10 Aug, 2020
3 commits
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Pull Kbuild updates from Masahiro Yamada:
- run the checker (e.g. sparse) after the compiler
- remove unneeded cc-option tests for old compiler flags
- fix tar-pkg to install dtbs
- introduce ccflags-remove-y and asflags-remove-y syntax
- allow to trace functions in sub-directories of lib/
- introduce hostprogs-always-y and userprogs-always-y syntax
- various Makefile cleanups
* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
kbuild: introduce hostprogs-always-y and userprogs-always-y
kbuild: sort hostprogs before passing it to ifneq
kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
kbuild: Replace HTTP links with HTTPS ones
kbuild: trace functions in subdirectories of lib/
kbuild: introduce ccflags-remove-y and asflags-remove-y
kbuild: do not export LDFLAGS_vmlinux
kbuild: always create directories of targets
powerpc/boot: add DTB to 'targets'
kbuild: buildtar: add dtbs support
kbuild: remove cc-option test of -ffreestanding
kbuild: remove cc-option test of -fno-stack-protector
Revert "kbuild: Create directory for target DTB"
kbuild: run the checker after the compiler -
ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)
exists here in sub-directories of lib/ to keep the behavior of
commit 2464a609ded0 ("ftrace: do not trace library functions").Since that commit, not only the objects in lib/ but also the ones in
the sub-directories are excluded from ftrace (although the commit
description did not explicitly mention this).However, most of library functions in sub-directories are not so hot.
Re-add them to ftrace.Going forward, only the objects right under lib/ will be excluded.
Cc: Ingo Molnar
Signed-off-by: Masahiro Yamada
Acked-by: Steven Rostedt (VMware) -
CFLAGS_REMOVE_.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a directory.Add ccflags-remove-y and asflags-remove-y to make it easily.
Use ccflags-remove-y to clean up some Makefiles.
The add/remove order works as follows:
[1] KBUILD_CFLAGS specifies compiler flags used globally
[2] ccflags-y adds compiler flags for all objects in the
current Makefile[3] ccflags-remove-y removes compiler flags for all objects in the
current Makefile (New feature)[4] CFLAGS_ adds compiler flags per file.
[5] CFLAGS_REMOVE_ removes compiler flags per file.
Having [3] before [4] allows us to remove flags from most (but not all)
objects in the current Makefile.For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE)
from all objects in the directory, then adds it back to
trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.oThe same applies to lib/livepatch/Makefile.
Please note ccflags-remove-y has no effect to the sub-directories.
In contrast, the previous notation got rid of compiler flags also from
all the sub-directories.The following are not affected because they have no sub-directories:
arch/arm/boot/compressed/
arch/powerpc/xmon/
arch/sh/
kernel/trace/However, lib/ has several sub-directories.
To keep the behavior, I added ccflags-remove-y to all Makefiles
in subdirectories of lib/, except the following:lib/vdso/Makefile - Kbuild does not descend into this Makefile
lib/raid/test/Makefile - This is not used for the kernel buildI think commit 2464a609ded0 ("ftrace: do not trace library functions")
excluded too much. In the next commit, I will remove ccflags-remove-y
from the sub-directories of lib/.Suggested-by: Sami Tolvanen
Signed-off-by: Masahiro Yamada
Acked-by: Steven Rostedt (VMware)
Acked-by: Michael Ellerman (powerpc)
Acked-by: Brendan Higgins (KUnit)
Tested-by: Anders Roxell
08 Jun, 2020
4 commits
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In some cases, when an error occurs during testing and the main test
routine returns, a memory leak occurs via leaving previously registered
shadow variables allocated in the kernel as well as shadow_ptr list
elements. From now on, in case of error, remove all allocated shadow
variables and shadow_ptr struct elements.Signed-off-by: Yannick Cote
Reviewed-by: Petr Mladek
Reviewed-by: Kamalesh Babulal
Acked-by: Miroslav Benes
Acked-by: Joe Lawrence
Signed-off-by: Petr Mladek
Link: https://lore.kernel.org/r/20200603182058.109470-5-ycote@redhat.com -
This change makes the test feel more familiar with narrowing to a
typical usage by operating on a number of identical structure instances
and populating the same two new shadow variables symmetrically while
keeping the same testing and verification criteria for the extra
variables.Signed-off-by: Yannick Cote
Reviewed-by: Kamalesh Babulal
Reviewed-by: Petr Mladek
Acked-by: Miroslav Benes
Acked-by: Joe Lawrence
Signed-off-by: Petr Mladek
Link: https://lore.kernel.org/r/20200603182058.109470-4-ycote@redhat.com -
The initial idea was to make a change to please cppcheck and remove void
pointer arithmetics found a few times:portability: 'obj' is of type 'void *'. When using void pointers
in calculations, the behaviour is undefined.
