| Message ID | 32a944171d5c48abf126259595b0088ce3122c91.1526331777.git.sean@mess.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/14/2018 02:10 PM, Sean Young wrote: > Add support for BPF_PROG_IR_DECODER. This type of BPF program can call Kconfig file below uses IR_BPF_DECODER instead of the symbol name above. and then patch 3 says a third choice: The context provided to a BPF_PROG_RAWIR_DECODER is a struct ir_raw_event; > rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report > that the last key should be repeated. > > Signed-off-by: Sean Young <sean@mess.org> > --- > drivers/media/rc/Kconfig | 8 +++ > drivers/media/rc/Makefile | 1 + > drivers/media/rc/ir-bpf-decoder.c | 93 +++++++++++++++++++++++++++++++ > include/linux/bpf_types.h | 3 + > include/uapi/linux/bpf.h | 16 +++++- > 5 files changed, 120 insertions(+), 1 deletion(-) > create mode 100644 drivers/media/rc/ir-bpf-decoder.c > > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig > index eb2c3b6eca7f..10ad6167d87c 100644 > --- a/drivers/media/rc/Kconfig > +++ b/drivers/media/rc/Kconfig > @@ -120,6 +120,14 @@ config IR_IMON_DECODER > remote control and you would like to use it with a raw IR > receiver, or if you wish to use an encoder to transmit this IR. > > +config IR_BPF_DECODER > + bool "Enable IR raw decoder using BPF" > + depends on BPF_SYSCALL > + depends on RC_CORE=y > + help > + Enable this option to make it possible to load custom IR > + decoders written in BPF. > + > endif #RC_DECODERS > > menuconfig RC_DEVICES > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile > index 2e1c87066f6c..12e1118430d0 100644 > --- a/drivers/media/rc/Makefile > +++ b/drivers/media/rc/Makefile > @@ -5,6 +5,7 @@ obj-y += keymaps/ > obj-$(CONFIG_RC_CORE) += rc-core.o > rc-core-y := rc-main.o rc-ir-raw.o > rc-core-$(CONFIG_LIRC) += lirc_dev.o > +rc-core-$(CONFIG_IR_BPF_DECODER) += ir-bpf-decoder.o
On Mon, May 14, 2018 at 2:10 PM, Sean Young <sean@mess.org> wrote: > Add support for BPF_PROG_IR_DECODER. This type of BPF program can call > rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report > that the last key should be repeated. > > Signed-off-by: Sean Young <sean@mess.org> > --- > drivers/media/rc/Kconfig | 8 +++ > drivers/media/rc/Makefile | 1 + > drivers/media/rc/ir-bpf-decoder.c | 93 +++++++++++++++++++++++++++++++ > include/linux/bpf_types.h | 3 + > include/uapi/linux/bpf.h | 16 +++++- > 5 files changed, 120 insertions(+), 1 deletion(-) > create mode 100644 drivers/media/rc/ir-bpf-decoder.c > > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig > index eb2c3b6eca7f..10ad6167d87c 100644 > --- a/drivers/media/rc/Kconfig > +++ b/drivers/media/rc/Kconfig > @@ -120,6 +120,14 @@ config IR_IMON_DECODER > remote control and you would like to use it with a raw IR > receiver, or if you wish to use an encoder to transmit this IR. > > +config IR_BPF_DECODER > + bool "Enable IR raw decoder using BPF" > + depends on BPF_SYSCALL > + depends on RC_CORE=y > + help > + Enable this option to make it possible to load custom IR > + decoders written in BPF. > + > endif #RC_DECODERS > > menuconfig RC_DEVICES > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile > index 2e1c87066f6c..12e1118430d0 100644 > --- a/drivers/media/rc/Makefile > +++ b/drivers/media/rc/Makefile > @@ -5,6 +5,7 @@ obj-y += keymaps/ > obj-$(CONFIG_RC_CORE) += rc-core.o > rc-core-y := rc-main.o rc-ir-raw.o > rc-core-$(CONFIG_LIRC) += lirc_dev.o > +rc-core-$(CONFIG_IR_BPF_DECODER) += ir-bpf-decoder.o > obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o > obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o > obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o > diff --git a/drivers/media/rc/ir-bpf-decoder.c b/drivers/media/rc/ir-bpf-decoder.c > new file mode 100644 > index 000000000000..aaa5e208b1a5 > --- /dev/null > +++ b/drivers/media/rc/ir-bpf-decoder.c > @@ -0,0 +1,93 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// ir-bpf-decoder.c - handles bpf decoders > +// > +// Copyright (C) 2018 Sean Young <sean@mess.org> > + > +#include <linux/bpf.h> > +#include <linux/filter.h> > +#include "rc-core-priv.h" > + > +/* > + * BPF interface for raw IR decoder > + */ > +const struct bpf_prog_ops ir_decoder_prog_ops = { > +}; > + > +BPF_CALL_1(bpf_rc_repeat, struct ir_raw_event*, event) > +{ > + struct ir_raw_event_ctrl *ctrl; > + > + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); > + > + rc_repeat(ctrl->dev); > + return 0; > +} > + > +static const struct bpf_func_proto rc_repeat_proto = { > + .func = bpf_rc_repeat, > + .gpl_only = true, // rc_repeat is EXPORT_SYMBOL_GPL > + .ret_type = RET_VOID, I suggest using RET_INTEGER here since we do return an integer 0. RET_INTEGER will also make it easy to extend if you want to return a non-zero value for error code or other reasons. > + .arg1_type = ARG_PTR_TO_CTX, > +}; > + > +BPF_CALL_4(bpf_rc_keydown, struct ir_raw_event*, event, u32, protocol, > + u32, scancode, u32, toggle) > +{ > + struct ir_raw_event_ctrl *ctrl; > + > + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); > + rc_keydown(ctrl->dev, protocol, scancode, toggle != 0); > + return 0; > +} > + > +static const struct bpf_func_proto rc_keydown_proto = { > + .func = bpf_rc_keydown, > + .gpl_only = true, // rc_keydown is EXPORT_SYMBOL_GPL > + .ret_type = RET_VOID, ditto. RET_INTEGER is preferable. > + .arg1_type = ARG_PTR_TO_CTX, > + .arg2_type = ARG_ANYTHING, > + .arg3_type = ARG_ANYTHING, > + .arg4_type = ARG_ANYTHING, > +}; > + > +static const struct bpf_func_proto *ir_decoder_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > +{ > + switch (func_id) { > + case BPF_FUNC_rc_repeat: > + return &rc_repeat_proto; > + case BPF_FUNC_rc_keydown: > + return &rc_keydown_proto; > + case BPF_FUNC_map_lookup_elem: > + return &bpf_map_lookup_elem_proto; > + case BPF_FUNC_map_update_elem: > + return &bpf_map_update_elem_proto; > + case BPF_FUNC_map_delete_elem: > + return &bpf_map_delete_elem_proto; > + case BPF_FUNC_ktime_get_ns: > + return &bpf_ktime_get_ns_proto; > + case BPF_FUNC_tail_call: > + return &bpf_tail_call_proto; > + case BPF_FUNC_get_prandom_u32: > + return &bpf_get_prandom_u32_proto; > + default: > + return NULL; > + } > +} > + > +static bool ir_decoder_is_valid_access(int off, int size, > + enum bpf_access_type type, > + const struct bpf_prog *prog, > + struct bpf_insn_access_aux *info) > +{ > + if (type == BPF_WRITE) > + return false; > + if (off < 0 || off + size > sizeof(struct ir_raw_event)) > + return false; You probably need more than just checking the boundary. From patch #3, the structure is: struct ir_raw_event { union { __u32 duration; __u32 carrier; }; __u8 duty_cycle; unsigned pulse:1; unsigned reset:1; unsigned timeout:1; unsigned carrier_report:1; }; You would like the memory access to be aligned, so accessing duration/carrier with 4-byte alignment, and pulse/reset/timeout/carrier_report 4-byte alignment as well. You could only allow __u32 access to duration/carrier. But if you want bpf program to access duration/carrier with code like (__u16)(ctx->duration), then the compiler may translate the load to a 2-byte load. You may need to handle endianness here. You can check net/core/filter.c function bpf_skb_is_valid_access for some examples. > + > + return true; > +} > + > +const