semctl
Partial in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long semctl(int semid, int semnum, int cmd, unsigned long arg);| Number (x86-64) | 66 |
| ABI | common |
| Kernel entry point | sys_semctl |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Queries, changes or removes a System V semaphore set or one of its semaphores.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
semid (arg0) |
int |
System V semaphore set id. |
semnum (arg1) |
int |
Index of the semaphore within the set. |
cmd (arg2) |
int |
Command or operation selector. |
arg (arg3) |
unsigned long |
Command-specific argument. |
Return value
Section titled “Return value”On success: a command-specific value, usually 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 |
|---|---|---|
-13 |
EACCES |
Permission denied. |
-22 |
EINVAL |
An argument is invalid. |
-1 |
EPERM |
The operation is not permitted for this process. |
Man page
Section titled “Man page”Captured by Antinomie
Section titled “Captured by Antinomie”Coverage mark: Partial. Known commands decode their structure, and GETALL/SETALL record the kernel’s own copy of the array. An unknown command records an ipc.unknown_selector “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 |
|---|---|---|---|---|
semid (arg0) |
Entry | raw scalar word | args.0, args.semid |
|
semnum (arg1) |
Entry | raw scalar word | args.1, args.semnum |
|
cmd (arg2) |
Entry | raw scalar word | args.2, args.cmd |
|
arg (arg3) |
Entry | raw scalar word | args.3, args.arg |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.semid(arg0),args.semnum(arg1),args.cmd(arg2),args.arg(arg3);args.0toargs.5by position. - Structure
seminfobehindarg(arg3):args.arg.<member>forsemaem,semmap,semmni,semmns,semmnu,semmsl,semopm,semume,semusz,semvmx.
See Syscall Trace filter for the full syntax.
Known gaps
Section titled “Known gaps”- An unknown command records
ipc.unknown_selectorwith 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.