forked from Minki/linux
0e253f7e55
Changing return value of kprobe's version of bpf_get_func_ip to return zero if the attach address is not on the function's entry point. For kprobes attached in the middle of the function we can't easily get to the function address especially now with the CONFIG_X86_KERNEL_IBT support. If user cares about current IP for kprobes attached within the function body, they can get it with PT_REGS_IP(ctx). Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martynas Pumputis <m@lambda.lt> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-6-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2801 lines
74 KiB
C
2801 lines
74 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
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* Copyright (c) 2016 Facebook
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/bpf.h>
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#include <linux/bpf_perf_event.h>
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#include <linux/btf.h>
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#include <linux/filter.h>
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#include <linux/uaccess.h>
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#include <linux/ctype.h>
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#include <linux/kprobes.h>
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#include <linux/spinlock.h>
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#include <linux/syscalls.h>
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#include <linux/error-injection.h>
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#include <linux/btf_ids.h>
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#include <linux/bpf_lsm.h>
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#include <linux/fprobe.h>
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#include <linux/bsearch.h>
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#include <linux/sort.h>
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#include <linux/key.h>
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#include <linux/verification.h>
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#include <net/bpf_sk_storage.h>
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#include <uapi/linux/bpf.h>
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#include <uapi/linux/btf.h>
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#include <asm/tlb.h>
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#include "trace_probe.h"
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#include "trace.h"
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#define CREATE_TRACE_POINTS
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#include "bpf_trace.h"
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#define bpf_event_rcu_dereference(p) \
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rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
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#ifdef CONFIG_MODULES
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struct bpf_trace_module {
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struct module *module;
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struct list_head list;
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};
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static LIST_HEAD(bpf_trace_modules);
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static DEFINE_MUTEX(bpf_module_mutex);
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static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
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{
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struct bpf_raw_event_map *btp, *ret = NULL;
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struct bpf_trace_module *btm;
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unsigned int i;
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mutex_lock(&bpf_module_mutex);
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list_for_each_entry(btm, &bpf_trace_modules, list) {
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for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
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btp = &btm->module->bpf_raw_events[i];
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if (!strcmp(btp->tp->name, name)) {
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if (try_module_get(btm->module))
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ret = btp;
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goto out;
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}
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}
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}
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out:
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mutex_unlock(&bpf_module_mutex);
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return ret;
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}
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#else
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static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
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{
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return NULL;
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}
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#endif /* CONFIG_MODULES */
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u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
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u64 flags, const struct btf **btf,
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s32 *btf_id);
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static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
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static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
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/**
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* trace_call_bpf - invoke BPF program
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* @call: tracepoint event
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* @ctx: opaque context pointer
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*
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* kprobe handlers execute BPF programs via this helper.
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* Can be used from static tracepoints in the future.
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*
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* Return: BPF programs always return an integer which is interpreted by
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* kprobe handler as:
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* 0 - return from kprobe (event is filtered out)
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* 1 - store kprobe event into ring buffer
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* Other values are reserved and currently alias to 1
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*/
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unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
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{
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unsigned int ret;
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cant_sleep();
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if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
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/*
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* since some bpf program is already running on this cpu,
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* don't call into another bpf program (same or different)
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* and don't send kprobe event into ring-buffer,
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* so return zero here
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*/
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ret = 0;
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goto out;
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}
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/*
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* Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
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* to all call sites, we did a bpf_prog_array_valid() there to check
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* whether call->prog_array is empty or not, which is
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* a heuristic to speed up execution.
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*
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* If bpf_prog_array_valid() fetched prog_array was
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* non-NULL, we go into trace_call_bpf() and do the actual
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* proper rcu_dereference() under RCU lock.
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* If it turns out that prog_array is NULL then, we bail out.
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* For the opposite, if the bpf_prog_array_valid() fetched pointer
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* was NULL, you'll skip the prog_array with the risk of missing
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* out of events when it was updated in between this and the
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* rcu_dereference() which is accepted risk.
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*/
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rcu_read_lock();
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ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
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ctx, bpf_prog_run);
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rcu_read_unlock();
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out:
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__this_cpu_dec(bpf_prog_active);
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return ret;
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}
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#ifdef CONFIG_BPF_KPROBE_OVERRIDE
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BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
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{
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regs_set_return_value(regs, rc);
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override_function_with_return(regs);
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return 0;
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}
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static const struct bpf_func_proto bpf_override_return_proto = {
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.func = bpf_override_return,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_CTX,
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.arg2_type = ARG_ANYTHING,
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};
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#endif
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static __always_inline int
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bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
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{
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int ret;
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ret = copy_from_user_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
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const void __user *, unsafe_ptr)
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{
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return bpf_probe_read_user_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_user_proto = {
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.func = bpf_probe_read_user,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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static __always_inline int
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bpf_probe_read_user_str_common(void *dst, u32 size,
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const void __user *unsafe_ptr)
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{
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int ret;
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/*
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* NB: We rely on strncpy_from_user() not copying junk past the NUL
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* terminator into `dst`.
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*
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* strncpy_from_user() does long-sized strides in the fast path. If the
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* strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
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* then there could be junk after the NUL in `dst`. If user takes `dst`
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* and keys a hash map with it, then semantically identical strings can
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* occupy multiple entries in the map.
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*/
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ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
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const void __user *, unsafe_ptr)
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{
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return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_user_str_proto = {
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.func = bpf_probe_read_user_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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static __always_inline int
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bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
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{
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int ret;
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ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_kernel_proto = {
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.func = bpf_probe_read_kernel,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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static __always_inline int
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bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
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{
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int ret;
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/*
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* The strncpy_from_kernel_nofault() call will likely not fill the
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* entire buffer, but that's okay in this circumstance as we're probing
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* arbitrary memory anyway similar to bpf_probe_read_*() and might
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* as well probe the stack. Thus, memory is explicitly cleared
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* only in error case, so that improper users ignoring return
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* code altogether don't copy garbage; otherwise length of string
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* is returned that can be used for bpf_perf_event_output() et al.
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*/
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ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
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.func = bpf_probe_read_kernel_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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if ((unsigned long)unsafe_ptr < TASK_SIZE) {
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return bpf_probe_read_user_common(dst, size,
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(__force void __user *)unsafe_ptr);
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}
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return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
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}
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static const struct bpf_func_proto bpf_probe_read_compat_proto = {
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.func = bpf_probe_read_compat,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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if ((unsigned long)unsafe_ptr < TASK_SIZE) {
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return bpf_probe_read_user_str_common(dst, size,
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(__force void __user *)unsafe_ptr);
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}
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return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
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}
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static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
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.func = bpf_probe_read_compat_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
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BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
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u32, size)
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{
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/*
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* Ensure we're in user context which is safe for the helper to
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* run. This helper has no business in a kthread.
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*
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* access_ok() should prevent writing to non-user memory, but in
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* some situations (nommu, temporary switch, etc) access_ok() does
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* not provide enough validation, hence the check on KERNEL_DS.
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*
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* nmi_uaccess_okay() ensures the probe is not run in an interim
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* state, when the task or mm are switched. This is specifically
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* required to prevent the use of temporary mm.
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*/
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if (unlikely(in_interrupt() ||
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current->flags & (PF_KTHREAD | PF_EXITING)))
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return -EPERM;
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if (unlikely(!nmi_uaccess_okay()))
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return -EPERM;
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return copy_to_user_nofault(unsafe_ptr, src, size);
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}
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static const struct bpf_func_proto bpf_probe_write_user_proto = {
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.func = bpf_probe_write_user,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_ANYTHING,
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.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
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.arg3_type = ARG_CONST_SIZE,
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};
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static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
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{
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if (!capable(CAP_SYS_ADMIN))
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return NULL;
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pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
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current->comm, task_pid_nr(current));
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return &bpf_probe_write_user_proto;
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}
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static DEFINE_RAW_SPINLOCK(trace_printk_lock);
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#define MAX_TRACE_PRINTK_VARARGS 3
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#define BPF_TRACE_PRINTK_SIZE 1024
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BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
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u64, arg2, u64, arg3)
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{
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u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
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u32 *bin_args;
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static char buf[BPF_TRACE_PRINTK_SIZE];
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unsigned long flags;
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int ret;
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ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args,
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MAX_TRACE_PRINTK_VARARGS);
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if (ret < 0)
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return ret;
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raw_spin_lock_irqsave(&trace_printk_lock, flags);
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ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
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trace_bpf_trace_printk(buf);
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raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
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bpf_bprintf_cleanup();
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return ret;
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}
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static const struct bpf_func_proto bpf_trace_printk_proto = {
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.func = bpf_trace_printk,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
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.arg2_type = ARG_CONST_SIZE,
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};
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|
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static void __set_printk_clr_event(void)
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{
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/*
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* This program might be calling bpf_trace_printk,
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* so enable the associated bpf_trace/bpf_trace_printk event.
