[PATCH AUTOSEL 5.10 36/47] kbuild: clamp SUBLEVEL to 255
From: Sasha Levin <sashal@kernel.org>
Date: 2021-03-02 13:23:32
Also in:
linux-kbuild, lkml
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
[ Upstream commit 9b82f13e7ef316cdc0a8858f1349f4defce3f9e0 ] Right now if SUBLEVEL becomes larger than 255 it will overflow into the territory of PATCHLEVEL, causing havoc in userspace that tests for specific kernel version. While userspace code tests for MAJOR and PATCHLEVEL, it doesn't test SUBLEVEL at any point as ABI changes don't happen in the context of stable tree. Thus, to avoid overflows, simply clamp SUBLEVEL to it's maximum value in the context of LINUX_VERSION_CODE. This does not affect "make kernelversion" and such. Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- Makefile | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index f700bdea626d..006011904269 100644
--- a/Makefile
+++ b/Makefile@@ -1247,9 +1247,15 @@ define filechk_utsrelease.h endef define filechk_version.h - echo \#define LINUX_VERSION_CODE $(shell \ - expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \ - echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))' + if [ $(SUBLEVEL) -gt 255 ]; then \ + echo \#define LINUX_VERSION_CODE $(shell \ + expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 255); \ + else \ + echo \#define LINUX_VERSION_CODE $(shell \ + expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \ + fi; \ + echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + \ + ((c) > 255 ? 255 : (c)))' endef $(version_h): FORCE
--
2.30.1