io_uring: decode struct io_uring_rsrc_register.flags field

Introduced by Linux commit v5.19-rc1~251^2~20.

* configure.ac: Remove struct io_uring_rsrc_register.resv check.
* src/xlat/uring_register_rsrc_flags.in: New file.
* src/io_uring.c: Include "xlat/uring_register_rsrc_flags.h".
(print_io_uring_register_rsrc): Remove CHECK_TYPE_SIZE for arg.resv,
decode flags field using PRINT_FIELD_FLAGS instead of optional decoding
of no longer existing resv field.
* tests/io_uring_register.c: Update expected output.

4 files changed, 16 insertions, 31 deletions

diff --git a/configure.ac b/configure.ac
index 2c68e5de2..4797b42dd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -581,12 +581,6 @@ AC_CHECK_MEMBERS(m4_normalize([
 		struct iocb.aio_rw_flags
 		]),,, [#include <linux/aio_abi.h>])
 
-AC_CHECK_TYPES([struct io_uring_rsrc_register], [
-	AC_CHECK_MEMBERS(m4_normalize([
-		struct io_uring_rsrc_register.resv
-	]),,, [#include <linux/io_uring.h>])
-],, [#include <linux/io_uring.h>])
-
 CPPFLAGS="$saved_CPPFLAGS"
 
 st_CHECK_ENUMS
diff --git a/src/io_uring.c b/src/io_uring.c
index a8602d27a..e59ccbe3c 100644
--- a/src/io_uring.c
+++ b/src/io_uring.c
@@ -19,6 +19,7 @@
 #include "xlat/uring_setup_flags.h"
 #include "xlat/uring_sqe_flags.h"
 #include "xlat/uring_register_opcodes.h"
+#include "xlat/uring_register_rsrc_flags.h"
 #include "xlat/uring_restriction_opcodes.h"
 
 static void
@@ -385,20 +386,12 @@ print_io_uring_rsrc_tags(struct tcb *tcp, const uint64_t tags,
 		    tfetch_mem, print_xint_array_member, NULL);
 }
 
-/* Work around field name change in Linux commit v5.19-rc1~251^2~20. */
-#ifdef HAVE_STRUCT_IO_URING_RSRC_REGISTER_RESV
-# define RESV resv
-#else
-# define RESV flags
-#endif
-
 static void
 print_io_uring_register_rsrc(struct tcb *tcp, const kernel_ulong_t addr,
 			     const unsigned int size, const unsigned int opcode)
 {
 	struct io_uring_rsrc_register arg;
 	CHECK_TYPE_SIZE(arg, 32);
-	CHECK_TYPE_SIZE(arg.RESV, sizeof(uint32_t));
 	CHECK_TYPE_SIZE(arg.resv2, sizeof(uint64_t));
 
 	if (size < 32) {
@@ -412,11 +405,9 @@ print_io_uring_register_rsrc(struct tcb *tcp, const kernel_ulong_t addr,
 	tprint_struct_begin();
 	PRINT_FIELD_U(arg, nr);
 
-	if (arg.RESV) {
-		tprint_struct_next();
-		tprints_field_name("resv");
-		PRINT_VAL_X(arg.RESV);
-	}
+	tprint_struct_next();
+	PRINT_FIELD_FLAGS(arg, flags, uring_register_rsrc_flags,
+			  "IORING_RSRC_REGISTER_???");
 
 	if (arg.resv2) {
 		tprint_struct_next();
@@ -435,8 +426,6 @@ print_io_uring_register_rsrc(struct tcb *tcp, const kernel_ulong_t addr,
 	tprint_struct_end();
 }
 
-#undef RESV
-
 static void
 print_io_uring_update_rsrc(struct tcb *tcp, const kernel_ulong_t addr,
 			   const unsigned int size, const unsigned int opcode)
diff --git a/src/xlat/uring_register_rsrc_flags.in b/src/xlat/uring_register_rsrc_flags.in
new file mode 100644
index 000000000..881ea8318
--- /dev/null
+++ b/src/xlat/uring_register_rsrc_flags.in
@@ -0,0 +1,2 @@
+#unconditional
+IORING_RSRC_REGISTER_SPARSE
diff --git a/tests/io_uring_register.c b/tests/io_uring_register.c
index 482b60f1b..b87b3c9bd 100644
--- a/tests/io_uring_register.c
+++ b/tests/io_uring_register.c
@@ -44,13 +44,6 @@
 
 #define ARR_ITEM(arr_, idx_) ((arr_)[(idx_) % ARRAY_SIZE(arr_)])
 
-/* Work around field name change in Linux commit v5.19-rc1~251^2~20. */
-#ifdef HAVE_STRUCT_IO_URING_RSRC_REGISTER_RESV
-# define RESV resv
-#else
-# define RESV flags
-#endif
-
 static const char path_null[] = "/dev/null";
 static const char path_full[] = "/dev/full";
 
@@ -652,6 +645,13 @@ main(void)
 		{ 13, "IORING_REGISTER_FILES2" },
 		{ 15, "IORING_REGISTER_BUFFERS2" },
 	};
+	static const struct strval32 rsrc_flags[] = {
+		{ ARG_STR(0) },
+		{ ARG_XLAT_KNOWN(0x1, "IORING_RSRC_REGISTER_SPARSE") },
+		{ ARG_XLAT_UNKNOWN(0x2, "IORING_RSRC_REGISTER_???") },
+		{ ARG_XLAT_KNOWN(0xbadc0ded,
+				 "IORING_RSRC_REGISTER_SPARSE|0xbadc0dec") },
+	};
 	static const uint64_t tags[] = { 0x1337, 1, 0xdead, 0xfacefeed,
 					 0xbadc0deddadfacedULL, 0 };
 	const uint64_t *arg_tags = tail_memdup(tags, sizeof(tags));
@@ -709,7 +709,7 @@ main(void)
 			rsrc_reg->nr += !!(j & 16);
 			rsrc_reg->nr &= ~-!(j & 32);
 
-			rsrc_reg->RESV = j & 64 ? 0xbadc0ded : 0;
+			rsrc_reg->flags = ARR_ITEM(rsrc_flags, j >> 6).val;
 			rsrc_reg->resv2 = j & 128 ? 0xfacecafebeeffeedULL : 0;
 
 			memcpy(big_rsrc_reg, rsrc_reg, sizeof(*rsrc_reg));
@@ -722,14 +722,14 @@ main(void)
 						      sizeof(*rsrc_reg)
 						      + (k / 2) * 8);
 				printf("io_uring_register(%u<%s>, " XLAT_FMT
-				       ", {nr=%zu%s%s",
+				       ", {nr=%zu, flags=%s%s",
 				       fd_null, path_null,
 				       XLAT_SEL(rsrc_reg_ops[i].op,
 						rsrc_reg_ops[i].str),
 				       j & 32 ? (i ? ARRAY_SIZE(iov)
 						   : ARRAY_SIZE(fds))
 						+ !!(j & 16) : 0,
-				       j & 64 ? ", resv=0xbadc0ded" : "",
+				       ARR_ITEM(rsrc_flags, j >> 6).str,
 				       j & 128 ? ", resv2=0xfacecafebeeffeed"
 					       : "");
 				print_rsrc_data(arg_iov, iov, arg_fds, fds,