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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/media/rc/bpf-lirc.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/rc/bpf-lirc.c')
-rw-r--r-- | drivers/media/rc/bpf-lirc.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c new file mode 100644 index 0000000000..fe17c7f98e --- /dev/null +++ b/drivers/media/rc/bpf-lirc.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0 +// bpf-lirc.c - handles bpf +// +// Copyright (C) 2018 Sean Young <sean@mess.org> + +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/bpf_lirc.h> +#include "rc-core-priv.h" + +#define lirc_rcu_dereference(p) \ + rcu_dereference_protected(p, lockdep_is_held(&ir_raw_handler_lock)) + +/* + * BPF interface for raw IR + */ +const struct bpf_prog_ops lirc_mode2_prog_ops = { +}; + +BPF_CALL_1(bpf_rc_repeat, u32*, sample) +{ + struct ir_raw_event_ctrl *ctrl; + + ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample); + + 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_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_4(bpf_rc_keydown, u32*, sample, u32, protocol, u64, scancode, + u32, toggle) +{ + struct ir_raw_event_ctrl *ctrl; + + ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample); + + 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_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_3(bpf_rc_pointer_rel, u32*, sample, s32, rel_x, s32, rel_y) +{ + struct ir_raw_event_ctrl *ctrl; + + ctrl = container_of(sample, struct ir_raw_event_ctrl, bpf_sample); + + input_report_rel(ctrl->dev->input_dev, REL_X, rel_x); + input_report_rel(ctrl->dev->input_dev, REL_Y, rel_y); + input_sync(ctrl->dev->input_dev); + + return 0; +} + +static const struct bpf_func_proto rc_pointer_rel_proto = { + .func = bpf_rc_pointer_rel, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, +}; + +static const struct bpf_func_proto * +lirc_mode2_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_rc_pointer_rel: + return &rc_pointer_rel_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_map_push_elem: + return &bpf_map_push_elem_proto; + case BPF_FUNC_map_pop_elem: + return &bpf_map_pop_elem_proto; + case BPF_FUNC_map_peek_elem: + return &bpf_map_peek_elem_proto; + case BPF_FUNC_ktime_get_ns: + return &bpf_ktime_get_ns_proto; + case BPF_FUNC_ktime_get_boot_ns: + return &bpf_ktime_get_boot_ns_proto; + case BPF_FUNC_tail_call: + return &bpf_tail_call_proto; + case BPF_FUNC_get_prandom_u32: + return &bpf_get_prandom_u32_proto; + case BPF_FUNC_trace_printk: + if (perfmon_capable()) + return bpf_get_trace_printk_proto(); + fallthrough; + default: + return NULL; + } +} + +static bool lirc_mode2_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + /* We have one field of u32 */ + return type == BPF_READ && off == 0 && size == sizeof(u32); +} + +const struct bpf_verifier_ops lirc_mode2_verifier_ops = { + .get_func_proto = lirc_mode2_func_proto, + .is_valid_access = lirc_mode2_is_valid_access +}; + +#define BPF_MAX_PROGS 64 + +static int lirc_bpf_attach(struct rc_dev *rcdev, struct bpf_prog *prog) +{ + struct bpf_prog_array *old_array; + struct bpf_prog_array *new_array; + struct ir_raw_event_ctrl *raw; + int ret; + + if (rcdev->driver_type != RC_DRIVER_IR_RAW) + return -EINVAL; + + ret = mutex_lock_interruptible(&ir_raw_handler_lock); + if (ret) + return ret; + + raw = rcdev->raw; + if (!raw) { + ret = -ENODEV; + goto unlock; + } + + old_array = lirc_rcu_dereference(raw->progs); + if (old_array && bpf_prog_array_length(old_array) >= BPF_MAX_PROGS) { + ret = -E2BIG; + goto unlock; + } + + ret = bpf_prog_array_copy(old_array, NULL, prog, 0, &new_array); + if (ret < 0) + goto