From dcdc460767ed0a650e06ff256fa2a52ff1b57047 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 29 Apr 2021 13:27:03 +0200 Subject: [PATCH] exec: Relax range check in ram_block_discard_range() We want to make use of ram_block_discard_range() in the RAM block resize callback when growing a RAM block, *before* used_length is changed. Let's relax the check. As RAM blocks always mmap the whole max_length area, we cannot corrupt unrelated data. Reviewed-by: Peter Xu Signed-off-by: David Hildenbrand Message-Id: <20210429112708.12291-6-david@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- softmmu/physmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 813a3efe8efa..e1da81ed2f9c 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -3500,7 +3500,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) goto err; } - if ((start + length) <= rb->used_length) { + if ((start + length) <= rb->max_length) { bool need_madvise, need_fallocate; if (!QEMU_IS_ALIGNED(length, rb->page_size)) { error_report("ram_block_discard_range: Unaligned length: %zx", @@ -3567,7 +3567,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) } else { error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64 "/%zx/" RAM_ADDR_FMT")", - rb->idstr, start, length, rb->used_length); + rb->idstr, start, length, rb->max_length); } err: