Use page_check_range instead, which uses the interval tree
instead of checking each page individually.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/mmap.c | 24 +++---------------------
1 file changed, 3 insertions(+), 21 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index e6463ecd8d..a2bef1ebe6 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -898,23 +898,6 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong
old_size,
return new_addr;
}
-static bool can_passthrough_madvise(abi_ulong start, abi_ulong end)
-{
- ulong addr;
-
- if ((start | end) & ~qemu_host_page_mask) {
- return false;
- }
-
- for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
- if (!(page_get_flags(addr) & PAGE_PASSTHROUGH)) {
- return false;
- }
- }
-
- return true;
-}
-
abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice)
{
abi_ulong len, end;
@@ -964,9 +947,8 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in,
int advice)
*
* A straight passthrough for those may not be safe because qemu sometimes
* turns private file-backed mappings into anonymous mappings.
- * can_passthrough_madvise() helps to check if a passthrough is possible by
- * comparing mappings that are known to have the same semantics in the host
- * and the guest. In this case passthrough is safe.
+ * If all guest pages have PAGE_PASSTHROUGH set, mappings have the
+ * same semantics for the host as for the guest.
*
* We pass through MADV_WIPEONFORK and MADV_KEEPONFORK if possible and
* return failure if not.
@@ -984,7 +966,7 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in,
int advice)
ret = -EINVAL;
/* fall through */
case MADV_DONTNEED:
- if (can_passthrough_madvise(start, end)) {
+ if (page_check_range(start, len, PAGE_PASSTHROUGH)) {
ret = get_errno(madvise(g2h_untagged(start), len, advice));
if ((advice == MADV_DONTNEED) && (ret == 0)) {
page_reset_target_data(start, start + len - 1);
--
2.34.1
