patch 'test/mbuf: fix crash in a forked process' has been queued to stable release 20.11.9

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.9

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/17/23. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/20ca7fc9ed8af54ded8d54163f095d6730624d7e

Thanks.

Luca Boccassi

---
>From 20ca7fc9ed8af54ded8d54163f095d6730624d7e Mon Sep 17 00:00:00 2001
From: Ruifeng Wang <ruifeng.wang at arm.com>
Date: Mon, 22 May 2023 14:01:37 +0800
Subject: [PATCH] test/mbuf: fix crash in a forked process

[ upstream commit b6c419dde10e9f5dec7a02098c48060a7493420c ]

Access of any memory in the hugepage shared file-backed area will trigger
an unexpected forked child process segment fault. The root cause is DPDK
doesn't support fork model [1] (calling rte_eal_init() before fork()).
Forked child process can't be treated as a secondary process.

Hence fix it by avoiding fork and doing verification in the main process.

[1] https://mails.dpdk.org/archives/dev/2018-July/108106.html

Fixes: af75078fece3 ("first public release")

Signed-off-by: Jia He <justin.he at arm.com>
Signed-off-by: Ruifeng Wang <ruifeng.wang at arm.com>
Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 app/test/test_mbuf.c | 49 +++++++++++++-------------------------------
 1 file changed, 14 insertions(+), 35 deletions(-)

diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c
index 9f851da162..93736d8148 100644
--- a/app/test/test_mbuf.c
+++ b/app/test/test_mbuf.c
@@ -1173,37 +1173,16 @@ err:
 #endif
 }
 
-#include <unistd.h>
-#include <sys/resource.h>
-#include <sys/time.h>
-#include <sys/wait.h>
-
-/* use fork() to test mbuf errors panic */
-static int
-verify_mbuf_check_panics(struct rte_mbuf *buf)
+/* Verify if mbuf can pass the check */
+static bool
+mbuf_check_pass(struct rte_mbuf *buf)
 {
-	int pid;
-	int status;
+	const char *reason;
 
-	pid = fork();
+	if (rte_mbuf_check(buf, 1, &reason) == 0)
+		return true;
 
-	if (pid == 0) {
-		struct rlimit rl;
-
-		/* No need to generate a coredump when panicking. */
-		rl.rlim_cur = rl.rlim_max = 0;
-		setrlimit(RLIMIT_CORE, &rl);
-		rte_mbuf_sanity_check(buf, 1); /* should panic */
-		exit(0);  /* return normally if it doesn't panic */
-	} else if (pid < 0) {
-		printf("Fork Failed\n");
-		return -1;
-	}
-	wait(&status);
-	if(status == 0)
-		return -1;
-
-	return 0;
+	return false;
 }
 
 static int
@@ -1220,47 +1199,47 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
 		return -1;
 
 	printf("Checking good mbuf initially\n");
-	if (verify_mbuf_check_panics(buf) != -1)
+	if (!mbuf_check_pass(buf))
 		return -1;
 
 	printf("Now checking for error conditions\n");
 
-	if (verify_mbuf_check_panics(NULL)) {
+	if (mbuf_check_pass(NULL)) {
 		printf("Error with NULL mbuf test\n");
 		return -1;
 	}
 
 	badbuf = *buf;
 	badbuf.pool = NULL;
-	if (verify_mbuf_check_panics(&badbuf)) {
+	if (mbuf_check_pass(&badbuf)) {
 		printf("Error with bad-pool mbuf test\n");
 		return -1;
 	}
 
 	badbuf = *buf;
 	badbuf.buf_iova = 0;
-	if (verify_mbuf_check_panics(&badbuf)) {
+	if (mbuf_check_pass(&badbuf)) {
 		printf("Error with bad-physaddr mbuf test\n");
 		return -1;
 	}
 
 	badbuf = *buf;
 	badbuf.buf_addr = NULL;
-	if (verify_mbuf_check_panics(&badbuf)) {
+	if (mbuf_check_pass(&badbuf)) {
 		printf("Error with bad-addr mbuf test\n");
 		return -1;
 	}
 
 	badbuf = *buf;
 	badbuf.refcnt = 0;
-	if (verify_mbuf_check_panics(&badbuf)) {
+	if (mbuf_check_pass(&badbuf)) {
 		printf("Error with bad-refcnt(0) mbuf test\n");
 		return -1;
 	}
 
 	badbuf = *buf;
 	badbuf.refcnt = UINT16_MAX;
-	if (verify_mbuf_check_panics(&badbuf)) {
+	if (mbuf_check_pass(&badbuf)) {
 		printf("Error with bad-refcnt(MAX) mbuf test\n");
 		return -1;
 	}
-- 
2.39.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-06-15 01:56:37.759264545 +0100
+++ 0061-test-mbuf-fix-crash-in-a-forked-process.patch	2023-06-15 01:56:34.727544800 +0100
@@ -1 +1 @@
-From b6c419dde10e9f5dec7a02098c48060a7493420c Mon Sep 17 00:00:00 2001
+From 20ca7fc9ed8af54ded8d54163f095d6730624d7e Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit b6c419dde10e9f5dec7a02098c48060a7493420c ]
+
@@ -16 +17,0 @@
-Cc: stable at dpdk.org
@@ -22,2 +23,2 @@
- app/test/test_mbuf.c | 50 +++++++++++++-------------------------------
- 1 file changed, 14 insertions(+), 36 deletions(-)
+ app/test/test_mbuf.c | 49 +++++++++++++-------------------------------
+ 1 file changed, 14 insertions(+), 35 deletions(-)
@@ -26 +27 @@
-index 8d8d3b9386..efac01806b 100644
+index 9f851da162..93736d8148 100644
@@ -29,2 +30,2 @@
-@@ -1167,38 +1167,16 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
- 	return TEST_SKIPPED;
+@@ -1173,37 +1173,16 @@ err:
+ #endif
@@ -32,2 +33 @@
- #else
--
+ 
@@ -75 +75 @@
-@@ -1215,19 +1193,19 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
+@@ -1220,47 +1199,47 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
@@ -98,10 +98,8 @@
-@@ -1235,7 +1213,7 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
- 	if (RTE_IOVA_IN_MBUF) {
- 		badbuf = *buf;
- 		rte_mbuf_iova_set(&badbuf, 0);
--		if (verify_mbuf_check_panics(&badbuf)) {
-+		if (mbuf_check_pass(&badbuf)) {
- 			printf("Error with bad-physaddr mbuf test\n");
- 			return -1;
- 		}
-@@ -1243,21 +1221,21 @@ test_failing_mbuf_sanity_check(struct rte_mempool *pktmbuf_pool)
+ 
+ 	badbuf = *buf;
+ 	badbuf.buf_iova = 0;
+-	if (verify_mbuf_check_panics(&badbuf)) {
++	if (mbuf_check_pass(&badbuf)) {
+ 		printf("Error with bad-physaddr mbuf test\n");
+ 		return -1;
+ 	}