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* Repeat this each time as it is possible a user has
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* disabled bpf_trace_printk events. By loading a program
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* calling bpf_trace_printk() however the user has expressed
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* the intent to see such events.
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*/
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if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
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pr_warn_ratelimited("could not enable bpf_trace_printk events");
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}
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const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
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{
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__set_printk_clr_event();
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return &bpf_trace_printk_proto;
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}
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|
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BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data,
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u32, data_len)
|
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{
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static char buf[BPF_TRACE_PRINTK_SIZE];
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unsigned long flags;
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int ret, num_args;
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u32 *bin_args;
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|
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if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
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(data_len && !data))
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return -EINVAL;
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num_args = data_len / 8;
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ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
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if (ret < 0)
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return ret;
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raw_spin_lock_irqsave(&trace_printk_lock, flags);
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ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
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|
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trace_bpf_trace_printk(buf);
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raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
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bpf_bprintf_cleanup();
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return ret;
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}
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|
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static const struct bpf_func_proto bpf_trace_vprintk_proto = {
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.func = bpf_trace_vprintk,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
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.arg2_type = ARG_CONST_SIZE,
|
|
.arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
|
|
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
|
|
{
|
|
__set_printk_clr_event();
|
|
return &bpf_trace_vprintk_proto;
|
|
}
|
|
|
|
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
|
|
const void *, data, u32, data_len)
|
|
{
|
|
int err, num_args;
|
|
u32 *bin_args;
|
|
|
|
if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
|
|
(data_len && !data))
|
|
return -EINVAL;
|
|
num_args = data_len / 8;
|
|
|
|
err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
seq_bprintf(m, fmt, bin_args);
|
|
|
|
bpf_bprintf_cleanup();
|
|
|
|
return seq_has_overflowed(m) ? -EOVERFLOW : 0;
|
|
}
|
|
|
|
BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
|
|
|
|
static const struct bpf_func_proto bpf_seq_printf_proto = {
|
|
.func = bpf_seq_printf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
.arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
|
|
{
|
|
return seq_write(m, data, len) ? -EOVERFLOW : 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_seq_write_proto = {
|
|
.func = bpf_seq_write,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
|
|
u32, btf_ptr_size, u64, flags)
|
|
{
|
|
const struct btf *btf;
|
|
s32 btf_id;
|
|
int ret;
|
|
|
|
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
|
|
.func = bpf_seq_printf_btf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_seq_file_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static __always_inline int
|
|
get_map_perf_counter(struct bpf_map *map, u64 flags,
|
|
u64 *value, u64 *enabled, u64 *running)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
unsigned int cpu = smp_processor_id();
|
|
u64 index = flags & BPF_F_INDEX_MASK;
|
|
struct bpf_event_entry *ee;
|
|
|
|
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
|
|
return -EINVAL;
|
|
if (index == BPF_F_CURRENT_CPU)
|
|
index = cpu;
|
|
if (unlikely(index >= array->map.max_entries))
|
|
return -E2BIG;
|
|
|
|
ee = READ_ONCE(array->ptrs[index]);
|
|
if (!ee)
|
|
return -ENOENT;
|
|
|
|
return perf_event_read_local(ee->event, value, enabled, running);
|
|
}
|
|
|
|
BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
|
|
{
|
|
u64 value = 0;
|
|
int err;
|
|
|
|
err = get_map_perf_counter(map, flags, &value, NULL, NULL);
|
|
/*
|
|
* this api is ugly since we miss [-22..-2] range of valid
|
|
* counter values, but that's uapi
|
|
*/
|
|
if (err)
|
|
return err;
|
|
return value;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_read_proto = {
|
|
.func = bpf_perf_event_read,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
|
|
struct bpf_perf_event_value *, buf, u32, size)
|
|
{
|
|
int err = -EINVAL;
|
|
|
|
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
|
|
goto clear;
|
|
err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
|
|
&buf->running);
|
|
if (unlikely(err))
|
|
goto clear;
|
|
return 0;
|
|
clear:
|
|
memset(buf, 0, size);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
|
|
.func = bpf_perf_event_read_value,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg4_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
static __always_inline u64
|
|
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
|
|
u64 flags, struct perf_sample_data *sd)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
unsigned int cpu = smp_processor_id();
|
|
u64 index = flags & BPF_F_INDEX_MASK;
|
|
struct bpf_event_entry *ee;
|
|
struct perf_event *event;
|
|
|
|
if (index == BPF_F_CURRENT_CPU)
|
|
index = cpu;
|
|
if (unlikely(index >= array->map.max_entries))
|
|
return -E2BIG;
|
|
|
|
ee = READ_ONCE(array->ptrs[index]);
|
|
if (!ee)
|
|
return -ENOENT;
|
|
|
|
event = ee->event;
|
|
if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
|
|
event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(event->oncpu != cpu))
|
|
return -EOPNOTSUPP;
|
|
|
|
return perf_event_output(event, sd, regs);
|
|
}
|
|
|
|
/*
|
|
* Support executing tracepoints in normal, irq, and nmi context that each call
|
|
* bpf_perf_event_output
|
|
*/
|
|
struct bpf_trace_sample_data {
|
|
struct perf_sample_data sds[3];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
|
|
static DEFINE_PER_CPU(int, bpf_trace_nest_level);
|
|
BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
|
|
u64, flags, void *, data, u64, size)
|
|
{
|
|
struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
|
|
int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
|
|
struct perf_raw_record raw = {
|
|
.frag = {
|
|
.size = size,
|
|
.data = data,
|
|
},
|
|
};
|
|
struct perf_sample_data *sd;
|
|
int err;
|
|
|
|
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
sd = &sds->sds[nest_level - 1];
|
|
|
|
if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
perf_sample_data_init(sd, 0, 0);
|
|
sd->raw = &raw;
|
|
|
|
err = __bpf_perf_event_output(regs, map, flags, sd);
|
|
|
|
out:
|
|
this_cpu_dec(bpf_trace_nest_level);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto = {
|
|
.func = bpf_perf_event_output,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
|
|
struct bpf_nested_pt_regs {
|
|
struct pt_regs regs[3];
|
|
};
|
|
static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
|
|
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
|
|
|
|
u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
|
|
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
|
|
{
|
|
int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
|
|
struct perf_raw_frag frag = {
|
|
.copy = ctx_copy,
|
|
.size = ctx_size,
|
|
.data = ctx,
|
|
};
|
|
struct perf_raw_record raw = {
|
|
.frag = {
|
|
{
|
|
.next = ctx_size ? &frag : NULL,
|
|
},
|
|
.size = meta_size,
|
|
.data = meta,
|
|
},
|
|
};
|
|
struct perf_sample_data *sd;
|
|
struct pt_regs *regs;
|
|
u64 ret;
|
|
|
|
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
|
|
regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
perf_sample_data_init(sd, 0, 0);
|
|
sd->raw = &raw;
|
|
|
|
ret = __bpf_perf_event_output(regs, map, flags, sd);
|
|
out:
|
|
this_cpu_dec(bpf_event_output_nest_level);
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_0(bpf_get_current_task)
|
|
{
|
|
return (long) current;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_current_task_proto = {
|
|
.func = bpf_get_current_task,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
BPF_CALL_0(bpf_get_current_task_btf)
|
|
{
|
|
return (unsigned long) current;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_current_task_btf_proto = {
|
|
.func = bpf_get_current_task_btf,
|
|
.gpl_only = true,
|
|
.ret_type = RET_PTR_TO_BTF_ID,
|
|
.ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
|
|
};
|
|
|
|
BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
|
|
{
|
|
return (unsigned long) task_pt_regs(task);
|
|
}
|
|
|
|
BTF_ID_LIST(bpf_task_pt_regs_ids)
|
|
BTF_ID(struct, pt_regs)
|
|
|
|
const struct bpf_func_proto bpf_task_pt_regs_proto = {
|
|
.func = bpf_task_pt_regs,
|
|
.gpl_only = true,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
|
|
.ret_type = RET_PTR_TO_BTF_ID,
|
|
.ret_btf_id = &bpf_task_pt_regs_ids[0],
|
|
};
|
|
|
|
BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
|
|
{
|
|
struct bpf_array *array = container_of(map, struct bpf_array, map);
|
|
struct cgroup *cgrp;
|
|
|
|
if (unlikely(idx >= array->map.max_entries))
|
|
return -E2BIG;
|
|
|
|
cgrp = READ_ONCE(array->ptrs[idx]);
|
|
if (unlikely(!cgrp))
|
|
return -EAGAIN;
|
|
|
|
return task_under_cgroup_hierarchy(current, cgrp);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
|
|
.func = bpf_current_task_under_cgroup,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
};
|
|
|
|
struct send_signal_irq_work {
|
|
struct irq_work irq_work;
|
|
struct task_struct *task;
|
|
u32 sig;
|
|
enum pid_type type;
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
|
|
|
|
static void do_bpf_send_signal(struct irq_work *entry)
|
|
{
|
|
struct send_signal_irq_work *work;
|
|
|
|
work = container_of(entry, struct send_signal_irq_work, irq_work);
|
|
group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
|
|
}
|
|
|
|
static int bpf_send_signal_common(u32 sig, enum pid_type type)
|
|
{
|
|
struct send_signal_irq_work *work = NULL;
|
|
|
|
/* Similar to bpf_probe_write_user, task needs to be
|
|
* in a sound condition and kernel memory access be
|
|
* permitted in order to send signal to the current
|
|
* task.
