Use autofree heap allocation instead of variable-length array on the
stack.
The codebase has very few VLAs, and if we can get rid of them all we
can make the compiler error on new additions. This is a defensive
measure against security bugs where an on-stack dynamic allocation
isn't correctly size-checked (e.g. CVE-2021-3527).
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20230824164706.2652277-1-peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
bdrv_pad_request() was the main user of qemu_iovec_init_extended().
HEAD^ has removed that use, so we can remove qemu_iovec_init_extended()
now.
The only remaining user is qemu_iovec_init_slice(), which can easily
inline the small part it really needs.
Note that qemu_iovec_init_extended() offered a memcpy() optimization to
initialize the new I/O vector. qemu_iovec_concat_iov(), which is used
to replace its functionality, does not, but calls qemu_iovec_add() for
every single element. If we decide this optimization was important, we
will need to re-implement it in qemu_iovec_concat_iov(), which might
also benefit its pre-existing users.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230411173418.19549-4-hreitz@redhat.com>
We want to inline qemu_iovec_init_extended() in block/io.c for padding
requests, and having access to qiov_slice() is useful for this. As a
public function, it is renamed to qemu_iovec_slice().
(We will need to count the number of I/O vector elements of a slice
there, and then later process this slice. Without qiov_slice(), we
would need to call qemu_iovec_subvec_niov(), and all further
IOV-processing functions may need to skip prefixing elements to
accomodate for a qiov_offset. Because qemu_iovec_subvec_niov()
internally calls qiov_slice(), we can just have the block/io.c code call
qiov_slice() itself, thus get the number of elements, and also create an
iovec array with the superfluous prefixing elements stripped, so the
following processing functions no longer need to skip them.)
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230411173418.19549-2-hreitz@redhat.com>
According to msdn documentation and Linux man pages, send() should try
to send as much as possible in blocking mode, while recv() may return
earlier with a smaller available amount, we should try to continue
send/recv from there.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20221006113657.2656108-3-marcandre.lureau@redhat.com>
Actually, we can't extend the io vector in all cases. Handle possible
MAX_IOV and size_t overflows.
For now add assertion to callers (actually they rely on success anyway)
and fix them in the following patch.
Add also some additional good assertions to qemu_iovec_init_slice()
while being here.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The iov_discard_front/back() operations are useful for parsing iovecs
but they modify the array elements. If the original array is needed
after parsing finishes there is currently no way to restore it.
Although g_memdup() can be used before performing destructive
iov_discard_front/back() operations, this is inefficient.
Introduce iov_discard_undo() to restore the array to the state prior to
an iov_discard_front/back() operation.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-Id: <20200917094455.822379-2-stefanha@redhat.com>
qemu_hexdump()'s pointer to the buffer and length of the
buffer are closely related arguments but are widely separated
in the argument list order (also, the format of <stdio.h>
function prototypes is usually to have the FILE* argument
coming first).
Reorder the arguments as "fp, prefix, buf, size" which is
more logical.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20200822180950.1343963-3-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Make it more obvious, that filling qiov corresponds to qiov allocation,
which in turn corresponds to total_niov calculation, based on mid_niov
(not mid_len). Still add an assertion to show that there should be no
difference.
[Added mingw "error: 'mid_iov' may be used uninitialized in this
function" compiler error fix suggested by Vladimir.
--Stefan]
Reported-by: Coverity (CID 1405302)
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190910090310.14032-1-vsementsov@virtuozzo.com
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190910090310.14032-1-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
fixup! util/ioc.c: try to reassure Coverity about qemu_iovec_init_extended
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
We'll need to check a part of qiov soon, so implement it now.
Optimization with align down to 4 * sizeof(long) is dropped due to:
1. It is strange: it aligns length of the buffer, but where is a
guarantee that buffer pointer is aligned itself?
2. buffer_is_zero() is a better place for optimizations and it has
them.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-3-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-3-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Introduce new initialization API, to create requests with padding. Will
be used in the following patch. New API uses qemu_iovec_init_buf if
resulting io vector has only one element, to avoid extra allocations.
So, we need to update qemu_iovec_destroy to support destroying such
QIOVs.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-2-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-2-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
In cases where iov_copy() is passed with zero 'bytes' argument and a
non-zero 'offset' argument, nothing gets copied - as expected.
However no copy iterations are performed, so 'offset' is left
unaltered, leading to the final assert(offset == 0) to fail.
Instead, change the loop condition to continue as long as 'offset || bytes',
similar to other iov_* functions.
This ensures 'offset' gets zeroed (even if no actual copy is made),
unless it is beyond end of source iov - which is asserted.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Message-Id: <1470130880-1050-1-git-send-email-shmulik.ladkani@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)
Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
qemu/iov.h includes qemu-common.h for QEMUIOVector stuff. Move all
that to qemu/iov.h and drop the ill-advised include. Include
qemu/iov.h where the QEMUIOVector stuff is now missing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memcpy can take a large amount of time for small reads and writes.
For virtio it is a common case that the first iovec can satisfy the
whole read or write. In that case, and if bytes is a constant to
avoid excessive growth of code, inline the first iteration
into the caller.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1450782213-14227-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-6-git-send-email-peter.maydell@linaro.org
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer,
for two reasons. One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.
This commit only touches allocations with size arguments of the form
sizeof(T).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
If the size of the scatter/gather list isn't a multiple of 512, the
number of sectors for the block layer request is rounded down, resulting
in a qiov that doesn't match the request length. Truncate the qiov to the
new length of the request.
This fixes the IDE qtest case /x86_64/ide/bmdma/short_prdt.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
qemu_iovec_compare() will be used to compare IOs vectors in quorum blkverify
mode. The patch extracts these functions in order to factorize the code.
Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Without this patch, iov_send_recv() never returns when do_send_recv()
returns zero.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
On FreeBSD libutil is used for openpty(), but it also provides a hexdump()
which conflicts with QEMU's.
Signed-off-by: Ed Maste <emaste@freebsd.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1368718348-15199-1-git-send-email-emaste@freebsd.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Commit e9d8fbf (qemu-file: do not use stdio for qemu_fdopen, 2013-03-27)
introduced a usage of writev, which mingw32 does not have. Even though
qemu_fdopen itself is not used on mingw32, the future-proof solution is
to add an implementation of it. This is simple and similar to how we
emulate sendmsg/recvmsg in util/iov.c.
Some files include osdep.h without qemu-common.h, so move the definition
of iovec to osdep.h too, and include osdep.h from qemu-common.h
unconditionally (protection against including files when NEED_CPU_H is
defined is not needed since the removal of AREG0).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Partial writes can still happen in sendmsg and recvmsg, if a
signal is received in the middle of a write. To handle this,
retry the operation with a new offset/bytes pair.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
"si" and "ei" are merged in a single variable.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not touch the "bytes" argument anymore. Instead, remember the
original length of the last iovec if we touch it, and restore it
afterwards.
This requires undoing the changes in opposite order. The previous
algorithm didn't care.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Once the initial part of the iov is dropped, it is not used anymore.
Modify iov/iovcnt directly instead of adjusting them with the "si"
variable.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Factor out the hexdumper functionality from iov for all to use. Useful for
creating verbose debug printfery that dumps packet data.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: faaac219c55ea586d3f748befaf5a2788fd271b8.1361853677.git.peter.crosthwaite@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Since these values can possibly be sent from guest (for hw/9pfs), do a sanity check
on them. A 9p write request with 0 bytes caused qemu to abort without this patch
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
