Merge tag 'ftracetest-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
[firefly-linux-kernel-4.4.55.git] / mm / iov_iter.c
index 39ad7137f739ebac65fa43f1f393799c0743f3d1..a1599ca4ab0ed0e27917276102612d2877038b08 100644 (file)
@@ -3,6 +3,7 @@
 #include <linux/pagemap.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
+#include <net/checksum.h>
 
 #define iterate_iovec(i, n, __v, __p, skip, STEP) {    \
        size_t left;                                    \
        n = wanted - n;                                 \
 }
 
+#define iterate_kvec(i, n, __v, __p, skip, STEP) {     \
+       size_t wanted = n;                              \
+       __p = i->kvec;                                  \
+       __v.iov_len = min(n, __p->iov_len - skip);      \
+       if (likely(__v.iov_len)) {                      \
+               __v.iov_base = __p->iov_base + skip;    \
+               (void)(STEP);                           \
+               skip += __v.iov_len;                    \
+               n -= __v.iov_len;                       \
+       }                                               \
+       while (unlikely(n)) {                           \
+               __p++;                                  \
+               __v.iov_len = min(n, __p->iov_len);     \
+               if (unlikely(!__v.iov_len))             \
+                       continue;                       \
+               __v.iov_base = __p->iov_base;           \
+               (void)(STEP);                           \
+               skip = __v.iov_len;                     \
+               n -= __v.iov_len;                       \
+       }                                               \
+       n = wanted;                                     \
+}
+
 #define iterate_bvec(i, n, __v, __p, skip, STEP) {     \
        size_t wanted = n;                              \
        __p = i->bvec;                                  \
        n = wanted;                                     \
 }
 
-#define iterate_all_kinds(i, n, v, I, B) {                     \
+#define iterate_all_kinds(i, n, v, I, B, K) {                  \
        size_t skip = i->iov_offset;                            \
        if (unlikely(i->type & ITER_BVEC)) {                    \
                const struct bio_vec *bvec;                     \
                struct bio_vec v;                               \
                iterate_bvec(i, n, v, bvec, skip, (B))          \
+       } else if (unlikely(i->type & ITER_KVEC)) {             \
+               const struct kvec *kvec;                        \
+               struct kvec v;                                  \
+               iterate_kvec(i, n, v, kvec, skip, (K))          \
        } else {                                                \
                const struct iovec *iov;                        \
                struct iovec v;                                 \
@@ -70,7 +98,7 @@
        }                                                       \
 }
 
-#define iterate_and_advance(i, n, v, I, B) {                   \
+#define iterate_and_advance(i, n, v, I, B, K) {                        \
        size_t skip = i->iov_offset;                            \
        if (unlikely(i->type & ITER_BVEC)) {                    \
                const struct bio_vec *bvec;                     \
                }                                               \
                i->nr_segs -= bvec - i->bvec;                   \
                i->bvec = bvec;                                 \
+       } else if (unlikely(i->type & ITER_KVEC)) {             \
+               const struct kvec *kvec;                        \
+               struct kvec v;                                  \
+               iterate_kvec(i, n, v, kvec, skip, (K))          \
+               if (skip == kvec->iov_len) {                    \
+                       kvec++;                                 \
+                       skip = 0;                               \
+               }                                               \
+               i->nr_segs -= kvec - i->kvec;                   \
+               i->kvec = kvec;                                 \
        } else {                                                \
                const struct iovec *iov;                        \
                struct iovec v;                                 \
        i->iov_offset = skip;                                   \
 }
 
