syslog
Partial in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long syslog(int type, char *buf, int len);| Number (x86-64) | 103 |
| ABI | common |
| Kernel entry point | sys_syslog |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Reads or controls the kernel log buffer, as dmesg does.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
type (arg0) |
int |
Type selector (socket type, key type or similar). |
buf (arg1) |
char * |
Pointer to a data buffer. |
len (arg2) |
int |
Length in bytes. |
Return value
Section titled “Return value”On success: a command-specific value.
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 |
|---|---|---|
-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. Read commands decode the log buffer. An unknown command records a syslog.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 |
|---|---|---|---|---|
type (arg0) |
Entry | raw scalar word | args.0, args.type |
|
buf (arg1) |
Entry | the pointer itself, as a raw word | args.1, args.raw[1] |
|
| ↳ pointee | Exit | log text; length min(len (arg2), result) |
arg1.log |
type is a read action (READ, READ_ALL, READ_CLEAR) and result is 0 or greater |
len (arg2) |
Entry | raw scalar word | args.2, args.len |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.type(arg0),args.buf(arg1),args.len(arg2);args.0toargs.5by position.
See Syscall Trace filter for the full syntax.
Known gaps
Section titled “Known gaps”- An unknown
typerecordssyslog.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.