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authorSasha Levin2021-02-05 22:50:32 -0500
committerMasahiro Yamada2021-02-16 12:01:45 +0900
commit9b82f13e7ef316cdc0a8858f1349f4defce3f9e0 (patch)
treeef2f3228421cb729a14a75950063009d95592f56
parent98cd6f521f1016171e9e263effc7d6edfbf61da1 (diff)
kbuild: clamp SUBLEVEL to 255
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>
-rw-r--r--Makefile12
1 files changed, 9 insertions, 3 deletions
diff --git a/Makefile b/Makefile
index 681bdb5d2f41..12607d389148 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