|
|
*/
|
|
if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
|
|
return -EPERM;
|
|
if (unlikely(!nmi_uaccess_okay()))
|
|
return -EPERM;
|
|
|
|
if (irqs_disabled()) {
|
|
/* Do an early check on signal validity. Otherwise,
|
|
* the error is lost in deferred irq_work.
|
|
*/
|
|
if (unlikely(!valid_signal(sig)))
|
|
return -EINVAL;
|
|
|
|
work = this_cpu_ptr(&send_signal_work);
|
|
if (irq_work_is_busy(&work->irq_work))
|
|
return -EBUSY;
|
|
|
|
/* Add the current task, which is the target of sending signal,
|
|
* to the irq_work. The current task may change when queued
|
|
* irq works get executed.
|
|
*/
|
|
work->task = current;
|
|
work->sig = sig;
|
|
work->type = type;
|
|
irq_work_queue(&work->irq_work);
|
|
return 0;
|
|
}
|
|
|
|
return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
|
|
}
|
|
|
|
BPF_CALL_1(bpf_send_signal, u32, sig)
|
|
{
|
|
return bpf_send_signal_common(sig, PIDTYPE_TGID);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_send_signal_proto = {
|
|
.func = bpf_send_signal,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_send_signal_thread, u32, sig)
|
|
{
|
|
return bpf_send_signal_common(sig, PIDTYPE_PID);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_send_signal_thread_proto = {
|
|
.func = bpf_send_signal_thread,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
|
|
{
|
|
long len;
|
|
char *p;
|
|
|
|
if (!sz)
|
|
return 0;
|
|
|
|
p = d_path(path, buf, sz);
|
|
if (IS_ERR(p)) {
|
|
len = PTR_ERR(p);
|
|
} else {
|
|
len = buf + sz - p;
|
|
memmove(buf, p, len);
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
BTF_SET_START(btf_allowlist_d_path)
|
|
#ifdef CONFIG_SECURITY
|
|
BTF_ID(func, security_file_permission)
|
|
BTF_ID(func, security_inode_getattr)
|
|
BTF_ID(func, security_file_open)
|
|
#endif
|
|
#ifdef CONFIG_SECURITY_PATH
|
|
BTF_ID(func, security_path_truncate)
|
|
#endif
|
|
BTF_ID(func, vfs_truncate)
|
|
BTF_ID(func, vfs_fallocate)
|
|
BTF_ID(func, dentry_open)
|
|
BTF_ID(func, vfs_getattr)
|
|
BTF_ID(func, filp_close)
|
|
BTF_SET_END(btf_allowlist_d_path)
|
|
|
|
static bool bpf_d_path_allowed(const struct bpf_prog *prog)
|
|
{
|
|
if (prog->type == BPF_PROG_TYPE_TRACING &&
|
|
prog->expected_attach_type == BPF_TRACE_ITER)
|
|
return true;
|
|
|
|
if (prog->type == BPF_PROG_TYPE_LSM)
|
|
return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
|
|
|
|
return btf_id_set_contains(&btf_allowlist_d_path,
|
|
prog->aux->attach_btf_id);
|
|
}
|
|
|
|
BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
|
|
|
|
static const struct bpf_func_proto bpf_d_path_proto = {
|
|
.func = bpf_d_path,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_BTF_ID,
|
|
.arg1_btf_id = &bpf_d_path_btf_ids[0],
|
|
.arg2_type = ARG_PTR_TO_MEM,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.allowed = bpf_d_path_allowed,
|
|
};
|
|
|
|
#define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
|
|
BTF_F_PTR_RAW | BTF_F_ZERO)
|
|
|
|
static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
|
|
u64 flags, const struct btf **btf,
|
|
s32 *btf_id)
|
|
{
|
|
const struct btf_type *t;
|
|
|
|
if (unlikely(flags & ~(BTF_F_ALL)))
|
|
return -EINVAL;
|
|
|
|
if (btf_ptr_size != sizeof(struct btf_ptr))
|
|
return -EINVAL;
|
|
|
|
*btf = bpf_get_btf_vmlinux();
|
|
|
|
if (IS_ERR_OR_NULL(*btf))
|
|
return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
|
|
|
|
if (ptr->type_id > 0)
|
|
*btf_id = ptr->type_id;
|
|
else
|
|
return -EINVAL;
|
|
|
|
if (*btf_id > 0)
|
|
t = btf_type_by_id(*btf, *btf_id);
|
|
if (*btf_id <= 0 || !t)
|
|
return -ENOENT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
|
|
u32, btf_ptr_size, u64, flags)
|
|
{
|
|
const struct btf *btf;
|
|
s32 btf_id;
|
|
int ret;
|
|
|
|
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
|
|
flags);
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_snprintf_btf_proto = {
|
|
.func = bpf_snprintf_btf,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_MEM,
|
|
.arg2_type = ARG_CONST_SIZE,
|
|
.arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg4_type = ARG_CONST_SIZE,
|
|
.arg5_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
return ((u64 *)ctx)[-2];
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
|
|
.func = bpf_get_func_ip_tracing,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
#ifdef CONFIG_X86_KERNEL_IBT
|
|
static unsigned long get_entry_ip(unsigned long fentry_ip)
|
|
{
|
|
u32 instr;
|
|
|
|
/* Being extra safe in here in case entry ip is on the page-edge. */
|
|
if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
|
|
return fentry_ip;
|
|
if (is_endbr(instr))
|
|
fentry_ip -= ENDBR_INSN_SIZE;
|
|
return fentry_ip;
|
|
}
|
|
#else
|
|
#define get_entry_ip(fentry_ip) fentry_ip
|
|
#endif
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
|
|
{
|
|
struct kprobe *kp = kprobe_running();
|
|
|
|
if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
|
|
return 0;
|
|
|
|
return get_entry_ip((uintptr_t)kp->addr);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
|
|
.func = bpf_get_func_ip_kprobe,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
|
|
.func = bpf_get_func_ip_kprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
|
|
{
|
|
return bpf_kprobe_multi_cookie(current->bpf_ctx);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
|
|
.func = bpf_get_attach_cookie_kprobe_multi,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
|
|
{
|
|
struct bpf_trace_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
|
|
return run_ctx->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
|
|
.func = bpf_get_attach_cookie_trace,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
|
|
{
|
|
return ctx->event->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
|
|
.func = bpf_get_attach_cookie_pe,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
|
|
{
|
|
struct bpf_trace_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
|
|
return run_ctx->bpf_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
|
|
.func = bpf_get_attach_cookie_tracing,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
|
|
{
|
|
#ifndef CONFIG_X86
|
|
return -ENOENT;
|
|
#else
|
|
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
|
|
u32 entry_cnt = size / br_entry_size;
|
|
|
|
entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
|
|
|
|
if (unlikely(flags))
|
|
return -EINVAL;
|
|
|
|
if (!entry_cnt)
|
|
return -ENOENT;
|
|
|
|
return entry_cnt * br_entry_size;
|
|
#endif
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
|
|
.func = bpf_get_branch_snapshot,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
u64 nr_args = ((u64 *)ctx)[-1];
|
|
|
|
if ((u64) n >= nr_args)
|
|
return -EINVAL;
|
|
*value = ((u64 *)ctx)[n];
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_arg_proto = {
|
|
.func = get_func_arg,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_LONG,
|
|
};
|
|
|
|
BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
u64 nr_args = ((u64 *)ctx)[-1];
|
|
|
|
*value = ((u64 *)ctx)[nr_args];
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_ret_proto = {
|
|
.func = get_func_ret,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_LONG,
|
|
};
|
|
|
|
BPF_CALL_1(get_func_arg_cnt, void *, ctx)
|
|
{
|
|
/* This helper call is inlined by verifier. */
|
|
return ((u64 *)ctx)[-1];
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
|
|
.func = get_func_arg_cnt,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
};
|
|
|
|
#ifdef CONFIG_KEYS
|
|
__diag_push();
|
|
__diag_ignore_all("-Wmissing-prototypes",
|
|
"kfuncs which will be used in BPF programs");
|
|
|
|
/**
|
|
* bpf_lookup_user_key - lookup a key by its serial
|
|
* @serial: key handle serial number
|
|
* @flags: lookup-specific flags
|
|
*
|
|
* Search a key with a given *serial* and the provided *flags*.
|
|
* If found, increment the reference count of the key by one, and
|
|
* return it in the bpf_key structure.
