| Message ID | 20201101170815.9795-5-rppt@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arch, mm: improve robustness of direct map manipulation | expand |
On 01.11.20 18:08, Mike Rapoport wrote: > From: Mike Rapoport <rppt@linux.ibm.com> > > For architectures that enable ARCH_HAS_SET_MEMORY having the ability to > verify that a page is mapped in the kernel direct map can be useful > regardless of hibernation. > > Add RISC-V implementation of kernel_page_present(), update its forward > declarations and stubs to be a part of set_memory API and remove ugly > ifdefery in inlcude/linux/mm.h around current declarations of > kernel_page_present(). > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > --- > arch/arm64/include/asm/cacheflush.h | 1 + > arch/arm64/mm/pageattr.c | 4 +--- > arch/riscv/include/asm/set_memory.h | 1 + > arch/riscv/mm/pageattr.c | 29 +++++++++++++++++++++++++++++ > arch/x86/include/asm/set_memory.h | 1 + > arch/x86/mm/pat/set_memory.c | 4 +--- > include/linux/mm.h | 7 ------- > include/linux/set_memory.h | 5 +++++ > 8 files changed, 39 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h > index 9384fd8fc13c..45217f21f1fe 100644 > --- a/arch/arm64/include/asm/cacheflush.h > +++ b/arch/arm64/include/asm/cacheflush.h > @@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable); > > int set_direct_map_invalid_noflush(struct page *page); > int set_direct_map_default_noflush(struct page *page); > +bool kernel_page_present(struct page *page); > > #include <asm-generic/cacheflush.h> > > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index 439325532be1..92eccaf595c8 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -186,8 +186,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > set_memory_valid((unsigned long)page_address(page), numpages, enable); > } > +#endif /* CONFIG_DEBUG_PAGEALLOC */ > > -#ifdef CONFIG_HIBERNATION > /* > * This function is used to determine if a linear map page has been marked as > * not-valid. Walk the page table and check the PTE_VALID bit. This is based > @@ -234,5 +234,3 @@ bool kernel_page_present(struct page *page) > ptep = pte_offset_kernel(pmdp, addr); > return pte_valid(READ_ONCE(*ptep)); > } > -#endif /* CONFIG_HIBERNATION */ > -#endif /* CONFIG_DEBUG_PAGEALLOC */ > diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h > index 4c5bae7ca01c..d690b08dff2a 100644 > --- a/arch/riscv/include/asm/set_memory.h > +++ b/arch/riscv/include/asm/set_memory.h > @@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } > > int set_direct_map_invalid_noflush(struct page *page); > int set_direct_map_default_noflush(struct page *page); > +bool kernel_page_present(struct page *page); > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c > index 321b09d2e2ea..87ba5a68bbb8 100644 > --- a/arch/riscv/mm/pageattr.c > +++ b/arch/riscv/mm/pageattr.c > @@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > __pgprot(0), __pgprot(_PAGE_PRESENT)); > } > #endif > + > +bool kernel_page_present(struct page *page) > +{ > + unsigned long addr = (unsigned long)page_address(page); > + pgd_t *pgd; > + pud_t *pud; > + p4d_t *p4d; > + pmd_t *pmd; > + pte_t *pte; > + > + pgd = pgd_offset_k(addr); > + if (!pgd_present(*pgd)) > + return false; > + > + p4d = p4d_offset(pgd, addr); > + if (!p4d_present(*p4d)) > + return false; > + > + pud = pud_offset(p4d, addr); > + if (!pud_present(*pud)) > + return false; > + > + pmd = pmd_offset(pud, addr); > + if (!pmd_present(*pmd)) > + return false; > + > + pte = pte_offset_kernel(pmd, addr); > + return pte_present(*pte); > +} > diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h > index 5948218f35c5..4352f08bfbb5 100644 > --- a/arch/x86/include/asm/set_memory.h > +++ b/arch/x86/include/asm/set_memory.h > @@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int numpages); > > int set_direct_map_invalid_noflush(struct page *page); > int set_direct_map_default_noflush(struct page *page); > +bool kernel_page_present(struct page *page); > > extern int kernel_set_to_readonly; > > diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c > index bc9be96b777f..16f878c26667 100644 > --- a/arch/x86/mm/pat/set_memory.c > +++ b/arch/x86/mm/pat/set_memory.c > @@ -2226,8 +2226,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > arch_flush_lazy_mmu_mode(); > } > +#endif /* CONFIG_DEBUG_PAGEALLOC */ > > -#ifdef CONFIG_HIBERNATION > bool kernel_page_present(struct page *page) > { > unsigned int level; > @@ -2239,8 +2239,6 @@ bool kernel_page_present(struct