[PATCH v2] build: try to get kernel version from kernel source

[Ferdinand Thiessen]

When building the kernel modules, try to get the kernel
version from the kernel sources first. This fixes the
kernel modules installation directory if the target kernel
version differs from the host kernel version, like for
CI build or when packaging for linux distributions.

Signed-off-by: Ferdinand Thiessen <rpm at fthiessen.de>
---
 kernel/linux/meson.build | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/kernel/linux/meson.build b/kernel/linux/meson.build
index d8fb20c1c3..16a0948994 100644
--- a/kernel/linux/meson.build
+++ b/kernel/linux/meson.build
@@ -12,15 +12,21 @@ cross_args = []
 if not meson.is_cross_build()
     # native build
     kernel_version = run_command('uname', '-r', check: true).stdout().strip()
+    if kernel_source_dir != ''
+        # Try kernel release from sources first
+        r = run_command('make', '-s', '-C', kernel_source_dir, 'kernelrelease', check: false)
+        if r.returncode() == 0
+            kernel_version = r.stdout().strip()
+        endif
+    else
+        # use default path for native builds
+        kernel_source_dir = '/lib/modules/' + kernel_version + '/source'
+    endif
     kernel_install_dir = '/lib/modules/' + kernel_version + '/extra/dpdk'
     if kernel_build_dir == ''
         # use default path for native builds
         kernel_build_dir = '/lib/modules/' + kernel_version + '/build'
     endif
-    if kernel_source_dir == ''
-        # use default path for native builds
-        kernel_source_dir = '/lib/modules/' + kernel_version + '/source'
-    endif
 
     # test running make in kernel directory, using "make kernelversion"
     make_returncode = run_command('make', '-sC', kernel_build_dir,
-- 
2.35.1