Commit 01e1455139 for qemu.org

commit 01e1455139196cc8d6bcde7d2f918348a90f7f26
Author: Tao Tang <tangtao1634@phytium.com.cn>
Date:   Thu Aug 27 00:37:53 2026 +0800

    util/cpuinfo-aarch64: Fix build with older glibc headers

    Commit 761bfe07b2c9 ("util/cpuinfo-aarch64: Detect FEAT_CSSC")
    started using HWCAP2_CSSC unconditionally. This macro was added to
    glibc's AArch64 bits/hwcap.h during the glibc 2.38 development cycle,
    so AArch64 hosts with older headers fail to build.

    Follow the existing HWCAP2_BTI handling and define HWCAP2_CSSC to
    zero when it is not provided by system headers. Such environments
    simply do not use FEAT_CSSC host optimizations.

    This has been tested on an Ubuntu 22.04 aarch64 host with glibc 2.35.

    Fixes: 761bfe07b2c9 ("util/cpuinfo-aarch64: Detect FEAT_CSSC")
    Signed-off-by: Tao Tang <tangtao1634@phytium.com.cn>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
    Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
    Message-ID: <20260826163753.459661-1-tangtao1634@phytium.com.cn>

diff --git a/util/cpuinfo-aarch64.c b/util/cpuinfo-aarch64.c
index 4ce6deb7c8..e344676214 100644
--- a/util/cpuinfo-aarch64.c
+++ b/util/cpuinfo-aarch64.c
@@ -16,6 +16,9 @@
 # ifndef HWCAP2_BTI
 #  define HWCAP2_BTI 0  /* added in glibc 2.32 */
 # endif
+# ifndef HWCAP2_CSSC
+#  define HWCAP2_CSSC 0  /* added in glibc 2.38 */
+# endif
 #endif
 #ifdef CONFIG_ELF_AUX_INFO
 #include <sys/auxv.h>