|
|
*
|
|
* The bpf_key structure must be passed to bpf_key_put() when done
|
|
* with it, so that the key reference count is decremented and the
|
|
* bpf_key structure is freed.
|
|
*
|
|
* Permission checks are deferred to the time the key is used by
|
|
* one of the available key-specific kfuncs.
|
|
*
|
|
* Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
|
|
* special keyring (e.g. session keyring), if it doesn't yet exist.
|
|
* Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
|
|
* for the key construction, and to retrieve uninstantiated keys (keys
|
|
* without data attached to them).
|
|
*
|
|
* Return: a bpf_key pointer with a valid key pointer if the key is found, a
|
|
* NULL pointer otherwise.
|
|
*/
|
|
struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
|
|
{
|
|
key_ref_t key_ref;
|
|
struct bpf_key *bkey;
|
|
|
|
if (flags & ~KEY_LOOKUP_ALL)
|
|
return NULL;
|
|
|
|
/*
|
|
* Permission check is deferred until the key is used, as the
|
|
* intent of the caller is unknown here.
|
|
*/
|
|
key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
|
|
if (IS_ERR(key_ref))
|
|
return NULL;
|
|
|
|
bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
|
|
if (!bkey) {
|
|
key_put(key_ref_to_ptr(key_ref));
|
|
return NULL;
|
|
}
|
|
|
|
bkey->key = key_ref_to_ptr(key_ref);
|
|
bkey->has_ref = true;
|
|
|
|
return bkey;
|
|
}
|
|
|
|
/**
|
|
* bpf_lookup_system_key - lookup a key by a system-defined ID
|
|
* @id: key ID
|
|
*
|
|
* Obtain a bpf_key structure with a key pointer set to the passed key ID.
|
|
* The key pointer is marked as invalid, to prevent bpf_key_put() from
|
|
* attempting to decrement the key reference count on that pointer. The key
|
|
* pointer set in such way is currently understood only by
|
|
* verify_pkcs7_signature().
|
|
*
|
|
* Set *id* to one of the values defined in include/linux/verification.h:
|
|
* 0 for the primary keyring (immutable keyring of system keys);
|
|
* VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
|
|
* (where keys can be added only if they are vouched for by existing keys
|
|
* in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
|
|
* keyring (primarily used by the integrity subsystem to verify a kexec'ed
|
|
* kerned image and, possibly, the initramfs signature).
|
|
*
|
|
* Return: a bpf_key pointer with an invalid key pointer set from the
|
|
* pre-determined ID on success, a NULL pointer otherwise
|
|
*/
|
|
struct bpf_key *bpf_lookup_system_key(u64 id)
|
|
{
|
|
struct bpf_key *bkey;
|
|
|
|
if (system_keyring_id_check(id) < 0)
|
|
return NULL;
|
|
|
|
bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
|
|
if (!bkey)
|
|
return NULL;
|
|
|
|
bkey->key = (struct key *)(unsigned long)id;
|
|
bkey->has_ref = false;
|
|
|
|
return bkey;
|
|
}
|
|
|
|
/**
|
|
* bpf_key_put - decrement key reference count if key is valid and free bpf_key
|
|
* @bkey: bpf_key structure
|
|
*
|
|
* Decrement the reference count of the key inside *bkey*, if the pointer
|
|
* is valid, and free *bkey*.
|
|
*/
|
|
void bpf_key_put(struct bpf_key *bkey)
|
|
{
|
|
if (bkey->has_ref)
|
|
key_put(bkey->key);
|
|
|
|
kfree(bkey);
|
|
}
|
|
|
|
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
|
|
/**
|
|
* bpf_verify_pkcs7_signature - verify a PKCS#7 signature
|
|
* @data_ptr: data to verify
|
|
* @sig_ptr: signature of the data
|
|
* @trusted_keyring: keyring with keys trusted for signature verification
|
|
*
|
|
* Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
|
|
* with keys in a keyring referenced by *trusted_keyring*.
|
|
*
|
|
* Return: 0 on success, a negative value on error.
|
|
*/
|
|
int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
|
|
struct bpf_dynptr_kern *sig_ptr,
|
|
struct bpf_key *trusted_keyring)
|
|
{
|
|
int ret;
|
|
|
|
if (trusted_keyring->has_ref) {
|
|
/*
|
|
* Do the permission check deferred in bpf_lookup_user_key().
|
|
* See bpf_lookup_user_key() for more details.
|
|
*
|
|
* A call to key_task_permission() here would be redundant, as
|
|
* it is already done by keyring_search() called by
|
|
* find_asymmetric_key().
|
|
*/
|
|
ret = key_validate(trusted_keyring->key);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return verify_pkcs7_signature(data_ptr->data,
|
|
bpf_dynptr_get_size(data_ptr),
|
|
sig_ptr->data,
|
|
bpf_dynptr_get_size(sig_ptr),
|
|
trusted_keyring->key,
|
|
VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
|
|
NULL);
|
|
}
|
|
#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
|
|
|
|
__diag_pop();
|
|
|
|
BTF_SET8_START(key_sig_kfunc_set)
|
|
BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
|
|
BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
|
|
BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
|
|
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
|
|
BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
|
|
#endif
|
|
BTF_SET8_END(key_sig_kfunc_set)
|
|
|
|
static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
|
|
.owner = THIS_MODULE,
|
|
.set = &key_sig_kfunc_set,
|
|
};
|
|
|
|
static int __init bpf_key_sig_kfuncs_init(void)
|
|
{
|
|
return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
|
|
&bpf_key_sig_kfunc_set);
|
|
}
|
|
|
|
late_initcall(bpf_key_sig_kfuncs_init);
|
|
#endif /* CONFIG_KEYS */
|
|
|
|
static const struct bpf_func_proto *
|
|
bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
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_map_lookup_percpu_elem:
|
|
return &bpf_map_lookup_percpu_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_current_pid_tgid:
|
|
return &bpf_get_current_pid_tgid_proto;
|
|
case BPF_FUNC_get_current_task:
|
|
return &bpf_get_current_task_proto;
|
|
case BPF_FUNC_get_current_task_btf:
|
|
return &bpf_get_current_task_btf_proto;
|
|
case BPF_FUNC_task_pt_regs:
|
|
return &bpf_task_pt_regs_proto;
|
|
case BPF_FUNC_get_current_uid_gid:
|
|
return &bpf_get_current_uid_gid_proto;
|
|
case BPF_FUNC_get_current_comm:
|
|
return &bpf_get_current_comm_proto;
|
|
case BPF_FUNC_trace_printk:
|
|
return bpf_get_trace_printk_proto();
|
|
case BPF_FUNC_get_smp_processor_id:
|
|
return &bpf_get_smp_processor_id_proto;
|
|
case BPF_FUNC_get_numa_node_id:
|
|
return &bpf_get_numa_node_id_proto;
|
|
case BPF_FUNC_perf_event_read:
|
|
return &bpf_perf_event_read_proto;
|
|
case BPF_FUNC_current_task_under_cgroup:
|
|
return &bpf_current_task_under_cgroup_proto;
|
|
case BPF_FUNC_get_prandom_u32:
|
|
return &bpf_get_prandom_u32_proto;
|
|
case BPF_FUNC_probe_write_user:
|
|
return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
|
|
NULL : bpf_get_probe_write_proto();
|
|
case BPF_FUNC_probe_read_user:
|
|
return &bpf_probe_read_user_proto;
|
|
case BPF_FUNC_probe_read_kernel:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_kernel_proto;
|
|
case BPF_FUNC_probe_read_user_str:
|
|
return &bpf_probe_read_user_str_proto;
|
|
case BPF_FUNC_probe_read_kernel_str:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_kernel_str_proto;
|
|
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
|
|
case BPF_FUNC_probe_read:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_compat_proto;
|
|
case BPF_FUNC_probe_read_str:
|
|
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
|
|
NULL : &bpf_probe_read_compat_str_proto;
|
|
#endif
|
|
#ifdef CONFIG_CGROUPS
|
|
case BPF_FUNC_get_current_cgroup_id:
|
|
return &bpf_get_current_cgroup_id_proto;
|
|
case BPF_FUNC_get_current_ancestor_cgroup_id:
|
|
return &bpf_get_current_ancestor_cgroup_id_proto;
|
|
#endif
|
|
case BPF_FUNC_send_signal:
|
|
return &bpf_send_signal_proto;
|
|
case BPF_FUNC_send_signal_thread:
|
|
return &bpf_send_signal_thread_proto;
|
|
case BPF_FUNC_perf_event_read_value:
|
|
return &bpf_perf_event_read_value_proto;
|
|
case BPF_FUNC_get_ns_current_pid_tgid:
|
|
return &bpf_get_ns_current_pid_tgid_proto;
|
|
case BPF_FUNC_ringbuf_output:
|
|
return &bpf_ringbuf_output_proto;
|
|
case BPF_FUNC_ringbuf_reserve:
|
|
return &bpf_ringbuf_reserve_proto;
|
|
case BPF_FUNC_ringbuf_submit:
|
|
return &bpf_ringbuf_submit_proto;
|
|
case BPF_FUNC_ringbuf_discard:
|
|
return &bpf_ringbuf_discard_proto;
|
|
case BPF_FUNC_ringbuf_query:
|
|
return &bpf_ringbuf_query_proto;
|
|
case BPF_FUNC_jiffies64:
|
|
return &bpf_jiffies64_proto;
|
|
case BPF_FUNC_get_task_stack:
|
|
return &bpf_get_task_stack_proto;
|
|
case BPF_FUNC_copy_from_user:
|
|
return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
|
|
case BPF_FUNC_copy_from_user_task:
|
|
return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL;
|
|
case BPF_FUNC_snprintf_btf:
|
|
return &bpf_snprintf_btf_proto;
|
|
case BPF_FUNC_per_cpu_ptr:
|
|
return &bpf_per_cpu_ptr_proto;
|
|
case BPF_FUNC_this_cpu_ptr:
|
|
return &bpf_this_cpu_ptr_proto;
|
|
case BPF_FUNC_task_storage_get:
|
|
return &bpf_task_storage_get_proto;
|
|
case BPF_FUNC_task_storage_delete:
|
|
return &bpf_task_storage_delete_proto;
|
|
case BPF_FUNC_for_each_map_elem:
|
|
return &bpf_for_each_map_elem_proto;
|
|
case BPF_FUNC_snprintf:
|
|
return &bpf_snprintf_proto;
|
|
case BPF_FUNC_get_func_ip:
|
|
return &bpf_get_func_ip_proto_tracing;
|
|
case BPF_FUNC_get_branch_snapshot:
|
|
return &bpf_get_branch_snapshot_proto;
|
|
case BPF_FUNC_find_vma:
|
|
return &bpf_find_vma_proto;
|
|
case BPF_FUNC_trace_vprintk:
|
|
return bpf_get_trace_vprintk_proto();
|
|
default:
|
|