page *page) > pte = lookup_address((unsigned long)page_address(page), &level); > return (pte_val(*pte) & _PAGE_PRESENT); > } > -#endif /* CONFIG_HIBERNATION */ > -#endif /* CONFIG_DEBUG_PAGEALLOC */ > > int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, > unsigned numpages, unsigned long page_flags) > diff --git a/include/linux/mm.h b/include/linux/mm.h > index ab0ef6bd351d..44b82f22e76a 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2937,16 +2937,9 @@ static inline void debug_pagealloc_map_pages(struct page *page, > if (debug_pagealloc_enabled_static()) > __kernel_map_pages(page, numpages, enable); > } > - > -#ifdef CONFIG_HIBERNATION > -extern bool kernel_page_present(struct page *page); > -#endif /* CONFIG_HIBERNATION */ > #else /* CONFIG_DEBUG_PAGEALLOC */ > static inline void debug_pagealloc_map_pages(struct page *page, > int numpages, int enable) {} > -#ifdef CONFIG_HIBERNATION > -static inline bool kernel_page_present(struct page *page) { return true; } > -#endif /* CONFIG_HIBERNATION */ > #endif /* CONFIG_DEBUG_PAGEALLOC */ > > #ifdef __HAVE_ARCH_GATE_AREA > diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h > index 860e0f843c12..fe1aa4e54680 100644 > --- a/include/linux/set_memory.h > +++ b/include/linux/set_memory.h > @@ -23,6 +23,11 @@ static inline int set_direct_map_default_noflush(struct page *page) > { > return 0; > } > + > +static inline bool kernel_page_present(struct page *page) > +{ > + return true; > +} > #endif > > #ifndef set_mce_nospec > It's somewhat weird to move this to set_memory.h - it's only one possible user. I think include/linux/mm.h is a better fit. Ack to making it independent of CONFIG_HIBERNATION. in include/linux/mm.h , I'd prefer: #if defined(CONFIG_DEBUG_PAGEALLOC) || \ defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) bool kernel_page_present(struct page *page); #else static inline bool kernel_page_present(struct page *page) { return true; } #endif -- Thanks, David / dhildenb
On Mon, Nov 02, 2020 at 10:28:14AM +0100, David Hildenbrand wrote: > On 01.11.20 18:08, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@linux.ibm.com> > > > > For architectures that enable ARCH_HAS_SET_MEMORY having the ability to > > verify that a page is mapped in the kernel direct map can be useful > > regardless of hibernation. > > > > Add RISC-V implementation of kernel_page_present(), update its forward > > declarations and stubs to be a part of set_memory API and remove ugly > > ifdefery in inlcude/linux/mm.h around current declarations of > > kernel_page_present(). > > > > Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > > --- > > arch/arm64/include/asm/cacheflush.h | 1 + > > arch/arm64/mm/pageattr.c | 4 +--- > > arch/riscv/include/asm/set_memory.h | 1 + > > arch/riscv/mm/pageattr.c | 29 +++++++++++++++++++++++++++++ > > arch/x86/include/asm/set_memory.h | 1 + > > arch/x86/mm/pat/set_memory.c | 4 +--- > > include/linux/mm.h | 7 ------- > > include/linux/set_memory.h | 5 +++++ > > 8 files changed, 39 insertions(+), 13 deletions(-) > > > > diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h > > index 9384fd8fc13c..45217f21f1fe 100644 > > --- a/arch/arm64/include/asm/cacheflush.h > > +++ b/arch/arm64/include/asm/cacheflush.h > > @@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable); > > int set_direct_map_invalid_noflush(struct page *page); > > int set_direct_map_default_noflush(struct page *page); > > +bool kernel_page_present(struct page *page); > > #include <asm-generic/cacheflush.h> > > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > > index 439325532be1..92eccaf595c8 100644 > > --- a/arch/arm64/mm/pageattr.c > > +++ b/arch/arm64/mm/pageattr.c > > @@ -186,8 +186,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > set_memory_valid((unsigned long)page_address(page), numpages, enable); > > } > > +#endif /* CONFIG_DEBUG_PAGEALLOC */ > > -#ifdef CONFIG_HIBERNATION > > /* > > * This function is used to determine if a linear map page has been marked as > > * not-valid. Walk the page table and check the PTE_VALID bit. This is based > > @@ -234,5 +234,3 @@ bool kernel_page_present(struct page *page) > > ptep = pte_offset_kernel(pmdp, addr); > > return pte_valid(READ_ONCE(*ptep)); > > } > > -#endif /* CONFIG_HIBERNATION */ > > -#endif /* CONFIG_DEBUG_PAGEALLOC */ > > diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h > > index 4c5bae7ca01c..d690b08dff2a 100644 > > --- a/arch/riscv/include/asm/set_memory.h > > +++ b/arch/riscv/include/asm/set_memory.h > > @@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } > > int set_direct_map_invalid_noflush(struct page *page); > > int set_direct_map_default_noflush(struct page *page); > > +bool kernel_page_present(struct page *page); > > #endif /* __ASSEMBLY__ */ > > diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c > > index 321b09d2e2ea..87ba5a68bbb8 100644 > > --- a/arch/riscv/mm/pageattr.c > > +++ b/arch/riscv/mm/pageattr.c > > @@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > __pgprot(0), __pgprot(_PAGE_PRESENT)); > > } > > #endif > > + > > +bool kernel_page_present(struct page *page) > > +{ > > + unsigned long addr = (unsigned long)page_address(page); > > + pgd_t *pgd; > > + pud_t *pud; > > + p4d_t *p4d; > > + pmd_t *pmd; > > + pte_t *pte; > > + > > + pgd = pgd_offset_k(addr); > > + if (!pgd_present(*pgd)) > > + return false; > > + > > + p4d = p4d_offset(pgd, addr); > > + if (!p4d_present(*p4d)) > > + return false; > > + > > + pud = pud_offset(p4d, addr); > > + if (!pud_present(*pud)) > > + return false; > > + > > + pmd = pmd_offset(pud, addr); > > + if (!pmd_present(*pmd)) > > + return false; > > + > > + pte = pte_offset_kernel(pmd, addr); > > + return pte_present(*pte); > > +} > > diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h > > index 5948218f35c5..4352f08bfbb5 100644 > > --- a/arch/x86/include/asm/set_memory.h > > +++ b/arch/x86/include/asm/set_memory.h > > @@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int numpages); > > int set_direct_map_invalid_noflush(struct page *page); > > int set_direct_map_default_noflush(struct page *page); > > +bool kernel_page_present(struct page *page); > > extern int kernel_set_to_readonly; > > diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c > > index bc9be96b777f..16f878c26667 100644 > > --- a/arch/x86/mm/pat/set_memory.c > > +++ b/arch/x86/mm/pat/set_memory.c > > @@ -2226,8 +2226,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) > > arch_flush_lazy_mmu_mode(); > > } > > +#endif /* CONFIG_DEBUG_PAGEALLOC */ > > -#ifdef CONFIG_HIBERNATION > > bool kernel_page_present(struct page *page) > > { > > unsigned int level; > > @@ -2239,8 +2239,6 @@ bool kernel_page_present(struct page *page) > > pte = lookup_address((unsigned long)page_address(page), &level); > > return (pte_val(*pte) & _PAGE_PRESENT); > > } > > -#endif /* CONFIG_HIBERNATION */ > > -#endif /* CONFIG_DEBUG_PAGEALLOC */ > > int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, > > unsigned numpages, unsigned long page_flags) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index ab0ef6bd351d..44b82f22e76a 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -2937,16 +2937,9 @@ static inline void debug_pagealloc_map_pages(struct page *page, > > if (debug_pagealloc_enabled_static()) > > __kernel_map_pages(page, numpages, enable); > > } > > - > > -#ifdef CONFIG_HIBERNATION > > -extern bool kernel_page_present(struct page *page); > > -#endif /* CONFIG_HIBERNATION */ > > #else /* CONFIG_DEBUG_PAGEALLOC */ > > static inline void debug_pagealloc_map_pages(struct page *page, > > int numpages, int enable) {} > > -#ifdef CONFIG_HIBERNATION > > -static inline bool kernel_page_present(struct page *page) { return true; } > > -#endif /* CONFIG_HIBERNATION */ > > #endif /* CONFIG_DEBUG_PAGEALLOC */ > > #ifdef __HAVE_ARCH_GATE_AREA > > diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h > > index 860e0f843c12..fe1aa4e54680 100644 > > --- a/include/linux/set_memory.h > > +++ b/include/linux/set_memory.h > > @@ -23,6 +23,11 @@ static inline int set_direct_map_default_noflush(struct page *page) > > { > > return 0; > > } > > + > > +static inline bool kernel_page_present(struct page *page) > > +{ > > + return true; > > +} > > #endif > > #ifndef set_mce_nospec > > > > It's somewhat weird to move this to set_memory.h - it's only one possible > user. I think include/linux/mm.h is a better fit. Ack to making it > independent of CONFIG_HIBERNATION. Semantically this is a part of direct map manipulation, that's primarily why I put it into set_memory.h > in include/linux/mm.h , I'd prefer: > > #if defined(CONFIG_DEBUG_PAGEALLOC) || \ > defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) The second reason was to avoid this ^ and the third is -7 lines to include/linux/mm.h :) > bool kernel_page_present(struct page *page); > #else > static inline bool kernel_page_present(struct page *page) > { > return true; > } > #endif > > -- > Thanks, > > David / dhildenb > > -- Sincerely yours, Mike.
