| Message ID | 20220809134603.1769279-2-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Commit | fa96b24204af42274ec13dfb2f2e6990d7510e55 |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Add kfuncs for PKCS#7 signature verification | expand |
On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > This allows to declare a kfunc as sleepable and prevents its use in > a non sleepable program. Nit: "Declare a kfunc as sleepable and prevent its use in a non-sleepable program." It's missing the part *how* the patch accomplishes its goals. > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > Co-developed-by: Yosry Ahmed <yosryahmed@google.com> > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > Signed-off-by: Hao Luo <haoluo@google.com> > --- > Documentation/bpf/kfuncs.rst | 6 ++++++ > include/linux/btf.h | 1 + > kernel/bpf/btf.c | 9 +++++++++ > 3 files changed, 16 insertions(+) > > diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst > index c0b7dae6dbf5..c8b21de1c772 100644 > --- a/Documentation/bpf/kfuncs.rst > +++ b/Documentation/bpf/kfuncs.rst > @@ -146,6 +146,12 @@ that operate (change some property, perform some operation) on an object that > was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer to > ensure the integrity of the operation being performed on the expected object. > > +2.4.6 KF_SLEEPABLE flag > +----------------------- > + > +The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can only > +be called by sleepable BPF programs (BPF_F_SLEEPABLE). > + > 2.5 Registering the kfuncs > -------------------------- > > diff --git a/include/linux/btf.h b/include/linux/btf.h > index cdb376d53238..976cbdd2981f 100644 > --- a/include/linux/btf.h > +++ b/include/linux/btf.h > @@ -49,6 +49,7 @@ > * for this case. > */ > #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */ > +#define KF_SLEEPABLE (1 << 5) /* kfunc may sleep */ > > struct btf; > struct btf_member; > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > index 7e64447659f3..d3e4c86b8fcd 100644 > --- a/kernel/bpf/btf.c > +++ b/kernel/bpf/btf.c > @@ -6175,6 +6175,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, > { > enum bpf_prog_type prog_type = resolve_prog_type(env->prog); > bool rel = false, kptr_get = false, trusted_arg = false; > + bool sleepable = false; > struct bpf_verifier_log *log = &env->log; > u32 i, nargs, ref_id, ref_obj_id = 0; > bool is_kfunc = btf_is_kernel(btf); > @@ -6212,6 +6213,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, > rel = kfunc_flags & KF_RELEASE; > kptr_get = kfunc_flags & KF_KPTR_GET; > trusted_arg = kfunc_flags & KF_TRUSTED_ARGS; > + sleepable = kfunc_flags & KF_SLEEPABLE; > } > > /* check that BTF function arguments match actual types that the > @@ -6419,6 +6421,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, > func_name); > return -EINVAL; > } > + > + if (sleepable && !env->prog->aux->sleepable) { > + bpf_log(log, "kernel function %s is sleepable but the program is not\n", > + func_name); > + return -EINVAL; > + } > + > /* returns argument register number > 0 in case of reference release kfunc */ > return rel ? ref_regno : 0; > } > -- > 2.25.1 > BR, Jarkko
> From: Jarkko Sakkinen [mailto:jarkko@kernel.org] > Sent: Tuesday, August 9, 2022 6:55 PM > On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > This allows to declare a kfunc as sleepable and prevents its use in > > a non sleepable program. > > Nit: "Declare a kfunc as sleepable and prevent its use in a > non-sleepable program." > > It's missing the part *how* the patch accomplishes its goals. I will add: If an eBPF program is going to call a kfunc declared as sleepable, eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is not set, execution of that program is denied. Roberto > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > Co-developed-by: Yosry Ahmed <yosryahmed@google.com> > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > > Signed-off-by: Hao Luo <haoluo@google.com> > > --- > > Documentation/bpf/kfuncs.rst | 6 ++++++ > > include/linux/btf.h | 1 + > > kernel/bpf/btf.c | 9 +++++++++ > > 3 files changed, 16 insertions(+) > > > > diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst > > index c0b7dae6dbf5..c8b21de1c772 100644 > > --- a/Documentation/bpf/kfuncs.rst > > +++ b/Documentation/bpf/kfuncs.rst > > @@ -146,6 +146,12 @@ that operate (change some property, perform some > operation) on an object that > > was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer > to > > ensure the integrity of the operation being performed on the expected object. > > > > +2.4.6 KF_SLEEPABLE flag > > +----------------------- > > + > > +The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can > only > > +be called by sleepable BPF programs (BPF_F_SLEEPABLE). > > + > > 2.5 Registering the kfuncs > > -------------------------- > > > > diff --git a/include/linux/btf.h b/include/linux/btf.h > > index cdb376d53238..976cbdd2981f 100644 > > --- a/include/linux/btf.h > > +++ b/include/linux/btf.h > > @@ -49,6 +49,7 @@ > > * for this case. > > */ > > #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer > arguments */ > > +#define KF_SLEEPABLE (1 << 5) /* kfunc may sleep */ > > > > struct btf; > > struct btf_member; > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > > index 7e64447659f3..d3e4c86b8fcd 100644 > > --- a/kernel/bpf/btf.c > > +++ b/kernel/bpf/btf.c > > @@ -6175,6 +6175,7 @@ static int btf_check_func_arg_match(struct > bpf_verifier_env *env, > > { > > enum bpf_prog_type prog_type = resolve_prog_type(env->prog); > > bool rel = false, kptr_get = false, trusted_arg = false; > > + bool sleepable = false; > > struct bpf_verifier_log *log = &env->log; > > u32 i, nargs, ref_id, ref_obj_id = 0; > > bool is_kfunc = btf_is_kernel(btf); > > @@ -6212,6 +6213,7 @@ static int btf_check_func_arg_match(struct > bpf_verifier_env *env, > > rel = kfunc_flags & KF_RELEASE; > > kptr_get = kfunc_flags & KF_KPTR_GET; > > trusted_arg = kfunc_flags & KF_TRUSTED_ARGS; > > + sleepable = kfunc_flags & KF_SLEEPABLE; > > } > > > > /* check that BTF function arguments match actual types that the > > @@ -6419,6 +6421,13 @@ static int btf_check_func_arg_match(struct > bpf_verifier_env *env, > > func_name); > > return -EINVAL; > > } > > + > > + if (sleepable && !env->prog->aux->sleepable) { > > + bpf_log(log, "kernel function %s is sleepable but the program is > not\n", > > + func_name); > > + return -EINVAL; > > + } > > + > > /* returns argument register number > 0 in case of reference release > kfunc */ > > return rel ? ref_regno : 0; > > } > > -- > > 2.25.1 > > > > BR, Jarkko
On Wed, Aug 10, 2022 at 3:44 PM Roberto Sassu <roberto.sassu@huawei.com> wrote: > > > From: Jarkko Sakkinen [mailto:jarkko@kernel.org] > > Sent: Tuesday, August 9, 2022 6:55 PM > > On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: > > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > > > This allows to declare a kfunc as sleepable and prevents its use in > > > a non sleepable program. > > > > Nit: "Declare a kfunc as sleepable and prevent its use in a > > non-sleepable program." > > > > It's missing the part *how* the patch accomplishes its goals. > > I will add: > > If an eBPF program is going to call a kfunc declared as sleepable, > eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is > not set, execution of that program is denied. All those changes are looking good to me. Thanks a lot for keeping pushing on this patch :) Cheers, Benjamin > > Roberto > > > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > Co-developed-by: Yosry Ahmed <yosryahmed@google.com> > > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > > > Signed-off-by: Hao Luo <haoluo@google.com> > > > --- > > > Documentation/bpf/kfuncs.rst | 6 ++++++ > > > include/linux/btf.h | 1 + > > > kernel/bpf/btf.c | 9 +++++++++ > > > 3 files changed, 16 insertions(+) > > > > > > diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst > > > index c0b7dae6dbf5..c8b21de1c772 100644 > > > --- a/Documentation/bpf/kfuncs.rst > > > +++ b/Documentation/bpf/kfuncs.rst > > > @@ -146,6 +146,12 @@ that operate (change some property, perform some > > operation) on an object that > > > was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer > > to > > > ensure the integrity of the operation being performed on the expected