diff options
| -rw-r--r-- | sys/sys/proc.h | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/sys/sys/proc.h b/sys/sys/proc.h index 81b5551..e96dffa 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -141,15 +141,9 @@ struct pargs { * m - Giant * n - not locked, lazy * - * If the locking identifier is followed by a plus '+', then the specified - * member follows these special rules: - * - It is only written to by the current process. - * - It can be read by the current process and other processes. - * Thus, the locking rules for it are slightly different, and allow us to - * optimize the case where a process reads its own such value: - * - Writes to this member are locked. - * - Reads of this value by other processes are locked. - * - Reads of this value by the current process need not be locked. + * If the locking key specifies two identifiers (for example, p_pptr) then + * either lock is sufficient for read access, but both locks must be held + * for write access. */ struct ithd; @@ -159,7 +153,7 @@ struct proc { LIST_ENTRY(proc) p_list; /* (d) List of all processes. */ /* substructures: */ - struct pcred *p_cred; /* (c+) Process owner's identity. */ + struct pcred *p_cred; /* (c + k) Process owner's identity. */ struct filedesc *p_fd; /* (b) Ptr to open files structure. */ struct pstats *p_stats; /* (b) Accounting/statistics (CPU). */ struct plimit *p_limit; /* (m) Process limits. */ @@ -180,14 +174,14 @@ struct proc { pid_t p_pid; /* (b) Process identifier. */ LIST_ENTRY(proc) p_hash; /* (d) Hash chain. */ LIST_ENTRY(proc) p_pglist; /* (c) List of processes in pgrp. */ - struct proc *p_pptr; /* (e) Pointer to parent process. */ + struct proc *p_pptr; /* (c + e) Pointer to parent process. */ LIST_ENTRY(proc) p_sibling; /* (e) List of sibling processes. */ LIST_HEAD(, proc) p_children; /* (e) Pointer to list of children. */ /* The following fields are all zeroed upon creation in fork. */ #define p_startzero p_oppid - pid_t p_oppid; /* (c) Save parent pid during ptrace. XXX */ + pid_t p_oppid; /* (c + e) Save parent pid during ptrace. XXX */ int p_dupfd; /* (c) Sideways ret value from fdopen. XXX */ struct vmspace *p_vmspace; /* (b) Address space. */ @@ -258,7 +252,7 @@ struct proc { struct pgrp *p_pgrp; /* (e?/c?) Pointer to process group. */ struct sysentvec *p_sysent; /* (b) System call dispatch information. */ - struct pargs *p_args; /* (b?) Process arguments. */ + struct pargs *p_args; /* (c + k) Process arguments. */ /* End area that is copied on creation. */ #define p_endcopy p_addr @@ -434,18 +428,24 @@ sigonstack(size_t sp) FREE(s, M_SESSION); \ } -/* STOPEVENT() is MP safe. */ #define STOPEVENT(p, e, v) do { \ PROC_LOCK(p); \ + _STOPEVENT((p), (e), (v)); \ + PROC_UNLOCK(p); \ +} while (0) +#define _STOPEVENT(p, e, v) do { \ + PROC_LOCK_ASSERT(p, MA_OWNED); \ if ((p)->p_stops & (e)) { \ stopevent((p), (e), (v)); \ } \ - PROC_UNLOCK(p); \ } while (0) /* Lock and unlock a process. */ #define PROC_LOCK(p) mtx_lock(&(p)->p_mtx) #define PROC_UNLOCK(p) mtx_unlock(&(p)->p_mtx) +#define PROC_UNLOCK_NOSWITCH(p) \ + mtx_unlock_flags(&(p)->p_mtx, MTX_NOSWITCH) +#define PROC_LOCK_ASSERT(p, type) mtx_assert(&(p)->p_mtx, (type)) /* Lock and unlock the proc lists. */ #define ALLPROC_LOCK(how) \ @@ -469,15 +469,23 @@ sigonstack(size_t sp) /* Hold process U-area in memory, normally for ptrace/procfs work. */ #define PHOLD(p) do { \ PROC_LOCK(p); \ - if ((p)->p_lock++ == 0) \ - faultin(p); \ + _PHOLD(p); \ PROC_UNLOCK(p); \ } while (0) +#define _PHOLD(p) do { \ + PROC_LOCK_ASSERT((p), MA_OWNED); \ + if ((p)->p_lock++ == 0) \ + faultin((p)); \ +} while (0) #define PRELE(p) do { \ - PROC_LOCK(p); \ + PROC_LOCK((p)); \ + _PRELE((p)); \ + PROC_UNLOCK((p)); \ +} while (0) +#define _PRELE(p) do { \ + PROC_LOCK_ASSERT((p), MA_OWNED); \ (--(p)->p_lock); \ - PROC_UNLOCK(p); \ } while (0) #define PIDHASH(pid) (&pidhashtbl[(pid) & pidhash]) |
