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>
kpatch_include_symbol() is confusing. Refactor it:
- Remove the "inclusion tree" debug messages. I never use them, and
they just help make the code more confusing and the debug output more
cluttered.
- Split it up into two functions: kpatch_include_symbol() and
kpatch_include_section(), so that kpatch_include_section() can be used
elsewhere.
- Call kpatch_include_section() from kpatch_include_standard_elements().
This covertly fixes#702, by also including the .rela.rodata section.
- Add a bunch of comments to clarify some of the trickier points.
Fixes#702.
Fixes#807.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Don't die outright when encountering an 'undefined reference' error,
instead write those down and check if needed symbols are provided by the
resulting module or core kpatch module.
Fixes#783.
v2:
- make undefined_references and new_symbols unique before comparing
- remove leftover $KMOD_PATH from new_symbols readelf
Signed-off-by: Artem Savkov <asavkov@redhat.com>
for-next branch of kbuild repo contains a "kbuild: rename built-in.o to
built-in.a" which renames all built-in.o instances. Filter on both .o
and .a in kpatch-gcc/kpatch-build to be prepared for this change.
Fixes#800.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
With kernel commit b1fca27d384 ("kernel debug: support resetting
WARN*_ONCE") the *_ONCE warnings are placed .data.once section.
Including .data.once section is valid, so add an check in
kpatch_verify_patchability() while checking for included invalid
sections.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Symbols with R_PPC64_REL24 relocation type are functions and it's
currently assumed that all functions are replaced with their respective
section symbols.
There are function whose reference are not straight forward section
symbol but section + offset. These function replacement should be
handled more like bundled sections. Remove the check, which imposes
the inital assumption.
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
.toc section entries are mostly place holder for relocation entries,
specified in .rela.toc section. Sometimes, .toc section may have
constants as entries. These constants are not reference to any symbols,
but plain instructions mostly due to some arthimetics in the functions
referring them.
They are referred by the functions like normal .toc entries, these
entries can not be resolved to any symbols. This patch creates a list
of constants if available for .toc sections and compares them in
rela_equal() to ensure their is no mismatch in the generated constants
for original and patched .o files.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
GCC 7.2.1 complains about the usage of the PPC64_LOCAL_ENTRY_OFFSET
macro:
create-diff-object.c: In function ‘is_gcc6_localentry_bundled_sym’:
create-diff-object.c:119:83: error: ‘<<’ in boolean context, did you mean ‘<’ ? [-Werror=int-in-bool-context]
(((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
create-diff-object.c:140:10: note: in expansion of macro ‘PPC64_LOCAL_ENTRY_OFFSET’
return (PPC64_LOCAL_ENTRY_OFFSET(sym->sym.st_other) &&
^~~~~~~~~~~~~~~~~~~~~~~~
Fix it by explicitly treating the macro as an integer instead of a bool.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
On ppc64le, building drivers/media/i2c/cx25840/cx25840.ko with GCC 4.85,
the plugin triggers the following errors:
{standard input}: Assembler messages:
{standard input}:1078: Error: operand out of range (0x0000000000008fd4 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:1288: Error: operand out of range (0x000000000000874c is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:3844: Error: operand out of range (0x00000000000080e8 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:4028: Error: operand out of range (0x00000000000082b4 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:4031: Error: operand out of range (0x00000000000080b4 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:6661: Error: operand out of range (0x000000000000841c is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:6664: Error: operand out of range (0x0000000000008214 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:6845: Error: operand out of range (0x00000000000089dc is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:6848: Error: operand out of range (0x00000000000087d4 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:7587: Error: operand out of range (0x0000000000008930 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:7590: Error: operand out of range (0x0000000000008728 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
{standard input}:14592: Error: operand out of range (0xffffffffffff79b8 is not between 0xffffffffffff8000 and 0x0000000000007ffc)
make[1]: *** [drivers/media/i2c/cx25840/cx25840-core.o] Error 1
The problem is that the plugin nops were inserted too late. GCC laid
out the code with knowledge about the distance between branches, but
then the plugin came along after that and increased the branch distances
by inserting the nops.
Fix it by inserting the nops as early as possible. The 'vregs' pass is
where the insn codes get initialized, so run the plugin immediately
afterwards.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Sometimes git doesn't see that the patches have been reverted, if that
happens during ./scripts/setlocalversion call the resulting patch module
is built with a wrong vermagic because the tree is still considered
dirty.
Fix by moving git update-index call into remove_patches function so that
it is called every time the patches are reverted, not only on cleanup.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Found in the scope of https://github.com/dynup/kpatch/pull/755 but not
related to the main problem discussed there.
kpatch_create_patches_sections() and kpatch_create_intermediate_sections()
used 'hint' in error messages.
However, the string 'hint' refers to is owned by 'kelf_base' and is
freed before kpatch_create_*_sections() are called. As a result, if
these functions try to output errors and print 'hint',
create-diff-object will crash.
As suggested in the mentioned PR, 'hint' is actually no longer needed at
that stage, so I have removed it from kpatch_create_*_sections().
By specifying -d, --debug multiple times, the following additional
debug modes can be enabled:
-d -d: Writes everything that is written to the logfile also to
stdout.
