The "kpatch install" command is broken because the kpatch script has
some missing dependencies in the initramfs. Make sure the new
dependencies (readelf and awk) are added to the initramfs.
Unload of kpatch module (and kpatch_shadow_hash table) before
all shadow variables free requests are processed can lead to
kernel crash.
Add rcu_barrier() to kpatch_exit() to wait for all outstanding
RCU callbacks to complete.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Bash doesn't correctly format the version string which causes the source
package to not be downloaded correctly.
Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
The current WARN detection logic catches the majority of cases, but
there are still a lot of outliers which it doesn't catch (thanks, gcc).
I looked at a much larger sample of WARN calls and came up with a more
generic algorithm.
The _rs variable is used for printk ratelimiting, similar to __warned,
which makes it a logical candidate to be "special": don't correlate it,
yet don't mark a function as changed just because it references it.
When patching a kernel module, if we can't find a needed dynrela symbol,
we currently assume it's exported. However, it's also possible that
it's provided by another .o in the patch module. Add support for that.
Fixes#445.
Currently unbundled section references are only replaced if the start of
the symbol is referenced. It's also useful to support replacement of
references which point to inside the symbol.
Improve the static local variable correlation logic, for the case where
a static local is used by multiple functions. For each usage of the
variable, look for a corresponding usage in the base object. If we find
at least one matching usage, consider it a twin.
Fix the object unlink error handling so that each function cleans up
after itself properly.
Also use find_symbol() instead of __symbol_get() to make cleanup easier.
When patching a module we don't need a reference to each symbol, since
we already have done a try_module_get() on the module.
Fixes#392.
Allow static locals to be used by two functions. This is possible if
the static's containing function is inlined. We only need to find one
of them to do the correlation.
The __func__ static local variable should be deemed "special", because
it doesn't need to be correlated and should be included when needed by
an include function.
I don't have a test case for F20, but this fixes the following types of
issues when doing a full-tree recompile on RHEL 7:
ERROR: cifssmb.o: object size mismatch: __func__.49322
ERROR: btmrvl_main.o: kpatch_correlate_static_local_variables: 982: static local variable __func__.44657 not used
ERROR: iwch_qp.o: .rodata.__func__.46024 section header details differ
Fixes an issue where attempting to call the shadow functions from a
module results in modpost failures:
ERROR: "kpatch_shadow_get" [net/mac80211/mac80211.ko] undefined!
ERROR: "kpatch_shadow_alloc" [net/mac80211/mac80211.ko] undefined!
LDFLAGS_MODULE is apparently not really needed.
Right now, unless the entire gcc version string, including build date
and package version, matches the distro kernel exactly, kpatch-build
won't proceed.
For some distros, it is very difficult to rollback to a previous
version of gcc and keep that version pinned on the system so that the
package manager doesn't update it.
For these user, add a --skip-gcc-check flag to kpatch-build to allow the
version check to be skipped. If the user does this, it is assumed they
know what they are doing. This flag is documented as "not recommended".
Signed-off-by: Seth Jennings <sjenning@redhat.com>
