Building with GCC 7.3.0 on Debian sid fails with the following error:
gcc -g -O2 -fdebug-prefix-map=/build/kpatch-0.6.0=. -fstack-protector-strong -Wformat -Werror=format-security -MMD -MP -I../kmod/patch -Iinsn -Wall -Wsign-compare -g -Werror -Wdate-time -D_FORTIFY_SOURCE=2 -c -c
create-diff-object.c: In function 'kpatch_compare_correlated_rela_section':
create-diff-object.c:316:20: error: 'toc_data1' may be used uninitialized in this function [-Werror=maybe-uninitialized]
return toc_data1 == toc_data2;
~~~~~~~~~~^~~~~~~~~~~~
create-diff-object.c:256:16: note: 'toc_data1' was declared here
unsigned long toc_data1, toc_data2;
^~~~~~~~~
cc1: all warnings being treated as errors
This is a false positive as the code only compares those two values
after initializing them. But lets keep GCC happy.
Signed-off-by: Simon Ruderich <simon@ruderich.org>
If $AWK_OPTIONS are blank gawk would treat "" as a blank script
resulting in none of the special struct being detected.
Fixes: 1330dcc "create-diff-object: add ORC section support"
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Convert magic exit status values into a common enum for clarity.
Suggested-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
None of the lib/* file are built with fentry calls, so we can't patch
them. Add these files to the list that kpatch-gcc skips.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Add a little more context ("in the vmlinux symbol table") to the
symbol-not-found message in find_local_syms().
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Change the "FILE symbol not found in base. Stripped?" (fatal) error
message into a warning. These crop up whenever a change is made to an
assembly file.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Finally add support for processing the ORC unwinder sections.
The ORC unwinder sections are more special than the other special
sections, so they need their own dedicated function to process them,
though the code is similar to kpatch_regenerate_special_sections().
BTW, upstream livepatch still doesn't support the ORC unwinder. That
change will be coming soon (probably Linux 4.19).
Fixes#785.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Since the codeset supports just the 64 bit variant, lets move
to __powerpc64__ and use it. I checked the ABI doc as well
and the kernel/gcc.
Signed-off-by: Balbir singh <bsingharora@gmail.com>
As discussed in #848, there is no known reason to do "make mrproper" on
every build. It seems to be an artifact from previous iterations (we
used to use 'O=' to build the kernel in a separate object tree.
It has many downsides:
- massive performance degradation
- breaks the '-t' option
- prevents the user from manually saving/restoring ~/.kpatch
Only do it where it's really needed, which is after first extracting the
source from an RPM.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
"make mrproper" combined with the '-t' flag is dangerous, as it results
in the Module.symvers file getting truncated, which causes
create-diff-object to create some funky dynrelas. Detect this condition
in kpatch-build and error out.
We will hopefully also be removing "make mrproper" soon, which will make
'-t' even more useful.
Fixes#589.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
In recent versions of Fedora, when building from a source RPM,
kpatch-build fails because it can't find the .config file. Get the file
from the canonical location: the configs subdirectory.
This also works with older versions of Fedora and RHEL, and ensures we
always have the right config file for the arch we're building for.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Before we were adding the undefined symbols to the lookup table, but we
were skipping them by setting the sym.skip flag.
With 3aa5abb807 ("kpatch-build: use symbol table instead of kobject"),
the skip flag was removed but the undefined symbol check was removed
with it.
The skip flag can remain gone. Instead of adding undefined symbols to
the table and skipping them when iterating the table, just don't add
them to start with.
Also make the sscanf conditional lines identical, to ease maintenance.
Fixes#869.
Fixes: 3aa5abb807 ("kpatch-build: use symbol table instead of kobject")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Deal with a few RHEL kernel-alt quirks for ppc64le:
- The RPM and spec names are "kernel-alt".
- 7.6 ALT is based on 4.14 but it doesn't have the 'immediate' flag.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
gcc8 introduces ".cold." optimization symbols that have arbitrary
trainling numbers in their names just like ".isra." and others.
