From 6435f773d81f02193228685a7e3fe65c983c5de0 Mon Sep 17 00:00:00 2001 From: Zong Li Date: Thu, 2 Jan 2020 11:12:39 +0800 Subject: riscv: mm: add support for CONFIG_DEBUG_VIRTUAL This patch implements CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys and __pa_symbol calls. virt_to_phys used for linear mapping check, and __pa_symbol used for kernel symbol check. In current RISC-V, kernel image maps to linear mapping area. If CONFIG_DEBUG_VIRTUAL is disable, these two functions calculate the offset on the address feded directly without any checks. The result of test_debug_virtual as follows: [ 0.358456] ------------[ cut here ]------------ [ 0.358738] virt_to_phys used for non-linear address: (____ptrval____) (0xffffffd000000000) [ 0.359174] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 __virt_to_phys+0x3c/0x50 [ 0.359409] Modules linked in: [ 0.359630] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc3-00002-g5133c5c0ca13 #57 [ 0.359861] epc: ffffffe000253d1a ra : ffffffe000253d1a sp : ffffffe03aa87da0 [ 0.360019] gp : ffffffe000ae03b0 tp : ffffffe03aa88000 t0 : ffffffe000af2660 [ 0.360175] t1 : 0000000000000064 t2 : 00000000000000b7 s0 : ffffffe03aa87dc0 [ 0.360330] s1 : ffffffd000000000 a0 : 000000000000004f a1 : 0000000000000000 [ 0.360492] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffe000a84358 [ 0.360672] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.360876] s2 : ffffffe000ae0600 s3 : ffffffe00000fc7c s4 : ffffffe0000224b0 [ 0.361067] s5 : ffffffe000030890 s6 : ffffffe000022470 s7 : 0000000000000008 [ 0.361267] s8 : ffffffe0000002c4 s9 : ffffffe000ae0640 s10: ffffffe000ae0630 [ 0.361453] s11: 0000000000000000 t3 : 0000000000000000 t4 : 000000000001e6d0 [ 0.361636] t5 : ffffffe000ae0a18 t6 : ffffffe000aee54e [ 0.361806] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003 [ 0.362056] ---[ end trace aec0bf78d4978122 ]--- [ 0.362404] PA: 0xfffffff080200000 for VA: 0xffffffd000000000 [ 0.362607] PA: 0x00000000baddd2d0 for VA: 0xffffffe03abdd2d0 Signed-off-by: Zong Li Reviewed-by: Paul Walmsley Tested-by: Paul Walmsley Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/page.h | 16 ++++++++++++++-- arch/riscv/mm/Makefile | 2 ++ arch/riscv/mm/physaddr.c | 37 +++++++++++++++++++++++++++++++++++++ 4 files changed, 54 insertions(+), 2 deletions(-) create mode 100644 arch/riscv/mm/physaddr.c diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index b04692fd4a63..73f029eae0cc 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -55,6 +55,7 @@ config RISCV select GENERIC_ARCH_TOPOLOGY if SMP select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_MMIOWB + select ARCH_HAS_DEBUG_VIRTUAL select HAVE_EBPF_JIT if 64BIT select EDAC_SUPPORT select ARCH_HAS_GIGANTIC_PAGE diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index ac699246ae7e..8ca1930caa44 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -100,8 +100,20 @@ extern unsigned long pfn_base; extern unsigned long max_low_pfn; extern unsigned long min_low_pfn; -#define __pa(x) ((unsigned long)(x) - va_pa_offset) -#define __va(x) ((void *)((unsigned long) (x) + va_pa_offset)) +#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) + +#ifdef CONFIG_DEBUG_VIRTUAL +extern phys_addr_t __virt_to_phys(unsigned long x); +extern phys_addr_t __phys_addr_symbol(unsigned long x); +#else +#define __virt_to_phys(x) __va_to_pa_nodebug(x) +#define __phys_addr_symbol(x) __va_to_pa_nodebug(x) +#endif /* CONFIG_DEBUG_VIRTUAL */ + +#define __pa_symbol(x) __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0)) +#define __pa(x) __virt_to_phys((unsigned long)(x)) +#define __va(x) ((void *)__pa_to_va_nodebug((phys_addr_t)(x))) #define phys_to_pfn(phys) (PFN_DOWN(phys)) #define pfn_to_phys(pfn) (PFN_PHYS(pfn)) diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile index 670de7c1fd25..50b7af58c566 100644 --- a/arch/riscv/mm/Makefile +++ b/arch/riscv/mm/Makefile @@ -21,3 +21,5 @@ ifdef CONFIG_KASAN KASAN_SANITIZE_kasan_init.o := n KASAN_SANITIZE_init.o := n endif + +obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c new file mode 100644 index 000000000000..e8e4dcd39fed --- /dev/null +++ b/arch/riscv/mm/physaddr.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include + +phys_addr_t __virt_to_phys(unsigned long x) +{ + phys_addr_t y = x - PAGE_OFFSET; + + /* + * Boundary checking aginst the kernel linear mapping space. + */ + WARN(y >= KERN_VIRT_SIZE, + "virt_to_phys used for non-linear address: %pK (%pS)\n", + (void *)x, (void *)x); + + return __va_to_pa_nodebug(x); +} +EXPORT_SYMBOL(__virt_to_phys); + +phys_addr_t __phys_addr_symbol(unsigned long x) +{ + unsigned long kernel_start = (unsigned long)PAGE_OFFSET; + unsigned long kernel_end = (unsigned long)_end; + + /* + * Boundary checking aginst the kernel image mapping. + * __pa_symbol should only be used on kernel symbol addresses. + */ + VIRTUAL_BUG_ON(x < kernel_start || x > kernel_end); + + return __va_to_pa_nodebug(x); +} +EXPORT_SYMBOL(__phys_addr_symbol); -- cgit v1.2.3