struct bpf_verifier_ops ir_decoder_verifier_ops = { > + .get_func_proto = ir_decoder_func_proto, > + .is_valid_access = ir_decoder_is_valid_access > +}; > diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h > index 2b28fcf6f6ae..ee5355715ee0 100644 > --- a/include/linux/bpf_types.h > +++ b/include/linux/bpf_types.h > @@ -25,6 +25,9 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint) > #ifdef CONFIG_CGROUP_BPF > BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev) > #endif > +#ifdef CONFIG_IR_BPF_DECODER > +BPF_PROG_TYPE(BPF_PROG_TYPE_RAWIR_DECODER, ir_decoder) > +#endif > > BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops) > BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops) > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index c5ec89732a8d..6ad053e831c0 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -137,6 +137,7 @@ enum bpf_prog_type { > BPF_PROG_TYPE_SK_MSG, > BPF_PROG_TYPE_RAW_TRACEPOINT, > BPF_PROG_TYPE_CGROUP_SOCK_ADDR, > + BPF_PROG_TYPE_RAWIR_DECODER, > }; > > enum bpf_attach_type { > @@ -755,6 +756,17 @@ union bpf_attr { > * @addr: pointer to struct sockaddr to bind socket to > * @addr_len: length of sockaddr structure > * Return: 0 on success or negative error code > + * > + * int bpf_rc_keydown(ctx, protocol, scancode, toggle) > + * Report decoded scancode with toggle value > + * @ctx: pointer to ctx > + * @protocol: decoded protocol > + * @scancode: decoded scancode > + * @toggle: set to 1 if button was toggled, else 0 > + * > + * int bpf_rc_repeat(ctx) > + * Repeat the last decoded scancode > + * @ctx: pointer to ctx The comment format has changed dramatically for documentation reason. Could you rebase your change on top of bpf-next tree? You will need to rewrite the above helper description so tools can generate proper documentation for them. > */ > #define __BPF_FUNC_MAPPER(FN) \ > FN(unspec), \ > @@ -821,7 +833,9 @@ union bpf_attr { > FN(msg_apply_bytes), \ > FN(msg_cork_bytes), \ > FN(msg_pull_data), \ > - FN(bind), > + FN(bind), \ > + FN(rc_repeat), \ > + FN(rc_keydown), > > /* integer value in 'imm' field of BPF_CALL instruction selects which helper > * function eBPF program intends to call > -- > 2.17.0 >
On Mon, May 14, 2018 at 09:48:05PM -0700, Y Song wrote: > On Mon, May 14, 2018 at 2:10 PM, Sean Young <sean@mess.org> wrote: > > Add support for BPF_PROG_IR_DECODER. This type of BPF program can call > > rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report > > that the last key should be repeated. > > > > Signed-off-by: Sean Young <sean@mess.org> > > --- > > drivers/media/rc/Kconfig | 8 +++ > > drivers/media/rc/Makefile | 1 + > > drivers/media/rc/ir-bpf-decoder.c | 93 +++++++++++++++++++++++++++++++ > > include/linux/bpf_types.h | 3 + > > include/uapi/linux/bpf.h | 16 +++++- > > 5 files changed, 120 insertions(+), 1 deletion(-) > > create mode 100644 drivers/media/rc/ir-bpf-decoder.c > > > > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig > > index eb2c3b6eca7f..10ad6167d87c 100644 > > --- a/drivers/media/rc/Kconfig > > +++ b/drivers/media/rc/Kconfig > > @@ -120,6 +120,14 @@ config IR_IMON_DECODER > > remote control and you would like to use it with a raw IR > > receiver, or if you wish to use an encoder to transmit this IR. > > > > +config IR_BPF_DECODER > > + bool "Enable IR raw decoder using BPF" > > + depends on BPF_SYSCALL > > + depends on RC_CORE=y > > + help > > + Enable this option to make it possible to load custom IR > > + decoders written in BPF. > > + > > endif #RC_DECODERS > > > > menuconfig RC_DEVICES > > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile > > index 