return bpf_base_func_proto(func_id);
|
|
}
|
|
}
|
|
|
|
static const struct bpf_func_proto *
|
|
kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto;
|
|
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
|
|
case BPF_FUNC_override_return:
|
|
return &bpf_override_return_proto;
|
|
#endif
|
|
case BPF_FUNC_get_func_ip:
|
|
return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
|
|
&bpf_get_func_ip_proto_kprobe_multi :
|
|
&bpf_get_func_ip_proto_kprobe;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
|
|
&bpf_get_attach_cookie_proto_kmulti :
|
|
&bpf_get_attach_cookie_proto_trace;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
/* bpf+kprobe programs can access fields of 'struct pt_regs' */
|
|
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off < 0 || off >= sizeof(struct pt_regs))
|
|
return false;
|
|
if (type != BPF_READ)
|
|
return false;
|
|
if (off % size != 0)
|
|
return false;
|
|
/*
|
|
* Assertion for 32 bit to make sure last 8 byte access
|
|
* (BPF_DW) to the last 4 byte member is disallowed.
|
|
*/
|
|
if (off + size > sizeof(struct pt_regs))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
const struct bpf_verifier_ops kprobe_verifier_ops = {
|
|
.get_func_proto = kprobe_prog_func_proto,
|
|
.is_valid_access = kprobe_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops kprobe_prog_ops = {
|
|
};
|
|
|
|
BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
|
|
u64, flags, void *, data, u64, size)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
/*
|
|
* r1 points to perf tracepoint buffer where first 8 bytes are hidden
|
|
* from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
|
|
* from there and call the same bpf_perf_event_output() helper inline.
|
|
*/
|
|
return ____bpf_perf_event_output(regs, map, flags, data, size);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
|
|
.func = bpf_perf_event_output_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
|
|
u64, flags)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
/*
|
|
* Same comment as in bpf_perf_event_output_tp(), only that this time
|
|
* the other helper's function body cannot be inlined due to being
|
|
* external, thus we need to call raw helper function.
|
|
*/
|
|
return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
|
|
flags, 0, 0);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
|
|
.func = bpf_get_stackid_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
|
|
u64, flags)
|
|
{
|
|
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
|
|
|
|
return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
|
|
(unsigned long) size, flags, 0);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stack_proto_tp = {
|
|
.func = bpf_get_stack_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_tp;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_tp;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return &bpf_get_attach_cookie_proto_trace;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
|
|
return false;
|
|
if (type != BPF_READ)
|
|
return false;
|
|
if (off % size != 0)
|
|
return false;
|
|
|
|
BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
|
|
return true;
|
|
}
|
|
|
|
const struct bpf_verifier_ops tracepoint_verifier_ops = {
|
|
.get_func_proto = tp_prog_func_proto,
|
|
.is_valid_access = tp_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops tracepoint_prog_ops = {
|
|
};
|
|
|
|
BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
|
|
struct bpf_perf_event_value *, buf, u32, size)
|
|
{
|
|
int err = -EINVAL;
|
|
|
|
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
|
|
goto clear;
|
|
err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
|
|
&buf->running);
|
|
if (unlikely(err))
|
|
goto clear;
|
|
return 0;
|
|
clear:
|
|
memset(buf, 0, size);
|
|
return err;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
|
|
.func = bpf_perf_prog_read_value,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
|
|
void *, buf, u32, size, u64, flags)
|
|
{
|
|
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
|
|
struct perf_branch_stack *br_stack = ctx->data->br_stack;
|
|
u32 to_copy;
|
|
|
|
if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(!br_stack))
|
|
return -ENOENT;
|
|
|
|
if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
|
|
return br_stack->nr * br_entry_size;
|
|
|
|
if (!buf || (size % br_entry_size != 0))
|
|
return -EINVAL;
|
|
|
|
to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
|
|
memcpy(buf, br_stack->entries, to_copy);
|
|
|
|
return to_copy;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_read_branch_records_proto = {
|
|
.func = bpf_read_branch_records,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_MEM_OR_NULL,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_pe;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_pe;
|
|
case BPF_FUNC_perf_prog_read_value:
|
|
return &bpf_perf_prog_read_value_proto;
|
|
case BPF_FUNC_read_branch_records:
|
|
return &bpf_read_branch_records_proto;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return &bpf_get_attach_cookie_proto_pe;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
|
|
* to avoid potential recursive reuse issue when/if tracepoints are added
|
|
* inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
|
|
*
|
|
* Since raw tracepoints run despite bpf_prog_active, support concurrent usage
|
|
* in normal, irq, and nmi context.
|
|
*/
|
|
struct bpf_raw_tp_regs {
|
|
struct pt_regs regs[3];
|
|
};
|
|
static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
|
|
static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
|
|
static struct pt_regs *get_bpf_raw_tp_regs(void)
|
|
{
|
|
struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
|
|
int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
|
|
|
|
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
|
|
this_cpu_dec(bpf_raw_tp_nest_level);
|
|
return ERR_PTR(-EBUSY);
|
|
}
|
|
|
|
return &tp_regs->regs[nest_level - 1];
|
|
}
|
|
|
|
static void put_bpf_raw_tp_regs(void)
|
|
{
|
|
this_cpu_dec(bpf_raw_tp_nest_level);
|
|
}
|
|
|
|
BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
struct bpf_map *, map, u64, flags, void *, data, u64, size)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
ret = ____bpf_perf_event_output(regs, map, flags, data, size);
|
|
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
|
|
.func = bpf_perf_event_output_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
|
|
};
|
|
|
|
extern const struct bpf_func_proto bpf_skb_output_proto;
|
|
extern const struct bpf_func_proto bpf_xdp_output_proto;
|
|
extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;
|
|
|
|
BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
struct bpf_map *, map, u64, flags)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
|
|
ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
|
|
flags, 0, 0);
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
|
|
.func = bpf_get_stackid_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
|
|
void *, buf, u32, size, u64, flags)
|
|
{
|
|
struct pt_regs *regs = get_bpf_raw_tp_regs();
|
|
int ret;
|
|
|
|
if (IS_ERR(regs))
|
|
return PTR_ERR(regs);
|
|
|
|
perf_fetch_caller_regs(regs);
|
|
ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
|
|
(unsigned long) size, flags, 0);
|
|
put_bpf_raw_tp_regs();
|
|
return ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
|
|
.func = bpf_get_stack_raw_tp,
|
|
.gpl_only = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_perf_event_output_proto_raw_tp;
|
|
case BPF_FUNC_get_stackid:
|
|
return &bpf_get_stackid_proto_raw_tp;
|
|
case BPF_FUNC_get_stack:
|
|
return &bpf_get_stack_proto_raw_tp;
|
|
default:
|
|
return bpf_tracing_func_proto(func_id, prog);
|
|
}
|
|
}
|
|
|
|
const struct bpf_func_proto *
|
|
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *fn;
|
|
|
|
switch (func_id) {
|
|
#ifdef CONFIG_NET
|
|
case BPF_FUNC_skb_output:
|
|
return &bpf_skb_output_proto;
|
|
case BPF_FUNC_xdp_output:
|
|
return &bpf_xdp_output_proto;
|
|
case BPF_FUNC_skc_to_tcp6_sock:
|
|
return &bpf_skc_to_tcp6_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_sock:
|
|
return &bpf_skc_to_tcp_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_timewait_sock:
|
|
return &bpf_skc_to_tcp_timewait_sock_proto;
|
|
case BPF_FUNC_skc_to_tcp_request_sock:
|
|
return &bpf_skc_to_tcp_request_sock_proto;
|
|
case BPF_FUNC_skc_to_udp6_sock:
|
|
return &bpf_skc_to_udp6_sock_proto;
|
|
case BPF_FUNC_skc_to_unix_sock:
|
|
return &bpf_skc_to_unix_sock_proto;
|
|
case BPF_FUNC_skc_to_mptcp_sock:
|
|
return &bpf_skc_to_mptcp_sock_proto;
|
|
case BPF_FUNC_sk_storage_get:
|
|
return &bpf_sk_storage_get_tracing_proto;
|
|
case BPF_FUNC_sk_storage_delete:
|
|
return &bpf_sk_storage_delete_tracing_proto;
|
|
case BPF_FUNC_sock_from_file:
|
|
return &bpf_sock_from_file_proto;
|
|
case BPF_FUNC_get_socket_cookie:
|
|
return &bpf_get_socket_ptr_cookie_proto;
|
|
case BPF_FUNC_xdp_get_buff_len:
|
|
return &bpf_xdp_get_buff_len_trace_proto;
|
|
#endif
|
|
case BPF_FUNC_seq_printf:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_printf_proto :
|
|
NULL;
|
|
case BPF_FUNC_seq_write:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_write_proto :
|
|
NULL;
|
|
case BPF_FUNC_seq_printf_btf:
|
|
return prog->expected_attach_type == BPF_TRACE_ITER ?
