io_uring_register
Partial in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long io_uring_register(unsigned int fd, unsigned int op, void *arg, unsigned int nr_args);| Number (x86-64) | 427 |
| ABI | common |
| Kernel entry point | sys_io_uring_register |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Registers buffers, files and other resources with an io_uring instance, or changes its behavior.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
fd (arg0) |
unsigned int |
File descriptor to operate on. |
op (arg1) |
unsigned int |
Operation selector. |
arg (arg2) |
void * |
Command-specific argument. |
nr_args (arg3) |
unsigned int |
Number of arguments. |
Return value
Section titled “Return value”On success: a command-specific value, often 0.
In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.
Common errors
Section titled “Common errors”| Raw return | Name | Meaning |
|---|---|---|
-9 |
EBADF |
A file descriptor is not valid for this operation. |
-22 |
EINVAL |
An argument is invalid. |
Man page
Section titled “Man page”io_uring_register(2) on man7.org
Captured by Antinomie
Section titled “Captured by Antinomie”Coverage mark: Partial. Known registration opcodes decode their argument. An unknown opcode records a register_variant “no decoder” gap.
Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).
Arguments
Section titled “Arguments”| Argument | When | How | Recorded field key | Condition |
|---|---|---|---|---|
fd (arg0) |
Entry | raw scalar word | args.0, args.fd |
|
op (arg1) |
Entry | raw scalar word | args.1, args.op |
|
arg (arg2) |
Entry | the pointer itself, as a raw word | args.2, args.raw[2] |
|
| ↳ pointee | Entry and exit | by opcode: the structure or array that opcode takes (buffers, files, eventfd, restrictions, rsrc registration, probe, buffer rings, …), count from nr_args (arg3) |
arg2.register |
phase by opcode: inputs at entry, outputs at exit when result is 0 or greater |
| ↳ pointee | Entry | nested arrays reached through the structure, for the resource registration and buffer ring opcodes | arg2.resources, arg2.tags, arg2.buffer_ring |
always |
nr_args (arg3) |
Entry | raw scalar word | args.3, args.nr_args |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.fd(arg0),args.op(arg1),args.arg(arg2),args.nr_args(arg3);args.0toargs.5by position.
See Syscall Trace filter for the full syntax.
Known gaps
Section titled “Known gaps”- An unknown opcode records
arg2.register_variantwith the “no decoder” status. - See the coverage mark above for the code paths that record a gap.
For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.