| Message ID | f8193e49-5c2d-a9a1-678c-762e5da1a716@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,jammy,PULL] Kernel livepatch support for s390x | expand |
On 04.03.23 00:06, John Cabaj wrote: > BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) > > [Impact] > * Enables Livepatch support for Jammy s390x generic kernel > > [Fix] > b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > 9c018ab00f18 ("s390/nospec: align and size extern thunks") > 110252959a61 ("s390/nospec: add an option to use thunk-extern") > 9183918aabab ("s390/nospec: generate single register thunks if possible") > f08372d421dd ("s390: remove unused expoline to BC instructions") > d1de041f86ad ("s390/entry: remove unused expoline thunk") > 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > 3a133e568eea ("sched: Simplify wake_up_*idle*()") > 360b90e726cd ("sched,livepatch: Use task_call_func()") > 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > > [Test Case] > * Boot test > * Tested a Livepatch (patch to /proc/meminfo module) > > [Other Info] > * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) > * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols > * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) > > [Where things could go wrong] > * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions > * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior > > ----- > > The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > > UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > > are available in the git repository at: > > git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch > > for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > > UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) > > ---------------------------------------------------------------- > Dimitri John Ledkov (1): > UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > > John Cabaj (1): > UBUNTU: [Config] s390x: Removing UBSAN from configuration > > Josh Poimboeuf (1): > bug: Use normal relative pointers in 'struct bug_entry' > > Peter Zijlstra (6): > sched: Improve try_invoke_on_locked_down_task() > sched,rcu: Rework try_invoke_on_locked_down_task() > sched,livepatch: Use task_call_func() > sched: Simplify wake_up_*idle*() > sched,livepatch: Use wake_up_if_idle() > sched: Improve wake_up_all_idle_cpus() take #2 I find this whole block of generic scheduler changes concerning. I have not looked into the actual changes but the delta but changing something related to RCU sounds potentially dangerous for any architecture. Even those not doing livepatch. Some more explanation about why this is needed and roughly what the purpose of those changes is would be much better. So not everyone checking has to go through the same research. > > Vasily Gorbik (6): > s390/entry: remove unused expoline thunk > s390: remove unused expoline to BC instructions > s390/nospec: generate single register thunks if possible > s390/nospec: add an option to use thunk-extern > s390/nospec: align and size extern thunks > s390/nospec: build expoline.o for modules_prepare target > > arch/arm64/include/asm/asm-bug.h | 4 ++-- > arch/powerpc/include/asm/bug.h | 14 ++++++++------ > arch/riscv/include/asm/bug.h | 4 ++-- > arch/s390/Kconfig | 15 +++++++++++++++ > arch/s390/Makefile | 20 +++++++++++++++----- > arch/s390/include/asm/bug.h | 5 +++-- > arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > arch/s390/kernel/entry.S | 1 - > arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > arch/s390/lib/Makefile | 2 ++ > arch/s390/lib/expoline/Makefile | 3 +++ > arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > arch/x86/include/asm/bug.h | 2 +- > debian.master/config/annotations | 5 +++-- > debian.master/config/config.common.ubuntu | 2 +- > debian/rules.d/2-binary-arch.mk | 4 ++++ > include/linux/sched/idle.h | 4 ++++ > include/linux/wait.h | 3 ++- > kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > kernel/rcu/tasks.h | 12 ++++++------ > kernel/rcu/tree_stall.h | 8 ++++---- > kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > kernel/smp.c | 12 +++++------- > lib/bug.c | 15 +++++++-------- > scripts/mod/modpost.c | 5 +++++ > 26 files changed, 263 insertions(+), 207 deletions(-) > create mode 100644 arch/s390/lib/expoline/Makefile > create mode 100644 arch/s390/lib/expoline/expoline.S > create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > - Stefan
On 3/6/23 4:32 AM, Stefan Bader wrote: > On 04.03.23 00:06, John Cabaj wrote: >> BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) >> >> [Impact] >> * Enables Livepatch support for Jammy s390x generic kernel >> >> [Fix] >> b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") >> f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") >> 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") >> ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") >> 9c018ab00f18 ("s390/nospec: align and size extern thunks") >> 110252959a61 ("s390/nospec: add an option to use thunk-extern") >> 9183918aabab ("s390/nospec: generate single register thunks if possible") >> f08372d421dd ("s390: remove unused expoline to BC instructions") >> d1de041f86ad ("s390/entry: remove unused expoline thunk") >> 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") >> 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") >> 3a133e568eea ("sched: Simplify wake_up_*idle*()") >> 360b90e726cd ("sched,livepatch: Use task_call_func()") >> 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") >> 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") >> >> [Test Case] >> * Boot test >> * Tested a Livepatch (patch to /proc/meminfo module) >> >> [Other Info] >> * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) >> * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols >> * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) >> >> [Where things could go wrong] >> * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions >> * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior >> >> ----- >> >> The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: >> >> UBUNTU: Start new release (2023-03-02 21:29:10 -0600) >> >> are available in the git repository at: >> >> git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch >> >> for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: >> >> UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) >> >> ---------------------------------------------------------------- >> Dimitri John Ledkov (1): >> UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x >> >> John Cabaj (1): >> UBUNTU: [Config] s390x: Removing UBSAN from configuration >> >> Josh Poimboeuf (1): >> bug: Use normal relative pointers in 'struct bug_entry' >> >> Peter Zijlstra (6): >> sched: Improve try_invoke_on_locked_down_task() >> sched,rcu: Rework try_invoke_on_locked_down_task() >> sched,livepatch: Use task_call_func() >> sched: Simplify wake_up_*idle*() >> sched,livepatch: Use wake_up_if_idle() >> sched: Improve wake_up_all_idle_cpus() take #2 > > I find this whole block of generic scheduler changes concerning. I have not looked into the actual changes but the delta but changing something related to RCU sounds