Re: [PATCH] riscv: Fix 32b kernel caused by 64b kernel mapping moving outside linear mapping
From: Alex Ghiti
Date: Fri Apr 23 2021 - 04:34:09 EST
Le 4/20/21 à 12:18 AM, Anup Patel a écrit :
On Sat, Apr 17, 2021 at 10:52 PM Alexandre Ghiti <alex@xxxxxxxx> wrote:
Fix multiple leftovers when moving the kernel mapping outside the linear
mapping for 64b kernel that left the 32b kernel unusable.
Fixes: 4b67f48da707 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
Quite a few #ifdef but I don't see any better way at the moment. Maybe we can
clean this later. Otherwise looks good to me.
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Thanks Anup!
@Palmer: This is not on for-next yet and then rv32 is broken. This does
not apply immediately on top of for-next though, so if you need a new
version, I can do that. But this squashes nicely with the patch it fixes
if you prefer.
Let me know, I can do that very quickly.
Alex
Regards,
Anup
---
arch/riscv/include/asm/page.h | 9 +++++++++
arch/riscv/include/asm/pgtable.h | 16 ++++++++++++----
arch/riscv/mm/init.c | 25 ++++++++++++++++++++++++-
3 files changed, 45 insertions(+), 5 deletions(-)
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 22cfb2be60dc..f64b61296c0c 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -90,15 +90,20 @@ typedef struct page *pgtable_t;
#ifdef CONFIG_MMU
extern unsigned long va_pa_offset;
+#ifdef CONFIG_64BIT
extern unsigned long va_kernel_pa_offset;
+#endif
extern unsigned long pfn_base;
#define ARCH_PFN_OFFSET (pfn_base)
#else
#define va_pa_offset 0
+#ifdef CONFIG_64BIT
#define va_kernel_pa_offset 0
+#endif
#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT)
#endif /* CONFIG_MMU */
+#ifdef CONFIG_64BIT
extern unsigned long kernel_virt_addr;
#define linear_mapping_pa_to_va(x) ((void *)((unsigned long)(x) + va_pa_offset))
@@ -112,6 +117,10 @@ extern unsigned long kernel_virt_addr;
(_x < kernel_virt_addr) ? \
linear_mapping_va_to_pa(_x) : kernel_mapping_va_to_pa(_x); \
})
+#else
+#define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_offset))
+#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset)
+#endif
#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 80e63a93e903..5afda75cc2c3 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -16,19 +16,27 @@
#else
#define ADDRESS_SPACE_END (UL(-1))
-/*
- * Leave 2GB for kernel and BPF at the end of the address space
- */
+
+#ifdef CONFIG_64BIT
+/* Leave 2GB for kernel and BPF at the end of the address space */
#define KERNEL_LINK_ADDR (ADDRESS_SPACE_END - SZ_2G + 1)
+#else
+#define KERNEL_LINK_ADDR PAGE_OFFSET
+#endif
#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)
+#ifdef CONFIG_64BIT
+/* KASLR should leave at least 128MB for BPF after the kernel */
#define BPF_JIT_REGION_START PFN_ALIGN((unsigned long)&_end)
#define BPF_JIT_REGION_END (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE)
+#else
+#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
+#define BPF_JIT_REGION_END (VMALLOC_END)
+#endif
/* Modules always live before the kernel */
#ifdef CONFIG_64BIT
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 093f3a96ecfc..dc9b988e0778 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -91,8 +91,10 @@ static void print_vm_layout(void)
(unsigned long)VMALLOC_END);
print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
(unsigned long)high_memory);
+#ifdef CONFIG_64BIT
print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,
(unsigned long)ADDRESS_SPACE_END);
+#endif
}
#else
static void print_vm_layout(void) { }
@@ -165,9 +167,11 @@ static struct pt_alloc_ops pt_ops;
/* Offset between linear mapping virtual address and kernel load address */
unsigned long va_pa_offset;
EXPORT_SYMBOL(va_pa_offset);
+#ifdef CONFIG_64BIT
/* Offset between kernel mapping virtual address and kernel load address */
unsigned long va_kernel_pa_offset;
EXPORT_SYMBOL(va_kernel_pa_offset);
+#endif
unsigned long pfn_base;
EXPORT_SYMBOL(pfn_base);
@@ -410,7 +414,9 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
load_sz = (uintptr_t)(&_end) - load_pa;
va_pa_offset = PAGE_OFFSET - load_pa;
+#ifdef CONFIG_64BIT
va_kernel_pa_offset = kernel_virt_addr - load_pa;
+#endif
pfn_base = PFN_DOWN(load_pa);
@@ -469,12 +475,16 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
#else /* CONFIG_BUILTIN_DTB */
+#ifdef CONFIG_64BIT
/*
* __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 = kernel_mapping_pa_to_va(dtb_pa);
+#else
+ dtb_early_va = __va(dtb_pa);
+#endif /* CONFIG_64BIT */
#endif /* CONFIG_BUILTIN_DTB */
#else
#ifndef CONFIG_BUILTIN_DTB
@@ -486,7 +496,11 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
#else /* CONFIG_BUILTIN_DTB */
+#ifdef CONFIG_64BIT
dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
+#else
+ dtb_early_va = __va(dtb_pa);
+#endif /* CONFIG_64BIT */
#endif /* CONFIG_BUILTIN_DTB */
#endif
dtb_early_pa = dtb_pa;
@@ -571,12 +585,21 @@ static void __init setup_vm_final(void)
for (pa = start; pa < end; pa += map_size) {
va = (uintptr_t)__va(pa);
create_pgd_mapping(swapper_pg_dir, va, pa,
- map_size, PAGE_KERNEL);
+ map_size,
+#ifdef CONFIG_64BIT
+ PAGE_KERNEL
+#else
+ PAGE_KERNEL_EXEC
+#endif
+ );
+
}
}
+#ifdef CONFIG_64BIT
/* Map the kernel */
create_kernel_page_table(swapper_pg_dir, PMD_SIZE);
+#endif
/* Clear fixmap PTE and PMD mappings */
clear_fixmap(FIX_PTE);
--
2.20.1