| Message ID | 20200715233301.933201-1-iii@linux.ibm.com |
|---|---|
| Headers | show |
| Series | s390/bpf: implement BPF_PROBE_MEM | expand |
On Wed, Jul 15, 2020 at 4:38 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote: > > This patch series implements BPF_PROBE_MEM opcode, which is used in BPF > programs that walk chains of kernel pointers. It consists of two parts: > patches 1 and 2 enhance s390 exception table infrastructure, patches 3 > and 4 contains the actual implementation and the test. > > We would like to take this series via s390 tree, because it contains > dependent s390 extable and bpf jit changes. However, it would be great > if someone knowledgeable could review patches 3 and 4. > > v1 -> v2: > > - Add `jit->excnt = 0` in order to fix WARNINGs and fallbacks to the > interpreter when running extra_pass. This wasn't easy to spot on > bpf-next, since tests passed anyway. However, on v5.8-rc5 this led > to panics. Applied. Thanks
Hi Alexei, On Tue, Jul 21, 2020 at 11:01:22AM -0700, Alexei Starovoitov wrote: > On Wed, Jul 15, 2020 at 4:38 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote: > > > > This patch series implements BPF_PROBE_MEM opcode, which is used in BPF > > programs that walk chains of kernel pointers. It consists of two parts: > > patches 1 and 2 enhance s390 exception table infrastructure, patches 3 > > and 4 contains the actual implementation and the test. > > > > We would like to take this series via s390 tree, because it contains > > dependent s390 extable and bpf jit changes. However, it would be great > > if someone knowledgeable could review patches 3 and 4. You probably missed this part? It should go upstream via the s390 tree, plus this version is broken since it crashes immediatly if KASLR is enabled. > Applied. Thanks A fixed variant is applied to the s390 tree: https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=05a68e892e89c97df6650cd8cc55058002657cbc
On Tue, Jul 21, 2020 at 1:16 PM Heiko Carstens <hca@linux.ibm.com> wrote: > > Hi Alexei, > > On Tue, Jul 21, 2020 at 11:01:22AM -0700, Alexei Starovoitov wrote: > > On Wed, Jul 15, 2020 at 4:38 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote: > > > > > > This patch series implements BPF_PROBE_MEM opcode, which is used in BPF > > > programs that walk chains of kernel pointers. It consists of two parts: > > > patches 1 and 2 enhance s390 exception table infrastructure, patches 3 > > > and 4 contains the actual implementation and the test. > > > > > > We would like to take this series via s390 tree, because it contains > > > dependent s390 extable and bpf jit changes. However, it would be great > > > if someone knowledgeable could review patches 3 and 4. > > You probably missed this part? It should go upstream via the s390 > tree, plus this version is broken since it crashes immediatly if KASLR > is enabled. Ahh. sorry. will drop.
This patch series implements BPF_PROBE_MEM opcode, which is used in BPF programs that walk chains of kernel pointers. It consists of two parts: patches 1 and 2 enhance s390 exception table infrastructure, patches 3 and 4 contains the actual implementation and the test. We would like to take this series via s390 tree, because it contains dependent s390 extable and bpf jit changes. However, it would be great if someone knowledgeable could review patches 3 and 4. v1 -> v2: - Add `jit->excnt = 0` in order to fix WARNINGs and fallbacks to the interpreter when running extra_pass. This wasn't easy to spot on bpf-next, since tests passed anyway. However, on v5.8-rc5 this led to panics. Ilya Leoshkevich (4): s390/kernel: unify EX_TABLE* implementations s390/kernel: expand the exception table logic to allow new handling options s390/bpf: implement BPF_PROBE_MEM selftests/bpf: add exception handling test arch/s390/include/asm/asm-const.h | 12 ++ arch/s390/include/asm/extable.h | 50 ++++++- arch/s390/include/asm/linkage.h | 35 ++--- arch/s390/kernel/kprobes.c | 4 +- arch/s390/kernel/traps.c | 7 +- arch/s390/mm/fault.c | 4 +- arch/s390/net/bpf_jit_comp.c | 139 +++++++++++++++++- scripts/sorttable.c | 25 ++++ .../selftests/bpf/prog_tests/bpf_iter.c | 17 +++ .../selftests/bpf/progs/bpf_iter_exception.c | 20 +++ 10 files changed, 273 insertions(+), 40 deletions(-) create mode 100644 arch/s390/include/asm/asm-const.h create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_exception.c