-static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)
-{
-       size_t skip, copy, left, wanted;
-       const struct iovec *iov;
-       char __user *buf;
-
-       if (unlikely(bytes > i->count))
-               bytes = i->count;
-
-       if (unlikely(!bytes))
-               return 0;
-
-       wanted = bytes;
-       iov = i->iov;
-       skip = i->iov_offset;
-       buf = iov->iov_base + skip;
-       copy = min(bytes, iov->iov_len - skip);
-
-       left = __copy_to_user(buf, from, copy);
-       copy -= left;
-       skip += copy;
-       from += copy;
-       bytes -= copy;
-       while (unlikely(!left && bytes)) {
-               iov++;
-               buf = iov->iov_base;
-               copy = min(bytes, iov->iov_len);
-               left = __copy_to_user(buf, from, copy);
-               copy -= left;
-               skip = copy;
-               from += copy;
-               bytes -= copy;
-       }
-
-       if (skip == iov->iov_len) {
-               iov++;
-               skip = 0;
-       }
-       i->count -= wanted - bytes;
-       i->nr_segs -= iov - i->iov;
-       i->iov = iov;
-       i->iov_offset = skip;
-       return wanted - bytes;
-}
-
-static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i)
-{
-       size_t skip, copy, left, wanted;
-       const struct iovec *iov;
-       char __user *buf;
-
-       if (unlikely(bytes > i->count))
-               bytes = i->count;
-
-       if (unlikely(!bytes))
-               return 0;
-
-       wanted = bytes;
-       iov = i->iov;
-       skip = i->iov_offset;
-       buf = iov->iov_base + skip;
-       copy = min(bytes, iov->iov_len - skip);
-
-       left = __copy_from_user(to, buf, copy);
-       copy -= left;
-       skip += copy;
-       to += copy;
-       bytes -= copy;
-       while (unlikely(!left && bytes)) {
-               iov++;
-               buf = iov->iov_base;
-               copy = min(bytes, iov->iov_len);
-               left = __copy_from_user(to, buf, copy);
-               copy -= left;
-               skip = copy;
-               to += copy;
-               bytes -= copy;
-       }
-
-       if (skip == iov->iov_len) {
-               iov++;
-               skip = 0;
-       }
-       i->count -= wanted - bytes;
-       i->nr_segs -= iov - i->iov;
-       i->iov = iov;
-       i->iov_offset = skip;
-       return wanted - bytes;
-}
-
 static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
@@ -360,7 +308,7 @@ done:
  */
 int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
 {
-       if (!(i->type & ITER_BVEC)) {
+       if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
                char __user *buf = i->iov->iov_base + i->iov_offset;
                bytes = min(bytes, i->iov->iov_len - i->iov_offset);
                return fault_in_pages_readable(buf, bytes);
@@ -374,10 +322,14 @@ void iov_iter_init(struct iov_iter *i, int direction,
                        size_t count)
 {
        /* It will get better.  Eventually... */
-       if (segment_eq(get_fs(), KERNEL_DS))
+       if (segment_eq(get_fs(), KERNEL_DS)) {
                direction |= ITER_KVEC;
-       i->type = direction;
-       i->iov = iov;
+               i->type = direction;
+               i->kvec = (struct kvec *)iov;
+       } else {
+               i->type = direction;
+               i->iov = iov;
+       }
        i->nr_segs = nr_segs;
        i->iov_offset = 0;
        i->count = count;
@@ -405,111 +357,78 @@ static void memzero_page(struct page *page, size_t offset, size_t len)
        kunmap_atomic(addr);
 }
 
-static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
-       size_t skip, copy, wanted;
-       const struct bio_vec *bvec;
-
+       char *from = addr;
        if (unlikely(bytes > i->count))
                bytes = i->count;
 
        if (unlikely(!bytes))
                return 0;
 
-       wanted = bytes;
-       bvec = i->bvec;
-       skip = i->iov_offset;
-       copy = min_t(size_t, bytes, bvec->bv_len - skip);
+       iterate_and_advance(i, bytes, v,
+               __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
+                              v.iov_len),
+               memcpy_to_page(v.bv_page, v.bv_offset,
+                              (from += v.bv_len) - v.bv_len, v.bv_len),
+               memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
+       )
 
-       memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy);
-       skip += copy;
-       from += copy;
-       bytes -= copy;
-       while (bytes) {
-               bvec++;
-               copy = min(bytes, (size_t)bvec->bv_len);
-               memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, copy);
-               skip = copy;
-               from += copy;
-               bytes -= copy;
-       }
-       if (skip == bvec->bv_len) {
-               bvec++;
-               skip = 0;
-       }
-       i->count -= wanted - bytes;
-       i->nr_segs -= bvec - i->bvec;
-       i->bvec = bvec;
-       i->iov_offset = skip;
-       return wanted - bytes;
+       return bytes;
 }
+EXPORT_SYMBOL(copy_to_iter);
 
-static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i)
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
-       size_t skip, copy, wanted;
-       const struct bio_vec *bvec;
-
+       char *to = addr;
        if (unlikely(bytes > i->count))
                bytes = i->count;
 
        if (unlikely(!bytes))
                return 0;
 
-       wanted = bytes;
-       bvec = i->bvec;
-       skip = i->iov_offset;
-
-       copy = min(bytes, bvec->bv_len - skip);
-
-       memcpy_from_page(to, bvec->bv_page, bvec->bv_offset + skip, copy);
-
-       to += copy;
-       skip += copy;
-       bytes -= copy;
+       iterate_and_advance(i, bytes, v,
+               __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
+                                v.iov_len),
+               memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+                                v.bv_offset, v.bv_len),
+               memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+       )
 