object. > > > > > > +2.4.6 KF_SLEEPABLE flag > > > +----------------------- > > > + > > > +The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can > > only > > > +be called by sleepable BPF programs (BPF_F_SLEEPABLE). > > > + > > > 2.5 Registering the kfuncs > > > -------------------------- > > > > > > diff --git a/include/linux/btf.h b/include/linux/btf.h > > > index cdb376d53238..976cbdd2981f 100644 > > > --- a/include/linux/btf.h > > > +++ b/include/linux/btf.h > > > @@ -49,6 +49,7 @@ > > > * for this case. > > > */ > > > #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer > > arguments */ > > > +#define KF_SLEEPABLE (1 << 5) /* kfunc may sleep */ > > > > > > struct btf; > > > struct btf_member; > > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > > > index 7e64447659f3..d3e4c86b8fcd 100644 > > > --- a/kernel/bpf/btf.c > > > +++ b/kernel/bpf/btf.c > > > @@ -6175,6 +6175,7 @@ static int btf_check_func_arg_match(struct > > bpf_verifier_env *env, > > > { > > > enum bpf_prog_type prog_type = resolve_prog_type(env->prog); > > > bool rel = false, kptr_get = false, trusted_arg = false; > > > + bool sleepable = false; > > > struct bpf_verifier_log *log = &env->log; > > > u32 i, nargs, ref_id, ref_obj_id = 0; > > > bool is_kfunc = btf_is_kernel(btf); > > > @@ -6212,6 +6213,7 @@ static int btf_check_func_arg_match(struct > > bpf_verifier_env *env, > > > rel = kfunc_flags & KF_RELEASE; > > > kptr_get = kfunc_flags & KF_KPTR_GET; > > > trusted_arg = kfunc_flags & KF_TRUSTED_ARGS; > > > + sleepable = kfunc_flags & KF_SLEEPABLE; > > > } > > > > > > /* check that BTF function arguments match actual types that the > > > @@ -6419,6 +6421,13 @@ static int btf_check_func_arg_match(struct > > bpf_verifier_env *env, > > > func_name); > > > return -EINVAL; > > > } > > > + > > > + if (sleepable && !env->prog->aux->sleepable) { > > > + bpf_log(log, "kernel function %s is sleepable but the program is > > not\n", > > > + func_name); > > > + return -EINVAL; > > > + } > > > + > > > /* returns argument register number > 0 in case of reference release > > kfunc */ > > > return rel ? ref_regno : 0; > > > } > > > -- > > > 2.25.1 > > > > > > > BR, Jarkko >
On 8/10/22 4:25 PM, Benjamin Tissoires wrote: > On Wed, Aug 10, 2022 at 3:44 PM Roberto Sassu <roberto.sassu@huawei.com> wrote: >>> From: Jarkko Sakkinen [mailto:jarkko@kernel.org] >>> Sent: Tuesday, August 9, 2022 6:55 PM >>> On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: >>>> From: Benjamin Tissoires <benjamin.tissoires@redhat.com> >>>> >>>> From: Benjamin Tissoires <benjamin.tissoires@redhat.com> >>>> >>>> This allows to declare a kfunc as sleepable and prevents its use in >>>> a non sleepable program. >>> >>> Nit: "Declare a kfunc as sleepable and prevent its use in a >>> non-sleepable program." >>> >>> It's missing the part *how* the patch accomplishes its goals. >> >> I will add: >> >> If an eBPF program is going to call a kfunc declared as sleepable, >> eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is >> not set, execution of that program is denied. > > All those changes are looking good to me. > > Thanks a lot for keeping pushing on this patch :) This single one from the series got already applied here: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=fa96b24204af42274ec13dfb2f2e6990d7510e55 >>>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> >>>> Co-developed-by: Yosry Ahmed <yosryahmed@google.com> >>>> Signed-off-by: Yosry Ahmed <yosryahmed@google.com> >>>> Signed-off-by: Hao Luo <haoluo@google.com> >>>> --- >>>> Documentation/bpf/kfuncs.rst | 6 ++++++ >>>> include/linux/btf.h | 1 + >>>> kernel/bpf/btf.c | 9 +++++++++ >>>> 3 files changed, 16 insertions(+) >>>> >>>> diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst >>>> index c0b7dae6dbf5..c8b21de1c772 100644 >>>> --- a/Documentation/bpf/kfuncs.rst >>>> +++ b/Documentation/bpf/kfuncs.rst >>>> @@ -146,6 +146,12 @@ that operate (change some property, perform some >>> operation) on an object that >>>> was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer >>> to >>>> ensure the integrity of the operation being performed on the expected object.
