[RFC 1/4] bpf: move tracing helpers to shared helpers
From: Sargun Dhillon <hidden>
Date: 2016-08-04 07:11:38
Also in:
lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [security & lsm] (security audit and enforcement using bpf), bpf [tracing], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, KP Singh, Matt Bobrowski, Song Liu, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Move bpf_probe_read and bpf_get_current_task to the shared helpers so that Checmate can use them. Signed-off-by: Sargun Dhillon <redacted> --- include/linux/bpf.h | 2 ++ kernel/bpf/helpers.c | 34 ++++++++++++++++++++++++++++++++++ kernel/trace/bpf_trace.c | 33 --------------------------------- 3 files changed, 36 insertions(+), 33 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 1113423..4e1fa57 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -314,6 +314,8 @@ extern const struct bpf_func_proto bpf_get_current_comm_proto; extern const struct bpf_func_proto bpf_skb_vlan_push_proto; extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; extern const struct bpf_func_proto bpf_get_stackid_proto; +extern const struct bpf_func_proto bpf_get_current_task_proto; +extern const struct bpf_func_proto bpf_probe_read_proto; /* Shared helpers among cBPF and eBPF. */ void bpf_user_rnd_init_once(void);
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 1ea3afb..c439afc 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c@@ -16,6 +16,7 @@ #include <linux/ktime.h> #include <linux/sched.h> #include <linux/uidgid.h> +#include <linux/uaccess.h> /* If kernel subsystem is allowing eBPF programs to call this function, * inside its own verifier_ops->get_func_proto() callback it should return
@@ -186,3 +187,36 @@ const struct bpf_func_proto bpf_get_current_comm_proto = { .arg1_type = ARG_PTR_TO_RAW_STACK, .arg2_type = ARG_CONST_STACK_SIZE, }; + +static u64 bpf_get_current_task(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +{ + 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, +}; + +static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) +{ + void *dst = (void *) (long) r1; + int ret, size = (int) r2; + void *unsafe_ptr = (void *) (long) r3; + + ret = probe_kernel_read(dst, unsafe_ptr, size); + if (unlikely(ret < 0)) + memset(dst, 0, size); + + return ret; +} + +const struct bpf_func_proto bpf_probe_read_proto = { + .func = bpf_probe_read, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_RAW_STACK, + .arg2_type = ARG_CONST_STACK_SIZE, + .arg3_type = ARG_ANYTHING, +};
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index b20438f..f7a107b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c@@ -59,28 +59,6 @@ unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx) } EXPORT_SYMBOL_GPL(trace_call_bpf); -static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) -{ - void *dst = (void *) (long) r1; - int ret, size = (int) r2; - void *unsafe_ptr = (void *) (long) r3; - - ret = probe_kernel_read(dst, unsafe_ptr, size); - if (unlikely(ret < 0)) - memset(dst, 0, size); - - return ret; -} - -static const struct bpf_func_proto bpf_probe_read_proto = { - .func = bpf_probe_read, - .gpl_only = true, - .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_RAW_STACK, - .arg2_type = ARG_CONST_STACK_SIZE, - .arg3_type = ARG_ANYTHING, -}; - static u64 bpf_probe_write_user(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) { void *unsafe_ptr = (void *) (long) r1;
@@ -365,17 +343,6 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, return __bpf_perf_event_output(regs, map, flags, &raw); } -static u64 bpf_get_current_task(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) -{ - return (long) current; -} - -static const struct bpf_func_proto bpf_get_current_task_proto = { - .func = bpf_get_current_task, - .gpl_only = true, - .ret_type = RET_INTEGER, -}; - static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id) { switch (func_id) {
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2.7.4