potentially dangerous for any architecture. Even those not doing livepatch. Some more explanation about why this is needed and roughly what the purpose of those changes is would be much better. So not everyone checking has to go through the same research. Working backwards from "sched: Improve wake_up_all_idle_cpus() take #2": * "sched: Improve wake_up_all_idle_cpus() take #2": Improvements from "sched: Simplify wake_up_*idle*()" * "sched,livepatch: Use wake_up_if_idle()": Uses wake_up_if_idle(cpu) function modified in "sched: Simplify wake_up_*idle*()" to have idle CPUs update patch state * "sched: Simplify wake_up_*idle*()": Doesn't disable kernel preemption to wake up all idle CPUs, rather locks CPU read state * "sched,livepatch: Use task_call_func()": Uses task_call_func() introduced in "sched,rcu: Rework try_invoke_on_locked_down_task()" * "sched,rcu: Rework try_invoke_on_locked_down_task()": Provides integer return value instead of "bool" to better handle specific errors * "sched: Improve try_invoke_on_locked_down_task()": Avoids rq->lock when task is blocked So the patches indicating "livepatch" largely depend on either enhancements from previous patches for waking idle CPUs, or updated function signatures from the task scheduler All patches are already in Kinetic 5.19, and Jammy HWE-5.19 as well >> >> Vasily Gorbik (6): >> s390/entry: remove unused expoline thunk >> s390: remove unused expoline to BC instructions >> s390/nospec: generate single register thunks if possible >> s390/nospec: add an option to use thunk-extern >> s390/nospec: align and size extern thunks >> s390/nospec: build expoline.o for modules_prepare target >> >> arch/arm64/include/asm/asm-bug.h | 4 ++-- >> arch/powerpc/include/asm/bug.h | 14 ++++++++------ >> arch/riscv/include/asm/bug.h | 4 ++-- >> arch/s390/Kconfig | 15 +++++++++++++++ >> arch/s390/Makefile | 20 +++++++++++++++----- >> arch/s390/include/asm/bug.h | 5 +++-- >> arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- >> arch/s390/kernel/entry.S | 1 - >> arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- >> arch/s390/lib/Makefile | 2 ++ >> arch/s390/lib/expoline/Makefile | 3 +++ >> arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ >> arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ >> arch/x86/include/asm/bug.h | 2 +- >> debian.master/config/annotations | 5 +++-- >> debian.master/config/config.common.ubuntu | 2 +- >> debian/rules.d/2-binary-arch.mk | 4 ++++ >> include/linux/sched/idle.h | 4 ++++ >> include/linux/wait.h | 3 ++- >> kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- >> kernel/rcu/tasks.h | 12 ++++++------ >> kernel/rcu/tree_stall.h | 8 ++++---- >> kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ >> kernel/smp.c | 12 +++++------- >> lib/bug.c | 15 +++++++-------- >> scripts/mod/modpost.c | 5 +++++ >> 26 files changed, 263 insertions(+), 207 deletions(-) >> create mode 100644 arch/s390/lib/expoline/Makefile >> create mode 100644 arch/s390/lib/expoline/expoline.S >> create mode 100755 arch/s390/tools/gcc-thunk-extern.sh >> > > - Stefan >
On 07.03.23 23:48, John Cabaj wrote: > On 3/6/23 4:32 AM, Stefan Bader wrote: >> On 04.03.23 00:06, John Cabaj wrote: >>> BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) >>> >>> [Impact] >>> * Enables Livepatch support for Jammy s390x generic kernel >>> >>> [Fix] >>> b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") >>> f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") >>> 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") >>> ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") >>> 9c018ab00f18 ("s390/nospec: align and size extern thunks") >>> 110252959a61 ("s390/nospec: add an option to use thunk-extern") >>> 9183918aabab ("s390/nospec: generate single register thunks if possible") >>> f08372d421dd ("s390: remove unused expoline to BC instructions") >>> d1de041f86ad ("s390/entry: remove unused expoline thunk") >>> 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") >>> 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") >>> 3a133e568eea ("sched: Simplify wake_up_*idle*()") >>> 360b90e726cd ("sched,livepatch: Use task_call_func()") >>> 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") >>> 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") >>> >>> [Test Case] >>> * Boot test >>> * Tested a Livepatch (patch to /proc/meminfo module) >>> >>> [Other Info] >>> * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) >>> * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols >>> * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) >>> >>> [Where things could go wrong] >>> * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions >>> * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior >>> >>> ----- >>> >>> The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: >>> >>> UBUNTU: Start new release (2023-03-02 21:29:10 -0600) >>> >>> are available in the git repository at: >>> >>> git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch >>> >>> for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: >>> >>> UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) >>> >>> ---------------------------------------------------------------- >>> Dimitri John Ledkov (1): >>> UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x >>> >>> John Cabaj (1): >>> UBUNTU: [Config] s390x: Removing UBSAN from configuration >>> >>> Josh Poimboeuf (1): >>> bug: Use normal relative pointers in 'struct bug_entry' >>> >>> Peter Zijlstra (6): >>> sched: Improve try_invoke_on_locked_down_task() >>> sched,rcu: Rework try_invoke_on_locked_down_task() >>> sched,livepatch: Use task_call_func() >>> sched: Simplify wake_up_*idle*() >>> sched,livepatch: Use wake_up_if_idle() >>> sched: Improve wake_up_all_idle_cpus() take #2 >> >> I find this whole block of generic scheduler changes concerning. I have not looked into the actual changes but the delta but changing something related to RCU sounds potentially dangerous for any architecture. Even those not doing livepatch. Some more explanation about why this is needed and roughly what the purpose of those changes is would be much better. So not everyone checking has to go through the same research. > Working backwards from "sched: Improve wake_up_all_idle_cpus() take #2": > > * "sched: Improve wake_up_all_idle_cpus() take #2": Improvements from "sched: Simplify wake_up_*idle*()" > * "sched,livepatch: Use wake_up_if_idle()": Uses wake_up_if_idle(cpu) function modified in "sched: Simplify wake_up_*idle*()" to have idle CPUs update patch state > * "sched: Simplify wake_up_*idle*()": Doesn't disable kernel preemption to wake up all idle CPUs, rather locks CPU read state > * "sched,livepatch: Use task_call_func()": Uses task_call_func() introduced in "sched,rcu: Rework try_invoke_on_locked_down_task()" > * "sched,rcu: Rework try_invoke_on_locked_down_task()": Provides integer return value instead of "bool" to better handle specific errors > * "sched: Improve try_invoke_on_locked_down_task()": Avoids rq->lock when task is blocked > > So the patches indicating "livepatch" largely depend on either enhancements from previous patches for waking idle CPUs, or updated