From cc02e6e21aa5f2ac0defe8c15e5a9d024da6e73d Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Fri, 10 Jun 2022 11:04:36 +0200 Subject: [PATCH] s390/crash: add missing iterator advance in copy_oldmem_page() 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 Tested-by: Alexander Egorenkov Signed-off-by: Alexander Gordeev --- 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 a2c1c55..2534a31 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; } -- 2.7.4