-d -d -d: Same as '-d -d' plus sets 'xtrace' in kpatch-build.
-d -d -d -d: Same as '-d -d -d' plus sets 'xtrace' in kpatch-gcc.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Add a logger funcition that can be used to log to both stdout and the
logfile or only to the logfile. This is needed for subsequent patches
where we introduce an alternate debug mode.
Since we're piping to a logger now, we need to set 'pipefail' otherwise
the return status of such a pipeline is always 0 (the exit status of the
logger) and we won't catch any errors.
From the bash manpage:
The return status of a pipeline is the exit status of the last command,
unless the pipefail option is enabled
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
This is in response to an upstream discussion for the following patch:
https://lkml.kernel.org/r/1508217523-18885-1-git-send-email-kamalesh@linux.vnet.ibm.com
This should hopefully make it a lot easier for the ppc64le kernel module
code to support klp relocations.
The gcc-common.h and gcc-generate-rtl-pass.h header files are copied
from the upstream Linux source tree.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
When searching for 'Linux version ...' in vmlinux, stop after the first
match so that we don't keep reading a potentially huge file.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
The current checks never fail, because the first grep in the pipeline
doesn't write anything to stdout.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
This can be used for building a kpatch module for a non-running
kernel. Note that the correct kernel and debug packages still need
to be installed.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
When creating .kpatch.relocations, there's no reason to convert the
relocation destinations to symbols. In fact, it's actively harmful
because it makes it harder for create-klp-module to deal with the GCC 6+
8-byte localentry gap.
This also fixes a regression which was introduced in 5888f316e6, which
broke ppc64le relocations.
Fixes#754.
Fixes: 5888f316e6 ("create-klp-module: support unbundled symbols")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
kpatch_relocation's 'dest' addend and 'offset' fields are redundant. In
fact, the 'offset' field isn't always accurate because it doesn't have a
relocation, so its value doesn't adjust when multiple .o files are
combined. Just use the 'dest' addend instead.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
kpatch_replace_sections_syms() assumes that all bundled symbols start at
section offset zero. With ppc64le and GCC 6+, that assumption is no
longer accurate. When replacing a rela symbol section with its
corresponding symbol, adjust the addend as necessary.
Also, with this fix in place, the workaround in
create_klp_relasecs_and_syms() can be removed.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
On ppc64le, adding a printk to total_mapping_size() caused it to change
from non-localentry to localentry, presumably because it was no longer a
leaf function. With GCC 6, a localentry function is offset by 8 in the
section, so different st_values are ok.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
The STT_FUNC and SHN_UNDEF checks aren't needed because they're already
implied by the localentry check.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
is_localentry_sym() isn't quite the right name, because it also checks
for the 8-byte gap introduced by GCC 6, and also checks that the
function is otherwise at the beginning of the section.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Replace stray spaces with tabs, except in the usage output where tabs
don't make much sense.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
This was introduced in commit 5352d8b01a ('build objects in separate
directory to fix caching') but is no longer necessary.
Fixes: 2e99d6b7a4 ('kpatch-build: build the kernel in ~/.kpatch/src again')
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Fix the version checks for when we enable CONFIG_LIVEPATCH on RHEL. It
will be based on the latest upstream code.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
The paravirt_patch_site struct has 12 bytes of data and 4 bytes of
padding, for a total of 16 bytes. However, when laying out the structs
in the .parainstructions section, the vmlinux script only aligns before
each struct's data, not after. So the last entry doesn't have the
4-byte padding, which breaks kpatch_regenerate_special_section()'s
assumption of a 16-byte struct, resulting in a memcpy past the end of
the section.
Fixes#747.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Replace find * with find ./* to prevent treating files with dashes as
options. The leading ./ is later used in comparisons and thus must be
removed before that.
Found by shellcheck.
gcc --version varies too much for sane comparisons with vmlinux's
.comment section. Therefore compile a test file and compare its .comment
section.
Also fix gcc 4.8 check which used a lexicographically comparison which
will break for gcc versions >= 10. Instead check for the required
compiler options.
Closes#565.
- Replace grep | wc -l with grep -c.
- Use find -print0 and xargs -0 to handle non-alphanumeric filenames
(shouldn't be an issue for us but it's good practice).
- Replace expr with $(( )).
Found by shellcheck.
The double quotes are confusing as they don't quote $UBUNTU_ABI and thus
have no real effect. As $UBUNTU_ABI is a number simply remove them and
put $UBUNTU_ABI into the surrounding quotes.
Found by shellcheck.
- Replace echo $(cmd) with just cmd.
- Replace $@ inside quotes with $*.
- Always die if cd fails.
- Ensure rm -rf "$TEMPDIR"/* never expands to rm -rf /*.
Found by shellcheck.
Without proper quoting kpatch fails if the argument contains spaces, the
other scripts might be affected as well.
Not all new quotes are strictly necessary but they were added for
consistency with the existing code and to prevent copy & paste errors in
the future.
There's one conversion which is not straight-forward:
- grepname=$grepname\\\.o
+ grepname="$grepname\.o"
There are different quoting rules with and without the double quotes.
