here and I'm pretty much tired=20 out for tonight. LMK if you don't have time to look at it and I'll try=20 to give it another shot.