litmus-rt.git - The LITMUS^RT kernel.

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author	Dave Airlie <airlied@redhat.com>	2014-02-04 23:47:45 -0500
committer	Dave Airlie <airlied@redhat.com>	2014-02-05 20:39:03 -0500
commit	8b7ad1bb3d440da888f2a939dc870eba429b9192 (patch)
tree	20f57727fe6a071847ada03c5bacbecf52970e26 /include/linux/kdebug.h
parent	ec22b4aa993abbd18f5bbbcb20a1c56be3b1d38b (diff)

drm/mgag200,ast,cirrus: fix regression with drm_can_sleep conversion

I totally sign inverted my way out of this one. Cc: stable@vger.kernel.org Reported-by: "Sabrina Dubroca" <sd@queasysnail.net> Signed-off-by: Dave Airlie <airlied@redhat.com>

Diffstat (limited to 'include/linux/kdebug.h')

0 files changed, 0 insertions, 0 deletions

/* * linux/mm/madvise.c * * Copyright (C) 1999 Linus Torvalds * Copyright (C) 2002 Christoph Hellwig */ #include <linux/mman.h> #include <linux/pagemap.h> #include <linux/syscalls.h> #include <linux/mempolicy.h> #include <linux/hugetlb.h> #include <linux/sched.h> /* * Any behaviour which results in changes to the vma->vm_flags needs to * take mmap_sem for writing. Others, which simply traverse vmas, need * to only take it for reading. */ static int madvise_need_mmap_write(int behavior) { switch (behavior) { case MADV_REMOVE: case MADV_WILLNEED: case MADV_DONTNEED: return 0; default: /* be safe, default to 1. list exceptions explicitly */ return 1; } } /* * We can potentially split a vm area into separate * areas, each area with its own behavior. */ static long madvise_behavior(struct vm_area_struct * vma, struct vm_area_struct **prev, unsigned long start, unsigned long end, int behavior) { struct mm_struct * mm = vma->vm_mm; int error = 0; pgoff_t pgoff; int new_flags = vma->vm_flags; switch (behavior) { case MADV_NORMAL: new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ; break; case MADV_SEQUENTIAL: new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ; break; case MADV_RANDOM: new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ; break; case MADV_DONTFORK: new_flags |= VM_DONTCOPY; break; case MADV_DOFORK: new_flags &= ~VM_DONTCOPY; break; } if (new_flags == vma->vm_flags) { *prev = vma; goto out; } pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); *prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma)); if (*prev) { vma = *prev; goto success; } *prev = vma; if (start != vma->vm_start) { error = split_vma(mm, vma, start, 1); if (error) goto out; } if (end != vma->vm_end) { error = split_vma(mm, vma, end, 0); if (error) goto out; } success: /* * vm_flags is protected by the mmap_sem held in write mode. */ vma->vm_flags = new_flags; out: if (error == -ENOMEM) error = -EAGAIN; return error; } /* * Schedule all required I/O operations. Do not wait for completion. */ static long madvise_willneed(struct vm_area_struct * vma, struct vm_area_struct ** prev, unsigned long start, unsigned long end) { struct file *file = vma->vm_file; if (!file) return -EBADF; if (file->f_mapping->a_ops->get_xip_mem) { /* no bad return value, but ignore advice */ return 0; } *prev = vma; start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; if (end > vma->vm_end) end = vma->vm_end; end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; force_page_cache_readahead(file->f_mapping, file, start, end - start); return 0; } /* * Application no longer needs these pages. If the pages are dirty, * it's OK to just throw them away. The app will be more careful about * data it wants to keep. Be sure to free swap resources too. The * zap_page_range call sets things up for shrink_active_list to actually free * these pages later if no one else has touched them in the meantime, * although we could add these pages to a global reuse list for * shrink_active_list to pick up before reclaiming other pages. * * NB: This interface discards data rather than pushes it out to swap, * as some implementations do. This has performance implications for * applications like large transactional databases which want to discard * pages in anonymous maps after committing to backing store the data * that was kept in them. There is no reason to write this data out to * the swap area if the application is discarding it. * * An interface that causes the system to free clean pages and flush * dirty pages is already available as msync(MS_INVALIDATE). */ static long madvise_dontneed(struct vm_area_struct * vma, struct vm_area_struct ** prev, unsigned long start, unsigned long end) { *prev = vma; if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) return -EINVAL; if (unlikely(vma->vm_flags & VM_NONLINEAR)) { struct zap_details details = { .nonlinear_vma = vma, .last_index = ULONG_MAX, }; zap_page_range(vma, start, end - start, &details); } else zap_page_range(vma, start, end - start, NULL); return 0; } /* * Application wants to free up the pages and associated backing store. * This is effectively punching a hole into the middle of a file. * * NOTE: Currently, only shmfs/tmpfs is supported for this operation. * Other filesystems return -ENOSYS. */ static long madvise_remove(struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start, unsigned