Instead of always using the maximum number of CPUs available, allow
user to tune the number of make jobs using the command line argument
('-j', '--jobs').
If an .LCx symbol gets renamed or changes sections, or if its section
gets renamed, kpatch-build will get confused.
They aren't *real* symbols, just string constants. So no need to
correlate and compare them.
Fixes#714.
Fixes#727.
This removes duplicate code which is already handled by make internally
and also respects CPPFLAGS.
LDFLAGS are general linker flags, LDLIBS should be used for the
libraries itself. Therefore switch to LDLIBS which is put after the
object files in the command line (which is not true for LDFLAGS).
With gcc-6 the function prologue is changeg by
moving the toc base resolution func - 0x8 bytes:
.globl my_func
.type my_func, @function
.quad .TOC.-my_func
my_func:
.reloc ., R_PPC64_ENTRY ; optional
ld r2,-8(r12)
add r2,r2,r12
.localentry my_func, .-my_func
Add support for function prologue, along with gcc-5.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Add support for ppc64le specific special sections:
- __ftr_fixup
- __mmu_ftr_fixup
- __fw_ftr_fixup
- __lwsync_fixup
This patch also add #ifdef guards for architecture specific
special sections.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
This patch adds support for livepatch hook based module
creation for PPC64le. It introduces PPC64le architecture
bits:
- Add relocation type of R_PPC64_ADDR64 while parsing powerpc ELF.
- Introduce .toc sections mainpulation.
- Skip kpatch specific details for livepatch hook.
Also remove the definition of rela_insn() for powerpc. The only
call site is been guarded by #ifdef x86.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
symbol->has_fentry_call is x86 specfic. Rename it to more
generic name, representing the general idea of calling
profiling function at function entry.
This patch converts all instance of symbol->has_fentry_call
to symbol->has_func_profiling and also renames functions:
kpatch_check_fentry_calls() -> kpatch_check_func_profiling_calls()
kpatch_find_fentry_calls() -> kpatch_find_func_profiling_calls()
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Move special section data checks to helper function
find_special_section_data(). Special section data will differ
between architectures and all architecture specific and common
checks can be handled better within a helper function.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
gcc -mprofile-kernel support is required on ppc64le for livepatch
to work. Check should be performed on the gcc, instead of relying
on the verion number.
This check is already performed during the kernel build by:
<linux-sources>/arch/poweprc/tools/gcc-check-mprofile-kernel.sh
Bail out, during the kernel build. Incase the gcc lacks the support
for -mprofile-kernel, instead of duplicating the check in kpatch-buid.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
kpatch-build/insn provides x86 instruction analysis, disable
the analyzer support when build on powerpc.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
If you give kpatch-build a bad argument for the '-s' option, it shows
the following error:
$ kpatch-build/kpatch-build -s foo
ERROR: source dir not found.
The supplied 'foo' argument isn't printed as intended.
Also fix some other options which have a similar issue.
With #650, we found that using -ffunction-sections and -fdata-sections
sometimes causes GCC to output the local symbols in a different order in
the symbol table. So don't assume they're in the same order, and
instead search all the locals.
This requires two passes: once going through the lookup table symbols
and once going through the .o symbols. This is needed to make sure
there aren't any extra symbols in one of the files.
I also reorganized the code a bit to simplify it.
When compiling with -O2, it fails with:
gcc -MMD -MP -O2 -I../kmod/patch -Iinsn -Wall -g -Werror -c -o lookup.o lookup.c
lookup.c: In function ‘lookup_open’:
lookup.c:132:21: error: ‘file_sym’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
table->local_syms = file_sym;
~~~~~~~~~~~~~~~~~~^~~~~~~~~~
lookup.c:83:30: note: ‘file_sym’ was declared here
struct object_symbol *sym, *file_sym;
^~~~~~~~
lookup.c:129:27: error: ‘child_sym’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (in_file && !child_sym->name) {
~~~~~~~~~^~~~~~
lookup.c:85:27: note: ‘child_sym’ was declared here
struct sym_compare_type *child_sym;
^~~~~~~~~
cc1: all warnings being treated as errors
Makefile:17: recipe for target 'lookup.o' failed
make[1]: *** [lookup.o] Error 1
make[1]: Leaving directory '/home/jpoimboe/git/kpatch/kpatch-build'
Makefile:14: recipe for target 'build-kpatch-build' failed
make: *** [build-kpatch-build] Error 2
As far as I can tell, these are false positive warnings. When in_file
is 1, file_sym and child_sym are properly initialized. But silence the
warnings anyway so Gentoo users can build with -O2.