> From: Daniel Borkmann [mailto:daniel@iogearbox.net] > Sent: Wednesday, August 10, 2022 4:39 PM > On 8/10/22 4:25 PM, Benjamin Tissoires wrote: > > On Wed, Aug 10, 2022 at 3:44 PM Roberto Sassu > <roberto.sassu@huawei.com> wrote: > >>> From: Jarkko Sakkinen [mailto:jarkko@kernel.org] > >>> Sent: Tuesday, August 9, 2022 6:55 PM > >>> On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: > >>>> From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > >>>> > >>>> From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > >>>> > >>>> This allows to declare a kfunc as sleepable and prevents its use in > >>>> a non sleepable program. > >>> > >>> Nit: "Declare a kfunc as sleepable and prevent its use in a > >>> non-sleepable program." > >>> > >>> It's missing the part *how* the patch accomplishes its goals. > >> > >> I will add: > >> > >> If an eBPF program is going to call a kfunc declared as sleepable, > >> eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is > >> not set, execution of that program is denied. > > > > All those changes are looking good to me. > > > > Thanks a lot for keeping pushing on this patch :) > > This single one from the series got already applied here: > > https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf- > next.git/commit/?id=fa96b24204af42274ec13dfb2f2e6990d7510e55 Ok, now I understood the merge message better. Roberto > >>>> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > >>>> Co-developed-by: Yosry Ahmed <yosryahmed@google.com> > >>>> Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > >>>> Signed-off-by: Hao Luo <haoluo@google.com> > >>>> --- > >>>> Documentation/bpf/kfuncs.rst | 6 ++++++ > >>>> include/linux/btf.h | 1 + > >>>> kernel/bpf/btf.c | 9 +++++++++ > >>>> 3 files changed, 16 insertions(+) > >>>> > >>>> diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst > >>>> index c0b7dae6dbf5..c8b21de1c772 100644 > >>>> --- a/Documentation/bpf/kfuncs.rst > >>>> +++ b/Documentation/bpf/kfuncs.rst > >>>> @@ -146,6 +146,12 @@ that operate (change some property, perform > some > >>> operation) on an object that > >>>> was obtained using an acquire kfunc. Such kfuncs need an unchanged > pointer > >>> to > >>>> ensure the integrity of the operation being performed on the expected > object.
On Wed, Aug 10, 2022 at 7:26 AM Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote: > > On Wed, Aug 10, 2022 at 3:44 PM Roberto Sassu <roberto.sassu@huawei.com> wrote: > > > > > From: Jarkko Sakkinen [mailto:jarkko@kernel.org] > > > Sent: Tuesday, August 9, 2022 6:55 PM > > > On Tue, Aug 09, 2022 at 03:45:54PM +0200, Roberto Sassu wrote: > > > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > > > > > From: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > > > > > This allows to declare a kfunc as sleepable and prevents its use in > > > > a non sleepable program. > > > > > > Nit: "Declare a kfunc as sleepable and prevent its use in a > > > non-sleepable program." > > > > > > It's missing the part *how* the patch accomplishes its goals. > > > > I will add: > > > > If an eBPF program is going to call a kfunc declared as sleepable, > > eBPF will look at the eBPF program flags. If BPF_F_SLEEPABLE is > > not set, execution of that program is denied. > > All those changes are looking good to me. > > Thanks a lot for keeping pushing on this patch :) Multiple series other than the HID one started resending your patch once you dropped it, it's obviously needed :) Thanks for sending it in the first place :) > > Cheers, > Benjamin > > > > > Roberto > > > > > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> > > > > Co-developed-by: Yosry Ahmed <yosryahmed@google.com> > > > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > > > > Signed-off-by: Hao Luo <haoluo@google.com> > > > > --- > > > > Documentation/bpf/kfuncs.rst | 6 ++++++ > > > > include/linux/btf.h | 1 + > > > > kernel/bpf/btf.c | 9 +++++++++ > > > > 3 files changed, 16 insertions(+) > > > > > > > > diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst > > > > index c0b7dae6dbf5..c8b21de1c772 100644 > > > > --- a/Documentation/bpf/kfuncs.rst > > > > +++ b/Documentation/bpf/kfuncs.rst > > > > @@ -146,6 +146,12 @@ that operate (change some property, perform some > > > operation) on an object that > > > > was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer > > > to > > > > ensure the integrity of the operation being performed on the expected