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 9384fd8fc13c..45217f21f1fe 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable); int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); #include <asm-generic/cacheflush.h> diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 439325532be1..92eccaf595c8 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -186,8 +186,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) set_memory_valid((unsigned long)page_address(page), numpages, enable); } +#endif /* CONFIG_DEBUG_PAGEALLOC */ -#ifdef CONFIG_HIBERNATION /* * This function is used to determine if a linear map page has been marked as * not-valid. Walk the page table and check the PTE_VALID bit. This is based @@ -234,5 +234,3 @@ bool kernel_page_present(struct page *page) ptep = pte_offset_kernel(pmdp, addr); return pte_valid(READ_ONCE(*ptep)); } -#endif /* CONFIG_HIBERNATION */ -#endif /* CONFIG_DEBUG_PAGEALLOC */ diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h index 4c5bae7ca01c..d690b08dff2a 100644 --- a/arch/riscv/include/asm/set_memory.h +++ b/arch/riscv/include/asm/set_memory.h @@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c index 321b09d2e2ea..87ba5a68bbb8 100644 --- a/arch/riscv/mm/pageattr.c +++ b/arch/riscv/mm/pageattr.c @@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) __pgprot(0), __pgprot(_PAGE_PRESENT)); } #endif + +bool kernel_page_present(struct page *page) +{ + unsigned long addr = (unsigned long)page_address(page); + pgd_t *pgd; + pud_t *pud; + p4d_t *p4d; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset_k(addr); + if (!pgd_present(*pgd)) + return false; + + p4d = p4d_offset(pgd, addr); + if (!p4d_present(*p4d)) + return false; + + pud = pud_offset(p4d, addr); + if (!pud_present(*pud)) + return false; + + pmd = pmd_offset(pud, addr); + if (!pmd_present(*pmd)) + return false; + + pte = pte_offset_kernel(pmd, addr); + return pte_present(*pte); +} diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h index 5948218f35c5..4352f08bfbb5 100644 --- a/arch/x86/include/asm/set_memory.h +++ b/arch/x86/include/asm/set_memory.h @@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int numpages); int set_direct_map_invalid_noflush(struct page *page); int set_direct_map_default_noflush(struct page *page); +bool kernel_page_present(struct page *page); extern int kernel_set_to_readonly; diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index bc9be96b777f..16f878c26667 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -2226,8 +2226,8 @@ void __kernel_map_pages(struct page *page, int numpages, int enable) arch_flush_lazy_mmu_mode(); } +#endif /* CONFIG_DEBUG_PAGEALLOC */ -#ifdef CONFIG_HIBERNATION bool kernel_page_present(struct page *page) { unsigned int level; @@ -2239,8 +2239,6 @@ bool kernel_page_present(struct page *page) pte = lookup_address((unsigned long)page_address(page), &level); return (pte_val(*pte) & _PAGE_PRESENT); } -#endif /* CONFIG_HIBERNATION */ -#endif /* CONFIG_DEBUG_PAGEALLOC */ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, unsigned numpages, unsigned long page_flags) diff --git a/include/linux/mm.h b/include/linux/mm.h index ab0ef6bd351d..44b82f22e76a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2937,16 +2937,9 @@ static inline void debug_pagealloc_map_pages(struct page *page, if (debug_pagealloc_enabled_static()) __kernel_map_pages(page, numpages, enable); } - -#ifdef CONFIG_HIBERNATION -extern bool kernel_page_present(struct page *page); -#endif /* CONFIG_HIBERNATION */ #else /* CONFIG_DEBUG_PAGEALLOC */ static inline void debug_pagealloc_map_pages(struct page *page, int numpages, int enable) {} -#ifdef CONFIG_HIBERNATION -static inline bool kernel_page_present(struct page *page) { return true; } -#endif /* CONFIG_HIBERNATION */ #endif /* CONFIG_DEBUG_PAGEALLOC */ #ifdef __HAVE_ARCH_GATE_AREA diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h index 860e0f843c12..fe1aa4e54680 100644 --- a/include/linux/set_memory.h +++ b/include/linux/set_memory.h @@ -23,6 +23,11 @@ static inline int set_direct_map_default_noflush(struct page *page) { return 0; } + +static inline bool kernel_page_present(struct page *page) +{ + return true; +} #endif #ifndef set_mce_nospec