Add ".cold." to a condition in kpatch_rename_mangled_functions()
Signed-off-by: Artem Savkov <asavkov@redhat.com>
plugin compilation fails on GCC 8:
In file included from gcc-plugins/gcc-common.h:100,
from gcc-plugins/ppc64le-plugin.c:1:
/usr/lib/gcc/powerpc64le-linux-gnu/8/plugin/include/attribs.h: In function ‘tree_node* canonicalize_attr_name(tree)’:
/usr/lib/gcc/powerpc64le-linux-gnu/8/plugin/include/attribs.h:118:11: error: ‘get_identifier_with_length’ was not declared in this scope
return get_identifier_with_length (s + 2, l - 4);
^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/powerpc64le-linux-gnu/8/plugin/include/attribs.h:118:11: note: suggested alternative: ‘get_attr_min_length’
return get_identifier_with_length (s + 2, l - 4);
^~~~~~~~~~~~~~~~~~~~~~~~~~
get_attr_min_length
Makefile:34: recipe for target 'gcc-plugins/ppc64le-plugin.so' failed
get_identifier_with_length() is defined under stringpool.h, include this
header file for GCC 8, before including attribs.h
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
When I made a patch to the nfsd module on a ppc64le system with a RHEL 7
based kernel, livepatch prevented the target module from loading with:
livepatch: symbol '.TOC.' not found in symbol table
References to this symbol are treated specially by the kernel module
loader, so references to it should never be converted to dynrelas.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
While building a gcc-consprop patch from integration tests gcc8 would place a
__timekeeping_inject_sleeptime.constprop.18.cold.27 symbol into
.text.unlikely.__timekeeping_inject_sleeptime.constprop.18 section. Because
section name doesn't have the '.cold.27' suffix this symbol fails
is_bundleable() check while still being bundleable and later exits early in
kpatch_rename_mangled_functions() without renaming the corresponding patched
function. All of this results in a create-diff-object errror:
ERROR: timekeeping.o: symbol changed sections: __timekeeping_inject_sleeptime.constprop.18.cold.27
/home/asavkov/dev/kpatch/kpatch-build/create-diff-object: unreconcilable difference
Fix by ignoring .cold.* name suffix in is_bundleable() for.text.unlikely
sections.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
From Oracle's Linker and Libraries Guide [1]:
"The symbols in a symbol table are written in the following order ...
The global symbols immediately follow the local symbols in the symbol
table. The first global symbol is identified by the symbol table sh_info
value. Local and global symbols are always kept separate in this manner,
and cannot be mixed together."
[1] https://docs.oracle.com/cd/E19120-01/open.solaris/819-0690/chapter6-79797/index.htmlFixes#854.
Signed-off-by: Joe Lawrence <joe.lawrence@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>
Use named variables instead of cmdline argument indexes so that it is
easier to read create-diff-object.c.
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 the `__LINE__` macro detection heuristics based on recent kernel
changes:
- __warn_printk(), used in the WARN macros, which put the line number in
%edx
- __might_fault(), used in the usercopy macros
- lockdep_rcu_suspicious(), used in the RCU_LOCKDEP_WARN macro
- printk(), used in the ASSERT_RTNL macro
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
With #755, we started using dynrelas for function pointers. However,
this behavior only makes sense for function pointers to existing
functions. For function pointers to *new* functions, just use a normal
rela.
The 'function-ptr-new' unit test is from the following patch:
https://github.com/dynup/kpatch/files/1927198/new-static-callback.patch.txtFixes#834.
Fixes: 495e619750 ("kpatch-build, x86: do not use the patched functions as callbacks directly")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Because $PLUGIN variable is a part of $TARGETS we are trying to install
gcc-plugins twice which is treated as an error by install command:
/usr/bin/install create-diff-object create-klp-module create-kpatch-module gcc-plugins/ppc64le-plugin.so kpatch-gcc gcc-plugins/ppc64le-plugin.so /usr/local/libexec/kpatch
/usr/bin/install: will not overwrite just-created '/usr/local/libexec/kpatch/ppc64le-plugin.so' with 'gcc-plugins/ppc64le-plugin.so'
Signed-off-by: Artem Savkov <asavkov@redhat.com>
- convert section/symbol indexes and rela->offset to unsigned int as I
couldn't find any way for them to become negative.
- cast a number of rela->addend comparisons to int (assuming an 64bit
system this should be enough)
- a number of simple for-loop counter conversions to the type it
compares against
Signed-off-by: Artem Savkov <asavkov@redhat.com>
If a patch failed a first time, kpatch-build is using the previous
cache directory on subsequent builds. The UBUNTU_KERNEL=1 variable is
not set in this case. Therefore, utsrelease.h is not updated correctly
and the appropriate structures are not used. Just check if distro is
Ubuntu and we didn't request our own specific directory.
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Because of signedness difference kpatch_check_relocations() would trigger
an error on any negative addend.
Fix by casting Elf_Data->d_size from size_t to int.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Check that none of the relocations are out-of-range of their
corresponding sections before writing the output elf.
Fixes: #618
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Heavy lifting of reading .toc rela entries for rela symbols
referring to .toc + offset, can be simplified using toc_rela() in
rela_equal() and remove the #ifdery guarding PowerPC code.
This patch also trims the commentary related to PowerPC.
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
On ppc64le, the static local variable correlation doesn't take into
account the .toc rela indirection for data references, meaning that it's
basically broken in many cases.
Fix it by making the code .toc-aware.
Fixes#793.
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Upstream 4.15 kernels provide support for pre and post (un)patch
callbacks, inspired by the kpatch load hooks. Add support for them
in the livepatch-patch-hook.
At the same time, convert the kpatch hooks to use the same API.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Cleanup some of the new bash script code to appease 'make check':
- kpatch: Use integer comparison for $MAX_LOAD_ATTEMPTS
- kpatch-build: Quote ${TEMPDIR} variable
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
