From dfad83cb7193effb6c853a5c7337ac2274a2e2fc Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 30 Mar 2021 20:22:07 -0700 Subject: [PATCH] MIPS: Add support for CONFIG_DEBUG_VIRTUAL Provide hooks to intercept bad usages of virt_to_phys() and __pa_symbol() throughout the kernel. To make this possible, we need to rename the current implement of virt_to_phys() into __virt_to_phys_nodebug() and wrap it around depending on CONFIG_DEBUG_VIRTUAL. A similar thing is needed for __pa_symbol() which is now aliased to __phys_addr_symbol() whose implementation is either the direct return of RELOC_HIDE or goes through the debug version. Signed-off-by: Florian Fainelli Signed-off-by: Thomas Bogendoerfer --- arch/mips/Kconfig | 1 + arch/mips/include/asm/io.h | 14 ++++++++- arch/mips/include/asm/page.h | 9 +++++- arch/mips/kernel/vdso.c | 5 ++-- arch/mips/mm/Makefile | 2 ++ arch/mips/mm/physaddr.c | 56 ++++++++++++++++++++++++++++++++++++ 6 files changed, 83 insertions(+), 4 deletions(-) create mode 100644 arch/mips/mm/physaddr.c diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index b72458215d20..7d509191168b 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -4,6 +4,7 @@ config MIPS default y select ARCH_32BIT_OFF_T if !64BIT select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT + select ARCH_HAS_DEBUG_VIRTUAL if !64BIT select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_KCOV select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h index 78537aa23500..2c138450ad3b 100644 --- a/arch/mips/include/asm/io.h +++ b/arch/mips/include/asm/io.h @@ -100,11 +100,23 @@ static inline void set_io_port_base(unsigned long base) * almost all conceivable cases a device driver should not be using * this function */ -static inline unsigned long virt_to_phys(volatile const void *address) +static inline unsigned long __virt_to_phys_nodebug(volatile const void *address) { return __pa(address); } +#ifdef CONFIG_DEBUG_VIRTUAL +extern phys_addr_t __virt_to_phys(volatile const void *x); +#else +#define __virt_to_phys(x) __virt_to_phys_nodebug(x) +#endif + +#define virt_to_phys virt_to_phys +static inline phys_addr_t virt_to_phys(const volatile void *x) +{ + return __virt_to_phys(x); +} + /* * phys_to_virt - map physical address to virtual * @address: address to remap diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index 65acab9c41f9..195ff4e9771f 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -210,9 +210,16 @@ static inline unsigned long ___pa(unsigned long x) * also affect MIPS so we keep this one until GCC 3.x has been retired * before we can apply https://patchwork.linux-mips.org/patch/1541/ */ +#define __pa_symbol_nodebug(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) + +#ifdef CONFIG_DEBUG_VIRTUAL +extern phys_addr_t __phys_addr_symbol(unsigned long x); +#else +#define __phys_addr_symbol(x) __pa_symbol_nodebug(x) +#endif #ifndef __pa_symbol -#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) +#define __pa_symbol(x) __phys_addr_symbol((unsigned long)(x)) #endif #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c index 7d0b91ad2581..3d0cf471f2fe 100644 --- a/arch/mips/kernel/vdso.c +++ b/arch/mips/kernel/vdso.c @@ -90,7 +90,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { struct mips_vdso_image *image = current->thread.abi->vdso; struct mm_struct *mm = current->mm; - unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn; + unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base; struct vm_area_struct *vma; int ret; @@ -158,7 +158,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) /* Map GIC user page. */ if (gic_size) { - gic_pfn = virt_to_phys(mips_gic_base + MIPS_GIC_USER_OFS) >> PAGE_SHIFT; + gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS; + gic_pfn = virt_to_phys((void *)gic_base) >> PAGE_SHIFT; ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size, pgprot_noncached(vma->vm_page_prot)); diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile index 865926a37775..fa1f729e0700 100644 --- a/arch/mips/mm/Makefile +++ b/arch/mips/mm/Makefile @@ -40,3 +40,5 @@ obj-$(CONFIG_R5000_CPU_SCACHE) += sc-r5k.o obj-$(CONFIG_RM7000_CPU_SCACHE) += sc-rm7k.o obj-$(CONFIG_MIPS_CPU_SCACHE) += sc-mips.o obj-$(CONFIG_SCACHE_DEBUGFS) += sc-debugfs.o + +obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o diff --git a/arch/mips/mm/physaddr.c b/arch/mips/mm/physaddr.c new file mode 100644 index 000000000000..a1ced5e44951 --- /dev/null +++ b/arch/mips/mm/physaddr.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +static inline bool __debug_virt_addr_valid(unsigned long x) +{ + /* high_memory does not get immediately defined, and there + * are early callers of __pa() against PAGE_OFFSET + */ + if (!high_memory && x >= PAGE_OFFSET) + return true; + + if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory) + return true; + + /* + * MAX_DMA_ADDRESS is a virtual address that may not correspond to an + * actual physical address. Enough code relies on + * virt_to_phys(MAX_DMA_ADDRESS) that we just need to work around it + * and always return true. + */ + if (x == MAX_DMA_ADDRESS) + return true; + + return false; +} + +phys_addr_t __virt_to_phys(volatile const void *x) +{ + WARN(!__debug_virt_addr_valid((unsigned long)x), + "virt_to_phys used for non-linear address: %pK (%pS)\n", + x, x); + + return __virt_to_phys_nodebug(x); +} +EXPORT_SYMBOL(__virt_to_phys); + +phys_addr_t __phys_addr_symbol(unsigned long x) +{ + /* This is bounds checking against the kernel image only. + * __pa_symbol should only be used on kernel symbol addresses. + */ + VIRTUAL_BUG_ON(x < (unsigned long)_text || + x > (unsigned long)_end); + + return __pa_symbol_nodebug(x); +} +EXPORT_SYMBOL(__phys_addr_symbol);