The patch titled access_process_vm device memory infrastructure has been removed from the -mm tree. Its filename was access_process_vm-device-memory-infrastructure.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: access_process_vm device memory infrastructure From: Rik van Riel <riel@xxxxxxxxxx> In order to be able to debug things like the X server and programs using the PPC Cell SPUs, the debugger needs to be able to access device memory through ptrace and /proc/pid/mem. This patch: Add the generic_access_phys access function and put the hooks in place to allow access_process_vm to access device or PPC Cell SPU memory. [riel@xxxxxxxxxx: Add documentation for the vm_ops->access function] Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Benjamin Herrensmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxx> Cc: Hugh Dickins <hugh@xxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/filesystems/Locking | 7 + arch/Kconfig | 3 arch/x86/Kconfig | 1 arch/x86/mm/ioremap.c | 8 + include/asm-x86/io_32.h | 2 include/asm-x86/io_64.h | 2 include/linux/mm.h | 8 + mm/memory.c | 131 ++++++++++++++++++++++++---- 8 files changed, 144 insertions(+), 18 deletions(-) diff -puN Documentation/filesystems/Locking~access_process_vm-device-memory-infrastructure Documentation/filesystems/Locking --- a/Documentation/filesystems/Locking~access_process_vm-device-memory-infrastructure +++ a/Documentation/filesystems/Locking @@ -510,6 +510,7 @@ prototypes: void (*close)(struct vm_area_struct*); int (*fault)(struct vm_area_struct*, struct vm_fault *); int (*page_mkwrite)(struct vm_area_struct *, struct page *); + int (*access)(struct vm_area_struct *, unsigned long, void*, int, int); locking rules: BKL mmap_sem PageLocked(page) @@ -517,6 +518,7 @@ open: no yes close: no yes fault: no yes page_mkwrite: no yes no +access: no yes ->page_mkwrite() is called when a previously read-only page is about to become writeable. The file system is responsible for @@ -525,6 +527,11 @@ taking to lock out truncate, the page ra within i_size. The page mapping should also be checked that it is not NULL. + ->access() is called when get_user_pages() fails in +acces_process_vm(), typically used to debug a process through +/proc/pid/mem or ptrace. This function is needed only for +VM_IO | VM_PFNMAP VMAs. + ================================================================================ Dubious stuff diff -puN arch/Kconfig~access_process_vm-device-memory-infrastructure arch/Kconfig --- a/arch/Kconfig~access_process_vm-device-memory-infrastructure +++ a/arch/Kconfig @@ -31,6 +31,9 @@ config KRETPROBES def_bool y depends on KPROBES && HAVE_KRETPROBES +config HAVE_IOREMAP_PROT + def_bool n + config HAVE_KPROBES def_bool n diff -puN arch/x86/Kconfig~access_process_vm-device-memory-infrastructure arch/x86/Kconfig --- a/arch/x86/Kconfig~access_process_vm-device-memory-infrastructure +++ a/arch/x86/Kconfig @@ -21,6 +21,7 @@ config X86 select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_IDE select HAVE_OPROFILE + select HAVE_IOREMAP_PROT select HAVE_KPROBES select HAVE_KRETPROBES select HAVE_DYNAMIC_FTRACE diff -puN arch/x86/mm/ioremap.c~access_process_vm-device-memory-infrastructure arch/x86/mm/ioremap.c --- a/arch/x86/mm/ioremap.c~access_process_vm-device-memory-infrastructure +++ a/arch/x86/mm/ioremap.c @@ -330,6 +330,14 @@ static void __iomem *ioremap_default(res return (void __iomem *)ret; } +void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size, + unsigned long prot_val) +{ + return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK), + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap_prot); + /** * iounmap - Free a IO remapping * @addr: virtual address from ioremap_* diff -puN include/asm-x86/io_32.h~access_process_vm-device-memory-infrastructure include/asm-x86/io_32.h --- a/include/asm-x86/io_32.h~access_process_vm-device-memory-infrastructure +++ a/include/asm-x86/io_32.h @@ -110,6 +110,8 @@ static inline void *phys_to_virt(unsigne */ extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size); extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size); +extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, + unsigned long prot_val); /* * The default ioremap() behavior is non-cached: diff -puN include/asm-x86/io_64.h~access_process_vm-device-memory-infrastructure include/asm-x86/io_64.h --- a/include/asm-x86/io_64.h~access_process_vm-device-memory-infrastructure +++ a/include/asm-x86/io_64.h @@ -175,6 +175,8 @@ extern void early_iounmap(void *addr, un */ extern void __iomem *ioremap_nocache(resource_size_t offset, unsigned long size); extern void __iomem *ioremap_cache(resource_size_t offset, unsigned long size); +extern void __iomem *ioremap_prot(resource_size_t offset, unsigned long size, + unsigned long prot_val); /* * The default ioremap() behavior is non-cached: diff -puN include/linux/mm.h~access_process_vm-device-memory-infrastructure include/linux/mm.h --- a/include/linux/mm.h~access_process_vm-device-memory-infrastructure +++ a/include/linux/mm.h @@ -170,6 +170,12 @@ struct vm_operations_struct { /* notification that a previously read-only page is about to become * writable, if an error is returned it will cause a SIGBUS */ int (*page_mkwrite)(struct vm_area_struct *vma, struct page *page); + + /* called by access_process_vm when get_user_pages() fails, typically + * for use by special VMAs that can switch between memory and hardware + */ + int (*access)(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write); #ifdef CONFIG_NUMA /* * set_policy() op must add a reference to any non-NULL @new mempolicy @@ -771,6 +777,8 @@ int copy_page_range(struct mm_struct *ds struct vm_area_struct *vma); void unmap_mapping_range(struct address_space *mapping, loff_t const holebegin, loff_t const holelen, int even_cows); +int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write); static inline void unmap_shared_mapping_range(struct address_space *mapping, loff_t const holebegin, loff_t const holelen) diff -puN mm/memory.c~access_process_vm-device-memory-infrastructure mm/memory.c --- a/mm/memory.c~access_process_vm-device-memory-infrastructure +++ a/mm/memory.c @@ -2751,6 +2751,86 @@ int in_gate_area_no_task(unsigned long a #endif /* __HAVE_ARCH_GATE_AREA */ +#ifdef CONFIG_HAVE_IOREMAP_PROT +static resource_size_t follow_phys(struct vm_area_struct *vma, + unsigned long address, unsigned int flags, + unsigned long *prot) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *ptep, pte; + spinlock_t *ptl; + resource_size_t phys_addr = 0; + struct mm_struct *mm = vma->vm_mm; + + VM_BUG_ON(!