1 files changed, 37 insertions, 334 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 0d23755c2747..a13f8644b357 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -372,188 +372,38 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
 	return &bpf_probe_write_user_proto;
 }
 
-static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
-		size_t bufsz)
-{
-	void __user *user_ptr = (__force void __user *)unsafe_ptr;
-
-	buf[0] = 0;
-
-	switch (fmt_ptype) {
-	case 's':
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-		if ((unsigned long)unsafe_ptr < TASK_SIZE) {
-			strncpy_from_user_nofault(buf, user_ptr, bufsz);
-			break;
-		}
-		fallthrough;
-#endif
-	case 'k':
-		strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
-		break;
-	case 'u':
-		strncpy_from_user_nofault(buf, user_ptr, bufsz);
-		break;
-	}
-}
-
 static DEFINE_RAW_SPINLOCK(trace_printk_lock);
 
-#define BPF_TRACE_PRINTK_SIZE   1024
+#define MAX_TRACE_PRINTK_VARARGS	3
+#define BPF_TRACE_PRINTK_SIZE		1024
 
-static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
+BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
+	   u64, arg2, u64, arg3)
 {
+	u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
+	enum bpf_printf_mod_type mod[MAX_TRACE_PRINTK_VARARGS];
 	static char buf[BPF_TRACE_PRINTK_SIZE];
 	unsigned long flags;
-	va_list ap;
 	int ret;
 
-	raw_spin_lock_irqsave(&trace_printk_lock, flags);
-	va_start(ap, fmt);
-	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
-	va_end(ap);
-	/* vsnprintf() will not append null for zero-length strings */
+	ret = bpf_printf_prepare(fmt, fmt_size, args, args, mod,
+				 MAX_TRACE_PRINTK_VARARGS);
+	if (ret < 0)
+		return ret;
+
+	ret = snprintf(buf, sizeof(buf), fmt, BPF_CAST_FMT_ARG(0, args, mod),
+		BPF_CAST_FMT_ARG(1, args, mod), BPF_CAST_FMT_ARG(2, args, mod));
+	/* snprintf() will not append null for zero-length strings */
 	if (ret == 0)
 		buf[0] = '\0';
+
+	raw_spin_lock_irqsave(&trace_printk_lock, flags);
 	trace_bpf_trace_printk(buf);
 	raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
 
-	return ret;
-}
-
-/*
- * Only limited trace_printk() conversion specifiers allowed:
- * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
- */
-BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
-	   u64, arg2, u64, arg3)
-{
-	int i, mod[3] = {}, fmt_cnt = 0;
-	char buf[64], fmt_ptype;
-	void *unsafe_ptr = NULL;
-	bool str_seen = false;
+	bpf_printf_cleanup();
 