|
|
&bpf_seq_printf_btf_proto :
|
|
NULL;
|
|
case BPF_FUNC_d_path:
|
|
return &bpf_d_path_proto;
|
|
case BPF_FUNC_get_func_arg:
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
|
|
case BPF_FUNC_get_func_ret:
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
|
|
case BPF_FUNC_get_func_arg_cnt:
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
|
|
case BPF_FUNC_get_attach_cookie:
|
|
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
|
|
default:
|
|
fn = raw_tp_prog_func_proto(func_id, prog);
|
|
if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
|
|
fn = bpf_iter_get_func_proto(func_id, prog);
|
|
return fn;
|
|
}
|
|
}
|
|
|
|
static bool raw_tp_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
return bpf_tracing_ctx_access(off, size, type);
|
|
}
|
|
|
|
static bool tracing_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
|
|
}
|
|
|
|
int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
|
|
const union bpf_attr *kattr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
|
|
.get_func_proto = raw_tp_prog_func_proto,
|
|
.is_valid_access = raw_tp_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops raw_tracepoint_prog_ops = {
|
|
#ifdef CONFIG_NET
|
|
.test_run = bpf_prog_test_run_raw_tp,
|
|
#endif
|
|
};
|
|
|
|
const struct bpf_verifier_ops tracing_verifier_ops = {
|
|
.get_func_proto = tracing_prog_func_proto,
|
|
.is_valid_access = tracing_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops tracing_prog_ops = {
|
|
.test_run = bpf_prog_test_run_tracing,
|
|
};
|
|
|
|
static bool raw_tp_writable_prog_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
if (off == 0) {
|
|
if (size != sizeof(u64) || type != BPF_READ)
|
|
return false;
|
|
info->reg_type = PTR_TO_TP_BUFFER;
|
|
}
|
|
return raw_tp_prog_is_valid_access(off, size, type, prog, info);
|
|
}
|
|
|
|
const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
|
|
.get_func_proto = raw_tp_prog_func_proto,
|
|
.is_valid_access = raw_tp_writable_prog_is_valid_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
|
|
};
|
|
|
|
static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
const int size_u64 = sizeof(u64);
|
|
|
|
if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
|
|
return false;
|
|
if (type != BPF_READ)
|
|
return false;
|
|
if (off % size != 0) {
|
|
if (sizeof(unsigned long) != 4)
|
|
return false;
|
|
if (size != 8)
|
|
return false;
|
|
if (off % size != 4)
|
|
return false;
|
|
}
|
|
|
|
switch (off) {
|
|
case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
|
|
bpf_ctx_record_field_size(info, size_u64);
|
|
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
|
|
return false;
|
|
break;
|
|
case bpf_ctx_range(struct bpf_perf_event_data, addr):
|
|
bpf_ctx_record_field_size(info, size_u64);
|
|
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
|
|
return false;
|
|
break;
|
|
default:
|
|
if (size != sizeof(long))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
|
|
const struct bpf_insn *si,
|
|
struct bpf_insn *insn_buf,
|
|
struct bpf_prog *prog, u32 *target_size)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
|
|
switch (si->off) {
|
|
case offsetof(struct bpf_perf_event_data, sample_period):
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
data), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, data));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
|
|
bpf_target_off(struct perf_sample_data, period, 8,
|
|
target_size));
|
|
break;
|
|
case offsetof(struct bpf_perf_event_data, addr):
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
data), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, data));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
|
|
bpf_target_off(struct perf_sample_data, addr, 8,
|
|
target_size));
|
|
break;
|
|
default:
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
|
|
regs), si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_perf_event_data_kern, regs));
|
|
*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
|
|
si->off);
|
|
break;
|
|
}
|
|
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
const struct bpf_verifier_ops perf_event_verifier_ops = {
|
|
.get_func_proto = pe_prog_func_proto,
|
|
.is_valid_access = pe_prog_is_valid_access,
|
|
.convert_ctx_access = pe_prog_convert_ctx_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops perf_event_prog_ops = {
|
|
};
|
|
|
|
static DEFINE_MUTEX(bpf_event_mutex);
|
|
|
|
#define BPF_TRACE_MAX_PROGS 64
|
|
|
|
int perf_event_attach_bpf_prog(struct perf_event *event,
|
|
struct bpf_prog *prog,
|
|
u64 bpf_cookie)
|
|
{
|
|
struct bpf_prog_array *old_array;
|
|
struct bpf_prog_array *new_array;
|
|
int ret = -EEXIST;
|
|
|
|
/*
|
|
* Kprobe override only works if they are on the function entry,
|
|
* and only if they are on the opt-in list.
|
|
*/
|
|
if (prog->kprobe_override &&
|
|
(!trace_kprobe_on_func_entry(event->tp_event) ||
|
|
!trace_kprobe_error_injectable(event->tp_event)))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
|
|
if (event->prog)
|
|
goto unlock;
|
|
|
|
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
if (old_array &&
|
|
bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
|
|
ret = -E2BIG;
|
|
goto unlock;
|
|
}
|
|
|
|
ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
|
|
if (ret < 0)
|
|
goto unlock;
|
|
|
|
/* set the new array to event->tp_event and set event->prog */
|
|
event->prog = prog;
|
|
event->bpf_cookie = bpf_cookie;
|
|
rcu_assign_pointer(event->tp_event->prog_array, new_array);
|
|
bpf_prog_array_free_sleepable(old_array);
|
|
|
|
unlock:
|
|
mutex_unlock(&bpf_event_mutex);
|
|
return ret;
|
|
}
|
|
|
|
void perf_event_detach_bpf_prog(struct perf_event *event)
|
|
{
|
|
struct bpf_prog_array *old_array;
|
|
struct bpf_prog_array *new_array;
|
|
int ret;
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
|
|
if (!event->prog)
|
|
goto unlock;
|
|
|
|
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
|
|
if (ret == -ENOENT)
|
|
goto unlock;
|
|
if (ret < 0) {
|
|
bpf_prog_array_delete_safe(old_array, event->prog);
|
|
} else {
|
|
rcu_assign_pointer(event->tp_event->prog_array, new_array);
|
|
bpf_prog_array_free_sleepable(old_array);
|
|
}
|
|
|
|
bpf_prog_put(event->prog);
|
|
event->prog = NULL;
|
|
|
|
unlock:
|
|
mutex_unlock(&bpf_event_mutex);
|
|
}
|
|
|
|
int perf_event_query_prog_array(struct perf_event *event, void __user *info)
|
|
{
|
|
struct perf_event_query_bpf __user *uquery = info;
|
|
struct perf_event_query_bpf query = {};
|
|
struct bpf_prog_array *progs;
|
|
u32 *ids, prog_cnt, ids_len;
|
|
int ret;
|
|
|
|
if (!perfmon_capable())
|
|
return -EPERM;
|
|
if (event->attr.type != PERF_TYPE_TRACEPOINT)
|
|
return -EINVAL;
|
|
if (copy_from_user(&query, uquery, sizeof(query)))
|
|
return -EFAULT;
|
|
|
|
ids_len = query.ids_len;
|
|
if (ids_len > BPF_TRACE_MAX_PROGS)
|
|
return -E2BIG;
|
|
ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
|
|
if (!ids)
|
|
return -ENOMEM;
|
|
/*
|
|
* The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
|
|
* is required when user only wants to check for uquery->prog_cnt.