(vma->vm_flags & (VM_IO | VM_PFNMAP))); + + pgd = pgd_offset(mm, address); + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) + goto no_page_table; + + pud = pud_offset(pgd, address); + if (pud_none(*pud) || unlikely(pud_bad(*pud))) + goto no_page_table; + + pmd = pmd_offset(pud, address); + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) + goto no_page_table; + + /* We cannot handle huge page PFN maps. Luckily they don't exist. */ + if (pmd_huge(*pmd)) + goto no_page_table; + + ptep = pte_offset_map_lock(mm, pmd, address, &ptl); + if (!ptep) + goto out; + + pte = *ptep; + if (!pte_present(pte)) + goto unlock; + if ((flags & FOLL_WRITE) && !pte_write(pte)) + goto unlock; + phys_addr = pte_pfn(pte); + phys_addr <<= PAGE_SHIFT; /* Shift here to avoid overflow on PAE */ + + *prot = pgprot_val(pte_pgprot(pte)); + +unlock: + pte_unmap_unlock(ptep, ptl); +out: + return phys_addr; +no_page_table: + return 0; +} + +int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + resource_size_t phys_addr; + unsigned long prot = 0; + void *maddr; + int offset = addr & (PAGE_SIZE-1); + + if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) + return -EINVAL; + + phys_addr = follow_phys(vma, addr, write, &prot); + + if (!phys_addr) + return -EINVAL; + + maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot); + if (write) + memcpy_toio(maddr + offset, buf, len); + else + memcpy_fromio(buf, maddr + offset, len); + iounmap(maddr); + + return len; +} +#endif + /* * Access another process' address space. * Source/target buffer must be kernel space, @@ -2760,7 +2840,6 @@ int access_process_vm(struct task_struct { struct mm_struct *mm; struct vm_area_struct *vma; - struct page *page; void *old_buf = buf; mm = get_task_mm(tsk); @@ -2772,28 +2851,44 @@ int access_process_vm(struct task_struct while (len) { int bytes, ret, offset; void *maddr; + struct page *page = NULL; ret = get_user_pages(tsk, mm, addr, 1, write, 1, &page, &vma); - if (ret <= 0) - break; - - bytes = len; - offset = addr & (PAGE_SIZE-1); - if (bytes > PAGE_SIZE-offset) - bytes = PAGE_SIZE-offset; - - maddr = kmap(page); - if (write) { - copy_to_user_page(vma, page, addr, - maddr + offset, buf, bytes); - set_page_dirty_lock(page); + if (ret <= 0) { + /* + * Check if this is a VM_IO | VM_PFNMAP VMA, which + * we can access using slightly different code. + */ +#ifdef CONFIG_HAVE_IOREMAP_PROT + vma = find_vma(mm, addr); + if (!vma) + break; + if (vma->vm_ops && vma->vm_ops->access) + ret = vma->vm_ops->access(vma, addr, buf, + len, write); + if (ret <= 0) +#endif + break; + bytes = ret; } else { - copy_from_user_page(vma, page, addr, - buf, maddr + offset, bytes); + bytes = len; + offset = addr & (PAGE_SIZE-1); + if (bytes > PAGE_SIZE-offset) + bytes = PAGE_SIZE-offset; + + maddr = kmap(page); + if (write) { + copy_to_user_page(vma, page, addr, + maddr + offset, buf, bytes); + set_page_dirty_lock(page); + } else { + copy_from_user_page(vma, page, addr, + buf, maddr + offset, bytes); + } + kunmap(page); + page_cache_release(page); } - kunmap(page); - page_cache_release(page); len -= bytes; buf += bytes; addr += bytes; _ Patches currently in -mm which might be from riel@xxxxxxxxxx are origin.patch ntp-let-update_persistent_clock-sleep.patch mmu-notifiers-add-list_del_init_rcu.patch mmu-notifiers-add-mm_take_all_locks-operation.patch mmu-notifier-core.patch vmscan-give-referenced-active-and-unmapped-pages-a-second-trip-around-the-lru.patch idr-change-the-idr-structure.patch idr-rename-some-of-the-idr-apis-internal-routines.patch idr-fix-a-printk-call.patch idr-error-checking-factorization.patch idr-make-idr_get_new-rcu-safe.patch idr-make-idr_get_new-rcu-safe-fix.patch idr-make-idr_find-rcu-safe.patch idr-make-idr_remove-rcu-safe.patch ipc-call-idr_find-without-locking-in-ipc_lock.patch ipc-get-rid-of-ipc_lock_down.patch mm-speculative-page-references-fix-migration_entry_wait-for-speculative-page-cache.patch vmscan-move-isolate_lru_page-to-vmscanc.patch vmscan-move-isolate_lru_page-to-vmscanc-fix.patch vmscan-use-an-indexed-array-for-lru-variables.patch