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From: Christian Brauner <brauner@kernel.org>
To: Jacob Lalonde <jalalonde@meta.com>, Josef Bacik <josef@toxicpanda.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
	 Andrew Morton <akpm@linux-foundation.org>,
	 David Hildenbrand <david@kernel.org>,
	Lorenzo Stoakes <ljs@kernel.org>,
	 "Liam R. Howlett" <liam@infradead.org>,
	Vlastimil Babka <vbabka@kernel.org>,
	 Mike Rapoport <rppt@kernel.org>,
	Suren Baghdasaryan <surenb@google.com>,
	 Michal Hocko <mhocko@suse.com>,
	Omar Sandoval <osandov@osandov.com>,
	 Jacob Lalonde <jalalonde@fb.com>, Shuah Khan <shuah@kernel.org>,
	 linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	 linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
	 "Christian Brauner (Amutable)" <brauner@kernel.org>
Subject: [PATCH 02/11] selftests/coredump: collapse the expected request check into the helper
Date: Tue, 11 Aug 2026 17:27:23 +0200	[thread overview]
Message-ID: <20260811-work-coredump-sparse-v1-2-cd3e8b1e356d@kernel.org> (raw)
In-Reply-To: <20260811-work-coredump-sparse-v1-0-cd3e8b1e356d@kernel.org>

All nine callers spell the expected flags. So every new feature bit the
kernel learns has to be cargo culted.

The callers also all pass COREDUMP_ACK_SIZE_VER0 as the minimum request
size although what is being validated is coredump_req->size. And
read_coredump_req() makes the same mixup twice more.

Clean this all up.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 .../coredump/coredump_socket_protocol_test.c       | 36 ++++++----------------
 tools/testing/selftests/coredump/coredump_test.h   |  3 +-
 .../selftests/coredump/coredump_test_helpers.c     | 35 +++++++++++++--------
 3 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/tools/testing/selftests/coredump/coredump_socket_protocol_test.c b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
index d9fa6239b5a9..60a357e628eb 100644
--- a/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
+++ b/tools/testing/selftests/coredump/coredump_socket_protocol_test.c
@@ -151,9 +151,7 @@ TEST_F(coredump, socket_request_kernel)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_kernel: check_coredump_req failed\n");
 			goto out;
 		}
@@ -301,9 +299,7 @@ TEST_F(coredump, socket_request_userspace)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_userspace: check_coredump_req failed\n");
 			goto out;
 		}
@@ -441,9 +437,7 @@ TEST_F(coredump, socket_request_reject)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_reject: check_coredump_req failed\n");
 			goto out;
 		}
@@ -581,9 +575,7 @@ TEST_F(coredump, socket_request_invalid_flag_combination)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_invalid_flag_combination: check_coredump_req failed\n");
 			goto out;
 		}
@@ -702,9 +694,7 @@ TEST_F(coredump, socket_request_unknown_flag)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_unknown_flag: check_coredump_req failed\n");
 			goto out;
 		}
@@ -822,9 +812,7 @@ TEST_F(coredump, socket_request_invalid_size_small)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_invalid_size_small: check_coredump_req failed\n");
 			goto out;
 		}
@@ -944,9 +932,7 @@ TEST_F(coredump, socket_request_invalid_size_large)
 			goto out;
 		}
 
-		if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-					COREDUMP_KERNEL | COREDUMP_USERSPACE |
-					COREDUMP_REJECT | COREDUMP_WAIT)) {
+		if (!check_coredump_req(&req)) {
 			fprintf(stderr, "socket_request_invalid_size_large: check_coredump_req failed\n");
 			goto out;
 		}
@@ -1355,9 +1341,7 @@ TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps, 500)
 				goto out;
 			}
 
-			if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-						COREDUMP_KERNEL | COREDUMP_USERSPACE |
-						COREDUMP_REJECT | COREDUMP_WAIT)) {
+			if (!check_coredump_req(&req)) {
 				fprintf(stderr, "check_coredump_req failed for fd %d\n", fd_coredump);
 				goto out;
 			}
@@ -1509,9 +1493,7 @@ TEST_F_TIMEOUT(coredump, socket_multiple_crashing_coredumps_epoll_workers, 500)
 				fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: read_coredump_req failed\n");
 				goto out;
 			}
-			if (!check_coredump_req(&req, COREDUMP_ACK_SIZE_VER0,
-						COREDUMP_KERNEL | COREDUMP_USERSPACE |
-						COREDUMP_REJECT | COREDUMP_WAIT)) {
+			if (!check_coredump_req(&req)) {
 				fprintf(stderr, "socket_multiple_crashing_coredumps_epoll_workers: check_coredump_req failed\n");
 				goto out;
 			}
diff --git a/tools/testing/selftests/coredump/coredump_test.h b/tools/testing/selftests/coredump/coredump_test.h
index ed47f01fa53c..a02809145e2d 100644
--- a/tools/testing/selftests/coredump/coredump_test.h
+++ b/tools/testing/selftests/coredump/coredump_test.h
@@ -51,8 +51,7 @@ bool read_marker(int fd, enum coredump_mark mark);
 bool read_coredump_req(int fd, struct coredump_req *req);
 bool send_coredump_ack(int fd, const struct coredump_req *req,
 		       __u64 mask, size_t size_ack);
-bool check_coredump_req(const struct coredump_req *req, size_t min_size,
-			__u64 required_mask);
+bool check_coredump_req(const struct coredump_req *req);
 int open_coredump_tmpfile(int fd_tmpfs_detached);
 void process_coredump_worker(int fd_coredump, int fd_peer_pidfd, int fd_core_file);
 