function signatures from the task scheduler > > All patches are already in Kinetic 5.19, and Jammy HWE-5.19 as well Those are part of 5.19 then with all the other changes between 5.15 and 5.19. The group of changes might be sufficient for livepatch. But one cannot completely rule out that having those will require additional changes in other places or cause problems even if only in corner cases. I guess Ideally we would have an artificial workload test which puts some stress on the scheduler. Maybe even checking timings. That we could run across arches to gain more confidence there is no regression hidden within. Call it old grumpy or experience, but changing things in the scheduler and even worse having those changes include RCU make a lot of alarm bells ring in my head. > >>> >>> Vasily Gorbik (6): >>> s390/entry: remove unused expoline thunk >>> s390: remove unused expoline to BC instructions >>> s390/nospec: generate single register thunks if possible >>> s390/nospec: add an option to use thunk-extern >>> s390/nospec: align and size extern thunks >>> s390/nospec: build expoline.o for modules_prepare target >>> >>> arch/arm64/include/asm/asm-bug.h | 4 ++-- >>> arch/powerpc/include/asm/bug.h | 14 ++++++++------ >>> arch/riscv/include/asm/bug.h | 4 ++-- >>> arch/s390/Kconfig | 15 +++++++++++++++ >>> arch/s390/Makefile | 20 +++++++++++++++----- >>> arch/s390/include/asm/bug.h | 5 +++-- >>> arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- >>> arch/s390/kernel/entry.S | 1 - >>> arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- >>> arch/s390/lib/Makefile | 2 ++ >>> arch/s390/lib/expoline/Makefile | 3 +++ >>> arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ >>> arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ >>> arch/x86/include/asm/bug.h | 2 +- >>> debian.master/config/annotations | 5 +++-- >>> debian.master/config/config.common.ubuntu | 2 +- >>> debian/rules.d/2-binary-arch.mk | 4 ++++ >>> include/linux/sched/idle.h | 4 ++++ >>> include/linux/wait.h | 3 ++- >>> kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- >>> kernel/rcu/tasks.h | 12 ++++++------ >>> kernel/rcu/tree_stall.h | 8 ++++---- >>> kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ >>> kernel/smp.c | 12 +++++------- >>> lib/bug.c | 15 +++++++-------- >>> scripts/mod/modpost.c | 5 +++++ >>> 26 files changed, 263 insertions(+), 207 deletions(-) >>> create mode 100644 arch/s390/lib/expoline/Makefile >>> create mode 100644 arch/s390/lib/expoline/expoline.S >>> create mode 100755 arch/s390/tools/gcc-thunk-extern.sh >>> >> >> - Stefan >> > - Stefan
On Wed, 8 Mar 2023 at 08:59, Stefan Bader <stefan.bader@canonical.com> wrote: > > On 07.03.23 23:48, John Cabaj wrote: > > On 3/6/23 4:32 AM, Stefan Bader wrote: > >> On 04.03.23 00:06, John Cabaj wrote: > >>> BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) > >>> > >>> [Impact] > >>> * Enables Livepatch support for Jammy s390x generic kernel > >>> > >>> [Fix] > >>> b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > >>> f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > >>> 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > >>> ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > >>> 9c018ab00f18 ("s390/nospec: align and size extern thunks") > >>> 110252959a61 ("s390/nospec: add an option to use thunk-extern") > >>> 9183918aabab ("s390/nospec: generate single register thunks if possible") > >>> f08372d421dd ("s390: remove unused expoline to BC instructions") > >>> d1de041f86ad ("s390/entry: remove unused expoline thunk") > >>> 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > >>> 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > >>> 3a133e568eea ("sched: Simplify wake_up_*idle*()") > >>> 360b90e726cd ("sched,livepatch: Use task_call_func()") > >>> 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > >>> 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > >>> > >>> [Test Case] > >>> * Boot test > >>> * Tested a Livepatch (patch to /proc/meminfo module) > >>> > >>> [Other Info] > >>> * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) > >>> * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols > >>> * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) > >>> > >>> [Where things could go wrong] > >>> * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions > >>> * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior > >>> > >>> ----- > >>> > >>> The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > >>> > >>> UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > >>> > >>> are available in the git repository at: > >>> > >>> git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch > >>> > >>> for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > >>> > >>> UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) > >>> > >>> ---------------------------------------------------------------- > >>> Dimitri John Ledkov (1): > >>> UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > >>> > >>> John Cabaj (1): > >>> UBUNTU: [Config] s390x: Removing UBSAN from configuration > >>> > >>> Josh Poimboeuf (1): > >>> bug: Use normal relative pointers in 'struct bug_entry' > >>> > >>> Peter Zijlstra (6): > >>> sched: Improve try_invoke_on_locked_down_task() > >>> sched,rcu: Rework try_invoke_on_locked_down_task() > >>> sched,livepatch: Use task_call_func() > >>> sched: Simplify wake_up_*idle*() > >>> sched,livepatch: Use wake_up_if_idle() > >>> sched: Improve wake_up_all_idle_cpus() take #2 > >> > >> I find this whole block of generic scheduler changes concerning. I have not looked into the actual changes but the delta but changing something related to RCU sounds potentially dangerous for any architecture. Even those not doing livepatch. Some more explanation about why this is needed and roughly what the purpose of those changes is would be much better. So not everyone checking has to go through the same research. > > Working backwards from "sched: Improve wake_up_all_idle_cpus() take #2": > > > > * "sched: Improve wake_up_all_idle_cpus() take #2": Improvements from "sched: Simplify wake_up_*idle*()" > > * "sched,livepatch: Use wake_up_if_idle()": Uses wake_up_if_idle(cpu) function modified in "sched: Simplify wake_up_*idle*()" to have idle CPUs update patch state > > * "sched: Simplify wake_up_*idle*()": Doesn't disable kernel preemption to wake up all idle CPUs, rather locks CPU read state > > * "sched,livepatch: Use task_call_func()": Uses task_call_func() introduced in "sched,rcu: Rework try_invoke_on_locked_down_task()" > > * "sched,rcu: Rework try_invoke_on_locked_down_task()": Provides integer return value instead of "bool" to better handle specific errors > > * "sched: Improve try_invoke_on_locked_down_task()": Avoids rq->lock when task is blocked > > > > So the patches indicating "livepatch" largely depend on either enhancements from previous patches for waking idle CPUs, or updated function signatures from the task scheduler > > > > All patches are already in Kinetic 5.19, and Jammy HWE-5.19 as well > > Those are part of 5.19 then with all the other changes between 5.15 and > 5.19. The group of changes might be sufficient for livepatch. But one > cannot completely rule out that having those will require additional > changes in other places or cause problems even if only in corner cases. > > I guess Ideally we would have an artificial workload test which puts > some stress on the scheduler. Maybe even checking timings. That we could > run across arches to gain more confidence there is no regression hidden > within. > Another derivative is running this in production on x86 and s390x, based on v5.15 with VM workloads. > Call it old grumpy or experience, but changing things in the scheduler > and even worse having those changes include RCU make a lot of alarm > bells ring in my head. > > > > >>> > >>> Vasily Gorbik (6): > >>> s390/entry: remove unused expoline thunk > >>> s390: remove unused expoline to BC instructions > >>> s390/nospec: generate single register thunks if possible > >>> s390/nospec: add an option to use thunk-extern > >>> s390/nospec: align and size extern thunks > >>> s390/nospec: build expoline.o for modules_prepare target > >>> > >>> arch/arm64/include/asm/asm-bug.h | 4 ++-- > >>> arch/powerpc/include/asm/bug.h | 14 ++++++++------ > >>> arch/riscv/include/asm/bug.h | 4 ++-- > >>> arch/s390/Kconfig | 15 +++++++++++++++ > >>> arch/s390/Makefile | 20 +++++++++++++++----- > >>> arch/s390/include/asm/bug.h | 5 +++-- > >>> arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > >>> arch/s390/kernel/entry.S | 1 - > >>> arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > >>> arch/s390/lib/Makefile | 2 ++ > >>> arch/s390/lib/expoline/Makefile | 3 +++ > >>> arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > >>> arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > >>> arch/x86/include/asm/bug.h | 2 +- > >>> debian.master/config/annotations | 5 +++-- > >>> debian.master/config/config.common.ubuntu | 2 +- > >>> debian/rules.d/2-binary-arch.mk | 4 ++++ > >>> include/linux/sched/idle.h | 4 ++++ > >>> include/linux/wait.h | 3 ++- > >>> kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > >>> kernel/rcu/tasks.h | 12 ++++++------ > >>> kernel/rcu/tree_stall.h | 8 ++++---- > >>> kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > >>> kernel/smp.c | 12 +++++------- > >>> lib/bug.c | 15 +++++++-------- > >>> scripts/mod/modpost.c | 5 +++++ > >>> 26 files changed, 263 insertions(+), 207 deletions(-) > >>> create mode 100644 arch/s390/lib/expoline/Makefile > >>> create mode 100644 arch/s390/lib/expoline/expoline.S > >>> create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > >>> > >> > >> - Stefan > >> > > > > - Stefan > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team
On 04.03.23 00:06, John Cabaj wrote: > BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) > > [Impact] > * Enables Livepatch support for Jammy s390x generic kernel > > [Fix] > b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > 9c018ab00f18 ("s390/nospec: align and size extern thunks") > 110252959a61 ("s390/nospec: add an option to use thunk-extern") > 9183918aabab ("s390/nospec: generate single register thunks if possible") > f08372d421dd ("s390: remove unused expoline to BC instructions") > d1de041f86ad ("s390/entry: remove unused expoline thunk") > 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > 3a133e568eea ("sched: Simplify wake_up_*idle*()") > 360b90e726cd ("sched,livepatch: Use task_call_func()") > 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > > [Test Case] > * Boot test > * Tested a Livepatch (patch to /proc/meminfo module) > > [Other Info] > * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) > * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols > * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) > > [Where things could go wrong] > * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions > * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior > > ----- > > The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > > UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > > are available in the git repository at: > > git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch > > for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > > UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) > > ---------------------------------------------------------------- > Dimitri John Ledkov (1): > UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > > John Cabaj (1): > UBUNTU: [Config] s390x: Removing UBSAN from configuration > > Josh Poimboeuf (1): > bug: Use normal relative pointers in 'struct bug_entry' > > Peter Zijlstra (6): > sched: Improve try_invoke_on_locked_down_task() > sched,rcu: Rework try_invoke_on_locked_down_task() > sched,livepatch: Use task_call_func() > sched: Simplify wake_up_*idle*() > sched,livepatch: Use wake_up_if_idle() > sched: Improve wake_up_all_idle_cpus() take #2 > > Vasily Gorbik (6): > s390/entry: remove unused expoline thunk > s390: remove unused expoline to BC instructions > s390/nospec: generate single register thunks if possible > s390/nospec: add an option to use thunk-extern > s390/nospec: align and size extern thunks > s390/nospec: build expoline.o for modules_prepare target > > arch/arm64/include/asm/asm-bug.h | 4 ++-- > arch/powerpc/include/asm/bug.h | 14 ++++++++------ > arch/riscv/include/asm/bug.h | 4 ++-- > arch/s390/Kconfig | 15 +++++++++++++++ > arch/s390/Makefile | 20 +++++++++++++++----- > arch/s390/include/asm/bug.h | 5 +++-- > arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > arch/s390/kernel/entry.S | 1 - > arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > arch/s390/lib/Makefile | 2 ++ > arch/s390/lib/expoline/Makefile | 3 +++ > arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > arch/x86/include/asm/bug.h | 2 +- > debian.master/config/annotations | 5 +++-- > debian.master/config/config.common.ubuntu | 2 +- > debian/rules.d/2-binary-arch.mk | 4 ++++ > include/linux/sched/idle.h | 4 ++++ > include/linux/wait.h | 3 ++- > kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > kernel/rcu/tasks.h | 12 ++++++------ > kernel/rcu/tree_stall.h | 8 ++++---- > kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > kernel/smp.c | 12 +++++------- > lib/bug.c | 15 +++++++-------- > scripts/mod/modpost.c | 5 +++++ > 26 files changed, 263 insertions(+), 207 deletions(-) > create mode 100644 arch/s390/lib/expoline/Makefile > create mode 100644 arch/s390/lib/expoline/expoline.S > create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > Ok, from what I hear we have this running in some derivative for a while and also done some testing beforehand. So hopefully this is enough. And queuing this for next cycle should be past 20.04.6 which gets 5.15 as hwe. Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com> I assume that UBSAN can get re-enabled once the kpatch issue gets resolved? - Luke On Fri, Mar 3, 2023 at 3:06 PM John Cabaj <john.cabaj@canonical.com> wrote: > BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch > support for s390x) > > [Impact] > * Enables Livepatch support for Jammy s390x generic kernel > > [Fix] > b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > 9c018ab00f18 ("s390/nospec: align and size extern thunks") > 110252959a61 ("s390/nospec: add an option to use thunk-extern") > 9183918aabab ("s390/nospec: generate single register thunks if possible") > f08372d421dd ("s390: remove unused expoline to BC instructions") > d1de041f86ad ("s390/entry: remove unused expoline thunk") > 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > 3a133e568eea ("sched: Simplify wake_up_*idle*()") > 360b90e726cd ("sched,livepatch: Use task_call_func()") > 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > > [Test Case] > * Boot test > * Tested a Livepatch (patch to /proc/meminfo module) > > [Other Info] > * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from > debian/patches and debian/rules.patch (LP#2002429) > * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x > as kpatch-build could not find symbols > * kpatch update being considered for UBSAN issue ( > https://github.com/dynup/kpatch/issues/1328) > > [Where things could go wrong] > * Functionality already exists upstream, kernel was boot and Livepatch > tested - should have no regressions > * s390x UBSAN functionality no longer included, may not catch previously > caught undefined behavior > > ----- > > The following changes since commit > ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > > UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > > are available in the git repository at: > > git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch > s390x-livepatch > > for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > > UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 > 21:36:26 -0600) > > ---------------------------------------------------------------- > Dimitri John Ledkov (1): > UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > > John Cabaj (1): > UBUNTU: [Config] s390x: Removing UBSAN from configuration > > Josh Poimboeuf (1): > bug: Use normal relative pointers in 'struct bug_entry' > > Peter Zijlstra (6): > sched: Improve try_invoke_on_locked_down_task() > sched,rcu: Rework try_invoke_on_locked_down_task() > sched,livepatch: Use task_call_func() > sched: Simplify wake_up_*idle*() > sched,livepatch: Use wake_up_if_idle() > sched: Improve wake_up_all_idle_cpus() take #2 > > Vasily Gorbik (6): > s390/entry: remove unused expoline thunk > s390: remove unused expoline to BC instructions > s390/nospec: generate single register thunks if possible > s390/nospec: add an option to use thunk-extern > s390/nospec: align and size extern thunks > s390/nospec: build expoline.o for modules_prepare target > > arch/arm64/include/asm/asm-bug.h | 4 ++-- > arch/powerpc/include/asm/bug.h | 14 ++++++++------ > arch/riscv/include/asm/bug.h | 4 ++-- > arch/s390/Kconfig | 15 +++++++++++++++ > arch/s390/Makefile | 20 +++++++++++++++----- > arch/s390/include/asm/bug.h | 5 +++-- > arch/s390/include/asm/nospec-insn.h | 91 > +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > arch/s390/kernel/entry.S | 1 - > arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > arch/s390/lib/Makefile | 2 ++ > arch/s390/lib/expoline/Makefile | 3 +++ > arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > arch/x86/include/asm/bug.h | 2 +- > debian.master/config/annotations | 5 +++-- > debian.master/config/config.common.ubuntu | 2 +- > debian/rules.d/2-binary-arch.mk | 4 ++++ > include/linux/sched/idle.h | 4 ++++ > include/linux/wait.h | 3 ++- > kernel/livepatch/transition.c | 95 > ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > kernel/rcu/tasks.h | 12 ++++++------ > kernel/rcu/tree_stall.h | 8 ++++---- > kernel/sched/core.c | 83 > +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > kernel/smp.c | 12 +++++------- > lib/bug.c | 15 +++++++-------- > scripts/mod/modpost.c | 5 +++++ > 26 files changed, 263 insertions(+), 207 deletions(-) > create mode 100644 arch/s390/lib/expoline/Makefile > create mode 100644 arch/s390/lib/expoline/expoline.S > create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team >
Hi, there is an update on UBSAN. Please have a look here: https://bugs.launchpad.net/ubuntu/+source/kpatch/+bug/2003374/comments/6 pointing to: https://github.com/dynup/kpatch/pull/1332 On Thu, Mar 9, 2023 at 6:37 PM Luke Nowakowski-Krijger < luke.nowakowskikrijger@canonical.com> wrote: > Acked-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com> > > I assume that UBSAN can get re-enabled once the kpatch issue gets > resolved? > > - Luke > > On Fri, Mar 3, 2023 at 3:06 PM John Cabaj <john.cabaj@canonical.com> > wrote: > >> BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch >> support for s390x) >> >> [Impact] >> * Enables Livepatch support for Jammy s390x generic kernel >> >> [Fix] >> b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") >> f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") >> 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") >> ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") >> 9c018ab00f18 ("s390/nospec: align and size extern thunks") >> 110252959a61 ("s390/nospec: add an option to use thunk-extern") >> 9183918aabab ("s390/nospec: generate single register thunks if possible") >> f08372d421dd ("s390: remove unused expoline to BC instructions") >> d1de041f86ad ("s390/entry: remove unused expoline thunk") >> 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") >> 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") >> 3a133e568eea ("sched: Simplify wake_up_*idle*()") >> 360b90e726cd ("sched,livepatch: Use task_call_func()") >> 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") >> 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") >> >> [Test Case] >> * Boot test >> * Tested a Livepatch (patch to /proc/meminfo module) >> >> [Other Info] >> * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from >> debian/patches and debian/rules.patch (LP#2002429) >> * UBSAN (Undefined Behavior Santizer) configuration was removed from >> s390x as kpatch-build could not find symbols >> * kpatch update being considered for UBSAN issue ( >> https://github.com/dynup/kpatch/issues/1328) >> >> [Where things could go wrong] >> * Functionality already exists upstream, kernel was boot and Livepatch >> tested - should have no regressions >> * s390x UBSAN functionality no longer included, may not catch previously >> caught undefined behavior >> >> ----- >> >> The following changes since commit >> ed81d4519af756cfde8c3c02b495c6006b6ee0e9: >> >> UBUNTU: Start new release (2023-03-02 21:29:10 -0600) >> >> are available in the git repository at: >> >> git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch >> s390x-livepatch >> >> for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: >> >> UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 >> 21:36:26 -0600) >> >> ---------------------------------------------------------------- >> Dimitri John Ledkov (1): >> UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x >> >> John Cabaj (1): >> UBUNTU: [Config] s390x: Removing UBSAN from configuration >> >> Josh Poimboeuf (1): >> bug: Use normal relative pointers in 'struct bug_entry' >> >> Peter Zijlstra (6): >> sched: Improve try_invoke_on_locked_down_task() >> sched,rcu: Rework try_invoke_on_locked_down_task() >> sched,livepatch: Use task_call_func() >> sched: Simplify