-       while (bytes) {
-               bvec++;
-               copy = min(bytes, (size_t)bvec->bv_len);
-               memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, copy);
-               skip = copy;
-               to += copy;
-               bytes -= copy;
-       }
-       if (skip == bvec->bv_len) {
-               bvec++;
-               skip = 0;
-       }
-       i->count -= wanted;
-       i->nr_segs -= bvec - i->bvec;
-       i->bvec = bvec;
-       i->iov_offset = skip;
-       return wanted;
+       return bytes;
 }
+EXPORT_SYMBOL(copy_from_iter);
 
-static size_t copy_page_to_iter_bvec(struct page *page, size_t offset,
-                                       size_t bytes, struct iov_iter *i)
+size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 {
-       void *kaddr = kmap_atomic(page);
-       size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i);
-       kunmap_atomic(kaddr);
-       return wanted;
-}
+       char *to = addr;
+       if (unlikely(bytes > i->count))
+               bytes = i->count;
 
-static size_t copy_page_from_iter_bvec(struct page *page, size_t offset,
-                                       size_t bytes, struct iov_iter *i)
-{
-       void *kaddr = kmap_atomic(page);
-       size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i);
-       kunmap_atomic(kaddr);
-       return wanted;
+       if (unlikely(!bytes))
+               return 0;
+
+       iterate_and_advance(i, bytes, v,
+               __copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+                                        v.iov_base, v.iov_len),
+               memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+                                v.bv_offset, v.bv_len),
+               memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+       )
+
+       return bytes;
 }
+EXPORT_SYMBOL(copy_from_iter_nocache);
 
 size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
-       if (i->type & ITER_BVEC)
-               return copy_page_to_iter_bvec(page, offset, bytes, i);
-       else
+       if (i->type & (ITER_BVEC|ITER_KVEC)) {
+               void *kaddr = kmap_atomic(page);
+               size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
+               kunmap_atomic(kaddr);
+               return wanted;
+       } else
                return copy_page_to_iter_iovec(page, offset, bytes, i);
 }
 EXPORT_SYMBOL(copy_page_to_iter);
@@ -517,31 +436,16 @@ EXPORT_SYMBOL(copy_page_to_iter);
 size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
-       if (i->type & ITER_BVEC)
-               return copy_page_from_iter_bvec(page, offset, bytes, i);
-       else
+       if (i->type & (ITER_BVEC|ITER_KVEC)) {
+               void *kaddr = kmap_atomic(page);
+               size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+               kunmap_atomic(kaddr);
+               return wanted;
+       } else
                return copy_page_from_iter_iovec(page, offset, bytes, i);
 }
 EXPORT_SYMBOL(copy_page_from_iter);
 
-size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
-{
-       if (i->type & ITER_BVEC)
-               return copy_to_iter_bvec(addr, bytes, i);
-       else
-               return copy_to_iter_iovec(addr, bytes, i);
-}
-EXPORT_SYMBOL(copy_to_iter);
-
-size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
-{
-       if (i->type & ITER_BVEC)
-               return copy_from_iter_bvec(addr, bytes, i);
-       else
-               return copy_from_iter_iovec(addr, bytes, i);
-}
-EXPORT_SYMBOL(copy_from_iter);
-
 size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 {
        if (unlikely(bytes > i->count))
@@ -552,7 +456,8 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 
        iterate_and_advance(i, bytes, v,
                __clear_user(v.iov_base, v.iov_len),
-               memzero_page(v.bv_page, v.bv_offset, v.bv_len)
+               memzero_page(v.bv_page, v.bv_offset, v.bv_len),
+               memset(v.iov_base, 0, v.iov_len)
        )
 
        return bytes;
@@ -567,7 +472,8 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
                __copy_from_user_inatomic((p += v.iov_len) - v.iov_len,
                                          v.iov_base, v.iov_len),
                memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
-                                v.bv_offset, v.bv_len)
+                                v.bv_offset, v.bv_len),
+               memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
        )
        kunmap_atomic(kaddr);
        return bytes;
@@ -576,7 +482,7 @@ EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
 
 void iov_iter_advance(struct iov_iter *i, size_t size)
 {
-       iterate_and_advance(i, size, v, 0, 0)
+       iterate_and_advance(i, size, v, 0, 0, 0)
 }
 EXPORT_SYMBOL(iov_iter_advance);
 
