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authorDan Williams <dan.j.williams@intel.com>2018-05-03 17:06:31 -0700
committerIngo Molnar <mingo@kernel.org>2018-05-15 08:32:42 +0200
commit8780356ef630aa577fd4daa49e49b79674711fae (patch)
tree104e73665ca067e220a59a70daee5539e50e0c99 /lib
parent12c89130a56ae8e8d85db753d70333c4ee0ea835 (diff)
downloadlinux-0-day-8780356ef630aa577fd4daa49e49b79674711fae.tar.gz
linux-0-day-8780356ef630aa577fd4daa49e49b79674711fae.tar.xz
x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()
Use the updated memcpy_mcsafe() implementation to define copy_user_mcsafe() and copy_to_iter_mcsafe(). The most significant difference from typical copy_to_iter() is that the ITER_KVEC and ITER_BVEC iterator types can fail to complete a full transfer. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539239150.31796.9189779163576449784.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/iov_iter.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 970212670b6a..70ebc8ede143 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -573,6 +573,67 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(_copy_to_iter);
+#ifdef CONFIG_ARCH_HAS_UACCESS_MCSAFE
+static int copyout_mcsafe(void __user *to, const void *from, size_t n)
+{
+ if (access_ok(VERIFY_WRITE, to, n)) {
+ kasan_check_read(from, n);
+ n = copy_to_user_mcsafe((__force void *) to, from, n);
+ }
+ return n;
+}
+
+static unsigned long memcpy_mcsafe_to_page(struct page *page, size_t offset,
+ const char *from, size_t len)
+{
+ unsigned long ret;
+ char *to;
+
+ to = kmap_atomic(page);
+ ret = memcpy_mcsafe(to + offset, from, len);
+ kunmap_atomic(to);
+
+ return ret;
+}
+
+size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
+{
+ const char *from = addr;
+ unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
+
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return 0;
+ }
+ if (iter_is_iovec(i))
+ might_fault();
+ iterate_and_advance(i, bytes, v,
+ copyout_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+ ({
+ rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len);
+ if (rem) {
+ curr_addr = (unsigned long) from;
+ bytes = curr_addr - s_addr - rem;
+ return bytes;
+ }
+ }),
+ ({
+ rem = memcpy_mcsafe(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len);
+ if (rem) {
+ curr_addr = (unsigned long) from;
+ bytes = curr_addr - s_addr - rem;
+ return bytes;
+ }
+ })
+ )
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
+#endif /* CONFIG_ARCH_HAS_UACCESS_MCSAFE */
+
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;