| Message ID | 20210809093437.876558-5-johan.almbladh@anyfinetworks.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | Fix MAX_TAIL_CALL_CNT handling in eBPF JITs | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 2 maintainers not CCed: linux-s390@vger.kernel.org borntraeger@de.ibm.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 18 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | Link |
On Mon, 2021-08-09 at 11:34 +0200, Johan Almbladh wrote: > Before, the eBPF JIT allowed up to MAX_TAIL_CALL_CNT + 1 tail calls. > Now, precisely MAX_TAIL_CALL_CNT is allowed, which is in line with the > behaviour of the interpreter. Verified with the test_bpf test suite > on qemu-system-s390x. > > Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> > --- > arch/s390/net/bpf_jit_comp.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/s390/net/bpf_jit_comp.c > b/arch/s390/net/bpf_jit_comp.c > index 88419263a89a..f6cdf13285ed 100644 > --- a/arch/s390/net/bpf_jit_comp.c > +++ b/arch/s390/net/bpf_jit_comp.c > @@ -1363,7 +1363,7 @@ static noinline int bpf_jit_insn(struct bpf_jit > *jit, struct bpf_prog *fp, > jit->prg); > > /* > - * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) > + * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT) > * goto out; > */ > > @@ -1377,8 +1377,8 @@ static noinline int bpf_jit_insn(struct bpf_jit > *jit, struct bpf_prog *fp, > EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, > REG_15, off); > /* clij %w1,MAX_TAIL_CALL_CNT,0x2,out */ This comment needs to be updated as well. > patch_2_clij = jit->prg; > - EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, > MAX_TAIL_CALL_CNT, > - 2, jit->prg); > + EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, > + MAX_TAIL_CALL_CNT - 1, 2, jit->prg); > > /* > * prog = array->ptrs[index]; With that: Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
On Mon, Aug 9, 2021 at 2:24 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote: > > On Mon, 2021-08-09 at 11:34 +0200, Johan Almbladh wrote: > > Before, the eBPF JIT allowed up to MAX_TAIL_CALL_CNT + 1 tail calls. > > Now, precisely MAX_TAIL_CALL_CNT is allowed, which is in line with the > > behaviour of the interpreter. Verified with the test_bpf test suite > > on qemu-system-s390x. > > > > Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> > > --- > > arch/s390/net/bpf_jit_comp.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/s390/net/bpf_jit_comp.c > > b/arch/s390/net/bpf_jit_comp.c > > index 88419263a89a..f6cdf13285ed 100644 > > --- a/arch/s390/net/bpf_jit_comp.c > > +++ b/arch/s390/net/bpf_jit_comp.c > > @@ -1363,7 +1363,7 @@ static noinline int bpf_jit_insn(struct bpf_jit > > *jit, struct bpf_prog *fp, > > jit->prg); > > > > /* > > - * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) > > + * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT) > > * goto out; > > */ > > > > @@ -1377,8 +1377,8 @@ static noinline int bpf_jit_insn(struct bpf_jit > > *jit, struct bpf_prog *fp, > > EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, > > REG_15, off); > > /* clij %w1,MAX_TAIL_CALL_CNT,0x2,out */ > > This comment needs to be updated as well. > > > patch_2_clij = jit->prg; > > - EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, > > MAX_TAIL_CALL_CNT, > > - 2, jit->prg); > > + EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, > > + MAX_TAIL_CALL_CNT - 1, 2, jit->prg); > > > > /* > > * prog = array->ptrs[index]; > > With that: > > Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> > Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> > Fixing it. Thanks!
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 88419263a89a..f6cdf13285ed 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1363,7 +1363,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, jit->prg); /* - * if (tail_call_cnt++ > MAX_TAIL_CALL_CNT) + * if (tail_call_cnt++ >= MAX_TAIL_CALL_CNT) * goto out; */ @@ -1377,8 +1377,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off); /* clij %w1,MAX_TAIL_CALL_CNT,0x2,out */ patch_2_clij = jit->prg; - EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT, - 2, jit->prg); + EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, + MAX_TAIL_CALL_CNT - 1, 2, jit->prg); /* * prog = array->ptrs[index];
Before, the eBPF JIT allowed up to MAX_TAIL_CALL_CNT + 1 tail calls. Now, precisely MAX_TAIL_CALL_CNT is allowed, which is in line with the behaviour of the interpreter. Verified with the test_bpf test suite on qemu-system-s390x. Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> --- arch/s390/net/bpf_jit_comp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)