diff options
author | Christoph Hellwig <hch@lst.de> | 2020-09-25 06:51:40 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-10-03 00:01:56 -0400 |
commit | bfdc59701d6d100c99c3b987bcffd1c204e393c8 (patch) | |
tree | a88294580eba288886916d767713789aa06507f2 /fs/aio.c | |
parent | fb041b598997d63c0f7d7305dfae70046bf66fe1 (diff) |
iov_iter: refactor rw_copy_check_uvector and import_iovec
Split rw_copy_check_uvector into two new helpers with more sensible
calling conventions:
- iovec_from_user copies a iovec from userspace either into the provided
stack buffer if it fits, or allocates a new buffer for it. Returns
the actually used iovec. It also verifies that iov_len does fit a
signed type, and handles compat iovecs if the compat flag is set.
- __import_iovec consolidates the native and compat versions of
import_iovec. It calls iovec_from_user, then validates each iovec
actually points to user addresses, and ensures the total length
doesn't overflow.
This has two major implications:
- the access_process_vm case loses the total lenght checking, which
wasn't required anyway, given that each call receives two iovecs
for the local and remote side of the operation, and it verifies
the total length on the local side already.
- instead of a single loop there now are two loops over the iovecs.
Given that the iovecs are cache hot this doesn't make a major
difference
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/aio.c')
0 files changed, 0 insertions, 0 deletions