WARNING: braces {} are not necessary for single statement blocks
#139: FILE: src/sgsn/gprs_gmm.c:2568:
+	if (mmctx) {
+		return !mmctx->attach_rau.foreign;
+	}

WARNING: braces {} are not necessary for single statement blocks
#166: FILE: src/sgsn/gprs_gmm.c:2597:
+	if (!mme) {
+		return -EINVAL;
+	}

WARNING: else is not generally useful after a break or return
#196: FILE: src/sgsn/gprs_gmm.c:2627:
+		return -1;
+	} else {

ERROR: need consistent spacing around '|' (ctx:VxW) (or typedef missing in osmo-ci/lint/checkpatch/typedefs_osmo.txt?)
#273: FILE: src/sgsn/gprs_rau_fsm.c:365:
+		.in_event_mask = S(GMM_RAU_E_UE_RAU_REQUEST) | S(GMM_RAU_E_GGSN_UPD_RESP) | S(GMM_RAU_E_VLR_RAU_REJECT) | S(GMM_RAU_E_VLR_TERM_SUCCESS)| S(GMM_RAU_E_VLR_TERM_FAIL),
 		                                                                                                                                       ^

WARNING: braces {} are not necessary for single statement blocks
#398: FILE: src/sgsn/sgsn_libgtp.c:190:
+	if (!ggsn->gsn) {
+		ggsn->gsn = sgsn->gsn;
+	}

ERROR: Macros starting with if should be enclosed by a do - while loop to avoid possible if/else logic defects
#459: FILE: src/sgsn/sgsn_libgtp.c:913:
+#define CHECK_SPACE_ERR(bytes) \
+	if (ptr - buf + (bytes) > size) { \
+		LOGP(DGPRS, LOGL_ERROR, "Ran out of space encoding mm ctx: %lu, %lu\n", (ptr - buf), (unsigned long) bytes); \
+		return -1; \
+	}

ERROR: Macros with multiple statements should be enclosed in a do - while loop
#464: FILE: src/sgsn/sgsn_libgtp.c:918:
+#define MEMCPY_CHK(dst, src, len) \
+	CHECK_SPACE_ERR((len)) \
+	memcpy((dst), (uint8_t *)(src), (len)); \
+	(dst) += (len);

WARNING: macros should not use a trailing semicolon
#464: FILE: src/sgsn/sgsn_libgtp.c:918:
+#define MEMCPY_CHK(dst, src, len) \
+	CHECK_SPACE_ERR((len)) \
+	memcpy((dst), (uint8_t *)(src), (len)); \
+	(dst) += (len);

WARNING: 'transfered' may be misspelled - perhaps 'transferred'?
#631: FILE: src/sgsn/sgsn_libgtp.c:1085:
+	LOGMMCTXP(LOGL_INFO, mmctx, "Ctx will be transfered to another SGSN/MME\n");
 	                                         ^^^^^^^^^^

WARNING: braces {} are not necessary for single statement blocks
#671: FILE: src/sgsn/sgsn_libgtp.c:1125:
+		if (buf_len <= 0) {
+			return gtp_sgsn_context_resp_error(gsn, local_ref, GTPCAUSE_SYS_FAIL);
+		}

WARNING: please, no space before tabs
#685: FILE: src/sgsn/sgsn_libgtp.c:1139:
+^I^I// ^Ibreak;$

ERROR: Instead of strncpy()/strcpy(), use osmo_strlcpy() or OSMO_STRLCPY_ARRAY()
#924: FILE: src/sgsn/sgsn_libgtp.c:1378:
+	strncpy(mmctx->imsi, imsi_str, sizeof(mmctx->imsi));

WARNING: braces {} are not necessary for single statement blocks
#934: FILE: src/sgsn/sgsn_libgtp.c:1388:
+	if (rc) {
+		LOGMMCTXP(LOGL_ERROR, mmctx, "SGSN Context resp: Mandatory MM context parsing failed. Ignoring, try to use RAU information\n");
+	}

total: 4 errors, 9 warnings, 936 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Your patch has style problems, please review.

NOTE: Ignored message types: ASSIGN_IN_IF AVOID_EXTERNS BLOCK_COMMENT_STYLE COMPLEX_MACRO CONSTANT_COMPARISON DEEP_INDENTATION EMBEDDED_FILENAME EMBEDDED_FUNCTION_NAME EXECUTE_PERMISSIONS FILE_PATH_CHANGES GLOBAL_INITIALISERS IF_0 INITIALISED_STATIC LINE_CONTINUATIONS LINE_SPACING LONG_LINE LONG_LINE_COMMENT LONG_LINE_STRING MACRO_WITH_FLOW_CONTROL MISSING_SPACE PREFER_DEFINED_ATTRIBUTE_MACRO PREFER_FALLTHROUGH REPEATED_WORD SPDX_LICENSE_TAG SPLIT_STRING STRING_FRAGMENTS SYMBOLIC_PERMS TRACING_LOGGING TRAILING_STATEMENTS UNNECESSARY_BREAK UNNECESSARY_INT UNSPECIFIED_INT VOLATILE

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.