From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Mon, 25 Jul 2022 13:41:00 +0000 (+0200)
Subject: linux-user: Do not treat madvise()'s advice as a bitmask
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f71fa4e3bb22f534ee668e7f4bdf64e59c193afd;p=qemu.git

linux-user: Do not treat madvise()'s advice as a bitmask

Advice is enum, not flags. Doing (advice & MADV_DONTNEED) also matches
e.g. MADV_MERGEABLE.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220725134100.128035-1-iii@linux.ibm.com>
Fixes: 892a4f6a750a ("linux-user: Add partial support for MADV_DONTNEED")
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 4e7a6be6ee..edceaca4a8 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -891,7 +891,7 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice)
      * anonymous mappings. In this case passthrough is safe, so do it.
      */
     mmap_lock();
-    if ((advice & MADV_DONTNEED) &&
+    if (advice == MADV_DONTNEED &&
         can_passthrough_madv_dontneed(start, end)) {
         ret = get_errno(madvise(g2h_untagged(start), len, MADV_DONTNEED));
     }