ipc/sem.c assumes that pid values are 16 bit:
try_atomic_semop():
>
> curr->sempid = (curr->sempid << 16) | pid;
>
> undo:
> curr->sempid >>= 16;
>
What about the attached fix?
-- Manfred
--- 2.5/ipc/sem.c Sat Oct 19 11:40:17 2002 +++ build-2.5/ipc/sem.c Sat Oct 19 11:52:36 2002 @@ -263,39 +263,39 @@ for (sop = sops; sop < sops + nsops; sop++) { curr = sma->sem_base + sop->sem_num; sem_op = sop->sem_op; - - if (!sem_op && curr->semval) + result = curr->semval; + + if (!sem_op && result) goto would_block; - curr->sempid = (curr->sempid << 16) | pid; - curr->semval += sem_op; - if (sop->sem_flg & SEM_UNDO) - { + result += sem_op; + if (result < 0) + goto would_block; + if (result > SEMVMX) + goto out_of_range; + if (sop->sem_flg & SEM_UNDO) { int undo = un->semadj[sop->sem_num] - sem_op; /* * Exceeding the undo range is an error. */ if (undo < (-SEMAEM - 1) || undo > SEMAEM) - { - /* Don't undo the undo */ - sop->sem_flg &= ~SEM_UNDO; goto out_of_range; - } - un->semadj[sop->sem_num] = undo; } - if (curr->semval < 0) - goto would_block; - if (curr->semval > SEMVMX) - goto out_of_range; + curr->semval = result; } - if (do_undo) - { - sop--; + if (do_undo) { result = 0; goto undo; } - + sop--; + while (sop >= sops) { + sma->sem_base[sop->sem_num].sempid = pid; + if (sop->sem_flg & SEM_UNDO) + un->semadj[sop->sem_num] -= sop->sem_op; + sop--; + } + sma->sem_otime = CURRENT_TIME; return 0; @@ -310,13 +310,9 @@ result = 1; undo: + sop--; while (sop >= sops) { - curr = sma->sem_base + sop->sem_num; - curr->semval -= sop->sem_op; - curr->sempid >>= 16; - - if (sop->sem_flg & SEM_UNDO) - un->semadj[sop->sem_num] += sop->sem_op; + sma->sem_base[sop->sem_num].semval -= sop->sem_op; sop--; } @@ -637,7 +633,7 @@ err = curr->semval; goto out_unlock; case GETPID: - err = curr->sempid & 0xffff; + err = curr->sempid; goto out_unlock; case GETNCNT: err = count_semncnt(sma,semnum);
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This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:00:47 EST