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authorDavid S. Miller <davem@davemloft.net>2019-12-11 20:13:45 -0800
committerDavid S. Miller <davem@davemloft.net>2019-12-11 20:13:45 -0800
commit148709bc278a2e49ff7b10cee2d8cdc33b894598 (patch)
treec27a039d9886cae1572f81d80e35af60bf9cd740
parent24dee0c7478d1a1e00abdf5625b7f921467325dc (diff)
parentfe3300897cbfd76c6cb825776e5ac0ca50a91ca4 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says: ==================== pull-request: bpf 2019-12-11 The following pull-request contains BPF updates for your *net* tree. We've added 8 non-merge commits during the last 1 day(s) which contain a total of 10 files changed, 126 insertions(+), 18 deletions(-). The main changes are: 1) Make BPF trampoline co-exist with ftrace-based tracers, from Alexei. 2) Fix build in minimal configurations, from Arnd. 3) Fix mips, riscv bpf_tail_call limit, from Paul. 4) Fix bpftool segfault, from Toke. 5) Fix samples/bpf, from Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--arch/mips/net/ebpf_jit.c9
-rw-r--r--arch/riscv/net/bpf_jit_comp.c4
-rw-r--r--include/linux/bpf.h1
-rw-r--r--kernel/bpf/btf.c1
-rw-r--r--kernel/bpf/trampoline.c64
-rw-r--r--samples/bpf/syscall_tp_kern.c18
-rw-r--r--samples/bpf/trace_event_user.c4
-rw-r--r--tools/bpf/bpftool/prog.c2
-rw-r--r--tools/bpf/bpftool/xlated_dumper.c2
-rwxr-xr-xtools/testing/selftests/bpf/test_ftrace.sh39
10 files changed, 126 insertions, 18 deletions
diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index 46b76751f3a5..3ec69d9cbe88 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -604,6 +604,7 @@ static void emit_const_to_reg(struct jit_ctx *ctx, int dst, u64 value)
static int emit_bpf_tail_call(struct jit_ctx *ctx, int this_idx)
{
int off, b_off;
+ int tcc_reg;
ctx->flags |= EBPF_SEEN_TC;
/*
@@ -616,14 +617,14 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int this_idx)
b_off = b_imm(this_idx + 1, ctx);
emit_instr(ctx, bne, MIPS_R_AT, MIPS_R_ZERO, b_off);
/*
- * if (--TCC < 0)
+ * if (TCC-- < 0)
* goto out;
*/
/* Delay slot */
- emit_instr(ctx, daddiu, MIPS_R_T5,
- (ctx->flags & EBPF_TCC_IN_V1) ? MIPS_R_V1 : MIPS_R_S4, -1);
+ tcc_reg = (ctx->flags & EBPF_TCC_IN_V1) ? MIPS_R_V1 : MIPS_R_S4;
+ emit_instr(ctx, daddiu, MIPS_R_T5, tcc_reg, -1);
b_off = b_imm(this_idx + 1, ctx);
- emit_instr(ctx, bltz, MIPS_R_T5, b_off);
+ emit_instr(ctx, bltz, tcc_reg, b_off);
/*
* prog = array->ptrs[index];
* if (prog == NULL)
diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c
index 5451ef3845f2..7fbf56aab661 100644
--- a/arch/riscv/net/bpf_jit_comp.c
+++ b/arch/riscv/net/bpf_jit_comp.c
@@ -631,14 +631,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx)
return -1;
emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx);
- /* if (--TCC < 0)
+ /* if (TCC-- < 0)
* goto out;
*/
emit(rv_addi(RV_REG_T1, tcc, -1), ctx);
off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2;
if (is_13b_check(off, insn))
return -1;
- emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx);
+ emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx);
/* prog = array->ptrs[index];
* if (!prog)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 35903f148be5..ac7de5291509 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -461,6 +461,7 @@ struct bpf_trampoline {
struct {
struct btf_func_model model;
void *addr;
+ bool ftrace_managed;
} func;
/* list of BPF programs using this trampoline */
struct hlist_head progs_hlist[BPF_TRAMP_MAX];
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7d40da240891..ed2075884724 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3470,6 +3470,7 @@ static u8 bpf_ctx_convert_map[] = {
[_id] = __ctx_convert##_id,
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
+ 0, /* avoid empty array */
};
#undef BPF_MAP_TYPE
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 7e89f1f49d77..23b0d5cfd47e 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -3,6 +3,7 @@
#include <linux/hash.h>
#include <linux/bpf.h>
#include <linux/filter.h>
+#include <linux/ftrace.h>
/* btf_vmlinux has ~22k attachable functions. 1k htab is enough. */
#define TRAMPOLINE_HASH_BITS 10
@@ -59,6 +60,60 @@ out:
return tr;
}
+static int is_ftrace_location(void *ip)
+{
+ long addr;
+
+ addr = ftrace_location((long)ip);
+ if (!addr)
+ return 0;
+ if (WARN_ON_ONCE(addr != (long)ip))
+ return -EFAULT;
+ return 1;
+}
+
+static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
+{
+ void *ip = tr->func.addr;
+ int ret;
+
+ if (tr->func.ftrace_managed)
+ ret = unregister_ftrace_direct((long)ip, (long)old_addr);
+ else
+ ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, NULL);
+ return ret;
+}
+
+static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr)
+{
