ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)
exists here in sub-directories of lib/ to keep the behavior of
commit 2464a609de ("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 <mingo@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
CFLAGS_REMOVE_<file>.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_<file> adds compiler flags per file.
[5] CFLAGS_REMOVE_<file> 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.o
The 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 build
I think commit 2464a609de ("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 <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit)
Tested-by: Anders Roxell <anders.roxell@linaro.org>
The commit e91c2518a5 ("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 <dan.carpenter@oracle.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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 <pmladek@suse.com>
Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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 <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
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 <joe.lawrence@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Petr Mladek <pmladek@suse.com>
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 API
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
