lili/qt5
1
0
Fork 0
mirror of git://code.qt.io/qt/qt5.git synced 2026-02-01 19:36:04 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fix failing assertions in QML when running under qemu

Browse Source 
Unfortunately the user-space emulation mode of qemu does not implement
MADV_DONTNEED, which is a feature that the garbage collector of QML
relies on. Patch is submitted to the qemu list and included here to fix
the imminent issue we're seeing.

Task-number: QTBUG-68349
Change-Id: I2bb15513a1e5a7ad03eeae98d77691336985a20f
Reviewed-by: Sami Nurmenniemi <sami.nurmenniemi@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This commit is contained in:
Simon Hausmann
2018-08-24 10:40:26 +02:00
committed by Liang Qi
parent 096780db16
commit 9a7555e54d
1 changed files with 72 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
coin/provisioning/qtci-linux-Ubuntu-16.04-x86_64/03-qemu.sh
View File

@@ -46,6 +46,78 @@ cd "$tempDir"
#latest commit from the master proven to work
git checkout c7f1cf01b8245762ca5864e835d84f6677ae8b1f
git submodule update --init pixman
patch -p1 <<EOT
From aad6a8f17dc7ad3681d2d98a01e474a8904a129b Mon Sep 17 00:00:00 2001
From: Simon Hausmann <simon.hausmann@qt.io>
Date: Fri, 24 Aug 2018 10:38:29 +0200
Subject: [PATCH] linux-user: add support for MADV_DONTNEED
Most flags to madvise() are just hints, so typically ignoring the
syscall and returning okay is fine. However applications exist that do
rely on MADV_DONTNEED behavior to guarantee that upon subsequent access
the mapping is refreshed from the backing file or zero for anonymous
mappings.
---
linux-user/mmap.c | 18 ++++++++++++++++++
linux-user/qemu.h | 1 +
linux-user/syscall.c | 6 +-----
3 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 61685bf79e..cb3069f27e 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -764,3 +764,16 @@ int target_msync(abi_ulong start, abi_ulong len, int flags)
start &= qemu_host_page_mask;
return msync(g2h(start), end - start, flags);
}
+
+int target_madvise(abi_ulong start, abi_ulong len, int flags)
+{
+ /* A straight passthrough may not be safe because qemu sometimes
+ turns private file-backed mappings into anonymous mappings.
+ Most flags are hints, except for MADV_DONTNEED that applications
+ may rely on to zero out pages, so we pass that through.
+ Otherwise returning success is ok. */
+ if (flags & MADV_DONTNEED) {
+ return madvise(g2h(start), len, MADV_DONTNEED);
+ }
+ return 0;
+}
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 4edd7d0c08..3c975909a1 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -429,6 +429,7 @@ int target_munmap(abi_ulong start, abi_ulong len);
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
abi_ulong new_size, unsigned long flags,
abi_ulong new_addr);
+int target_madvise(abi_ulong start, abi_ulong len, int flags);
int target_msync(abi_ulong start, abi_ulong len, int flags);
extern unsigned long last_brk;
extern abi_ulong mmap_next_start;
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 11a311f9db..94d8abc745 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -11148,11 +11148,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
#ifdef TARGET_NR_madvise
case TARGET_NR_madvise:
- /* A straight passthrough may not be safe because qemu sometimes
- turns private file-backed mappings into anonymous mappings.
- This will break MADV_DONTNEED.
- This is a hint, so ignoring and returning success is ok. */
- ret = get_errno(0);
+ ret = get_errno(target_madvise(arg1, arg2, arg3));
break;
#endif
#if TARGET_ABI_BITS == 32
--
2.17.1
EOT
./configure --target-list=arm-linux-user,aarch64-linux-user --static
make
sudo make install