wake_up_*idle*() >> sched,livepatch: Use wake_up_if_idle() >> sched: Improve wake_up_all_idle_cpus() take #2 >> >> Vasily Gorbik (6): >> s390/entry: remove unused expoline thunk >> s390: remove unused expoline to BC instructions >> s390/nospec: generate single register thunks if possible >> s390/nospec: add an option to use thunk-extern >> s390/nospec: align and size extern thunks >> s390/nospec: build expoline.o for modules_prepare target >> >> arch/arm64/include/asm/asm-bug.h | 4 ++-- >> arch/powerpc/include/asm/bug.h | 14 ++++++++------ >> arch/riscv/include/asm/bug.h | 4 ++-- >> arch/s390/Kconfig | 15 +++++++++++++++ >> arch/s390/Makefile | 20 +++++++++++++++----- >> arch/s390/include/asm/bug.h | 5 +++-- >> arch/s390/include/asm/nospec-insn.h | 91 >> +++++++++++++++++++++++++++++++++++-------------------------------------------------------- >> arch/s390/kernel/entry.S | 1 - >> arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- >> arch/s390/lib/Makefile | 2 ++ >> arch/s390/lib/expoline/Makefile | 3 +++ >> arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ >> arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ >> arch/x86/include/asm/bug.h | 2 +- >> debian.master/config/annotations | 5 +++-- >> debian.master/config/config.common.ubuntu | 2 +- >> debian/rules.d/2-binary-arch.mk | 4 ++++ >> include/linux/sched/idle.h | 4 ++++ >> include/linux/wait.h | 3 ++- >> kernel/livepatch/transition.c | 95 >> ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- >> kernel/rcu/tasks.h | 12 ++++++------ >> kernel/rcu/tree_stall.h | 8 ++++---- >> kernel/sched/core.c | 83 >> +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ >> kernel/smp.c | 12 +++++------- >> lib/bug.c | 15 +++++++-------- >> scripts/mod/modpost.c | 5 +++++ >> 26 files changed, 263 insertions(+), 207 deletions(-) >> create mode 100644 arch/s390/lib/expoline/Makefile >> create mode 100644 arch/s390/lib/expoline/expoline.S >> create mode 100755 arch/s390/tools/gcc-thunk-extern.sh >> >> -- >> kernel-team mailing list >> kernel-team@lists.ubuntu.com >> https://lists.ubuntu.com/mailman/listinfo/kernel-team >> > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team >
On Thu, 9 Mar 2023 at 17:37, Luke Nowakowski-Krijger < luke.nowakowskikrijger@canonical.com> wrote: > Acked-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com> > > I assume that UBSAN can get re-enabled once the kpatch issue gets > resolved? > > - Luke > Once we have updated kpatch in our service, we will work on re-enabling UBSAN back. So yes, this is a temporary solution (TBD how many SRU cycles in practice). Regards, Dimitri. > > On Fri, Mar 3, 2023 at 3:06 PM John Cabaj <john.cabaj@canonical.com> > wrote: > >> BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch >> support for s390x) >> >> [Impact] >> * Enables Livepatch support for Jammy s390x generic kernel >> >> [Fix] >> b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") >> f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") >> 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") >> ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") >> 9c018ab00f18 ("s390/nospec: align and size extern thunks") >> 110252959a61 ("s390/nospec: add an option to use thunk-extern") >> 9183918aabab ("s390/nospec: generate single register thunks if possible") >> f08372d421dd ("s390: remove unused expoline to BC instructions") >> d1de041f86ad ("s390/entry: remove unused expoline thunk") >> 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") >> 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") >> 3a133e568eea ("sched: Simplify wake_up_*idle*()") >> 360b90e726cd ("sched,livepatch: Use task_call_func()") >> 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") >> 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") >> >> [Test Case] >> * Boot test >> * Tested a Livepatch (patch to /proc/meminfo module) >> >> [Other Info] >> * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from >> debian/patches and debian/rules.patch (LP#2002429) >> * UBSAN (Undefined Behavior Santizer) configuration was removed from >> s390x as kpatch-build could not find symbols >> * kpatch update being considered for UBSAN issue ( >> https://github.com/dynup/kpatch/issues/1328) >> >> [Where things could go wrong] >> * Functionality already exists upstream, kernel was boot and Livepatch >> tested - should have no regressions >> * s390x UBSAN functionality no longer included, may not catch previously >> caught undefined behavior >> >> ----- >> >> The following changes since commit >> ed81d4519af756cfde8c3c02b495c6006b6ee0e9: >> >> UBUNTU: Start new release (2023-03-02 21:29:10 -0600) >> >> are available in the git repository at: >> >> git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch >> s390x-livepatch >> >> for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: >> >> UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 >> 21:36:26 -0600) >> >> ---------------------------------------------------------------- >> Dimitri John Ledkov (1): >> UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x >> >> John Cabaj (1): >> UBUNTU: [Config] s390x: Removing UBSAN from configuration >> >> Josh Poimboeuf (1): >> bug: Use normal relative pointers in 'struct bug_entry' >> >> Peter Zijlstra (6): >> sched: Improve try_invoke_on_locked_down_task() >> sched,rcu: Rework try_invoke_on_locked_down_task() >> sched,livepatch: Use task_call_func() >> sched: Simplify wake_up_*idle*() >> sched,livepatch: Use wake_up_if_idle() >> sched: Improve wake_up_all_idle_cpus() take #2 >> >> Vasily Gorbik (6): >> s390/entry: remove unused expoline thunk >> s390: remove unused expoline to BC instructions >> s390/nospec: generate single register thunks if possible >> s390/nospec: add an option to use thunk-extern >> s390/nospec: align and size extern thunks >> s390/nospec: build expoline.o for modules_prepare target >> >> arch/arm64/include/asm/asm-bug.h | 4 ++-- >> arch/powerpc/include/asm/bug.h | 14 ++++++++------ >> arch/riscv/include/asm/bug.h | 4 ++-- >> arch/s390/Kconfig | 15 +++++++++++++++ >> arch/s390/Makefile | 20 +++++++++++++++----- >> arch/s390/include/asm/bug.h | 5 +++-- >> arch/s390/include/asm/nospec-insn.h | 91 >> +++++++++++++++++++++++++++++++++++-------------------------------------------------------- >> arch/s390/kernel/entry.S | 1 - >> arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- >> arch/s390/lib/Makefile | 2 ++ >> arch/s390/lib/expoline/Makefile | 3 +++ >> arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ >> arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ >> arch/x86/include/asm/bug.h | 2 +- >> debian.master/config/annotations | 5 +++-- >> debian.master/config/config.common.ubuntu | 2 +- >> debian/rules.d/2-binary-arch.mk | 4 ++++ >> include/linux/sched/idle.h | 4 ++++ >> include/linux/wait.h | 3 ++- >> kernel/livepatch/transition.c | 95 >> ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- >> kernel/rcu/tasks.h | 12 ++++++------ >> kernel/rcu/tree_stall.h | 8 ++++---- >> kernel/sched/core.c | 83 >> +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ >> kernel/smp.c | 12 +++++------- >> lib/bug.c | 15 +++++++-------- >> scripts/mod/modpost.c | 5 +++++ >> 26 files changed, 263 insertions(+), 207 deletions(-) >> create mode 100644 arch/s390/lib/expoline/Makefile >> create mode 100644 arch/s390/lib/expoline/expoline.S >> create mode 100755 arch/s390/tools/gcc-thunk-extern.sh >> >> -- >> kernel-team mailing list >> kernel-team@lists.ubuntu.com >> https://lists.ubuntu.com/mailman/listinfo/kernel-team >> > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team >
