qemu: Fix segfaults in webkitgtk:do_compile on debian11

Add a work around for segfaults we're seeing with qemu 8.2.0 when
compiling webkitgtk on debian 11 autobuilder workers.

The issue has been reported upstream to work out an official fix.

[YOCTO #15367]

(From OE-Core rev: 28ab691587e689872b2e2ddd210507cc2ae86f9b)

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

2 files changed, 48 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index ccb2880402..bc1440249d 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -34,6 +34,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://fixedmeson.patch \
            file://0001-vfio-Include-libgen.h-for-basename-API.patch \
            file://no-pip.patch \
+           file://fix_segv.patch \
            file://qemu-guest-agent.init \
            file://qemu-guest-agent.udev \
            "
diff --git a/meta/recipes-devtools/qemu/qemu/fix_segv.patch b/meta/recipes-devtools/qemu/qemu/fix_segv.patch
new file mode 100644
index 0000000000..da5ae87e0c
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/fix_segv.patch
@@ -0,0 +1,47 @@
+With qemu 8.2.0 we started seeing SEGV errors when compiling webkitgtk from
+usermode qemu:
+
+qemu-x86_64: QEMU internal SIGSEGV {code=MAPERR, addr=0x20}
+Segmentation fault
+
+By bisection, this was tracked down to:
+
+commit 7b7a3366e142d3baeb3fd1d3660a50e7956c19eb
+Author: Richard Henderson <richard.henderson@linaro.org>
+Date:   Tue Aug 8 20:02:19 2023 -0700
+
+    linux-user: Use walk_memory_regions for open_self_maps
+    
+    Replace the by-hand method of region identification with
+    the official user-exec interface.  Cross-check the region
+    provided to the callback with the interval tree from
+    read_self_maps().
+    
+    Tested-by: Helge Deller <deller@gmx.de>
+    Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
+    Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
+
+and specifically to 'n' being NULL. For now, just skip in that case
+until a proper fix can be identified.
+
+Reported upstream: https://www.mail-archive.com/qemu-devel@nongnu.org/msg1018813.html
+
+YOCTO #15367
+
+Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
+Upstream-Status: Pending
+
+diff --git a/linux-user/syscall.c b/linux-user/syscall.c
+index e384e14248..2577fb770d 100644
+--- a/linux-user/syscall.c
++++ b/linux-user/syscall.c
+@@ -8085,6 +8085,9 @@ static int open_self_maps_2(void *opaque, target_ulong guest_start,
+     while (1) {
+         IntervalTreeNode *n =
+             interval_tree_iter_first(d->host_maps, host_start, host_start);
++        if (!n) {
++            return 0;
++        }
+         MapInfo *mi = container_of(n, MapInfo, itree);
+         uintptr_t this_hlast = MIN(host_last, n->last);
+         target_ulong this_gend = h2g(this_hlast) + 1;