* See: clock_gettime(CLOCK_BOOTTIME)
* Return
* Current *ktime*.
+ *
+ * int bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len)
+ * Description
+ * seq_printf uses seq_file seq_printf() to print out the format string.
+ * The *m* represents the seq_file. The *fmt* and *fmt_size* are for
+ * the format string itself. The *data* and *data_len* are format string
+ * arguments. The *data* are a u64 array and corresponding format string
+ * values are stored in the array. For strings and pointers where pointees
+ * are accessed, only the pointer values are stored in the *data* array.
+ * The *data_len* is the *data* size in term of bytes.
+ *
+ * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
+ * Reading kernel memory may fail due to either invalid address or
+ * valid address but requiring a major memory fault. If reading kernel memory
+ * fails, the string for **%s** will be an empty string, and the ip
+ * address for **%p{i,I}{4,6}** will be 0. Not returning error to
+ * bpf program is consistent with what bpf_trace_printk() does for now.
+ * Return
+ * 0 on success, or a negative errno in case of failure.
+ *
+ * * **-EBUSY** Percpu memory copy buffer is busy, can try again
+ * by returning 1 from bpf program.
+ * * **-EINVAL** Invalid arguments, or invalid/unsupported formats.
+ * * **-E2BIG** Too many format specifiers.
+ * * **-EOVERFLOW** Overflow happens, the same object will be tried again.
+ *
+ * int bpf_seq_write(struct seq_file *m, const void *data, u32 len)
+ * Description
+ * seq_write uses seq_file seq_write() to write the data.
+ * The *m* represents the seq_file. The *data* and *len* represent the
+ * data to write in bytes.
+ * Return
+ * 0 on success, or a negative errno in case of failure.
+ *
+ * * **-EOVERFLOW** Overflow happens, the same object will be tried again.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
FN(get_netns_cookie), \
FN(get_current_ancestor_cgroup_id), \
FN(sk_assign), \
- FN(ktime_get_boot_ns),
+ FN(ktime_get_boot_ns), \
+ FN(seq_printf), \
+ FN(seq_write),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
return &bpf_trace_printk_proto;
}
+#define MAX_SEQ_PRINTF_VARARGS 12
+#define MAX_SEQ_PRINTF_MAX_MEMCPY 6
+#define MAX_SEQ_PRINTF_STR_LEN 128
+
+struct bpf_seq_printf_buf {
+ char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
+};
+static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
+static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
+
+BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
+ const void *, data, u32, data_len)
+{
+ int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
+ int i, buf_used, copy_size, num_args;
+ u64 params[MAX_SEQ_PRINTF_VARARGS];
+ struct bpf_seq_printf_buf *bufs;
+ const u64 *args = data;
+
+ buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
+ if (WARN_ON_ONCE(buf_used > 1)) {
+ err = -EBUSY;
+ goto out;
+ }
+
+ bufs = this_cpu_ptr(&bpf_seq_printf_buf);
+
+ /*
+ * bpf_check()->check_func_arg()->check_stack_boundary()
+ * guarantees that fmt points to bpf program stack,
+ * fmt_size bytes of it were initialized and fmt_size > 0
+ */
+ if (fmt[--fmt_size] != 0)
+ goto out;
+
+ if (data_len & 7)
+ goto out;
+
+ for (i = 0; i < fmt_size; i++) {
+ if (fmt[i] == '%') {
+ if (fmt[i + 1] == '%')
+ i++;
+ else if (!data || !data_len)
+ goto out;
+ }
+ }
+
+ num_args = data_len / 8;
+
+ /* check format string for allowed specifiers */
+ for (i = 0; i < fmt_size; i++) {
+ /* only printable ascii for now. */
+ if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (fmt[i] != '%')
+ continue;
+
+ if (fmt[i + 1] == '%') {
+ i++;
+ continue;
+ }
+
+ if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
+ err = -E2BIG;
+ goto out;
+ }
+
+ if (fmt_cnt >= num_args) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ /* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
+ i++;
+
+ /* skip optional "[0 +-][num]" width formating field */
+ while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' ||
+ fmt[i] == ' ')
+ i++;
+ if (fmt[i] >= '1' && fmt[i] <= '9') {
+ i++;
+ while (fmt[i] >= '0' && fmt[i] <= '9')
+ i++;
+ }
+
+ if (fmt[i] == 's') {
+ /* try our best to copy */
+ if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
+ err = -E2BIG;
+ goto out;
+ }
+
+ err = strncpy_from_unsafe(bufs->buf[memcpy_cnt],
+ (void *) (long) args[fmt_cnt],
+ MAX_SEQ_PRINTF_STR_LEN);
+ if (err < 0)
+ bufs->buf[memcpy_cnt][0] = '\0';
