The patch titled /dev/mem: introduce size_inside_page() has been added to the -mm tree. Its filename is dev-mem-introduce-size_inside_page.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: /dev/mem: introduce size_inside_page() From: Wu Fengguang <fengguang.wu@xxxxxxxxx> Introduce size_inside_page() to replace duplicate /dev/mem code. Also apply it to /dev/kmem, whose alignment logic was buggy. Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Cc: Avi Kivity <avi@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/mem.c | 60 +++++++++++++------------------------------ 1 file changed, 19 insertions(+), 41 deletions(-) diff -puN drivers/char/mem.c~dev-mem-introduce-size_inside_page drivers/char/mem.c --- a/drivers/char/mem.c~dev-mem-introduce-size_inside_page +++ a/drivers/char/mem.c @@ -35,6 +35,19 @@ # include <linux/efi.h> #endif +static inline unsigned long size_inside_page(unsigned long start, + unsigned long size) +{ + unsigned long sz; + + if (-start & (PAGE_SIZE - 1)) + sz = -start & (PAGE_SIZE - 1); + else + sz = PAGE_SIZE; + + return min_t(unsigned long, sz, size); +} + /* * Architectures vary in how they handle caching for addresses * outside of main memory. @@ -142,15 +155,7 @@ static ssize_t read_mem(struct file * fi #endif while (count > 0) { - /* - * Handle first page in case it's not aligned - */ - if (-p & (PAGE_SIZE - 1)) - sz = -p & (PAGE_SIZE - 1); - else - sz = PAGE_SIZE; - - sz = min_t(unsigned long, sz, count); + sz = size_inside_page(p, count); if (!range_is_allowed(p >> PAGE_SHIFT, count)) return -EPERM; @@ -209,15 +214,7 @@ static ssize_t write_mem(struct file * f #endif while (count > 0) { - /* - * Handle first page in case it's not aligned - */ - if (-p & (PAGE_SIZE - 1)) - sz = -p & (PAGE_SIZE - 1); - else - sz = PAGE_SIZE; - - sz = min_t(unsigned long, sz, count); + sz = size_inside_page(p, count); if (!range_is_allowed(p >> PAGE_SHIFT, sz)) return -EPERM; @@ -430,15 +427,7 @@ static ssize_t read_kmem(struct file *fi } #endif while (low_count > 0) { - /* - * Handle first page in case it's not aligned - */ - if (-p & (PAGE_SIZE - 1)) - sz = -p & (PAGE_SIZE - 1); - else - sz = PAGE_SIZE; - - sz = min_t(unsigned long, sz, low_count); + sz = size_inside_page(p, low_count); /* * On ia64 if a page has been mapped somewhere as @@ -462,10 +451,8 @@ static ssize_t read_kmem(struct file *fi if (!kbuf) return -ENOMEM; while (count > 0) { - int len = count; + int len = size_inside_page(p, count); - if (len > PAGE_SIZE) - len = PAGE_SIZE; len = vread(kbuf, (char *)p, len); if (!len) break; @@ -510,15 +497,8 @@ do_write_kmem(void *p, unsigned long rea while (count > 0) { char *ptr; - /* - * Handle first page in case it's not aligned - */ - if (-realp & (PAGE_SIZE - 1)) - sz = -realp & (PAGE_SIZE - 1); - else - sz = PAGE_SIZE; - sz = min_t(unsigned long, sz, count); + sz = size_inside_page(realp, count); /* * On ia64 if a page has been mapped somewhere as @@ -578,10 +558,8 @@ static ssize_t write_kmem(struct file * if (!kbuf) return wrote ? wrote : -ENOMEM; while (count > 0) { - int len = count; + int len = size_inside_page(p, count); - if (len > PAGE_SIZE) - len = PAGE_SIZE; written = copy_from_user(kbuf, buf, len); if (written) { if (wrote + virtr) _ Patches currently in -mm which might be from fengguang.wu@xxxxxxxxx are linux-next.patch mm-memory-failure-remove-config_unevictable_lru-config-option.patch readahead-add-blk_run_backing_dev.patch readahead-add-blk_run_backing_dev-fix.patch readahead-add-blk_run_backing_dev-fix-fix-2.patch mm-clean-up-page_remove_rmap.patch mm-oom-analysis-add-per-zone-statistics-to-show_free_areas.patch mm-oom-analysis-add-buffer-cache-information-to-show_free_areas.patch mm-oom-analysis-add-shmem-vmstat.patch mm-shrink_inactive_list-nr_scan-accounting-fix-fix.patch mm-vmstat-add-isolate-pages.patch mm-vmstat-add-isolate-pages-fix.patch vmscan-throttle-direct-reclaim-when-too-many-pages-are-isolated-already.patch mm-remove-__addsub_zone_page_state.patch mm-count-only-reclaimable-lru-pages-v2.patch vmscan-move-clearpageactive-from-move_active_pages-to-shrink_active_list.patch vmscan-kill-unnecessary-page-flag-test.patch vmscan-kill-unnecessary-prefetch.patch ksm-add-mmu_notifier-set_pte_at_notify.patch ksm-first-tidy-up-madvise_vma.patch ksm-define-madv_mergeable-and-madv_unmergeable.patch ksm-the-mm-interface-to-ksm.patch ksm-no-debug-in-page_dup_rmap.patch ksm-identify-pageksm-pages.patch ksm-kernel-samepage-merging.patch ksm-prevent-mremap-move-poisoning.patch ksm-change-copyright-message.patch ksm-change-ksm-nice-level-to-be-5.patch mm-do-batched-scans-for-mem_cgroup.patch mm-vsmcan-check-shrink_active_list-sc-isolate_pages-return-value.patch dev-mem-remove-redundant-test-on-len.patch dev-mem-introduce-size_inside_page.patch dev-mem-cleanup-unxlate_dev_mem_ptr-calls.patch dev-mem-cleanup-unxlate_dev_mem_ptr-calls-fix.patch documentation-vm-gitignore-add-page-types.patch page-types-add-feature-for-walking-process-address-space.patch page-types-add-feature-for-walking-process-address-space-checkpatch-fixes.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