io_uring: Fix probe of disabled operations

io_probe checks io_issue_def->not_supported, but we never really set
that field, as we mark non-supported functions through a specific ->prep
handler.  This means we end up returning IO_URING_OP_SUPPORTED, even for
disabled operations.  Fix it by just checking the prep handler itself.

Fixes: 66f4af93da57 ("io_uring: add support for probing opcodes")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240619020620.5301-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 2dd49cf22f642de056cb1d30715610bbc7ede22c..a2be3bbca5ffa17ed4295bfbec80d4abc1369462 100644 (file)
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -751,6 +751,14 @@ const char *io_uring_get_opcode(u8 opcode)
        return "INVALID";
 }
 
+bool io_uring_op_supported(u8 opcode)
+{
+       if (opcode < IORING_OP_LAST &&
+           io_issue_defs[opcode].prep != io_eopnotsupp_prep)
+               return true;
+       return false;
+}
+
 void __init io_uring_optable_init(void)
 {
        int i;

diff --git a/io_uring/opdef.h b/io_uring/opdef.h
index 7ee6f5aa90aa3cd4f2882c8cd9700b7ebb7106dc..14456436ff74ac20613aeda0eeff5bcc5157da11 100644 (file)
--- a/io_uring/opdef.h
+++ b/io_uring/opdef.h
@@ -17,8 +17,6 @@ struct io_issue_def {
        unsigned                poll_exclusive : 1;
        /* op supports buffer selection */
        unsigned                buffer_select : 1;
-       /* opcode is not supported by this kernel */
-       unsigned                not_supported : 1;
        /* skip auditing */
        unsigned                audit_skip : 1;
        /* supports ioprio */
@@ -47,5 +45,7 @@ struct io_cold_def {
 extern const struct io_issue_def io_issue_defs[];
 extern const struct io_cold_def io_cold_defs[];
 
+bool io_uring_op_supported(u8 opcode);
+
 void io_uring_optable_init(void);
 #endif

diff --git a/io_uring/register.c b/io_uring/register.c
index f121e02f5e10e6c4ed4c9d8da0831b4284531642..e28cc226217cdb119863b3bf846dc8471356c0dc 100644 (file)
--- a/io_uring/register.c
+++ b/io_uring/register.c
@@ -59,7 +59,7 @@ static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg,
 
        for (i = 0; i < nr_args; i++) {
                p->ops[i].op = i;
-               if (!io_issue_defs[i].not_supported)
+               if (io_uring_op_supported(i))
                        p->ops[i].flags = IO_URING_OP_SUPPORTED;
        }
        p->ops_len = i;