swap-use-an-array-for-the-lru-pagevecs.patch vmscan-free-swap-space-on-swap-in-activation.patch define-page_file_cache-function.patch define-page_file_cache-function-fix.patch define-page_file_cache-function-fix-splitlru-shmem_getpage-setpageswapbacked-sooner.patch vmscan-split-lru-lists-into-anon-file-sets.patch vmscan-split-lru-lists-into-anon-file-sets-collect-lru-meminfo-statistics-from-correct-offset.patch vmscan-split-lru-lists-into-anon-file-sets-prevent-incorrect-oom-under-split_lru.patch vmscan-split-lru-lists-into-anon-file-sets-split_lru-fix-pagevec_move_tail-doesnt-treat-unevictable-page.patch vmscan-split-lru-lists-into-anon-file-sets-splitlru-memcg-swapbacked-pages-active.patch vmscan-split-lru-lists-into-anon-file-sets-splitlru-bdi_cap_swap_backed.patch vmscan-split-lru-lists-into-anon-file-sets-units-fix.patch vmscan-second-chance-replacement-for-anonymous-pages.patch vmscan-second-chance-replacement-for-anonymous-pages-fix.patch vmscan-second-chance-replacement-for-anonymous-pages-memcg-lru-scan-fix.patch vmscan-fix-pagecache-reclaim-referenced-bit-check.patch vmscan-add-newly-swapped-in-pages-to-the-inactive-list.patch more-aggressively-use-lumpy-reclaim.patch pageflag-helpers-for-configed-out-flags.patch unevictable-lru-infrastructure.patch unevictable-lru-infrastructure-fix.patch unevictable-lru-infrastructure-kconfig-fix.patch unevictable-lru-infrastructure-remove-redundant-page-mapping-check.patch unevictable-lru-infrastructure-kill-unnecessary-lock_page-in-vmscanc.patch unevictable-lru-infrastructure-revert-migration-change-of-unevictable-lru-infrastructure.patch unevictable-lru-page-statistics.patch unevictable-lru-page-statistics-fix-printk-in-show_free_areas.patch unevictable-lru-page-statistics-units-fix.patch ramfs-and-ram-disk-pages-are-unevictable.patch ramfs-and-ram-disk-pages-are-unevictable-undo-the-brdc-part.patch shm_locked-pages-are-unevictable.patch shm_locked-pages-are-unevictable-revert-shm-change-of-shm_locked-pages-are-unevictable-patch.patch mlock-mlocked-pages-are-unevictable.patch mlock-mlocked-pages-are-unevictable-fix.patch mlock-mlocked-pages-are-unevictable-fix-fix.patch mlock-mlocked-pages-are-unevictable-fix-3.patch mlock-mlocked-pages-are-unevictable-fix-fix-munlock-page-table-walk-now-requires-mm.patch mlock-mlocked-pages-are-unevictable-restore-patch-failure-hunk-of-mlock-mlocked-pages-are-unevictablepatch.patch mlock-downgrade-mmap-sem-while-populating-mlocked-regions.patch mmap-handle-mlocked-pages-during-map-remap-unmap.patch mmap-handle-mlocked-pages-during-map-remap-unmap-cleanup.patch fix-double-unlock_page-in-2626-rc5-mm3-kernel-bug-at-mm-filemapc-575.patch introduce-__get_user_pages.patch introduce-__get_user_pages-fix.patch split-lru-munlock-rework.patch revert-to-unevictable-lru-infrastructure-kconfig-fixpatch.patch vmstat-mlocked-pages-statistics.patch vmstat-mlocked-pages-statistics-fix-incorrect-mlocked-field-of-proc-meminfo.patch swap-cull-unevictable-pages-in-fault-path.patch swap-cull-unevictable-pages-in-fault-path-fix.patch vmstat-unevictable-and-mlocked-pages-vm-events.patch vmscan-unevictable-lru-scan-sysctl.patch vmscan-unevictable-lru-scan-sysctl-nommu-fix.patch vmscan-unevictable-lru-scan-sysctl-add-sys_device-parameter.patch mlock-count-attempts-to-free-mlocked-page.patch doc-unevictable-lru-and-mlocked-pages-documentation.patch vmscam-kill-unused-lru-functions.patch mm-more-likely-reclaim-madv_sequential-mappings.patch make-mm-rmapc-anon_vma_cachep-static.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html