diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-02-12 10:48:33 -0800 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2021-02-16 11:04:53 +0000 |
| commit | 26bab757d41b853ea84cb52a10fafc9c10069658 (patch) | |
| tree | 90ec65d72b68d4f1cbd150369c704d0b9225e19c /linux-user/mmap.c | |
| parent | d9c5858570a57f374b71216c5da39ee381fa92f5 (diff) | |
linux-user: Introduce PAGE_ANON
Record whether the backing page is anonymous, or if it has file
backing. This will allow us to get close to the Linux AArch64
ABI for MTE, which allows tag memory only on ram-backed VMAs.
The real ABI allows tag memory on files, when those files are
on ram-backed filesystems, such as tmpfs. We will not be able
to implement that in QEMU linux-user.
Thankfully, anonymous memory for malloc arenas is the primary
consumer of this feature, so this restricted version should
still be of use.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'linux-user/mmap.c')
| -rw-r--r-- | linux-user/mmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c index ac0624f31a..c52b60482e 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -599,6 +599,9 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, } } the_end1: + if (flags & MAP_ANONYMOUS) { + page_flags |= PAGE_ANON; + } page_flags |= PAGE_RESET; page_set_flags(start, start + len, page_flags); the_end: |