@@ -594,6 +500,19 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
 }
 EXPORT_SYMBOL(iov_iter_single_seg_count);
 
+void iov_iter_kvec(struct iov_iter *i, int direction,
+                       const struct kvec *iov, unsigned long nr_segs,
+                       size_t count)
+{
+       BUG_ON(!(direction & ITER_KVEC));
+       i->type = direction;
+       i->kvec = (struct kvec *)iov;
+       i->nr_segs = nr_segs;
+       i->iov_offset = 0;
+       i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_kvec);
+
 unsigned long iov_iter_alignment(const struct iov_iter *i)
 {
        unsigned long res = 0;
@@ -604,7 +523,8 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 
        iterate_all_kinds(i, size, v,
                (res |= (unsigned long)v.iov_base | v.iov_len, 0),
-               res |= v.bv_offset | v.bv_len
+               res |= v.bv_offset | v.bv_len,
+               res |= (unsigned long)v.iov_base | v.iov_len
        )
        return res;
 }
@@ -639,6 +559,8 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
                *start = v.bv_offset;
                get_page(*pages = v.bv_page);
                return v.bv_len;
+       }),({
+               return -EFAULT;
        })
        )
        return 0;
@@ -691,12 +613,102 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
                        return -ENOMEM;
                get_page(*p = v.bv_page);
                return v.bv_len;
+       }),({
+               return -EFAULT;
        })
        )
        return 0;
 }
 EXPORT_SYMBOL(iov_iter_get_pages_alloc);
 
+size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+                              struct iov_iter *i)
+{
+       char *to = addr;
+       __wsum sum, next;
+       size_t off = 0;
+       if (unlikely(bytes > i->count))
+               bytes = i->count;
+
+       if (unlikely(!bytes))
+               return 0;
+
+       sum = *csum;
+       iterate_and_advance(i, bytes, v, ({
+               int err = 0;
+               next = csum_and_copy_from_user(v.iov_base, 
+                                              (to += v.iov_len) - v.iov_len,
+                                              v.iov_len, 0, &err);
+               if (!err) {
+                       sum = csum_block_add(sum, next, off);
+                       off += v.iov_len;
+               }
+               err ? v.iov_len : 0;
+       }), ({
+               char *p = kmap_atomic(v.bv_page);
+               next = csum_partial_copy_nocheck(p + v.bv_offset,
+                                                (to += v.bv_len) - v.bv_len,
+                                                v.bv_len, 0);
+               kunmap_atomic(p);
+               sum = csum_block_add(sum, next, off);
+               off += v.bv_len;
+       }),({
+               next = csum_partial_copy_nocheck(v.iov_base,
+                                                (to += v.iov_len) - v.iov_len,
+                                                v.iov_len, 0);
+               sum = csum_block_add(sum, next, off);
+               off += v.iov_len;
+       })
+       )
+       *csum = sum;
+       return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter);
+
+size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum,
+                            struct iov_iter *i)
+{
+       char *from = addr;
+       __wsum sum, next;
+       size_t off = 0;
+       if (unlikely(bytes > i->count))
+               bytes = i->count;
+
+       if (unlikely(!bytes))
+               return 0;
+
+       sum = *csum;
+       iterate_and_advance(i, bytes, v, ({
+               int err = 0;
+               next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
+                                            v.iov_base, 
+                                            v.iov_len, 0, &err);
+               if (!err) {
+                       sum = csum_block_add(sum, next, off);
+                       off += v.iov_len;
+               }
+               err ? v.iov_len : 0;
+       }), ({
+               char *p = kmap_atomic(v.bv_page);
+               next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
+                                                p + v.bv_offset,
+                                                v.bv_len, 0);
+               kunmap_atomic(p);
+               sum = csum_block_add(sum, next, off);
+               off += v.bv_len;
+       }),({
+               next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
+                                                v.iov_base,
+                                                v.iov_len, 0);
+               sum = csum_block_add(sum, next, off);
+               off += v.iov_len;
+       })
+       )
+       *csum = sum;
+       return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_to_iter);
+
 int iov_iter_npages(const struct iov_iter *i, int maxpages)
 {
        size_t size = i->count;
@@ -715,6 +727,12 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
                npages++;
                if (npages >= maxpages)
                        return maxpages;
+       }),({
+               unsigned long p = (unsigned long)v.iov_base;
+               npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+                       - p / PAGE_SIZE;
+               if (npages >= maxpages)
+                       return maxpages;
        })
        )
        return npages;