Fixes: #675
On Debian/Ubuntu, the `vmlinux` from `-dbg` package has a version number
appended to it. For example:
`/usr/lib/debug/boot/vmlinux-3.13.0-117-generic`. Make it work
nonetheless.
On Ubuntu Trusty, HWE kernels don't come with a linux-source
package. Use dget to retrieve the source package instead. This is not
the case anymore with Xenial as the linux-source package is also
provided for the HWE kernels. For Debian, backports always come with the
linux-source package.
SUSE-based kernels have a DWARF unwinder, so they build with the gcc
'-fasynchronous-unwind-tables' flag, which adds .eh_frame and
.eh_frame_hdr sections. Treat those sections like the other debug
sections.
Fixes: #703
Joe saw the following errors when loading Linux commit 128394eff343
("sg_write()/bsg_write() is not fit to be called under KERNEL_DS"):
Skipped dynrela for copy_user_generic_unrolled (0xffffffffa0475942 <- 0xffffffff813211e0): the instruction has been changed already.
Skipped dynrela for copy_user_generic_unrolled (0xffffffffa0475a57 <- 0xffffffff813211e0): the instruction has been changed already.
That is known issue #580, but it can be avoided by leaving
'copy_user_generic_unrolled' as a normal relocation instead of
converting it to a dynrela, because it's an exported symbol.
Also remove the manual check for '__fentry__' because it's covered by
the exported symbol check.
Also remove a duplicate comment about unexported global object symbols
being in another .o in the patch object.
Fixes#695.
Upstream kernel commit 7f2084fa55e6 ("[kbuild] handle exports in lib-y
objects reliably") (v4.9+) added temporary dummy .lib_exports.o objects
to the kernel build. As these ephemeral files don't contain any code,
update the kpatch-gcc glob pattern to ignore them.
(glob pattern suggested by flaming-toast)
Fixes#686.
Strip kpatch_ignore_func_* and __UNIQUE_ID_kpatch_ignore_section_*
symbols to prevent the inclusion of .kpatch.ignore.functions and
.kpatch.ignore.sections. Mark the symbols as SAME, otherwise they are
considered NEW and are recursively included. This includes the
corresponding ignore sections and rela sections and may also create new,
unnecessary dynrelas.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
A couple of minor cleanups:
- move the `if (locals)` check to find_local_syms()
- remove the explicit initialization of `local_syms`, the entire struct
was already previously cleared to zero.
When wiping out the ~/.kpatch cache before replacing it with a new
kernel source, there's no need to keep anything around. Just wipe it
all out and start over.
Also, when building with the -s option, it doesn't need to touch
~/.kpatch/version or ~/.kpatch/src, so it can just skip the cleaning.
That keeps the previous cache around for the next incantation of
kpatch-build without '-s'.
Once upon a time, kpatch-build did the kernel build in three passes.
The extra pass was done without '-ffunction-sections -fdata-sections',
so it could produce the original vmlinux file.
At that time, there was no ~/.kpatch/obj directory. The kernel was
built directly in ~/.kpatch/src. Because the same directory was used
for both the original kernel build and the '-ffunction-sections
-fdata-sections' build, the entire tree had to be rebuilt twice for
every kpatch-build incantation, making it very slow.
That situation was improved with the following commit:
5352d8b01a ("build objects in separate directory to fix caching")
That built the regular and special binaries in ~/.kpatch/obj and
~/.kpatch/obj2, respectively.
Since then we've simplified things so that it only does two build
passes: original and patched, both with '-ffunction-sections
-fdata-sections', and ~/.kpatch/obj2 was removed. However,
~/.kpatch/obj still remained. That's because we never had a reason to
change it, until now.
Recent commit aa2907df29 ("support dup file+symbol")
triggers a new warning:
create-diff-object: ERROR: dynamic_debug.o: find_local_syms: 124: find_local_syms for dynamic_debug.c: found_none
This was actually a preexisting issue which that commit helped uncover.
