Bump the submodule reference and modify the unit test Makefile to check
all supported architectures.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Upstream v5.14+ kernel change a358f40600b3 ("once: implement
DO_ONCE_LITE for non-fast-path "do once" functionality") consolidated a
bunch of do-once macros into a common macro:
#define DO_ONCE_LITE_IF(condition, func, ...) \
({ \
static bool __section(".data.once") __already_done; \
...
which replaced static local variable __warned with __already_done.
Update any __warned static local checks to also look for the new
__already_done variable as well.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Building data-read-mostly.patch on rhel-9.0-beta for ppc64le leads to a
segmentation fault:
Program received signal SIGSEGV, Segmentation fault.
kpatch_check_relocations (kelf=0x10040490) at create-diff-object.c:2571
2571 sdata = rela->sym->sec->data;
(gdb) bt
(gdb) p rela->sym->sec->data
Cannot access memory at address 0x160000007e
Valgrind narrows the problem down to invalid reads through rela->sym in
kpatch-check-relocations().
The culprits are kpatch_create_intermediate_sections(), which marks
symbols referenced by rela sections that are now dynrelas to be
stripped, and kpatch_strip_unneeded_syms(), which removes and frees
them.
The problem with the symbol stripping is that multiple relas may
reference the same ELF symbol. If any remaining relocation references a
shared symbol, we must keep it.
Replace the symbol->strip boolean with an enumeration:
SYMBOL_DEFAULT - initial value, symbol usage unknown
SYMBOL_USED - symbol is definitely used by a rela
SYMBOL_STRIP - symbol was only referenced by dynrela(s)
Allow transitions from SYMBOL_DEFAULT to SYMBOL_* and SYMBOL_STRIP to
SYMBOL_USED, but _not_ SYMBOL_USED to SYMBOL_*.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
For each printk() call site, CONFIG_PRINTK_INDEX makes a static local
struct named `_entry`, and then adds a pointer to it in the
`.printk_index` section.
When regenerating the `.printk_index` section for the patch module, we
only need to include those entries which are referenced by included
functions. Luckily this is a common pattern already used by several
other "special" sections. Add `.printk_index` to the special section
handling logic.
Fixes: #1206
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
CONFIG_PRINTK_INDEX creates a static local struct variable named
`_entry` for every call site to printk(). The initializer for that
struct assigns the `__LINE__` macro to one of its fields.
Similarly to the WARN macro's usage [1] of `__LINE__`, it causes
problems because it results in the line number getting directly embedded
in the struct. If a line is added or removed higher up in the source
file, the `_entry` struct changes accordingly due to a change in the
printk() call site line number.
`_entry` is similar to other "special" static locals, in that we don't
need to correlate the patched version with the original version. We can
instead just ignore any changes to it.
Any substantial (non-line-number) change to the `_entry` struct would be
a second-order (dependent) effect of a first-order code change, which
would be detected using other means. In that case the patched version
of `_entry` will be included, due to being referenced by the changed
function.
Fixes: #1206
[1] See kpatch_line_macro_change_only()
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Add the __mcount_loc section on ppc64le. It has pointers to all the
mcount calls. This will enable the ftrace hook to be used for patched
functions.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> (rebased)
Some theoretically unchanged functions can have undesired changes if the
compiler decides to perform inlining in a different way (e.g. because of
newly added references). In such a case, it can be useful to discard
changes to functions that don't actually need modification.
Sadly, this currently doesn't work for functions missing the ftrace hook
(e.g. notrace code) as presence of the hook is checked before
identifying elements to ignore.
Look for functions/sections to ignore earlier.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
The current code to find the twin of a local static variable allows two
variables of the same name to be wrongly matched with the other's twin.
While there isn't a magic formula to avoid this, make stricter
requirements for twining static local from the original object with
a symbol from the patched object. This reduces the risk of erroneous
matches.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
The RHEL powerpc kernel is compiled with -O3, which triggers some
"interesting" new optimizations. One of them, which seems to be
relatively common, is the replacing of a function with two separate
"constprop" functions.
Previously we only ever saw a single constprop clone, so we just renamed
the patched version of the function to match the original version. Now
that we can have two such clones, that no longer makes sense.
