AsInject

Fill a frozen process’s address space from parsed ELF data. Second step of the three-step process spawn sequence:

1. PSpawn creates a new FROZEN process and returns its handle.
2. AsInject fills the new process’s address space with parsed ELF data.
3. Kickstart marks the process as schedulable. This is the privileged step between PSpawn and Kickstart. The asinject struct is AsInjectArgs, defined in spawn_args.h:

typedef struct
{
    uint32_t size;        /* sizeof(AsInjectArgs); wrapper sets it */
    Handle taskHandle;     // handle of the target task
    VirtAddr DestVAddr;     // destination virtual address in the target task's address space
    const void *src_buf;  // pointer to the source buffer in the current task's address space
    size_t len;           // length of the source buffer in bytes
    MemProt prot;         // memory protection flags for the destination mapping (e.g., PROT_READ | PROT_WRITE)
    uint32_t flags;       // ASINJECT_FLAG_* bits; 0 for the original copy-in behavior
} AsInjectArgs;

flags accepts ASINJECT_FLAG_RESERVE: instead of copying len bytes from src_buf, it reserves [DestVAddr, DestVAddr + len) as demand-zero anonymous memory in the target address space. src_buf must be NULL when this flag is set, since no bytes are copied up front.

Pitfalls

Only the init process may call this. Ordinary processes spawn children by messaging init, not by calling AsInject directly. The init process is granted the permission via the PROC_FLAG_INIT flag in the PCB.

Arguments

Returns

0 on success.

Errors