X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Flib%2Fmsgpack%2Fmsgpack.c;h=54d5692679cd926fec304dc4bff0821142e6197e;hb=95ab0b458d258f604de7a1ef387e4be0d1c7ceb5;hp=16658d11b7843aaebe995126367e05d88ad8edd5;hpb=caf6ac496bf11139aefc46a69d2913e7f7222733;p=lttng-modules.git

diff --git a/src/lib/msgpack/msgpack.c b/src/lib/msgpack/msgpack.c
index 16658d11..54d56926 100644
--- a/src/lib/msgpack/msgpack.c
+++ b/src/lib/msgpack/msgpack.c
@@ -20,7 +20,6 @@
 
 #define _GNU_SOURCE
 #define _LGPL_SOURCE
-#include <stddef.h>
 
 #define MSGPACK_FIXSTR_ID_MASK		0xA0
 #define MSGPACK_FIXMAP_ID_MASK		0x80
@@ -58,6 +57,7 @@
 #include <asm/byteorder.h>
 
 #include <lttng/msgpack.h>
+#include <lttng/probe-user.h>
 
 #define INT8_MIN		(-128)
 #define INT16_MIN		(-32767-1)
@@ -114,6 +114,30 @@ end:
 	return ret;
 }
 
+static inline int lttng_msgpack_append_user_buffer(
+		struct lttng_msgpack_writer *writer,
+		const uint8_t __user *ubuf,
+		size_t length)
+{
+	int ret = 0;
+
+	lttng_msgpack_assert(ubuf);
+
+	/* Ensure we are not trying to write after the end of the buffer. */
+	if (writer->write_pos + length > writer->end_write_pos) {
+		ret = -1;
+		goto end;
+	}
+
+	if (lttng_copy_from_user_check_nofault(writer->write_pos, ubuf, length)) {
+		ret = -1;
+		goto end;
+	}
+	writer->write_pos += length;
+end:
+	return ret;
+}
+
 static inline int lttng_msgpack_append_u8(
 		struct lttng_msgpack_writer *writer, uint8_t value)
 {
@@ -144,20 +168,6 @@ static inline int lttng_msgpack_append_u64(
 	return lttng_msgpack_append_buffer(writer, (uint8_t *) &value, sizeof(value));
 }
 
-static inline int lttng_msgpack_append_f64(
-		struct lttng_msgpack_writer *writer, double value)
-{
-
-	union {
-		double d;
-		uint64_t u;
-	} u;
-
-	u.d = value;
-
-	return lttng_msgpack_append_u64(writer, u.u);
-}
-
 static inline int lttng_msgpack_append_i8(
 		struct lttng_msgpack_writer *writer, int8_t value)
 {
@@ -182,23 +192,6 @@ static inline int lttng_msgpack_append_i64(
 	return lttng_msgpack_append_u64(writer, (uint64_t) value);
 }
 
-static inline int lttng_msgpack_encode_f64(
-		struct lttng_msgpack_writer *writer, double value)
-{
-	int ret;
-
-	ret = lttng_msgpack_append_u8(writer, MSGPACK_FLOAT64_ID);
-	if (ret)
-		goto end;
-
-	ret = lttng_msgpack_append_f64(writer, value);
-	if (ret)
-		goto end;
-
-end:
-	return ret;
-}
-
 static inline int lttng_msgpack_encode_fixmap(
 		struct lttng_msgpack_writer *writer, uint8_t count)
 {
@@ -313,6 +306,53 @@ end:
 	return ret;
 }
 
+static inline int lttng_msgpack_encode_user_fixstr(
+		struct lttng_msgpack_writer *writer,
+		const char __user *ustr,
+		uint8_t len)
+{
+	int ret;
+
+	lttng_msgpack_assert(len <= MSGPACK_FIXSTR_MAX_LENGTH);
+
+	ret = lttng_msgpack_append_u8(writer, MSGPACK_FIXSTR_ID_MASK | len);
+	if (ret)
+		goto end;
+
+	ret = lttng_msgpack_append_user_buffer(writer, (uint8_t __user *) ustr, len);
+	if (ret)
+		goto end;
+
+end:
+	return ret;
+}
+
+static inline int lttng_msgpack_encode_user_str16(
+		struct lttng_msgpack_writer *writer,
+		const char __user *ustr,
+		uint16_t len)
+{
+	int ret;
+
+	lttng_msgpack_assert(len > MSGPACK_FIXSTR_MAX_LENGTH);
+
+	ret = lttng_msgpack_append_u8(writer, MSGPACK_STR16_ID);
+	if (ret)
+		goto end;
+
+	ret = lttng_msgpack_append_u16(writer, len);
+	if (ret)
+		goto end;
+
+	ret = lttng_msgpack_append_user_buffer(writer, (uint8_t __user *) ustr, len);
+	if (ret)
+		goto end;
+
+end:
+	return ret;
+}
+
+
 int lttng_msgpack_begin_map(struct lttng_msgpack_writer *writer, size_t count)
 {
 	int ret;
@@ -386,6 +426,30 @@ end:
 	return ret;
 }
 
+/*
+ * Provide the same behavior on lttng_strlen_user_inatomic page fault as the
+ * lttng ring buffer: truncate the last string character.
+ */
+int lttng_msgpack_write_user_str(struct lttng_msgpack_writer *writer,
+		const char __user *ustr)
+{
+	int ret;
+	size_t length = max_t(size_t, lttng_strlen_user_inatomic(ustr), 1);
+
+	if (length >= (1 << 16)) {
+		ret = -1;
+		goto end;
+	}
+
+	if (length <= MSGPACK_FIXSTR_MAX_LENGTH)
+		ret = lttng_msgpack_encode_user_fixstr(writer, ustr, length);
+	else
+		ret = lttng_msgpack_encode_user_str16(writer, ustr, length);
+
+end:
+	return ret;
+}
+
 int lttng_msgpack_write_nil(struct lttng_msgpack_writer *writer)
 {
 	return lttng_msgpack_append_u8(writer, MSGPACK_NIL_ID);
@@ -494,9 +558,16 @@ end:
 	return ret;
 }
 
-int lttng_msgpack_write_double(struct lttng_msgpack_writer *writer, double value)
+int lttng_msgpack_save_writer_pos(struct lttng_msgpack_writer *writer, uint8_t **pos)
+{
+	*pos = writer->write_pos;
+	return 0;
+}
+
+int lttng_msgpack_restore_writer_pos(struct lttng_msgpack_writer *writer, uint8_t *pos)
 {
-	return lttng_msgpack_encode_f64(writer, value);
+	writer->write_pos = pos;
+	return 0;
 }
 
 void lttng_msgpack_writer_init(struct lttng_msgpack_writer *writer,