object. > > > > > > > > +2.4.6 KF_SLEEPABLE flag > > > > +----------------------- > > > > + > > > > +The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can > > > only > > > > +be called by sleepable BPF programs (BPF_F_SLEEPABLE). > > > > + > > > > 2.5 Registering the kfuncs > > > > -------------------------- > > > > > > > > diff --git a/include/linux/btf.h b/include/linux/btf.h > > > > index cdb376d53238..976cbdd2981f 100644 > > > > --- a/include/linux/btf.h > > > > +++ b/include/linux/btf.h > > > > @@ -49,6 +49,7 @@ > > > > * for this case. > > > > */ > > > > #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer > > > arguments */ > > > > +#define KF_SLEEPABLE (1 << 5) /* kfunc may sleep */ > > > > > > > > struct btf; > > > > struct btf_member; > > > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > > > > index 7e64447659f3..d3e4c86b8fcd 100644 > > > > --- a/kernel/bpf/btf.c > > > > +++ b/kernel/bpf/btf.c > > > > @@ -6175,6 +6175,7 @@ static int btf_check_func_arg_match(struct > > > bpf_verifier_env *env, > > > > { > > > > enum bpf_prog_type prog_type = resolve_prog_type(env->prog); > > > > bool rel = false, kptr_get = false, trusted_arg = false; > > > > + bool sleepable = false; > > > > struct bpf_verifier_log *log = &env->log; > > > > u32 i, nargs, ref_id, ref_obj_id = 0; > > > > bool is_kfunc = btf_is_kernel(btf); > > > > @@ -6212,6 +6213,7 @@ static int btf_check_func_arg_match(struct > > > bpf_verifier_env *env, > > > > rel = kfunc_flags & KF_RELEASE; > > > > kptr_get = kfunc_flags & KF_KPTR_GET; > > > > trusted_arg = kfunc_flags & KF_TRUSTED_ARGS; > > > > + sleepable = kfunc_flags & KF_SLEEPABLE; > > > > } > > > > > > > > /* check that BTF function arguments match actual types that the > > > > @@ -6419,6 +6421,13 @@ static int btf_check_func_arg_match(struct > > > bpf_verifier_env *env, > > > > func_name); > > > > return -EINVAL; > > > > } > > > > + > > > > + if (sleepable && !env->prog->aux->sleepable) { > > > > + bpf_log(log, "kernel function %s is sleepable but the program is > > > not\n", > > > > + func_name); > > > > + return -EINVAL; > > > > + } > > > > + > > > > /* returns argument register number > 0 in case of reference release > > > kfunc */ > > > > return rel ? ref_regno : 0; > > > > } > > > > -- > > > > 2.25.1 > > > > > > > > > > BR, Jarkko > > >
diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst index c0b7dae6dbf5..c8b21de1c772 100644 --- a/Documentation/bpf/kfuncs.rst +++ b/Documentation/bpf/kfuncs.rst @@ -146,6 +146,12 @@ that operate (change some property, perform some operation) on an object that was obtained using an acquire kfunc. Such kfuncs need an unchanged pointer to ensure the integrity of the operation being performed on the expected object. +2.4.6 KF_SLEEPABLE flag +----------------------- + +The KF_SLEEPABLE flag is used for kfuncs that may sleep. Such kfuncs can only +be called by sleepable BPF programs (BPF_F_SLEEPABLE). + 2.5 Registering the kfuncs -------------------------- diff --git a/include/linux/btf.h b/include/linux/btf.h index cdb376d53238..976cbdd2981f 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -49,6 +49,7 @@ * for this case. */ #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */ +#define KF_SLEEPABLE (1 << 5) /* kfunc may sleep */ struct btf; struct btf_member; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 7e64447659f3..d3e4c86b8fcd 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6175,6 +6175,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, { enum bpf_prog_type prog_type = resolve_prog_type(env->prog); bool rel = false, kptr_get = false, trusted_arg = false; + bool sleepable = false; struct bpf_verifier_log *log = &env->log; u32 i, nargs, ref_id, ref_obj_id = 0; bool is_kfunc = btf_is_kernel(btf); @@ -6212,6 +6213,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, rel = kfunc_flags & KF_RELEASE; kptr_get = kfunc_flags & KF_KPTR_GET; trusted_arg = kfunc_flags & KF_TRUSTED_ARGS; + sleepable = kfunc_flags & KF_SLEEPABLE; } /* check that BTF function arguments match actual types that the @@ -6419,6 +6421,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, func_name); return -EINVAL; } + + if (sleepable && !env->prog->aux->sleepable) { + bpf_log(log, "kernel function %s is sleepable but the program is not\n", + func_name); + return -EINVAL; + } + /* returns argument register number > 0 in case of reference release kfunc */ return rel ? ref_regno : 0; }