|
|
* There is no need to check for it since the case is handled
|
|
* gracefully in bpf_prog_array_copy_info.
|
|
*/
|
|
|
|
mutex_lock(&bpf_event_mutex);
|
|
progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
|
|
ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
|
|
mutex_unlock(&bpf_event_mutex);
|
|
|
|
if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
|
|
copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
|
|
ret = -EFAULT;
|
|
|
|
kfree(ids);
|
|
return ret;
|
|
}
|
|
|
|
extern struct bpf_raw_event_map __start__bpf_raw_tp[];
|
|
extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
|
|
|
|
struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
|
|
{
|
|
struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
|
|
|
|
for (; btp < __stop__bpf_raw_tp; btp++) {
|
|
if (!strcmp(btp->tp->name, name))
|
|
return btp;
|
|
}
|
|
|
|
return bpf_get_raw_tracepoint_module(name);
|
|
}
|
|
|
|
void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
|
|
{
|
|
struct module *mod;
|
|
|
|
preempt_disable();
|
|
mod = __module_address((unsigned long)btp);
|
|
module_put(mod);
|
|
preempt_enable();
|
|
}
|
|
|
|
static __always_inline
|
|
void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
|
|
{
|
|
cant_sleep();
|
|
if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
|
|
bpf_prog_inc_misses_counter(prog);
|
|
goto out;
|
|
}
|
|
rcu_read_lock();
|
|
(void) bpf_prog_run(prog, args);
|
|
rcu_read_unlock();
|
|
out:
|
|
this_cpu_dec(*(prog->active));
|
|
}
|
|
|
|
#define UNPACK(...) __VA_ARGS__
|
|
#define REPEAT_1(FN, DL, X, ...) FN(X)
|
|
#define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
|
|
#define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
|
|
#define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
|
|
|
|
#define SARG(X) u64 arg##X
|
|
#define COPY(X) args[X] = arg##X
|
|
|
|
#define __DL_COM (,)
|
|
#define __DL_SEM (;)
|
|
|
|
#define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
|
|
|
|
#define BPF_TRACE_DEFN_x(x) \
|
|
void bpf_trace_run##x(struct bpf_prog *prog, \
|
|
REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
|
|
{ \
|
|
u64 args[x]; \
|
|
REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
|
|
__bpf_trace_run(prog, args); \
|
|
} \
|
|
EXPORT_SYMBOL_GPL(bpf_trace_run##x)
|
|
BPF_TRACE_DEFN_x(1);
|
|
BPF_TRACE_DEFN_x(2);
|
|
BPF_TRACE_DEFN_x(3);
|
|
BPF_TRACE_DEFN_x(4);
|
|
BPF_TRACE_DEFN_x(5);
|
|
BPF_TRACE_DEFN_x(6);
|
|
BPF_TRACE_DEFN_x(7);
|
|
BPF_TRACE_DEFN_x(8);
|
|
BPF_TRACE_DEFN_x(9);
|
|
BPF_TRACE_DEFN_x(10);
|
|
BPF_TRACE_DEFN_x(11);
|
|
BPF_TRACE_DEFN_x(12);
|
|
|
|
static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
|
|
{
|
|
struct tracepoint *tp = btp->tp;
|
|
|
|
/*
|
|
* check that program doesn't access arguments beyond what's
|
|
* available in this tracepoint
|
|
*/
|
|
if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
|
|
return -EINVAL;
|
|
|
|
if (prog->aux->max_tp_access > btp->writable_size)
|
|
return -EINVAL;
|
|
|
|
return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func,
|
|
prog);
|
|
}
|
|
|
|
int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
|
|
{
|
|
return __bpf_probe_register(btp, prog);
|
|
}
|
|
|
|
int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
|
|
{
|
|
return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
|
|
}
|
|
|
|
int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
|
|
u32 *fd_type, const char **buf,
|
|
u64 *probe_offset, u64 *probe_addr)
|
|
{
|
|
bool is_tracepoint, is_syscall_tp;
|
|
struct bpf_prog *prog;
|
|
int flags, err = 0;
|
|
|
|
prog = event->prog;
|
|
if (!prog)
|
|
return -ENOENT;
|
|
|
|
/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
|
|
if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
|
|
return -EOPNOTSUPP;
|
|
|
|
*prog_id = prog->aux->id;
|
|
flags = event->tp_event->flags;
|
|
is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
|
|
is_syscall_tp = is_syscall_trace_event(event->tp_event);
|
|
|
|
if (is_tracepoint || is_syscall_tp) {
|
|
*buf = is_tracepoint ? event->tp_event->tp->name
|
|
: event->tp_event->name;
|
|
*fd_type = BPF_FD_TYPE_TRACEPOINT;
|
|
*probe_offset = 0x0;
|
|
*probe_addr = 0x0;
|
|
} else {
|
|
/* kprobe/uprobe */
|
|
err = -EOPNOTSUPP;
|
|
#ifdef CONFIG_KPROBE_EVENTS
|
|
if (flags & TRACE_EVENT_FL_KPROBE)
|
|
err = bpf_get_kprobe_info(event, fd_type, buf,
|
|
probe_offset, probe_addr,
|
|
event->attr.type == PERF_TYPE_TRACEPOINT);
|
|
#endif
|
|
#ifdef CONFIG_UPROBE_EVENTS
|
|
if (flags & TRACE_EVENT_FL_UPROBE)
|
|
err = bpf_get_uprobe_info(event, fd_type, buf,
|
|
probe_offset,
|
|
event->attr.type == PERF_TYPE_TRACEPOINT);
|
|
#endif
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int __init send_signal_irq_work_init(void)
|
|
{
|
|
int cpu;
|
|
struct send_signal_irq_work *work;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
work = per_cpu_ptr(&send_signal_work, cpu);
|
|
init_irq_work(&work->irq_work, do_bpf_send_signal);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
subsys_initcall(send_signal_irq_work_init);
|
|
|
|
#ifdef CONFIG_MODULES
|
|
static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
|
|
void *module)
|
|
{
|
|
struct bpf_trace_module *btm, *tmp;
|
|
struct module *mod = module;
|
|
int ret = 0;
|
|
|
|
if (mod->num_bpf_raw_events == 0 ||
|
|
(op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
|
|
goto out;
|
|
|
|
mutex_lock(&bpf_module_mutex);
|
|
|
|
switch (op) {
|
|
case MODULE_STATE_COMING:
|
|
btm = kzalloc(sizeof(*btm), GFP_KERNEL);
|
|
if (btm) {
|
|
btm->module = module;
|
|
list_add(&btm->list, &bpf_trace_modules);
|
|
} else {
|
|
ret = -ENOMEM;
|
|
}
|
|
break;
|
|
case MODULE_STATE_GOING:
|
|
list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
|
|
if (btm->module == module) {
|
|
list_del(&btm->list);
|
|
kfree(btm);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
mutex_unlock(&bpf_module_mutex);
|
|
|
|
out:
|
|
return notifier_from_errno(ret);
|
|
}
|
|
|
|
static struct notifier_block bpf_module_nb = {
|
|
.notifier_call = bpf_event_notify,
|
|
};
|
|
|
|
static int __init bpf_event_init(void)
|
|
{
|
|
register_module_notifier(&bpf_module_nb);
|
|
return 0;
|
|
}
|
|
|
|
fs_initcall(bpf_event_init);
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
#ifdef CONFIG_FPROBE
|
|
struct bpf_kprobe_multi_link {
|
|
struct bpf_link link;
|
|
struct fprobe fp;
|
|
unsigned long *addrs;
|
|
u64 *cookies;
|
|
u32 cnt;
|
|
};
|
|
|
|
struct bpf_kprobe_multi_run_ctx {
|
|
struct bpf_run_ctx run_ctx;
|
|
struct bpf_kprobe_multi_link *link;
|
|
unsigned long entry_ip;
|
|
};
|
|
|
|
struct user_syms {
|
|
const char **syms;
|
|
char *buf;
|
|
};
|
|
|
|
static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
|
|
{
|
|
unsigned long __user usymbol;
|
|
const char **syms = NULL;
|
|
char *buf = NULL, *p;
|
|
int err = -ENOMEM;
|
|
unsigned int i;
|
|
|
|
syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
|
|
if (!syms)
|
|
goto error;
|
|
|
|
buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
|
|
if (!buf)
|
|
goto error;
|
|
|
|
for (p = buf, i = 0; i < cnt; i++) {
|
|
if (__get_user(usymbol, usyms + i)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
|
|
if (err == KSYM_NAME_LEN)
|
|
err = -E2BIG;
|
|