+ void *ip = tr->func.addr;
+ int ret;
+
+ if (tr->func.ftrace_managed)
+ ret = modify_ftrace_direct((long)ip, (long)old_addr, (long)new_addr);
+ else
+ ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, new_addr);
+ return ret;
+}
+
+/* first time registering */
+static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
+{
+ void *ip = tr->func.addr;
+ int ret;
+
+ ret = is_ftrace_location(ip);
+ if (ret < 0)
+ return ret;
+ tr->func.ftrace_managed = ret;
+
+ if (tr->func.ftrace_managed)
+ ret = register_ftrace_direct((long)ip, (long)new_addr);
+ else
+ ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, NULL, new_addr);
+ return ret;
+}
+
/* Each call __bpf_prog_enter + call bpf_func + call __bpf_prog_exit is ~50
* bytes on x86. Pick a number to fit into PAGE_SIZE / 2
*/
@@ -77,8 +132,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr)
int err;
if (fentry_cnt + fexit_cnt == 0) {
- err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_CALL,
- old_image, NULL);
+ err = unregister_fentry(tr, old_image);
tr->selector = 0;
goto out;
}
@@ -105,12 +159,10 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr)
if (tr->selector)
/* progs already running at this address */
- err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_CALL,
- old_image, new_image);
+ err = modify_fentry(tr, old_image, new_image);
else
/* first time registering */
- err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_CALL, NULL,
- new_image);
+ err = register_fentry(tr, new_image);
if (err)
goto out;
tr->selector++;
diff --git a/samples/bpf/syscall_tp_kern.c b/samples/bpf/syscall_tp_kern.c
index 1d78819ffef1..630ce8c4d5a2 100644
--- a/samples/bpf/syscall_tp_kern.c
+++ b/samples/bpf/syscall_tp_kern.c
@@ -47,13 +47,27 @@ static __always_inline void count(void *map)
SEC("tracepoint/syscalls/sys_enter_open")
int trace_enter_open(struct syscalls_enter_open_args *ctx)
{
- count((void *)&enter_open_map);
+ count(&enter_open_map);
+ return 0;
+}
+
+SEC("tracepoint/syscalls/sys_enter_openat")
+int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
+{
+ count(&enter_open_map);
return 0;
}
SEC("tracepoint/syscalls/sys_exit_open")
int trace_enter_exit(struct syscalls_exit_open_args *ctx)
{
- count((void *)&exit_open_map);
+ count(&exit_open_map);
+ return 0;
+}
+
+SEC("tracepoint/syscalls/sys_exit_openat")
+int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
+{
+ count(&exit_open_map);
return 0;
}
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index 16a16eadd509..749a50f2f9f3 100644
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c
@@ -37,9 +37,9 @@ static void print_ksym(__u64 addr)
}
printf("%s;", sym->name);
- if (!strcmp(sym->name, "sys_read"))
+ if (!strstr(sym->name, "sys_read"))
sys_read_seen = true;
- else if (!strcmp(sym->name, "sys_write"))
+ else if (!strstr(sym->name, "sys_write"))
sys_write_seen = true;
}
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 4535c863d2cd..2ce9c5ba1934 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -493,7 +493,7 @@ static int do_dump(int argc, char **argv)
info = &info_linear->info;
if (mode == DUMP_JITED) {
- if (info->jited_prog_len == 0) {
+ if (info->jited_prog_len == 0 || !info->jited_prog_insns) {
p_info("no instructions returned");
goto err_free;
}
diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c
index 494d7ae3614d..5b91ee65a080 100644
--- a/tools/bpf/bpftool/xlated_dumper.c
+++ b/tools/bpf/bpftool/xlated_dumper.c
@@ -174,7 +174,7 @@ static const char *print_call(void *private_data,
struct kernel_sym *sym;
if (insn->src_reg == BPF_PSEUDO_CALL &&
- (__u32) insn->imm < dd->nr_jited_ksyms)
+ (__u32) insn->imm < dd->nr_jited_ksyms && dd->jited_ksyms)
address = dd->jited_ksyms[insn->imm];
sym = kernel_syms_search(dd, address);
diff --git a/tools/testing/selftests/bpf/test_ftrace.sh b/tools/testing/selftests/bpf/test_ftrace.sh
new file mode 100755
index 000000000000..20de7bb873bc
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_ftrace.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+TR=/sys/kernel/debug/tracing/
+clear_trace() { # reset trace output
+ echo > $TR/trace
+}
+
+disable_tracing() { # stop trace recording
+ echo 0 > $TR/tracing_on
+}
+
+enable_tracing() { # start trace recording
+ echo 1 > $TR/tracing_on
+}
+
+reset_tracer() { # reset the current tracer
+ echo nop > $TR/current_tracer
+}
+
+disable_tracing
+clear_trace
+
+echo "" > $TR/set_ftrace_filter
+echo '*printk* *console* *wake* *serial* *lock*' > $TR/set_ftrace_notrace
+
+echo "bpf_prog_test*" > $TR/set_graph_function
+echo "" > $TR/set_graph_notrace
+
+echo function_graph > $TR/current_tracer
+
+enable_tracing
+./test_progs -t fentry
+./test_progs -t fexit
+disable_tracing
+clear_trace
+
+reset_tracer
+
+exit 0