-	/*
-	 * 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)
-		return -EINVAL;
-
-	/* check format string for allowed specifiers */
-	for (i = 0; i < fmt_size; i++) {
-		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
-			return -EINVAL;
-
-		if (fmt[i] != '%')
-			continue;
-
-		if (fmt_cnt >= 3)
-			return -EINVAL;
-
-		/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
-		i++;
-		if (fmt[i] == 'l') {
-			mod[fmt_cnt]++;
-			i++;
-		} else if (fmt[i] == 'p') {
-			mod[fmt_cnt]++;
-			if ((fmt[i + 1] == 'k' ||
-			     fmt[i + 1] == 'u') &&
-			    fmt[i + 2] == 's') {
-				fmt_ptype = fmt[i + 1];
-				i += 2;
-				goto fmt_str;
-			}
-
-			if (fmt[i + 1] == 'B') {
-				i++;
-				goto fmt_next;
-			}
-
-			/* disallow any further format extensions */
-			if (fmt[i + 1] != 0 &&
-			    !isspace(fmt[i + 1]) &&
-			    !ispunct(fmt[i + 1]))
-				return -EINVAL;
-
-			goto fmt_next;
-		} else if (fmt[i] == 's') {
-			mod[fmt_cnt]++;
-			fmt_ptype = fmt[i];
-fmt_str:
-			if (str_seen)
-				/* allow only one '%s' per fmt string */
-				return -EINVAL;
-			str_seen = true;
-
-			if (fmt[i + 1] != 0 &&
-			    !isspace(fmt[i + 1]) &&
-			    !ispunct(fmt[i + 1]))
-				return -EINVAL;
-
-			switch (fmt_cnt) {
-			case 0:
-				unsafe_ptr = (void *)(long)arg1;
-				arg1 = (long)buf;
-				break;
-			case 1:
-				unsafe_ptr = (void *)(long)arg2;
-				arg2 = (long)buf;
-				break;
-			case 2:
-				unsafe_ptr = (void *)(long)arg3;
-				arg3 = (long)buf;
-				break;
-			}
-
-			bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
-					sizeof(buf));
-			goto fmt_next;
-		}
-
-		if (fmt[i] == 'l') {
-			mod[fmt_cnt]++;
-			i++;
-		}
-
-		if (fmt[i] != 'i' && fmt[i] != 'd' &&
-		    fmt[i] != 'u' && fmt[i] != 'x')
-			return -EINVAL;
-fmt_next:
-		fmt_cnt++;
-	}
-
-/* Horrid workaround for getting va_list handling working with different
- * argument type combinations generically for 32 and 64 bit archs.
- */
-#define __BPF_TP_EMIT()	__BPF_ARG3_TP()
-#define __BPF_TP(...)							\
-	bpf_do_trace_printk(fmt, ##__VA_ARGS__)
-
-#define __BPF_ARG1_TP(...)						\
-	((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64))	\
-	  ? __BPF_TP(arg1, ##__VA_ARGS__)				\
-	  : ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32))	\
-	      ? __BPF_TP((long)arg1, ##__VA_ARGS__)			\
-	      : __BPF_TP((u32)arg1, ##__VA_ARGS__)))
-
-#define __BPF_ARG2_TP(...)						\
-	((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64))	\
-	  ? __BPF_ARG1_TP(arg2, ##__VA_ARGS__)				\
-	  : ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32))	\
-	      ? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__)		\
-	      : __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
-
-#define __BPF_ARG3_TP(...)						\
-	((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64))	\
-	  ? __BPF_ARG2_TP(arg3, ##__VA_ARGS__)				\
-	  : ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32))	\
-	      ? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__)		\
-	      : __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
-
-	return __BPF_TP_EMIT();
+	return ret;
 }
 
 static const struct bpf_func_proto bpf_trace_printk_proto = {
@@ -581,184 +431,37 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
 }
 
 #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;
-		}
-	}
+	enum bpf_printf_mod_type mod[MAX_SEQ_PRINTF_VARARGS];
+	u64 args[MAX_SEQ_PRINTF_VARARGS];
+	int err, num_args;
 
+	if (data_len & 7 || data_len > MAX_SEQ_PRINTF_VARARGS * 8 ||
+	    (data_len && !data))
+		return -EINVAL;
 	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') {
-			void *unsafe_ptr;
-
-			/* try our best to copy */
-			if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
-				err = -E2BIG;
-				goto out;
-			}
-
-			unsafe_ptr = (void *)(long)args[fmt_cnt];
-			err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
-					unsafe_ptr, 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' ||
-			    fmt[i + 1] == 'B') {
-				/* 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 = copy_from_kernel_nofault(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' &&
-		    fmt[i] != 'X') {
-			err = -EINVAL;
-			goto out;
-		}
-
-		params[fmt_cnt] = args[fmt_cnt];
-		fmt_cnt++;
-	}
+	err = bpf_printf_prepare(fmt, fmt_size, data, args, mod, num_args);
+	if (err < 0)
+		return err;
 
 	/* 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]);
+	seq_printf(m, fmt, BPF_CAST_FMT_ARG(0, args, mod),
+		BPF_CAST_FMT_ARG(1, args, mod), BPF_CAST_FMT_ARG(2, args, mod),
+		BPF_CAST_FMT_ARG(3, args, mod), BPF_CAST_FMT_ARG(4, args, mod),
+		BPF_CAST_FMT_ARG(5, args, mod), BPF_CAST_FMT_ARG(6, args, mod),
+		BPF_CAST_FMT_ARG(7, args, mod), BPF_CAST_FMT_ARG(8, args, mod),
+		BPF_CAST_FMT_ARG(9, args, mod), BPF_CAST_FMT_ARG(10, args, mod),
+		BPF_CAST_FMT_ARG(11, args, mod));
 
-	err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
-out:
-	this_cpu_dec(bpf_seq_printf_buf_used);
-	return err;
+	bpf_printf_cleanup();
+
+	return seq_has_overflowed(m) ? -EOVERFLOW : 0;
 }
 
 BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)