| Message ID | 20210818121426.195205-1-dimitri.ledkov@canonical.com |
|---|---|
| Headers | show |
| Series | Disable ftrace of sbi functions | expand |
Acked-by: Tim Gardner <tim.gardner@canonical.com> On 8/18/21 6:14 AM, Dimitri John Ledkov wrote: > [Impact] > > * A kernel build can fail to boot with Oops and illegal instruction > as seen at > https://bugs.launchpad.net/ubuntu/+source/linux-riscv-5.11/+bug/1934548 > on Unmatched board. > > * One cannot frace functions, used in frace setup. On RISC-V these > are sbi calls to firmware from sbi.c which were not excluded for > tracing. Similar functions on other arches are already excluded. > > * Previously we have identified one call that was racing and causing > failure to boot and marked it for notrace. But the upstream solution > is to disable all functions in sbi.c which was implemented in v5.12 > but did not make it to stable/earlier trees. > > * Note that this failure to boot is racy, meaning some lucky builds > of kernel always boot or always fail, as was observed on Unmatched. > > [Test Plan] > > * Kernel should boot on baremetal Unmatched, Unleashed, and qemu > > [Where problems could occur] > > * This patch disables profiling and tracing of sbi.c function > calls. Previously it was possible to trace them, somewhat, either > successfully in a racy manner or to cause a kernel panic. > > BugLink: https://bugs.launchpad.net/bugs/1940426 > > Changes since v1: > * Use a new buglink > * Add buglink to all patches > > Dimitri John Ledkov (1): > Revert "UBUNTU: SAUCE: RISC-V: prevent sbi_send_cpumask_ipi race with > ftrace" > > Guo Ren (2): > riscv: Fixup wrong ftrace remove cflag > riscv: Fixup patch_text panic in ftrace > > arch/riscv/kernel/Makefile | 5 +++-- > arch/riscv/kernel/sbi.c | 2 +- > arch/riscv/mm/Makefile | 3 ++- > 3 files changed, 6 insertions(+), 4 deletions(-) >
On 18.08.21 14:14, Dimitri John Ledkov wrote: > [Impact] > > * A kernel build can fail to boot with Oops and illegal instruction > as seen at > https://bugs.launchpad.net/ubuntu/+source/linux-riscv-5.11/+bug/1934548 > on Unmatched board. > > * One cannot frace functions, used in frace setup. On RISC-V these > are sbi calls to firmware from sbi.c which were not excluded for > tracing. Similar functions on other arches are already excluded. > > * Previously we have identified one call that was racing and causing > failure to boot and marked it for notrace. But the upstream solution > is to disable all functions in sbi.c which was implemented in v5.12 > but did not make it to stable/earlier trees. > > * Note that this failure to boot is racy, meaning some lucky builds > of kernel always boot or always fail, as was observed on Unmatched. > > [Test Plan] > > * Kernel should boot on baremetal Unmatched, Unleashed, and qemu > > [Where problems could occur] > > * This patch disables profiling and tracing of sbi.c function > calls. Previously it was possible to trace them, somewhat, either > successfully in a racy manner or to cause a kernel panic. > > BugLink: https://bugs.launchpad.net/bugs/1940426 > > Changes since v1: > * Use a new buglink > * Add buglink to all patches > > Dimitri John Ledkov (1): > Revert "UBUNTU: SAUCE: RISC-V: prevent sbi_send_cpumask_ipi race with > ftrace" > > Guo Ren (2): > riscv: Fixup wrong ftrace remove cflag > riscv: Fixup patch_text panic in ftrace > > arch/riscv/kernel/Makefile | 5 +++-- > arch/riscv/kernel/sbi.c | 2 +- > arch/riscv/mm/Makefile | 3 ++- > 3 files changed, 6 insertions(+), 4 deletions(-) > I probably would suggest to move the BugLink either to the first line of commit message or before the new s-o-b area. That can be done when applying. I tried to leave that possibility also for adding the missing bug reference on the fly. But I guess my cheery morning mood did not suggest that. Acked-by: Stefan Bader <stefan.bader@canonical.com>
On 18.08.21 14:14, Dimitri John Ledkov wrote: > [Impact] > > * A kernel build can fail to boot with Oops and illegal instruction > as seen at > https://bugs.launchpad.net/ubuntu/+source/linux-riscv-5.11/+bug/1934548 > on Unmatched board. > > * One cannot frace functions, used in frace setup. On RISC-V these > are sbi calls to firmware from sbi.c which were not excluded for > tracing. Similar functions on other arches are already excluded. > > * Previously we have identified one call that was racing and causing > failure to boot and marked it for notrace. But the upstream solution > is to disable all functions in sbi.c which was implemented in v5.12 > but did not make it to stable/earlier trees. > > * Note that this failure to boot is racy, meaning some lucky builds > of kernel always boot or always fail, as was observed on Unmatched. > > [Test Plan] > > * Kernel should boot on baremetal Unmatched, Unleashed, and qemu > > [Where problems could occur] > > * This patch disables profiling and tracing of sbi.c function > calls. Previously it was possible to trace them, somewhat, either > successfully in a racy manner or to cause a kernel panic. > > BugLink: https://bugs.launchpad.net/bugs/1940426 > > Changes since v1: > * Use a new buglink > * Add buglink to all patches > > Dimitri John Ledkov (1): > Revert "UBUNTU: SAUCE: RISC-V: prevent sbi_send_cpumask_ipi race with > ftrace" > > Guo Ren (2): > riscv: Fixup wrong ftrace remove cflag > riscv: Fixup patch_text panic in ftrace > > arch/riscv/kernel/Makefile | 5 +++-- > arch/riscv/kernel/sbi.c | 2 +- > arch/riscv/mm/Makefile | 3 ++- > 3 files changed, 6 insertions(+), 4 deletions(-) > Applied to hirsute:linux-riscv/master. Thanks. -Stefan
[Impact] * A kernel build can fail to boot with Oops and illegal instruction as seen at https://bugs.launchpad.net/ubuntu/+source/linux-riscv-5.11/+bug/1934548 on Unmatched board. * One cannot frace functions, used in frace setup. On RISC-V these are sbi calls to firmware from sbi.c which were not excluded for tracing. Similar functions on other arches are already excluded. * Previously we have identified one call that was racing and causing failure to boot and marked it for notrace. But the upstream solution is to disable all functions in sbi.c which was implemented in v5.12 but did not make it to stable/earlier trees. * Note that this failure to boot is racy, meaning some lucky builds of kernel always boot or always fail, as was observed on Unmatched. [Test Plan] * Kernel should boot on baremetal Unmatched, Unleashed, and qemu [Where problems could occur] * This patch disables profiling and tracing of sbi.c function calls. Previously it was possible to trace them, somewhat, either successfully in a racy manner or to cause a kernel panic. BugLink: https://bugs.launchpad.net/bugs/1940426 Changes since v1: * Use a new buglink * Add buglink to all patches Dimitri John Ledkov (1): Revert "UBUNTU: SAUCE: RISC-V: prevent sbi_send_cpumask_ipi race with ftrace" Guo Ren (2): riscv: Fixup wrong ftrace remove cflag riscv: Fixup patch_text panic in ftrace arch/riscv/kernel/Makefile | 5 +++-- arch/riscv/kernel/sbi.c | 2 +- arch/riscv/mm/Makefile | 3 ++- 3 files changed, 6 insertions(+), 4 deletions(-)