Instead of renaming functions, just improve the correlation logic such
that they can be correlated despite having slightly different symbol
names. The first clone in the original object is correlated with the
first clone in the patched object; the second clone is correlated with
the second clone; and so on.
This assumes that the order of the symbols and sections doesn't change,
which seems to be a reasonable assumption based on past experience with
the compiler. Otherwise it will just unnecessarily mark the cloned
constprop functions as changed, which is annoying but harmless, and
noticeable by a human anyway.
Fixes#935.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
While static keys (jump labels) are currently broken in livepatch, a
broken dynamic debug static key is harmless since it just disables
dynamically enabled debug printks in the patched code.
Fixes: #1021
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Use make's .DELETE_ON_ERROR special target to make sure we don't have
any .OUTPUT.o leftovers for failed tests.
Fixes: #999
Signed-off-by: Artem Savkov <asavkov@redhat.com>
The ppc64le unit tests are failing because the lookup code is getting
confused by the "[<localentry>: 8]" string in the readelf symbol table
output.
Remove the string so the lookup code can parse it correctly.
kpatch-build already uses the same sed, so they should match.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Make 3.8 doesn't support the "file" function, which is used by the unit
test Makefile to output the contents of a custom env file, if one
exists. Use shell instead.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
"make unit" automatically rebases the submodule, which causes a lot of
surprises. Instead, just print a warning if it's out of date.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
readelf is more standard, using readelf insteaded
test/difftree.sh: the symbol name may be with "FILE", which may be
get a incorrect count, here add "awk".
test/unit/Makefile.include: use "readelf -s --wide" instead of
"eu-readelf -s".
Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
Some unit tests may need debug symbols to reproduce problems (see
issue #928 for example), so skip the unit-test Makefile.include
check_stripped call for objects that include "NOSTRIP" in their
filename.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
This reverts commit 87c64519fc.
The jump label support doesn't work with upstream livepatch. Joe
Lawrence found the following ordering issue:
load_module
apply_relocations
/* Livepatch relocation sections are applied by livepatch */
if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
continue;
post_relocation
module_finalize
jump_label_apply_nops << crash
...
do_init_module
do_one_initcall(mod->init)
__init patch_init [kpatch-patch]
klp_register_patch
klp_init_patch
klp_init_object
klp_init_object_loaded
klp_write_object_relocations
So jump_label_apply_nops() is called *before*
klp_write_object_relocations() has had a chance to write the klp
relocations (.klp.rela.kvm_intel.__jump_table, for example).
We need to resolve this upstream first.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Add support for jump labels, also known as static jumps, static keys,
static branches, and jump tables. Luckily,
kpatch_process_special_sections() is already generic enough to make this
an easy fix.
Fixes: #931
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Add support for optional <test-name>.env files that contain additional
environment variables. This can also be used to override per-arch env
vars we have because last value assigned will be used.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Bump unit-test-objs submodule head pointer to include latest test:
f82c458 x86_64: added a test for a function that uses _THIS_IP_
4a097d9 ppc64le: Test const var requiring .data.rel relocation
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Update submodule pointer to include new gcc8 unit tests.
This update also includes unit-test for https://github.com/dynup/kpatch/pull/892
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Don't try to call unittest clean if objfile dir is non-existant (e.g.
when objfile submodule wasn't cloned). Another solution would be to make
clean target dependant on objdir but that would mean downloading a lot
of unneeded data for users who don't run unit-tests.
Fixes: #872
Signed-off-by: Artem Savkov <asavkov@redhat.com>
This fixes the following error with an older version of git
(1.8.3.1):
make -C test/unit
make[1]: Entering directory `/root/kpatch/test/unit'
git submodule update --init --rebase
You need to run this command from the toplevel of the working tree.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
create-diff-object doesn't really need the full kernel object file as
input. All it requires is a symbol table. Switch to using "eu-readelf -s"'s
output instead of object files. This will enable us to cover more cases
in unit tests.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
ppc64le lacked kpatch_line_macro_change_only() implementation. Add one
based on x86_64 version and available unit tests.
Fixes: #843
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Update submodule to 6774fbc "ppc64le: initial object files"
Remove CDO_ENV since it is moved to per-arch makefiles.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