diff --git a/tools/testing/selftests/coredump/coredump_test_helpers.c b/tools/testing/selftests/coredump/coredump_test_helpers.c
index 524fa5370593..d32d96436779 100644
--- a/tools/testing/selftests/coredump/coredump_test_helpers.c
+++ b/tools/testing/selftests/coredump/coredump_test_helpers.c
@@ -200,7 +200,7 @@ bool read_marker(int fd, enum coredump_mark mark)
 bool read_coredump_req(int fd, struct coredump_req *req)
 {
 	ssize_t ret;
-	size_t field_size, user_size, ack_size, kernel_size, remaining_size;
+	size_t field_size, user_size, known, kernel_size, remaining_size;
 
 	memset(req, 0, sizeof(*req));
 	field_size = sizeof(req->size);
@@ -214,9 +214,9 @@ bool read_coredump_req(int fd, struct coredump_req *req)
 	}
 	kernel_size = req->size;
 
-	if (kernel_size < COREDUMP_ACK_SIZE_VER0) {
+	if (kernel_size < COREDUMP_REQ_SIZE_VER0) {
 		fprintf(stderr, "read_coredump_req: kernel_size %zu < min %d\n",
-			kernel_size, COREDUMP_ACK_SIZE_VER0);
+			kernel_size, COREDUMP_REQ_SIZE_VER0);
 		return false;
 	}
 	if (kernel_size >= PAGE_SIZE) {
@@ -225,11 +225,11 @@ bool read_coredump_req(int fd, struct coredump_req *req)
 		return false;
 	}
 
-	/* Use the minimum of user and kernel size to read the full request. */
+	/* Consume as much of the request as we know about. */
 	user_size = sizeof(struct coredump_req);
-	ack_size = user_size < kernel_size ? user_size : kernel_size;
-	ret = recv(fd, req, ack_size, MSG_WAITALL);
-	if (ret != ack_size)
+	known = user_size < kernel_size ? user_size : kernel_size;
+	ret = recv(fd, req, known, MSG_WAITALL);
+	if (ret != known)
 		return false;
 
 	fprintf(stderr, "Read coredump request with size %u and mask 0x%llx\n",
@@ -287,15 +287,24 @@ bool send_coredump_ack(int fd, const struct coredump_req *req,
 	return true;
 }
 
-bool check_coredump_req(const struct coredump_req *req, size_t min_size,
-			__u64 required_mask)
+/* Every option the kernel is expected to advertise in coredump_req->mask. */
+#define COREDUMP_REQ_MASK_ALL					\
+	(COREDUMP_KERNEL | COREDUMP_USERSPACE |			\
+	 COREDUMP_REJECT | COREDUMP_WAIT)
+
+bool check_coredump_req(const struct coredump_req *req)
 {
-	if (req->size < min_size)
-		return false;
-	if ((req->mask & required_mask) != required_mask)
+	if (req->size < COREDUMP_REQ_SIZE_VER0) {
+		fprintf(stderr, "%s: size %u below minimum %d\n",
+			__func__, req->size, COREDUMP_REQ_SIZE_VER0);
 		return false;
-	if (req->mask & ~required_mask)
+	}
+	if (req->mask != COREDUMP_REQ_MASK_ALL) {
+		fprintf(stderr, "%s: mask 0x%llx, expected 0x%llx\n",
+			__func__, (unsigned long long)req->mask,
+			(unsigned long long)COREDUMP_REQ_MASK_ALL);
 		return false;
+	}
 	return true;
 }
 

-- 
2.53.0


  parent reply	other threads:[~2026-08-11 15:27 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-11 15:27 [PATCH 00/11] coredump: allow to create sparse coredumps on the coredump socket Christian Brauner
2026-08-11 15:27 ` [PATCH 01/11] selftests/coredump: discard the right amount after the coredump request Christian Brauner
2026-08-11 15:27 ` Christian Brauner [this message]
2026-08-11 15:27 ` [PATCH 03/11] coredump: pin the protocol struct sizes Christian Brauner
2026-08-11 15:27 ` [PATCH 04/11] coredump: move the negotiated mask into struct coredump_params Christian Brauner
2026-08-11 15:27 ` [PATCH 05/11] coredump: deduplicate the to_skip flush Christian Brauner
2026-08-11 15:27 ` [PATCH 06/11] coredump: add COREDUMP_HEADER to the coredump socket protocol Christian Brauner
2026-08-11 15:27 ` [PATCH 07/11] coredump: add COREDUMP_SPARSE " Christian Brauner
2026-08-11 15:27 ` [PATCH 08/11] tools: sync coredump.h header Christian Brauner
2026-08-11 15:27 ` [PATCH 09/11] coredump: frame the coredump when COREDUMP_HEADER is negotiated Christian Brauner
2026-08-11 15:27 ` [PATCH 10/11] coredump: describe the holes when COREDUMP_SPARSE " Christian Brauner
2026-08-11 15:27 ` [PATCH 11/11] selftests/coredump: test COREDUMP_HEADER and COREDUMP_SPARSE Christian Brauner
2026-08-11 19:07 ` [PATCH 00/11] coredump: allow to create sparse coredumps on the coredump socket Jann Horn
2026-08-11 19:39   ` Jann Horn
2026-08-11 20:55     ` Christian Brauner

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