From: Alexander Gordeev agordeev@linux.ibm.com
[ Upstream commit cc02e6e21aa5f2ac0defe8c15e5a9d024da6e73d ]
In case old memory was successfully copied the passed iterator should be advanced as well. Currently copy_oldmem_page() is always called with single-segment iterator. Should that ever change - copy_oldmem_user and copy_oldmem_kernel() functions would need a rework to deal with multi-segment iterators.
Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter") Reviewed-by: Alexander Egorenkov egorenar@linux.ibm.com Tested-by: Alexander Egorenkov egorenar@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kernel/crash_dump.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index a2c1c55daec0..2534a31d2550 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -219,6 +219,11 @@ ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, unsigned long src; int rc;
+ if (!(iter_is_iovec(iter) || iov_iter_is_kvec(iter))) + return -EINVAL; + /* Multi-segment iterators are not supported */ + if (iter->nr_segs > 1) + return -EINVAL; if (!csize) return 0; src = pfn_to_phys(pfn) + offset; @@ -228,6 +233,8 @@ ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, rc = copy_oldmem_user(iter->iov->iov_base, src, csize); else rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize); + if (!rc) + iov_iter_advance(iter, csize); return rc; }