mmap
Implemented in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, unsigned long offset);| Number (x86-64) | 9 |
| ABI | common |
| Kernel entry point | sys_mmap |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Maps a file, or anonymous memory, into the address space of the process with the requested protection and sharing.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
addr (arg0) |
unsigned long |
Preferred address, or 0 to let the kernel choose. |
len (arg1) |
unsigned long |
Length of the mapping in bytes. |
prot (arg2) |
unsigned long |
Memory protection bits: PROT_READ, PROT_WRITE, PROT_EXEC. |
flags (arg3) |
unsigned long |
Mapping type and options: MAP_SHARED or MAP_PRIVATE, MAP_ANONYMOUS, MAP_FIXED, and others. |
fd (arg4) |
unsigned long |
File descriptor of the file to map; ignored for anonymous mappings. |
offset (arg5) |
unsigned long |
Value of type unsigned long. |
Return value
Section titled “Return value”On success: the address of the new mapping.
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. |
-9 |
EBADF |
A file descriptor is not valid for this operation. |
-22 |
EINVAL |
An argument is invalid. |
-12 |
ENOMEM |
The kernel is out of memory. |
Man page
Section titled “Man page”Captured by Antinomie
Section titled “Captured by Antinomie”Coverage mark: Implemented. All arguments are plain values, recorded as the raw argument words at entry. There is no pointee to copy and no known 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 |
|---|---|---|---|---|
addr (arg0) |
Entry | raw scalar word | args.0, args.addr |
|
len (arg1) |
Entry | raw scalar word | args.1, args.len |
|
prot (arg2) |
Entry | raw scalar word; Syscall Trace also decodes it into flag names (protection group), listing unknown bits separately |
args.2, args.prot |
|
flags (arg3) |
Entry | raw scalar word; Syscall Trace also decodes it into flag names (mmap group), listing unknown bits separately |
args.3, args.flags |
|
fd (arg4) |
Entry | raw scalar word | args.4, args.fd |
|
offset (arg5) |
Entry | raw scalar word | args.5, args.offset |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.addr(arg0),args.len(arg1),args.prot(arg2),args.flags(arg3),args.fd(arg4),args.offset(arg5);args.0toargs.5by position.
See Syscall Trace filter for the full syntax.
For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.