long end) { struct address_space *mapping; loff_t offset, endoff; int error; *prev = NULL; /* tell sys_madvise we drop mmap_sem */ if (vma->vm_flags & (VM_LOCKED|VM_NONLINEAR|VM_HUGETLB)) return -EINVAL; if (!vma->vm_file || !vma->vm_file->f_mapping || !vma->vm_file->f_mapping->host) { return -EINVAL; } if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE)) return -EACCES; mapping = vma->vm_file->f_mapping; offset = (loff_t)(start - vma->vm_start) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); endoff = (loff_t)(end - vma->vm_start - 1) + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); /* vmtruncate_range needs to take i_mutex and i_alloc_sem */ up_read(&current->mm->mmap_sem); error = vmtruncate_range(mapping->host, offset, endoff); down_read(&current->mm->mmap_sem); return error; } static long madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start, unsigned long end, int behavior) { long error; switch (behavior) { case MADV_DOFORK: if (vma->vm_flags & VM_IO) { error = -EINVAL; break; } case MADV_DONTFORK: case MADV_NORMAL: case MADV_SEQUENTIAL: case MADV_RANDOM: error = madvise_behavior(vma, prev, start, end, behavior); break; case MADV_REMOVE: error = madvise_remove(vma, prev, start, end); break; case MADV_WILLNEED: error = madvise_willneed(vma, prev, start, end); break; case MADV_DONTNEED: error = madvise_dontneed(vma, prev, start, end); break; default: BUG(); break; } return error; } static int madvise_behavior_valid(int behavior) { switch (behavior) { case MADV_DOFORK: case MADV_DONTFORK: case MADV_NORMAL: case MADV_SEQUENTIAL: case MADV_RANDOM: case MADV_REMOVE: case MADV_WILLNEED: case MADV_DONTNEED: return 1; default: return 0; } } /* * The madvise(2) system call. * * Applications can use madvise() to advise the kernel how it should * handle paging I/O in this VM area. The idea is to help the kernel * use appropriate read-ahead and caching techniques. The information * provided is advisory only, and can be safely disregarded by the * kernel without affecting the correct operation of the application. * * behavior values: * MADV_NORMAL - the default behavior is to read clusters. This * results in some read-ahead and read-behind. * MADV_RANDOM - the system should read the minimum amount of data * on any access, since it is unlikely that the appli- * cation will need more than what it asks for. * MADV_SEQUENTIAL - pages in the given range will probably be accessed * once, so they can be aggressively read ahead, and * can be freed soon after they are accessed. * MADV_WILLNEED - the application is notifying the system to read * some pages ahead. * MADV_DONTNEED - the application is finished with the given range, * so the kernel can free resources associated with it. * MADV_REMOVE - the application wants to free up the given range of * pages and associated backing store. * * return values: * zero - success * -EINVAL - start + len < 0, start is not page-aligned, * "behavior" is not a valid value, or application * is attempting to release locked or shared pages. * -ENOMEM - addresses in the specified range are not currently * mapped, or are outside the AS of the process. * -EIO - an I/O error occurred while paging in data. * -EBADF - map exists, but area maps something that isn't a file. * -EAGAIN - a kernel resource was temporarily unavailable. */ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) { unsigned long end, tmp; struct vm_area_struct * vma, *prev; int unmapped_error = 0; int error = -EINVAL; int write; size_t len; if (!madvise_behavior_valid(behavior)) return error; write = madvise_need_mmap_write(behavior); if (write) down_write(&current->mm->mmap_sem); else down_read(&current->mm->mmap_sem); if (start & ~PAGE_MASK) goto out; len = (len_in + ~PAGE_MASK) & PAGE_MASK; /* Check to see whether len was rounded up from small -ve to zero */ if (len_in && !len) goto out; end = start + len; if (end < start) goto out; error = 0; if (end == start) goto out; /* * If the interval [start,end) covers some unmapped address * ranges, just ignore them, but return -ENOMEM at the end. * - different from the way of handling in mlock etc. */ vma = find_vma_prev(current->mm, start, &prev); if (vma && start > vma->vm_start) prev = vma; for (;;) { /* Still start < end. */ error = -ENOMEM; if (!vma) goto out; /* Here start < (end|vma->vm_end). */ if (start < vma->vm_start) { unmapped_error = -ENOMEM; start = vma->vm_start; if (start >= end) goto out; } /* Here vma->vm_start <= start < (end|vma->vm_end) */ tmp = vma->vm_end; if (end < tmp) tmp = end; /* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */ error = madvise_vma(vma, &prev, start, tmp, behavior); if (error) goto out; start = tmp; if (prev && start < prev->vm_end) start = prev->vm_end; error = unmapped_error; if (start >= end) goto out; if (prev) vma = prev->vm_next; else /* madvise_remove dropped mmap_sem */ vma = find_vma(current->mm, start); } out: if (write) up_write(&current->mm->mmap_sem); else up_read(&current->mm->mmap_sem); return error; }


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