lkml.org 
[lkml]   [2021]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 5.4 25/33] kbuild: clamp SUBLEVEL to 255
Date
[ 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 f56442751d2c..e8a1989032bd 100644
--- a/Makefile
+++ b/Makefile
@@ -1175,9 +1175,15 @@ 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
\
 
 \ /
  Last update: 2021-03-02 17:10    [W:0.206 / U:24.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site