The root issue is that dynamic_debug.c has some creative uses of the
`__FILE__` macro. When building the kernel objects outside the source
tree, the macro results in a absolute path like:
/home/jpoimboe/.kpatch/src/lib/dynamic_debug.c
But when building inside the source tree it's a relative path:
lib/dynamic_debug.c
The Fedora kernel is built in-tree, and I would imagine most other
distros are also built that way. So the way kpatch builds can result in
a slightly different 'original' object than the distro version, thanks
to the __FILE__ macro.
In this case, the order of the symbol table changed slightly between
vmlinux and the 'orig' object. Presumably, the difference in string
lengths was enough to convince the compiler to shuffle things around a
bit.
So considering that bug, and the possibility of other mismatches, go
back to building the kernel in the source tree.
For some reason, the backticks on this line confuse my editor's syntax
highlighter! Make vim happy by using the other form of command
substition.
Also convert the function definition syntax to comply with the
kpatch-build coding guidelines ;-)
A few symbols are discarded in the kernel linking phase, which means
they won't be in the lookup table. Skip their comparison.
This fixes a bunch of warnings seen when building a patch which triggers
a tree-wide rebuild:
create-diff-object: ERROR: aes_glue.o: find_local_syms: 112: find_local_syms for aes_glue.c: found_none
create-diff-object: ERROR: aesni-intel_glue.o: find_local_syms: 112: find_local_syms for aesni-intel_glue.c: found_none
create-diff-object: ERROR: init.o: find_local_syms: 112: find_local_syms for init.c: found_none
create-diff-object: ERROR: iosf_mbi.o: find_local_syms: 112: find_local_syms for iosf_mbi.c: found_none
create-diff-object: ERROR: setup.o: find_local_syms: 112: find_local_syms for setup.c: found_none
...
After this patch, there's still one warning remaining:
create-diff-object: ERROR: dynamic_debug.o: find_local_syms: 133: find_local_syms for dynamic_debug.c: found_none
That one has a completely different cause, which I'll fix in another
pull request (coming soon).
Fixes: #676
Normal correlated symbols are marked the SAME initially but static local
variables are correlated in a separate function. Also mark these the
SAME.
This fixes an issue where patching a function which called printk_once
(which uses a static local variable) would fail to build because the
static local variable was considered new and thus introduced a new data
member into .data..read_mostly which is not allowed to change.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Rename a couple of the variables in find_local_syms() to better reflect
their purpose. The passed in 'locals' are from the childobj (e.g.
foo.o) rather than the parent (e.g. vmlinux).
When CONFIG_DEBUG_ATOMIC_SLEEP is enabled, might_sleep calls will add
the line number to the instruction stream. Detect and ignore any such
changes.
Fixes: #657.
CONFIG_PARAVIRT is not required for building kpatch patch modules. The
sizeof paravirt_patch_site struct was only needed to create
.parainstructions sections as part of create-diff-object. As long as
the original objects were built without such sections then
this kernel option (and struct handling) can be considered optional.
The CONFIG_DEBUG_INFO_SPLIT kernel .config option places debug
information into separate .dwo files. As no known distribution is
currently shipping .dwo in their debuginfo packages, leave it as
unsupported for now.
When building a kernel with CONFIG_DEBUG_INFO_REDUCED, it was observed
that subsequent readelf -wi output may not always display structure size
information first. The affects the kpatch-build awk script that needs
to consider readelf output like the following:
<1><26393>: Abbrev Number: 12 (DW_TAG_structure_type)
<26394> DW_AT_name : (indirect string, offset: 0x914f): alt_instr
<26398> DW_AT_declaration : 12
...
<1><169d1b>: Abbrev Number: 13 (DW_TAG_structure_type)
<169d1c> DW_AT_name : (indirect string, offset: 0x914f): alt_instr
<169d20> DW_AT_byte_size : 13
Therefore the awk state machine should reset if it doesn't encounter
"DW_AT_byte_size" after given structure name match.
Fixes: #668.
Support for gawk '\s' (whitespace) GNU Regexp Operator was added
somewhere between gawk 3 and 4 (RHEL6 and RHEL7). Use the [[:space:]]
bracket expression to support older releases of gawk.
We use kelf_base->symbols to find a unique matching FILE+locals combination
when we call lookup_open(). If we can't find one matching or we find more
than one matching, we error out.
If we find a unique one, we setup table->local_syms in lookup_open(),
so later lookup_local_symbol() could do its lookup based on table->local_syms.
Fixes#604.
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