[arithOperationsOnVoidPointer]The rest of the changes are to help make the test read as an example
while continuing to verify the shadow variable code. The logic of the
test is unchanged but restructured to use descriptive names.Signed-off-by: Yannick Cote
Reviewed-by: Petr Mladek
Reviewed-by: Kamalesh Babulal
Acked-by: Miroslav Benes
Acked-by: Joe Lawrence
Signed-off-by: Petr Mladek
Link: https://lore.kernel.org/r/20200603182058.109470-3-ycote@redhat.com -
The test-klp-callbacks script includes a few tests which rely on kernel
task timings that may not always execute as expected under system load.
These may generate out of sequence kernel log messages that result in
test failure.Instead of using sleep timing windows to orchestrate these tests, add a
block_transition module parameter to communicate the test purpose and
utilize flush_queue() to serialize the test module's task output.Signed-off-by: Joe Lawrence
Reviewed-by: Petr Mladek
Acked-by: Miroslav Benes
Signed-off-by: Petr Mladek
Link: https://lore.kernel.org/r/20200603182058.109470-2-ycote@redhat.com
17 Jan, 2020
2 commits
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The commit e91c2518a5d22a ("livepatch: Initialize shadow variables
safely by a custom callback") leads to the following static checker
warning:samples/livepatch/livepatch-shadow-fix1.c:86 livepatch_fix1_dummy_alloc()
error: 'klp_shadow_alloc()' 'leak' too small (4 vs 8)It is because klp_shadow_alloc() is used a wrong way:
int *leak;
shadow_leak = klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL,
shadow_leak_ctor, leak);The code is supposed to store the "leak" pointer into the shadow variable.
3rd parameter correctly passes size of the data (size of pointer). But
the 5th parameter is wrong. It should pass pointer to the data (pointer
to the pointer) but it passes the pointer directly.It works because shadow_leak_ctor() handle "ctor_data" as the data
instead of pointer to the data. But it is semantically wrong and
confusing.The same problem is also in the module used by selftests. In this case,
"pvX" variables are introduced. They represent the data stored in
the shadow variables.Reported-by: Dan Carpenter
Signed-off-by: Petr Mladek
Reviewed-by: Joe Lawrence
Acked-by: Miroslav Benes
Reviewed-by: Kamalesh Babulal
Signed-off-by: Jiri Kosina -
The shadow variable selftest is quite tricky. Especially it is problematic
to understand what values are stored, returned, and printed.Make it easier to understand by using "int *var, **sv" variables
consistently everywhere instead of the generic "void *", "ret",
and "ctor_data".Signed-off-by: Petr Mladek
Reviewed-by: Joe Lawrence
Acked-by: Miroslav Benes
Reviewed-by: Kamalesh Babulal
Signed-off-by: Jiri Kosina
01 Nov, 2019
1 commit
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Four selftests for the new API.
Link: http://lkml.kernel.org/r/20191030154313.13263-6-pmladek@suse.com
To: Jiri Kosina
Cc: Kamalesh Babulal
Cc: Nicolai Stange
Cc: live-patching@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Miroslav Benes
Acked-by: Joe Lawrence
Acked-by: Josh Poimboeuf
Signed-off-by: Petr Mladek
06 Feb, 2019
2 commits
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Add proper error handling when allocating or getting shadow variables
in the selftest. It prevents an invalid pointer access in some situations.
It shows the good programming practice in the others.The error codes are just the best guess and specific for this particular
test. In general, klp_shadow_alloc() returns NULL also when the given
shadow variable has already been allocated. In addition, both
klp_shadow_alloc() and klp_shadow_get_or_alloc() might fail from
other reasons when the constructor fails.Note, that the error code is not really important even in the real life.
The use of shadow variables should be transparent for the original
livepatched code.Acked-by: Miroslav Benes
Acked-by: Joe Lawrence
Signed-off-by: Petr Mladek -
Fixes the following smatch warning:
lib/livepatch/test_klp_shadow_vars.c:47 ptr_id() warn: returning -1 instead of -ENOMEM is sloppy
Signed-off-by: Joe Lawrence
Acked-by: Miroslav Benes
Signed-off-by: Petr Mladek
12 Jan, 2019
1 commit
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Add a few livepatch modules and simple target modules that the included
regression suite can run tests against:- basic livepatching (multiple patches, atomic replace)
- pre/post (un)patch callbacks
- shadow variable APISigned-off-by: Joe Lawrence
Signed-off-by: Petr Mladek
Tested-by: Miroslav Benes
Tested-by: Alice Ferrazzi
Acked-by: Joe Lawrence
Acked-by: Josh Poimboeuf
Signed-off-by: Jiri Kosina