2e1c87066f6c..12e1118430d0 100644 > > --- a/drivers/media/rc/Makefile > > +++ b/drivers/media/rc/Makefile > > @@ -5,6 +5,7 @@ obj-y += keymaps/ > > obj-$(CONFIG_RC_CORE) += rc-core.o > > rc-core-y := rc-main.o rc-ir-raw.o > > rc-core-$(CONFIG_LIRC) += lirc_dev.o > > +rc-core-$(CONFIG_IR_BPF_DECODER) += ir-bpf-decoder.o > > obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o > > obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o > > obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o > > diff --git a/drivers/media/rc/ir-bpf-decoder.c b/drivers/media/rc/ir-bpf-decoder.c > > new file mode 100644 > > index 000000000000..aaa5e208b1a5 > > --- /dev/null > > +++ b/drivers/media/rc/ir-bpf-decoder.c > > @@ -0,0 +1,93 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +// ir-bpf-decoder.c - handles bpf decoders > > +// > > +// Copyright (C) 2018 Sean Young <sean@mess.org> > > + > > +#include <linux/bpf.h> > > +#include <linux/filter.h> > > +#include "rc-core-priv.h" > > + > > +/* > > + * BPF interface for raw IR decoder > > + */ > > +const struct bpf_prog_ops ir_decoder_prog_ops = { > > +}; > > + > > +BPF_CALL_1(bpf_rc_repeat, struct ir_raw_event*, event) > > +{ > > + struct ir_raw_event_ctrl *ctrl; > > + > > + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); > > + > > + rc_repeat(ctrl->dev); > > + return 0; > > +} > > + > > +static const struct bpf_func_proto rc_repeat_proto = { > > + .func = bpf_rc_repeat, > > + .gpl_only = true, // rc_repeat is EXPORT_SYMBOL_GPL > > + .ret_type = RET_VOID, > > I suggest using RET_INTEGER here since we do return an integer 0. > RET_INTEGER will also make it easy to extend if you want to return > a non-zero value for error code or other reasons. Ok. > > + .arg1_type = ARG_PTR_TO_CTX, > > +}; > > + > > +BPF_CALL_4(bpf_rc_keydown, struct ir_raw_event*, event, u32, protocol, > > + u32, scancode, u32, toggle) > > +{ > > + struct ir_raw_event_ctrl *ctrl; > > + > > + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); > > + rc_keydown(ctrl->dev, protocol, scancode, toggle != 0); > > + return 0; > > +} > > + > > +static const struct bpf_func_proto rc_keydown_proto = { > > + .func = bpf_rc_keydown, > > + .gpl_only = true, // rc_keydown is EXPORT_SYMBOL_GPL > > + .ret_type = RET_VOID, > > ditto. RET_INTEGER is preferable. Ok. > > + .arg1_type = ARG_PTR_TO_CTX, > > + .arg2_type = ARG_ANYTHING, > > + .arg3_type = ARG_ANYTHING, > > + .arg4_type = ARG_ANYTHING, > > +}; > > + > > +static const struct bpf_func_proto *ir_decoder_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > > +{ > > + switch (func_id) { > > + case BPF_FUNC_rc_repeat: > > + return &rc_repeat_proto; > > + case BPF_FUNC_rc_keydown: > > + return &rc_keydown_proto; > > + case BPF_FUNC_map_lookup_elem: > > + return &bpf_map_lookup_elem_proto; > > + case BPF_FUNC_map_update_elem: > > + return &bpf_map_update_elem_proto; > > + case BPF_FUNC_map_delete_elem: > > + return &bpf_map_delete_elem_proto; > > + case BPF_FUNC_ktime_get_ns: > > + return &bpf_ktime_get_ns_proto; > > + case BPF_FUNC_tail_call: > > + return &bpf_tail_call_proto; > > + case BPF_FUNC_get_prandom_u32: > > + return &bpf_get_prandom_u32_proto; > > + default: > > + return NULL; > > + } > > +} > > + > > +static bool ir_decoder_is_valid_access(int off, int size, > > + enum bpf_access_type type, > > + const struct bpf_prog *prog, > > + struct bpf_insn_access_aux *info) > > +{ > > + if (type == BPF_WRITE) > > + return false; > > + if (off < 0 || off + size > sizeof(struct ir_raw_event)) > > + return false; > > You probably need more than just checking the boundary. > >From patch #3, the structure is: > struct ir_raw_event { > union { > __u32 duration; > __u32 carrier; > }; > __u8 duty_cycle; > > unsigned pulse:1; > unsigned reset:1; > unsigned timeout:1; > unsigned carrier_report:1; > }; > > You would like the memory access to be aligned, > so accessing duration/carrier with 4-byte alignment, and > pulse/reset/timeout/carrier_report 4-byte alignment as well. > > You could only allow __u32 access to duration/carrier. > But if you want bpf program to access duration/carrier with > code like (__u16)(ctx->duration), then the compiler may > translate the load to a 2-byte load. You may need to handle > endianness here. You can check net/core/filter.c function > bpf_skb_is_valid_access for some examples. Thanks, yes that makes sense. Actually exposing a struct with bit fields isn't great. I think I can rework into something simpler (two u32 fields). > > + > > + return true; > > +} > > + > > +const struct bpf_verifier_ops ir_decoder_verifier_ops = { > > + .get_func_proto = ir_decoder_func_proto, > > + .is_valid_access = ir_decoder_is_valid_access > > +}; > > diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h > > index 2b28fcf6f6ae..ee5355715ee0 100644 > > --- a/include/linux/bpf_types.h > > +++ b/include/linux/bpf_types.h > > @@ -25,6 +25,9 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint) > > #ifdef CONFIG_CGROUP_BPF > > BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev) > > #endif > > +#ifdef CONFIG_IR_BPF_DECODER > > +BPF_PROG_TYPE(BPF_PROG_TYPE_RAWIR_DECODER, ir_decoder) > > +#endif > > > > BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops) > > BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index c5ec89732a8d..6ad053e831c0 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -137,6 +137,7 @@ enum bpf_prog_type { > > BPF_PROG_TYPE_SK_MSG, > > BPF_PROG_TYPE_RAW_TRACEPOINT, > > BPF_PROG_TYPE_CGROUP_SOCK_ADDR, > > + BPF_PROG_TYPE_RAWIR_DECODER, > > }; > > > > enum bpf_attach_type { > > @@ -755,6 +756,17 @@ union bpf_attr { > > * @addr: pointer to struct sockaddr to bind socket to > > * @addr_len: length of sockaddr structure > > * Return: 0 on success or negative error code > > + * > > + * int bpf_rc_keydown(ctx, protocol, scancode, toggle) > > + * Report decoded scancode with toggle value > > + * @ctx: pointer to ctx > > + * @protocol: decoded protocol > > + * @scancode: decoded scancode > > + * @toggle: set to 1 if button was toggled, else 0 > > + * > > + * int bpf_rc_repeat(ctx) > > + * Repeat the last decoded scancode > > + * @ctx: pointer to ctx > > The comment format has changed dramatically for > documentation reason. Could you rebase your change > on top of bpf-next tree? You will need to rewrite the above > helper description so tools can generate proper documentation > for them. Ah, I need to rebase on top of bpf-next. Thanks! > > */ > > #define __BPF_FUNC_MAPPER(FN) \ > > FN(unspec), \ > > @@ -821,7 +833,9 @@ union bpf_attr { > > FN(msg_apply_bytes), \ > > FN(msg_cork_bytes), \ > > FN(msg_pull_data), \ > > - FN(bind), > > + FN(bind), \ > > + FN(rc_repeat), \ > > + FN(rc_keydown), > > > > /* integer value in 'imm' field of BPF_CALL instruction selects which helper > > * function eBPF program intends to call > > -- > > 2.17.0 > >
