diff mbox series

[wrynose] qemu: guard RESOLVE_CACHED strace flag

Message ID 20260819111828.4061079-1-deeratho@cisco.com
State New
Headers show
Series [wrynose] qemu: guard RESOLVE_CACHED strace flag | expand

Commit Message

Deepak Rathore -X (deeratho - E INFOCHIPS PRIVATE LIMITED at Cisco) Aug. 19, 2026, 11:18 a.m. UTC 
From: Himanshu Jadon <hjadon@cisco.com>

qemu-native build can fail on build hosts which have an older
linux/openat2.h header. The header is new enough to enable
HAVE_OPENAT2_H, but it does not have RESOLVE_CACHED because that flag
was added later in kernel 5.12.

In that case linux-user/strace.c tries to use RESOLVE_CACHED and build
fails with:

    error: 'RESOLVE_CACHED' undeclared here

This is mainly seen with qemu-native because it is built for the host
and can pick the host kernel UAPI header. The buildtools header may have
RESOLVE_CACHED, but native build still has to be safe with older host
headers also.

Add the upstream QEMU fix which checks RESOLVE_CACHED before using it.
This does not change anything on newer hosts. On older hosts QEMU just
does not print this one strace flag because the local header does not
know about it.

Signed-off-by: Himanshu Jadon <hjadon@cisco.com>
---
 meta/recipes-devtools/qemu/qemu.inc           |  1 +
 ...-if-RESOLVE_CACHED-flag-is-defined-b.patch | 38 +++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 meta/recipes-devtools/qemu/qemu/0012-linux-user-Check-if-RESOLVE_CACHED-flag-is-defined-b.patch
diff mbox series

Patch

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 60a5c62fe9..cc8f2ecdfa 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -41,6 +41,7 @@  SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://CVE-2026-0665.patch \
            file://CVE-2025-14876_p1.patch \
            file://CVE-2025-14876_p2.patch \
+           file://0012-linux-user-Check-if-RESOLVE_CACHED-flag-is-defined-b.patch \
            "
 # file index at download.qemu.org isn't reliable: https://gitlab.com/qemu-project/qemu-web/-/issues/9
 UPSTREAM_CHECK_URI = "https://www.qemu.org"
diff --git a/meta/recipes-devtools/qemu/qemu/0012-linux-user-Check-if-RESOLVE_CACHED-flag-is-defined-b.patch b/meta/recipes-devtools/qemu/qemu/0012-linux-user-Check-if-RESOLVE_CACHED-flag-is-defined-b.patch
new file mode 100644
index 0000000000..fc86d68e7d
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/0012-linux-user-Check-if-RESOLVE_CACHED-flag-is-defined-b.patch
@@ -0,0 +1,38 @@ 
+From 09e077b87eed754cc0aac0f54d193d49f978c93f Mon Sep 17 00:00:00 2001
+From: Frank Chang <frank.chang@sifive.com>
+Date: Thu, 12 Feb 2026 17:54:49 +0800
+Subject: [PATCH] linux-user: Check if RESOLVE_CACHED flag is defined before
+ using it
+
+Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/7ac4bded6af90a15a9562515743a789236b062d1]
+
+openat2.h was introduced in Linux kernel 5.6. However, RESOLVE_CACHED
+flag was only added in kernel 5.12 and later. Therefore, we need to check
+if RESOLVE_CACHED flag is defined before using it.
+
+Signed-off-by: Frank Chang <frank.chang@sifive.com>
+Reviewed-by: Helge Deller <deller@gmx.de>
+Signed-off-by: Helge Deller <deller@gmx.de>
+(cherry picked from commit 7ac4bded6af90a15a9562515743a789236b062d1)
+Signed-off-by: Himanshu Jadon <hjadon@cisco.com>
+---
+ linux-user/strace.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/linux-user/strace.c b/linux-user/strace.c
+index 758c5d32b6..a903b414fd 100644
+--- a/linux-user/strace.c
++++ b/linux-user/strace.c
+@@ -1125,7 +1125,9 @@ UNUSED static const struct flags openat2_resolve_flags[] = {
+     FLAG_GENERIC(RESOLVE_NO_SYMLINKS),
+     FLAG_GENERIC(RESOLVE_BENEATH),
+     FLAG_GENERIC(RESOLVE_IN_ROOT),
++#ifdef RESOLVE_CACHED
+     FLAG_GENERIC(RESOLVE_CACHED),
++#endif
+ #endif
+     FLAG_END,
+ };
+-- 
+2.35.6
+