With some obscure drivers, the same object file can be linked into
multiple parent objects. Only call this out as an error if the object
has changed, otherwise it doesn't matter.
Fixes the following issue:
ERROR: two parent matches for drivers/media/radio/si470x/radio-si470x-common.o.
vdso files aren't kpatch-compatible, and give errors like the following:
ERROR: invalid ancestor arch/x86/vdso/vdso32-sysenter.so.dbg for arch/x86/vdso/vdso32/sysenter.o
If we have to do a deep find (e.g. search the entire tree) to find a
parent object, first try searching in the last successful deep find
directory. This is a performance improvement in the case of a full tree
rebuild, because deep finds are very expensive, and it's not uncommon
for there to be multiple objects in a directory being linked into an
object in another directory.
There are a few more valid ancestors for vmlinux other than built-in.o.
This fixes errors similar to the following:
ERROR: invalid ancestor arch/x86/lib/lib.a for arch/x86/lib/usercopy_64.o
Fixes an error when the following is an argument to gcc:
'-DIPATH_IDSTR="QLogic' kernel.org 'driver"'
gcc: error: kernel.org: No such file or directory
gcc: error: driver": No such file or directory
yumdownloader is problematic because it doesn't allow you to download
anything but the latest released kernel. It can also be slow at times.
Instead, for Fedora, download the RPMs from koji.
Add KVER and KREL variables, and use them where appropriate. Also
remove the setting of ARCHVERSION in the '-s' case, since it's not
actually used anywhere in that case.
The special sections should be processed after all the other inclusion
logic has run, so that should_keep_rela_group() can work properly.
Otherwise it might remove a needed rela group from a special section.
If hyphen doesn't exist in uname -r (ARCHVERSION), then it is probably a
non-distro kernel and we don't need to create the localversion file.
Fixes#376
Signed-off-by: Seth Jennings <sjenning@redhat.com>
Fix the mangled function strcmp so that it compares all of the string
except for the numbered parts. foo.isra.35 should match foo.isra.1, but
not foo.isra.35.part.36.
Fixes#352.
It's possible for a static local variable's data section to have
a relocation which refers to the variable symbol itself. Fix the logic
which searches for the user of a static local variable by only looking
in text sections (i.e. functions).
Fixes#411.
This fixes a seg fault in the test suite caused by a debug section
referencing an un-included unbundled symbol (though its section was
included). The symbol was a __warned symbol and the section was
.data.unlikely.
For debug sections, there is no need to replace section references with
symbols because we don't compare debug sections.
Add support for the __key and __warned "special" static local variables.
I'm calling them that for lack of a better term, analagous to the
kernel's special sections that we have to deal with.
__warned: Used by WARN_ONCE et al as an indicator as to whether a
message has already been printed. I think it makes sense (and is much
easier) to reset this counter for a given function when replacing the
function, since the user may expect the new function to warn again.
__key: Used by lockdep as an identifier for a given lock initialization
code path (see http://lwn.net/Articles/185666/ for more info). I think
it makes sense (and is much easier) to create a new key for a given
function when replacing the function, because the locking semantics may
have changed, so it makes sense for lockdep to use a new key to validate
the new locking behavior.
So for both __warned and __key static variables, the new version of the
variable should be used when referenced by an included function.
Made the following changes to support these special variables:
- Ignore their suffixes when comparing them in rela_equal, so that gcc
renaming them will not result in a function being marked as changed
just because it referenced a renamed static local
- Don't ever correlate them, so that their new versions will be included
if a changed or new function uses their corresponding symbols
Fixes#402.
In order to safely re-enable patch modules, add a special
.kpatch.checksum section containing an md5sum of a patch module's
contents. The contents of this section are exported to sysfs via
patch_init and double checked when kpatch load finds that a module of
the same name is already loaded.
When working on large patches that are bound to have lots of
errors, it can be frustrating to have to re-run the build and wait
after every error you fix. With this patch, you get a chance to see
most (if not all) of the errors you'll be facing, at least across
the different object files.
This adds support for shadow variables, which allow you to add new
"shadow" fields to existing data structures.
To allow patches to call the shadow functions in the core module, I had
to add a funky hack to use --warn-unresolved-symbols when linking, which
allows the patched vmlinux to link with the missing symbols. I also
added greps to the log file to ensure that only unresolved symbols to
kpatch_shadow_* are allowed. We can remove this hack once the core
module gets moved into the kernel tree.
Fixes#314.
In the case that a new global symbol is defined in a file but not used
by a changed function, the symbol will currently not be included.
However, since it is global, another file in the patch my reference it,
but it will not be there.
This commit includes new global symbols so that they may be referenced
by changes in other files within the same patch.
Signed-off-by: Seth Jennings <sjenning@redhat.com>
WARN_ON_ONCE places the __warned static local variable in the
.data.unlikely section, so it's not bundled (i.e. ignored by the
-fdata-sections gcc flag). There's no reason why we can't rename
unbundled symbols, so add support for them.
Fixes#394.
If a patch adds a new function in foo.c, and calls that function from
bar.c, currently it fails with something like:
kpatch_create_dynamic_rela_sections: 2115: lookup_global_symbol failed for tpe_allow_file, needed for .text.do_mmap_pgoff
This (crudely) fixes the issue by assuming that if we can't find the
global symbol in the original vmlinux, that it will be provided by
another object in the patch module. If that assumption is incorrect,
the module will fail to load due to the missing symbol dependency.
A (perhaps) better way to fix this is to search for the symbol in the
patched version of the vmlinux. But I think this approach is good
enough, for now at least.
Fixes#388.
The naming of variables in this function is confusing, and really threw
me for a loop: sec is first used as an iterator, then sec is reused to
point to the dynrela section, then sec2 is used as another iterator.
Instead make sec the iterator for both loops and dynsec the dynrela
section pointer.
When a function foo.isra.1 has a switch statement, it might have a
corresponding .rodata.foo.isra.1 section (in addition to its
.text.foo.isra.1 section). If so, rename that section too.
Otherwise kpatch-build will get confused when comparing the function's
relas which reference the .rodata section, and will mark the function's
rela section as changed because the rela symbol names differ.
I found this bug when trying to build the patch from upstream Linux
commit a3c54931. Unfortunately this issue is already fixed on F20 and I
wasn't able to come up with a similarly failing test case for the
integration test suite.