On Mon, May 14, 2018 at 04:27:19PM -0700, Randy Dunlap wrote: > On 05/14/2018 02:10 PM, Sean Young wrote: > > Add support for BPF_PROG_IR_DECODER. This type of BPF program can call > > Kconfig file below uses IR_BPF_DECODER instead of the symbol name above. > > and then patch 3 says a third choice: > The context provided to a BPF_PROG_RAWIR_DECODER is a struct ir_raw_event; Yes, you're right. I guess the source/trigger is raw IR events; decoding is something you're likely to do, but not necessarily. So: bpf type: BPF_PROG_TYPE_RAWIR_EVENT, has context struct bpf_rawir_event. Then we can call the Kconfig option CONFIG_BPF_RAW_IR_EVENT Sean > > > rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report > > that the last key should be repeated. > > > > Signed-off-by: Sean Young <sean@mess.org> > > --- > > drivers/media/rc/Kconfig | 8 +++ > > drivers/media/rc/Makefile | 1 + > > drivers/media/rc/ir-bpf-decoder.c | 93 +++++++++++++++++++++++++++++++ > > include/linux/bpf_types.h | 3 + > > include/uapi/linux/bpf.h | 16 +++++- > > 5 files changed, 120 insertions(+), 1 deletion(-) > > create mode 100644 drivers/media/rc/ir-bpf-decoder.c > > > > diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig > > index eb2c3b6eca7f..10ad6167d87c 100644 > > --- a/drivers/media/rc/Kconfig > > +++ b/drivers/media/rc/Kconfig > > @@ -120,6 +120,14 @@ config IR_IMON_DECODER > > remote control and you would like to use it with a raw IR > > receiver, or if you wish to use an encoder to transmit this IR. > > > > +config IR_BPF_DECODER > > + bool "Enable IR raw decoder using BPF" > > + depends on BPF_SYSCALL > > + depends on RC_CORE=y > > + help > > + Enable this option to make it possible to load custom IR > > + decoders written in BPF. > > + > > endif #RC_DECODERS > > > > menuconfig RC_DEVICES > > diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile > > index 2e1c87066f6c..12e1118430d0 100644 > > --- a/drivers/media/rc/Makefile > > +++ b/drivers/media/rc/Makefile > > @@ -5,6 +5,7 @@ obj-y += keymaps/ > > obj-$(CONFIG_RC_CORE) += rc-core.o > > rc-core-y := rc-main.o rc-ir-raw.o > > rc-core-$(CONFIG_LIRC) += lirc_dev.o > > +rc-core-$(CONFIG_IR_BPF_DECODER) += ir-bpf-decoder.o > > > -- > ~Randy
diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig index eb2c3b6eca7f..10ad6167d87c 100644 --- a/drivers/media/rc/Kconfig +++ b/drivers/media/rc/Kconfig @@ -120,6 +120,14 @@ config IR_IMON_DECODER remote control and you would like to use it with a raw IR receiver, or if you wish to use an encoder to transmit this IR. +config IR_BPF_DECODER + bool "Enable IR raw decoder using BPF" + depends on BPF_SYSCALL + depends on RC_CORE=y + help + Enable this option to make it possible to load custom IR + decoders written in BPF. + endif #RC_DECODERS menuconfig RC_DEVICES diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile index 2e1c87066f6c..12e1118430d0 100644 --- a/drivers/media/rc/Makefile +++ b/drivers/media/rc/Makefile @@ -5,6 +5,7 @@ obj-y += keymaps/ obj-$(CONFIG_RC_CORE) += rc-core.o rc-core-y := rc-main.o rc-ir-raw.o rc-core-$(CONFIG_LIRC) += lirc_dev.o +rc-core-$(CONFIG_IR_BPF_DECODER) += ir-bpf-decoder.o obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o obj-$(CONFIG_IR_RC6_DECODER) += ir-rc6-decoder.o diff --git a/drivers/media/rc/ir-bpf-decoder.c b/drivers/media/rc/ir-bpf-decoder.c new file mode 100644 index 000000000000..aaa5e208b1a5 --- /dev/null +++ b/drivers/media/rc/ir-bpf-decoder.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +// ir-bpf-decoder.c - handles bpf decoders +// +// Copyright (C) 2018 Sean Young <sean@mess.org> + +#include <linux/bpf.h> +#include <linux/filter.h> +#include "rc-core-priv.h" + +/* + * BPF interface for raw IR decoder + */ +const struct bpf_prog_ops ir_decoder_prog_ops = { +}; + +BPF_CALL_1(bpf_rc_repeat, struct ir_raw_event*, event) +{ + struct ir_raw_event_ctrl *ctrl; + + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); + + rc_repeat(ctrl->dev); + return 0; +} + +static const struct bpf_func_proto rc_repeat_proto = { + .func = bpf_rc_repeat, + .gpl_only = true, // rc_repeat is EXPORT_SYMBOL_GPL + .ret_type = RET_VOID, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_4(bpf_rc_keydown, struct ir_raw_event*, event, u32, protocol, + u32, scancode, u32, toggle) +{ + struct ir_raw_event_ctrl *ctrl; + + ctrl = container_of(event, struct ir_raw_event_ctrl, prev_ev); + rc_keydown(ctrl->dev, protocol, scancode, toggle != 0); + return 0; +} + +static const struct bpf_func_proto rc_keydown_proto = { + .func = bpf_rc_keydown, + .gpl_only = true, // rc_keydown is EXPORT_SYMBOL_GPL + .ret_type = RET_VOID, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, +}; + +static const struct bpf_func_proto *ir_decoder_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_rc_repeat: + return &rc_repeat_proto; + case BPF_FUNC_rc_keydown: + return &rc_keydown_proto; + case BPF_FUNC_map_lookup_elem: + return &bpf_map_lookup_elem_proto; + case BPF_FUNC_map_update_elem: + return &bpf_map_update_elem_proto; + case BPF_FUNC_map_delete_elem: + return &bpf_map_delete_elem_proto; + case BPF_FUNC_ktime_get_ns: + return &bpf_ktime_get_ns_proto; + case BPF_FUNC_tail_call: + return &bpf_tail_call_proto; + case BPF_FUNC_get_prandom_u32: + return &bpf_get_prandom_u32_proto; + default: + return NULL; + } +} + +static bool ir_decoder_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + if (type == BPF_WRITE) + return false; + if (off < 0 || off + size > sizeof(struct ir_raw_event)) + return false; + + return true; +} + +const struct bpf_verifier_ops ir_decoder_verifier_ops = { + .get_func_proto = ir_decoder_func_proto, + .is_valid_access = ir_decoder_is_valid_access +}; diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index 2b28fcf6f6ae..ee5355715ee0 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -25,6 +25,9 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint) #ifdef CONFIG_CGROUP_BPF BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev) #endif +#ifdef CONFIG_IR_BPF_DECODER +BPF_PROG_TYPE(BPF_PROG_TYPE_RAWIR_DECODER, ir_decoder) +#endif BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c5ec89732a8d..6ad053e831c0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -137,6 +137,7 @@ enum bpf_prog_type { BPF_PROG_TYPE_SK_MSG, BPF_PROG_TYPE_RAW_TRACEPOINT, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_PROG_TYPE_RAWIR_DECODER, }; enum bpf_attach_type { @@ -755,6 +756,17 @@ union bpf_attr { * @addr: pointer to struct sockaddr to bind socket to * @addr_len: length of sockaddr structure * Return: 0 on success or negative error code + * + * int bpf_rc_keydown(ctx, protocol, scancode, toggle) + * Report decoded scancode with toggle value + * @ctx: pointer to ctx + * @protocol: decoded protocol + * @scancode: decoded scancode + * @toggle: set to 1 if button was toggled, else 0 + * + * int bpf_rc_repeat(ctx) + * Repeat the last decoded scancode + * @ctx: pointer to ctx */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -821,7 +833,9 @@ union bpf_attr { FN(msg_apply_bytes), \ FN(msg_cork_bytes), \ FN(msg_pull_data), \ - FN(bind), + FN(bind), \ + FN(rc_repeat), \ + FN(rc_keydown), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call
Add support for BPF_PROG_IR_DECODER. This type of BPF program can call rc_keydown() to reported decoded IR scancodes, or rc_repeat() to report that the last key should be repeated. Signed-off-by: Sean Young <sean@mess.org> --- drivers/media/rc/Kconfig | 8 +++ drivers/media/rc/Makefile | 1 + drivers/media/rc/ir-bpf-decoder.c | 93 +++++++++++++++++++++++++++++++ include/linux/bpf_types.h | 3 + include/uapi/linux/bpf.h | 16 +++++- 5 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 drivers/media/rc/ir-bpf-decoder.c