qemu: Add some user space mmap tweaks to address musl 32 bit build issues

(From OE-Core rev: 18a37fcd7c0a64a339d1eea88b16ba75c017c5d5)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 57 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 286901fb1f..cfa65f99d0 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -27,6 +27,8 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://0001-Add-enable-disable-udev.patch \
            file://0001-qemu-Do-not-include-file-if-not-exists.patch \
            file://mingwfix.patch \
+           file://mmap.patch \
+           file://mmap2.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/mmap.patch b/meta/recipes-devtools/qemu/qemu/mmap.patch
new file mode 100644
index 0000000000..0f7d2ce04c
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/mmap.patch
@@ -0,0 +1,29 @@
+If mremap() is called without the MREMAP_MAYMOVE flag with a start address
+just before the end of memory (reserved_va) where new_size would exceed 
+GUEST_ADD_MAX, the assert(end - 1 <= GUEST_ADDR_MAX) in page_set_flags() 
+would trigger.
+
+Add an extra guard to the guest_range_valid() checks to prevent this and
+avoid asserting binaries when reserved_va is set.
+
+This meant a test case now gives the same behaviour regardless of whether
+reserved_va is set or not.
+
+Upstream-Status: Pending
+Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org
+
+Index: qemu-5.2.0/linux-user/mmap.c
+===================================================================
+--- qemu-5.2.0.orig/linux-user/mmap.c
++++ qemu-5.2.0/linux-user/mmap.c
+@@ -727,7 +727,9 @@ abi_long target_mremap(abi_ulong old_add
+ 
+     if (!guest_range_valid(old_addr, old_size) ||
+         ((flags & MREMAP_FIXED) &&
+-         !guest_range_valid(new_addr, new_size))) {
++         !guest_range_valid(new_addr, new_size)) ||
++        ((flags & MREMAP_MAYMOVE) == 0 &&
++         !guest_range_valid(old_addr, new_size))) {
+         errno = ENOMEM;
+         return -1;
+     }
diff --git a/meta/recipes-devtools/qemu/qemu/mmap2.patch b/meta/recipes-devtools/qemu/qemu/mmap2.patch
new file mode 100644
index 0000000000..9d40565938
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/mmap2.patch
@@ -0,0 +1,26 @@
+When using qemu-i386 to build qemux86 webkitgtk on musl, it sits in an
+infinite loop of mremap calls of ever decreasing/increasing addresses.
+
+I suspect something in the musl memory allocation code loops indefinitely
+if it only sees ENOMEM and only exits when it hits EFAULT.
+
+According to the docs, trying to mremap outside the address space
+can/should return EFAULT and changing this allows the build to succeed.
+Whether this should be fixed in qemu and/or musl, not sure.
+
+Upstream-Status: Pending
+Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org
+
+Index: qemu-5.2.0/linux-user/mmap.c
+===================================================================
+--- qemu-5.2.0.orig/linux-user/mmap.c
++++ qemu-5.2.0/linux-user/mmap.c
+@@ -727,7 +727,7 @@ abi_long target_mremap(abi_ulong old_add
+          !guest_range_valid(new_addr, new_size)) ||
+         ((flags & MREMAP_MAYMOVE) == 0 &&
+          !guest_range_valid(old_addr, new_size))) {
+-        errno = ENOMEM;
++        errno = EFAULT;
+         return -1;
+     }
+