unlock; + + rcu_assign_pointer(raw->progs, new_array); + bpf_prog_array_free(old_array); + +unlock: + mutex_unlock(&ir_raw_handler_lock); + return ret; +} + +static int lirc_bpf_detach(struct rc_dev *rcdev, struct bpf_prog *prog) +{ + struct bpf_prog_array *old_array; + struct bpf_prog_array *new_array; + struct ir_raw_event_ctrl *raw; + int ret; + + if (rcdev->driver_type != RC_DRIVER_IR_RAW) + return -EINVAL; + + ret = mutex_lock_interruptible(&ir_raw_handler_lock); + if (ret) + return ret; + + raw = rcdev->raw; + if (!raw) { + ret = -ENODEV; + goto unlock; + } + + old_array = lirc_rcu_dereference(raw->progs); + ret = bpf_prog_array_copy(old_array, prog, NULL, 0, &new_array); + /* + * Do not use bpf_prog_array_delete_safe() as we would end up + * with a dummy entry in the array, and the we would free the + * dummy in lirc_bpf_free() + */ + if (ret) + goto unlock; + + rcu_assign_pointer(raw->progs, new_array); + bpf_prog_array_free(old_array); + bpf_prog_put(prog); +unlock: + mutex_unlock(&ir_raw_handler_lock); + return ret; +} + +void lirc_bpf_run(struct rc_dev *rcdev, u32 sample) +{ + struct ir_raw_event_ctrl *raw = rcdev->raw; + + raw->bpf_sample = sample; + + if (raw->progs) { + rcu_read_lock(); + bpf_prog_run_array(rcu_dereference(raw->progs), + &raw->bpf_sample, bpf_prog_run); + rcu_read_unlock(); + } +} + +/* + * This should be called once the rc thread has been stopped, so there can be + * no concurrent bpf execution. + * + * Should be called with the ir_raw_handler_lock held. + */ +void lirc_bpf_free(struct rc_dev *rcdev) +{ + struct bpf_prog_array_item *item; + struct bpf_prog_array *array; + + array = lirc_rcu_dereference(rcdev->raw->progs); + if (!array) + return; + + for (item = array->items; item->prog; item++) + bpf_prog_put(item->prog); + + bpf_prog_array_free(array); +} + +int lirc_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct rc_dev *rcdev; + int ret; + + if (attr->attach_flags) + return -EINVAL; + + rcdev = rc_dev_get_from_fd(attr->target_fd); + if (IS_ERR(rcdev)) + return PTR_ERR(rcdev); + + ret = lirc_bpf_attach(rcdev, prog); + + put_device(&rcdev->dev); + + return ret; +} + +int lirc_prog_detach(const union bpf_attr *attr) +{ + struct bpf_prog *prog; + struct rc_dev *rcdev; + int ret; + + if (attr->attach_flags) + return -EINVAL; + + prog = bpf_prog_get_type(attr->attach_bpf_fd, + BPF_PROG_TYPE_LIRC_MODE2); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + rcdev = rc_dev_get_from_fd(attr->target_fd); + if (IS_ERR(rcdev)) { + bpf_prog_put(prog); + return PTR_ERR(rcdev); + } + + ret = lirc_bpf_detach(rcdev, prog); + + bpf_prog_put(prog); + put_device(&rcdev->dev); + + return ret; +} + +int lirc_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) +{ + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); + struct bpf_prog_array *progs; + struct rc_dev *rcdev; + u32 cnt, flags = 0; + int ret; + + if (attr->query.query_flags) + return -EINVAL; + + rcdev = rc_dev_get_from_fd(attr->query.target_fd); + if (IS_ERR(rcdev)) + return PTR_ERR(rcdev); + + if (rcdev->driver_type != RC_DRIVER_IR_RAW) { + ret = -EINVAL; + goto put; + } + + ret = mutex_lock_interruptible(&ir_raw_handler_lock); + if (ret) + goto put; + + progs = lirc_rcu_dereference(rcdev->raw->progs); + cnt = progs ? bpf_prog_array_length(progs) : 0; + + if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) { + ret = -EFAULT; + goto unlock; + } + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) { + ret = -EFAULT; + goto unlock; + } + + if (attr->query.prog_cnt != 0 && prog_ids && cnt) + ret = bpf_prog_array_copy_to_user(progs, prog_ids, + attr->query.prog_cnt); + +unlock: + mutex_unlock(&ir_raw_handler_lock); +put: + put_device(&rcdev->dev); + + return ret; +} |