On 3/9/23 12:07 PM, Dimitri John Ledkov wrote: > > > On Thu, 9 Mar 2023 at 17:37, Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com <mailto:luke.nowakowskikrijger@canonical.com>> wrote: > > Acked-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com <mailto:luke.nowakowskikrijger@canonical.com>> > > I assume that UBSAN can get re-enabled once the kpatch issue gets resolved? > > - Luke > > > > Once we have updated kpatch in our service, we will work on re-enabling UBSAN back. So yes, this is a temporary solution (TBD how many SRU cycles in practice). > > Regards, > > Dimitri. I added the Jammy package to LP#2003374 so we don't lose track once kpatch is fixed. -John > > > > > On Fri, Mar 3, 2023 at 3:06 PM John Cabaj <john.cabaj@canonical.com <mailto:john.cabaj@canonical.com>> wrote: > > BugLink: https://bugs.launchpad.net/bugs/1639924 <https://bugs.launchpad.net/bugs/1639924> (Kernel livepatch support for s390x) > > [Impact] > * Enables Livepatch support for Jammy s390x generic kernel > > [Fix] > b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > 9c018ab00f18 ("s390/nospec: align and size extern thunks") > 110252959a61 ("s390/nospec: add an option to use thunk-extern") > 9183918aabab ("s390/nospec: generate single register thunks if possible") > f08372d421dd ("s390: remove unused expoline to BC instructions") > d1de041f86ad ("s390/entry: remove unused expoline thunk") > 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > 3a133e568eea ("sched: Simplify wake_up_*idle*()") > 360b90e726cd ("sched,livepatch: Use task_call_func()") > 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > > [Test Case] > * Boot test > * Tested a Livepatch (patch to /proc/meminfo module) > > [Other Info] > * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) > * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols > * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328 <https://github.com/dynup/kpatch/issues/1328>) > > [Where things could go wrong] > * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions > * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior > > ----- > > The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > > UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > > are available in the git repository at: > > git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch > > for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > > UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) > > ---------------------------------------------------------------- > Dimitri John Ledkov (1): > UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > > John Cabaj (1): > UBUNTU: [Config] s390x: Removing UBSAN from configuration > > Josh Poimboeuf (1): > bug: Use normal relative pointers in 'struct bug_entry' > > Peter Zijlstra (6): > sched: Improve try_invoke_on_locked_down_task() > sched,rcu: Rework try_invoke_on_locked_down_task() > sched,livepatch: Use task_call_func() > sched: Simplify wake_up_*idle*() > sched,livepatch: Use wake_up_if_idle() > sched: Improve wake_up_all_idle_cpus() take #2 > > Vasily Gorbik (6): > s390/entry: remove unused expoline thunk > s390: remove unused expoline to BC instructions > s390/nospec: generate single register thunks if possible > s390/nospec: add an option to use thunk-extern > s390/nospec: align and size extern thunks > s390/nospec: build expoline.o for modules_prepare target > > arch/arm64/include/asm/asm-bug.h | 4 ++-- > arch/powerpc/include/asm/bug.h | 14 ++++++++------ > arch/riscv/include/asm/bug.h | 4 ++-- > arch/s390/Kconfig | 15 +++++++++++++++ > arch/s390/Makefile | 20 +++++++++++++++----- > arch/s390/include/asm/bug.h | 5 +++-- > arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > arch/s390/kernel/entry.S | 1 - > arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > arch/s390/lib/Makefile | 2 ++ > arch/s390/lib/expoline/Makefile | 3 +++ > arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > arch/x86/include/asm/bug.h | 2 +- > debian.master/config/annotations | 5 +++-- > debian.master/config/config.common.ubuntu | 2 +- > debian/rules.d/2-binary-arch.mk <http://2-binary-arch.mk> | 4 ++++ > include/linux/sched/idle.h | 4 ++++ > include/linux/wait.h | 3 ++- > kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > kernel/rcu/tasks.h | 12 ++++++------ > kernel/rcu/tree_stall.h | 8 ++++---- > kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > kernel/smp.c | 12 +++++------- > lib/bug.c | 15 +++++++-------- > scripts/mod/modpost.c | 5 +++++ > 26 files changed, 263 insertions(+), 207 deletions(-) > create mode 100644 arch/s390/lib/expoline/Makefile > create mode 100644 arch/s390/lib/expoline/expoline.S > create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com <mailto:kernel-team@lists.ubuntu.com> > https://lists.ubuntu.com/mailman/listinfo/kernel-team <https://lists.ubuntu.com/mailman/listinfo/kernel-team> > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com <mailto:kernel-team@lists.ubuntu.com> > https://lists.ubuntu.com/mailman/listinfo/kernel-team <https://lists.ubuntu.com/mailman/listinfo/kernel-team> > > > > -- > okurrr, > > Dimitri
On 04.03.23 00:06, John Cabaj wrote: > BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) > > [Impact] > * Enables Livepatch support for Jammy s390x generic kernel > > [Fix] > b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") > f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") > 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") > ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") > 9c018ab00f18 ("s390/nospec: align and size extern thunks") > 110252959a61 ("s390/nospec: add an option to use thunk-extern") > 9183918aabab ("s390/nospec: generate single register thunks if possible") > f08372d421dd ("s390: remove unused expoline to BC instructions") > d1de041f86ad ("s390/entry: remove unused expoline thunk") > 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") > 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") > 3a133e568eea ("sched: Simplify wake_up_*idle*()") > 360b90e726cd ("sched,livepatch: Use task_call_func()") > 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") > 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") > > [Test Case] > * Boot test > * Tested a Livepatch (patch to /proc/meminfo module) > > [Other Info] > * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) > * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols > * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) > > [Where things could go wrong] > * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions > * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior > > ----- > > The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: > > UBUNTU: Start new release (2023-03-02 