Draft: create-diff-object: __patchable_function_entries section support #1415
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
joe-lawrence
force-pushed
the
patchable_function_entries
branch
from
b000cf3
to
422b699
Compare
Fix the following:
In kpatch/kpatch line 358:
break
^-- SC2317 (info): Command appears to be unreachable. Check usage (or ignore if invoked indirectly).
In kpatch-build/kpatch-build line 1424:
"$TOOLSDIR"/create-diff-object $CDO_FLAGS "orig/$i" "patched/$i" "$KOBJFILE_NAME" \
^--------^ SC2086 (info): Double quote to prevent globbing and word splitting.
In kpatch-build/kpatch-build line 1494:
MAKEVARS[$idx]=${MAKEVARS[$idx]/${KPATCH_CC_PREFIX}/}
^--^ SC2004 (style): $/${} is unnecessary on arithmetic variables.
In kpatch-build/kpatch-build line 1510:
"$TOOLSDIR"/create-klp-module $extra_flags "$TEMPDIR/patch/tmp.ko" "$TEMPDIR/patch/$MODNAME.ko" 2>&1 | logger 1
^----------^ SC2086 (info): Double quote to prevent globbing and word splitting.
In test/integration/lib.sh line 119:
tdnf install -y linux-$flavor-debuginfo
^-----^ SC2086 (info): Double quote to prevent globbing and word splitting.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
squash
The __mcount_loc section contains the addresses of patchable ftrace sites which is used by the ftrace infrastructure in the kernel to create a list of tracable functions and to know where to patch to enable tracing of them. On some kernel configurations, section is called __patchable_function_entries and is generated by the compiler. Either of __mcount_loc or __patchable_function_entries is recognised by the kernel but for these configurations, use __patchable_function_entries as it is what is expected. Note that x86_64 arch is special (of course). Unlike other arches (ppc64le and aarch64) a x86_64 kernel built with -fpatchable-function-entry will generate nops AND create rela__patchable_function_entries for functions even marked as notrace. For this arch, always create __mount_loc sections and rely on __fentry__ relocations to indicate ftrace call sites. Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Pete Swain <swine@google.com> Signed-off-by: Mihails Strasuns <mstrasun@amazon.com> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
joe-lawrence
force-pushed
the
patchable_function_entries
branch
from
422b699
to
a527949
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The __mcount_loc section contains the addresses of patchable ftrace sites which is used by the ftrace infrastructure in the kernel to create a list of tracable functions and to know where to patch to enable tracing of them. On some kernel configurations, section is called __patchable_function_entries and is generated by the compiler. Either of __mcount_loc or __patchable_function_entries is recognised by the kernel but for these configurations, use __patchable_function_entries as it is what is expected.
Note that x86_64 arch is special (of course). Unlike other arches (ppc64le and aarch64) a x86_64 kernel built with -fpatchable-function-entry will generate nops AND create rela__patchable_function_entries for functions even marked as notrace. For this arch, always create __mount_loc sections and rely on fentry relocations to indicate ftrace call sites.