+ params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
+
+ fmt_cnt++;
+ memcpy_cnt++;
+ continue;
+ }
+
+ if (fmt[i] == 'p') {
+ if (fmt[i + 1] == 0 ||
+ fmt[i + 1] == 'K' ||
+ fmt[i + 1] == 'x') {
+ /* just kernel pointers */
+ params[fmt_cnt] = args[fmt_cnt];
+ fmt_cnt++;
+ continue;
+ }
+
+ /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
+ if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
+ err = -EINVAL;
+ goto out;
+ }
+ if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
+ err = -E2BIG;
+ goto out;
+ }
+
+
+ copy_size = (fmt[i + 2] == '4') ? 4 : 16;
+
+ err = probe_kernel_read(bufs->buf[memcpy_cnt],
+ (void *) (long) args[fmt_cnt],
+ copy_size);
+ if (err < 0)
+ memset(bufs->buf[memcpy_cnt], 0, copy_size);
+ params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
+
+ i += 2;
+ fmt_cnt++;
+ memcpy_cnt++;
+ continue;
+ }
+
+ if (fmt[i] == 'l') {
+ i++;
+ if (fmt[i] == 'l')
+ i++;
+ }
+
+ if (fmt[i] != 'i' && fmt[i] != 'd' &&
+ fmt[i] != 'u' && fmt[i] != 'x') {
+ err = -EINVAL;
+ goto out;
+ }
+
+ params[fmt_cnt] = args[fmt_cnt];
+ fmt_cnt++;
+ }
+
+ /* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
+ * all of them to seq_printf().
+ */
+ seq_printf(m, fmt, params[0], params[1], params[2], params[3],
+ params[4], params[5], params[6], params[7], params[8],
+ params[9], params[10], params[11]);
+
+ err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
+out:
+ this_cpu_dec(bpf_seq_printf_buf_used);
+ return err;
+}
+
+static int bpf_seq_printf_btf_ids[5];
+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,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg5_type = ARG_CONST_SIZE_OR_ZERO,
+ .btf_id = bpf_seq_printf_btf_ids,
+};
+
+BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
+{
+ return seq_write(m, data, len) ? -EOVERFLOW : 0;
+}
+
+static int bpf_seq_write_btf_ids[5];
+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,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE_OR_ZERO,
+ .btf_id = bpf_seq_write_btf_ids,
+};
+
static __always_inline int
get_map_perf_counter(struct bpf_map *map, u64 flags,
u64 *value, u64 *enabled, u64 *running)
case BPF_FUNC_xdp_output:
return &bpf_xdp_output_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;
default:
return raw_tp_prog_func_proto(func_id, prog);
}
* See: clock_gettime(CLOCK_BOOTTIME)
* Return
* Current *ktime*.
+ *
+ * int bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len)
+ * Description
+ * seq_printf uses seq_file seq_printf() to print out the format string.
+ * The *m* represents the seq_file. The *fmt* and *fmt_size* are for
+ * the format string itself. The *data* and *data_len* are format string
+ * arguments. The *data* are a u64 array and corresponding format string
+ * values are stored in the array. For strings and pointers where pointees
+ * are accessed, only the pointer values are stored in the *data* array.
+ * The *data_len* is the *data* size in term of bytes.
+ *
+ * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
+ * Reading kernel memory may fail due to either invalid address or
+ * valid address but requiring a major memory fault. If reading kernel memory
+ * fails, the string for **%s** will be an empty string, and the ip
+ * address for **%p{i,I}{4,6}** will be 0. Not returning error to
+ * bpf program is consistent with what bpf_trace_printk() does for now.
+ * Return
+ * 0 on success, or a negative errno in case of failure.
+ *
+ * * **-EBUSY** Percpu memory copy buffer is busy, can try again
+ * by returning 1 from bpf program.
+ * * **-EINVAL** Invalid arguments, or invalid/unsupported formats.
+ * * **-E2BIG** Too many format specifiers.
+ * * **-EOVERFLOW** Overflow happens, the same object will be tried again.
+ *
+ * int bpf_seq_write(struct seq_file *m, const void *data, u32 len)
+ * Description
+ * seq_write uses seq_file seq_write() to write the data.
+ * The *m* represents the seq_file. The *data* and *len* represent the
+ * data to write in bytes.
+ * Return
+ * 0 on success, or a negative errno in case of failure.
+ *
+ * * **-EOVERFLOW** Overflow happens, the same object will be tried again.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
FN(get_netns_cookie), \
FN(get_current_ancestor_cgroup_id), \
FN(sk_assign), \
- FN(ktime_get_boot_ns),
+ FN(ktime_get_boot_ns), \
+ FN(seq_printf), \
+ FN(seq_write),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
projects / users / hch / misc.git / commitdiff