21:29:10 -0600) > > are available in the git repository at: > > git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch > > for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: > > UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) > > ---------------------------------------------------------------- > Dimitri John Ledkov (1): > UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x > > John Cabaj (1): > UBUNTU: [Config] s390x: Removing UBSAN from configuration > > Josh Poimboeuf (1): > bug: Use normal relative pointers in 'struct bug_entry' > > Peter Zijlstra (6): > sched: Improve try_invoke_on_locked_down_task() > sched,rcu: Rework try_invoke_on_locked_down_task() > sched,livepatch: Use task_call_func() > sched: Simplify wake_up_*idle*() > sched,livepatch: Use wake_up_if_idle() > sched: Improve wake_up_all_idle_cpus() take #2 > > Vasily Gorbik (6): > s390/entry: remove unused expoline thunk > s390: remove unused expoline to BC instructions > s390/nospec: generate single register thunks if possible > s390/nospec: add an option to use thunk-extern > s390/nospec: align and size extern thunks > s390/nospec: build expoline.o for modules_prepare target > > arch/arm64/include/asm/asm-bug.h | 4 ++-- > arch/powerpc/include/asm/bug.h | 14 ++++++++------ > arch/riscv/include/asm/bug.h | 4 ++-- > arch/s390/Kconfig | 15 +++++++++++++++ > arch/s390/Makefile | 20 +++++++++++++++----- > arch/s390/include/asm/bug.h | 5 +++-- > arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- > arch/s390/kernel/entry.S | 1 - > arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- > arch/s390/lib/Makefile | 2 ++ > arch/s390/lib/expoline/Makefile | 3 +++ > arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ > arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ > arch/x86/include/asm/bug.h | 2 +- > debian.master/config/annotations | 5 +++-- > debian.master/config/config.common.ubuntu | 2 +- > debian/rules.d/2-binary-arch.mk | 4 ++++ > include/linux/sched/idle.h | 4 ++++ > include/linux/wait.h | 3 ++- > kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- > kernel/rcu/tasks.h | 12 ++++++------ > kernel/rcu/tree_stall.h | 8 ++++---- > kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ > kernel/smp.c | 12 +++++------- > lib/bug.c | 15 +++++++-------- > scripts/mod/modpost.c | 5 +++++ > 26 files changed, 263 insertions(+), 207 deletions(-) > create mode 100644 arch/s390/lib/expoline/Makefile > create mode 100644 arch/s390/lib/expoline/expoline.S > create mode 100755 arch/s390/tools/gcc-thunk-extern.sh > Applied to jammy:linux/master-next. Thanks. -Stefan
BugLink: https://bugs.launchpad.net/bugs/1639924 (Kernel livepatch support for s390x) [Impact] * Enables Livepatch support for Jammy s390x generic kernel [Fix] b56340e565fd ("UBUNTU: [Config] s390x: Removing UBSAN from configuration") f0bd174678a9 ("UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x") 145dd7c7bfc6 ("s390/nospec: build expoline.o for modules_prepare target") ad24b243a0be ("bug: Use normal relative pointers in 'struct bug_entry'") 9c018ab00f18 ("s390/nospec: align and size extern thunks") 110252959a61 ("s390/nospec: add an option to use thunk-extern") 9183918aabab ("s390/nospec: generate single register thunks if possible") f08372d421dd ("s390: remove unused expoline to BC instructions") d1de041f86ad ("s390/entry: remove unused expoline thunk") 376e067eb888 ("sched: Improve wake_up_all_idle_cpus() take #2") 16fa7242e5b9 ("sched,livepatch: Use wake_up_if_idle()") 3a133e568eea ("sched: Simplify wake_up_*idle*()") 360b90e726cd ("sched,livepatch: Use task_call_func()") 3c01d492a326 ("sched,rcu: Rework try_invoke_on_locked_down_task()") 2a989b8ace35 ("sched: Improve try_invoke_on_locked_down_task()") [Test Case] * Boot test * Tested a Livepatch (patch to /proc/meminfo module) [Other Info] * Requires patch to GCC-11.3, removing gcc-ibmz-plt-revert.diff from debian/patches and debian/rules.patch (LP#2002429) * UBSAN (Undefined Behavior Santizer) configuration was removed from s390x as kpatch-build could not find symbols * kpatch update being considered for UBSAN issue (https://github.com/dynup/kpatch/issues/1328) [Where things could go wrong] * Functionality already exists upstream, kernel was boot and Livepatch tested - should have no regressions * s390x UBSAN functionality no longer included, may not catch previously caught undefined behavior ----- The following changes since commit ed81d4519af756cfde8c3c02b495c6006b6ee0e9: UBUNTU: Start new release (2023-03-02 21:29:10 -0600) are available in the git repository at: git+ssh://user@kathleen/home/john-cabaj/for-review/jammy-s390x-livepatch s390x-livepatch for you to fetch changes up to b56340e565fdae9b6fc53b573e01194435a65e3e: UBUNTU: [Config] s390x: Removing UBSAN from configuration (2023-03-02 21:36:26 -0600) ---------------------------------------------------------------- Dimitri John Ledkov (1): UBUNTU: [Config] Enable EXPOLINE_EXTERN on s390x John Cabaj (1): UBUNTU: [Config] s390x: Removing UBSAN from configuration Josh Poimboeuf (1): bug: Use normal relative pointers in 'struct bug_entry' Peter Zijlstra (6): sched: Improve try_invoke_on_locked_down_task() sched,rcu: Rework try_invoke_on_locked_down_task() sched,livepatch: Use task_call_func() sched: Simplify wake_up_*idle*() sched,livepatch: Use wake_up_if_idle() sched: Improve wake_up_all_idle_cpus() take #2 Vasily Gorbik (6): s390/entry: remove unused expoline thunk s390: remove unused expoline to BC instructions s390/nospec: generate single register thunks if possible s390/nospec: add an option to use thunk-extern s390/nospec: align and size extern thunks s390/nospec: build expoline.o for modules_prepare target arch/arm64/include/asm/asm-bug.h | 4 ++-- arch/powerpc/include/asm/bug.h | 14 ++++++++------ arch/riscv/include/asm/bug.h | 4 ++-- arch/s390/Kconfig | 15 +++++++++++++++ arch/s390/Makefile | 20 +++++++++++++++----- arch/s390/include/asm/bug.h | 5 +++-- arch/s390/include/asm/nospec-insn.h | 91 +++++++++++++++++++++++++++++++++++-------------------------------------------------------- arch/s390/kernel/entry.S | 1 - arch/s390/kernel/nospec-branch.c | 25 +++++-------------------- arch/s390/lib/Makefile | 2 ++ arch/s390/lib/expoline/Makefile | 3 +++ arch/s390/lib/expoline/expoline.S | 12 ++++++++++++ arch/s390/tools/gcc-thunk-extern.sh | 24 ++++++++++++++++++++++++ arch/x86/include/asm/bug.h | 2 +- debian.master/config/annotations | 5 +++-- debian.master/config/config.common.ubuntu | 2 +- debian/rules.d/2-binary-arch.mk | 4 ++++ include/linux/sched/idle.h | 4 ++++ include/linux/wait.h | 3 ++- kernel/livepatch/transition.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------- kernel/rcu/tasks.h | 12 ++++++------ kernel/rcu/tree_stall.h | 8 ++++---- kernel/sched/core.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++------------------------------------ kernel/smp.c | 12 +++++------- lib/bug.c | 15 +++++++-------- scripts/mod/modpost.c | 5 +++++ 26 files changed, 263 insertions(+), 207 deletions(-) create mode 100644 arch/s390/lib/expoline/Makefile create mode 100644 arch/s390/lib/expoline/expoline.S create mode 100755 arch/s390/tools/gcc-thunk-extern.sh