if (err < 0)
|
|
goto error;
|
|
syms[i] = p;
|
|
p += err + 1;
|
|
}
|
|
|
|
us->syms = syms;
|
|
us->buf = buf;
|
|
return 0;
|
|
|
|
error:
|
|
if (err) {
|
|
kvfree(syms);
|
|
kvfree(buf);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void free_user_syms(struct user_syms *us)
|
|
{
|
|
kvfree(us->syms);
|
|
kvfree(us->buf);
|
|
}
|
|
|
|
static void bpf_kprobe_multi_link_release(struct bpf_link *link)
|
|
{
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
unregister_fprobe(&kmulti_link->fp);
|
|
}
|
|
|
|
static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
|
|
{
|
|
struct bpf_kprobe_multi_link *kmulti_link;
|
|
|
|
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
|
|
kvfree(kmulti_link->addrs);
|
|
kvfree(kmulti_link->cookies);
|
|
kfree(kmulti_link);
|
|
}
|
|
|
|
static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
|
|
.release = bpf_kprobe_multi_link_release,
|
|
.dealloc = bpf_kprobe_multi_link_dealloc,
|
|
};
|
|
|
|
static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
|
|
{
|
|
const struct bpf_kprobe_multi_link *link = priv;
|
|
unsigned long *addr_a = a, *addr_b = b;
|
|
u64 *cookie_a, *cookie_b;
|
|
|
|
cookie_a = link->cookies + (addr_a - link->addrs);
|
|
cookie_b = link->cookies + (addr_b - link->addrs);
|
|
|
|
/* swap addr_a/addr_b and cookie_a/cookie_b values */
|
|
swap(*addr_a, *addr_b);
|
|
swap(*cookie_a, *cookie_b);
|
|
}
|
|
|
|
static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b)
|
|
{
|
|
const unsigned long *addr_a = a, *addr_b = b;
|
|
|
|
if (*addr_a == *addr_b)
|
|
return 0;
|
|
return *addr_a < *addr_b ? -1 : 1;
|
|
}
|
|
|
|
static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
|
|
{
|
|
return __bpf_kprobe_multi_cookie_cmp(a, b);
|
|
}
|
|
|
|
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx *run_ctx;
|
|
struct bpf_kprobe_multi_link *link;
|
|
u64 *cookie, entry_ip;
|
|
unsigned long *addr;
|
|
|
|
if (WARN_ON_ONCE(!ctx))
|
|
return 0;
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
|
|
link = run_ctx->link;
|
|
if (!link->cookies)
|
|
return 0;
|
|
entry_ip = run_ctx->entry_ip;
|
|
addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
|
|
__bpf_kprobe_multi_cookie_cmp);
|
|
if (!addr)
|
|
return 0;
|
|
cookie = link->cookies + (addr - link->addrs);
|
|
return *cookie;
|
|
}
|
|
|
|
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx *run_ctx;
|
|
|
|
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
|
|
return run_ctx->entry_ip;
|
|
}
|
|
|
|
static int
|
|
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
|
|
unsigned long entry_ip, struct pt_regs *regs)
|
|
{
|
|
struct bpf_kprobe_multi_run_ctx run_ctx = {
|
|
.link = link,
|
|
.entry_ip = entry_ip,
|
|
};
|
|
struct bpf_run_ctx *old_run_ctx;
|
|
int err;
|
|
|
|
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
|
|
err = 0;
|
|
goto out;
|
|
}
|
|
|
|
migrate_disable();
|
|
rcu_read_lock();
|
|
old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
|
|
err = bpf_prog_run(link->link.prog, regs);
|
|
bpf_reset_run_ctx(old_run_ctx);
|
|
rcu_read_unlock();
|
|
migrate_enable();
|
|
|
|
out:
|
|
__this_cpu_dec(bpf_prog_active);
|
|
return err;
|
|
}
|
|
|
|
static void
|
|
kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct bpf_kprobe_multi_link *link;
|
|
|
|
link = container_of(fp, struct bpf_kprobe_multi_link, fp);
|
|
kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
|
|
}
|
|
|
|
static int symbols_cmp_r(const void *a, const void *b, const void *priv)
|
|
{
|
|
const char **str_a = (const char **) a;
|
|
const char **str_b = (const char **) b;
|
|
|
|
return strcmp(*str_a, *str_b);
|
|
}
|
|
|
|
struct multi_symbols_sort {
|
|
const char **funcs;
|
|
u64 *cookies;
|
|
};
|
|
|
|
static void symbols_swap_r(void *a, void *b, int size, const void *priv)
|
|
{
|
|
const struct multi_symbols_sort *data = priv;
|
|
const char **name_a = a, **name_b = b;
|
|
|
|
swap(*name_a, *name_b);
|
|
|
|
/* If defined, swap also related cookies. */
|
|
if (data->cookies) {
|
|
u64 *cookie_a, *cookie_b;
|
|
|
|
cookie_a = data->cookies + (name_a - data->funcs);
|
|
cookie_b = data->cookies + (name_b - data->funcs);
|
|
swap(*cookie_a, *cookie_b);
|
|
}
|
|
}
|
|
|
|
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
struct bpf_kprobe_multi_link *link = NULL;
|
|
struct bpf_link_primer link_primer;
|
|
void __user *ucookies;
|
|
unsigned long *addrs;
|
|
u32 flags, cnt, size;
|
|
void __user *uaddrs;
|
|
u64 *cookies = NULL;
|
|
void __user *usyms;
|
|
int err;
|
|
|
|
/* no support for 32bit archs yet */
|
|
if (sizeof(u64) != sizeof(void *))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
|
|
return -EINVAL;
|
|
|
|
flags = attr->link_create.kprobe_multi.flags;
|
|
if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
|
|
return -EINVAL;
|
|
|
|
uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
|
|
usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
|
|
if (!!uaddrs == !!usyms)
|
|
return -EINVAL;
|
|
|
|
cnt = attr->link_create.kprobe_multi.cnt;
|
|
if (!cnt)
|
|
return -EINVAL;
|
|
|
|
size = cnt * sizeof(*addrs);
|
|
addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
|
|
if (!addrs)
|
|
return -ENOMEM;
|
|
|
|
ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
|
|
if (ucookies) {
|
|
cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
|
|
if (!cookies) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
if (copy_from_user(cookies, ucookies, size)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
if (uaddrs) {
|
|
if (copy_from_user(addrs, uaddrs, size)) {
|
|
err = -EFAULT;
|
|
goto error;
|
|
}
|
|
} else {
|
|
struct multi_symbols_sort data = {
|
|
.cookies = cookies,
|
|
};
|
|
struct user_syms us;
|
|
|
|
err = copy_user_syms(&us, usyms, cnt);
|
|
if (err)
|
|
goto error;
|
|
|
|
if (cookies)
|
|
data.funcs = us.syms;
|
|
|
|
sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
|
|
symbols_swap_r, &data);
|
|
|
|
err = ftrace_lookup_symbols(us.syms, cnt, addrs);
|
|
free_user_syms(&us);
|
|
if (err)
|
|
goto error;
|
|
}
|
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL);
|
|
if (!link) {
|
|
err = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
|
|
&bpf_kprobe_multi_link_lops, prog);
|
|
|
|
err = bpf_link_prime(&link->link, &link_primer);
|
|
if (err)
|
|
goto error;
|
|
|
|
if (flags & BPF_F_KPROBE_MULTI_RETURN)
|
|
link->fp.exit_handler = kprobe_multi_link_handler;
|
|
else
|
|
link->fp.entry_handler = kprobe_multi_link_handler;
|
|
|
|
link->addrs = addrs;
|
|
link->cookies = cookies;
|
|
link->cnt = cnt;
|
|
|
|
if (cookies) {
|
|
/*
|
|
* Sorting addresses will trigger sorting cookies as well
|
|
* (check bpf_kprobe_multi_cookie_swap). This way we can
|
|
* find cookie based on the address in bpf_get_attach_cookie
|
|
* helper.
|
|
*/
|
|
sort_r(addrs, cnt, sizeof(*addrs),
|
|
bpf_kprobe_multi_cookie_cmp,
|
|
bpf_kprobe_multi_cookie_swap,
|
|
link);
|
|
}
|
|
|
|
err = register_fprobe_ips(&link->fp, addrs, cnt);
|
|
if (err) {
|
|
bpf_link_cleanup(&link_primer);
|
|
return err;
|
|
}
|
|
|
|
return bpf_link_settle(&link_primer);
|
|
|
|
error:
|
|
kfree(link);
|
|
kvfree(addrs);
|
|
kvfree(cookies);
|
|
return err;
|
|
}
|
|
#else /* !CONFIG_FPROBE */
|
|
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|