Messages in this thread Patch in this message | | | Date | Fri, 28 Jul 2006 16:08:19 -0400 | From | nhorman@tuxdrive ... | Subject | [KJ] audit return code handling for kernel_thread [11/11] |
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Audit/Cleanup of kernel_thread calls, specifically checking of return codes. Problems seemed to fall into 3 main categories:
1) callers of kernel_thread were inconsistent about meaning of a zero return code. Some callers considered a zero return code to mean success, others took it to mean failure. a zero return code, while not actually possible in the current implementation, should be considered a success (pid 0 is/should be valid). fixed all callers to treat zero return as success
2) caller of kernel_thread saved return code of kernel_thread for later use without ever checking its value. Callers who did this tended to assume a non-zero return was success, and would often wait for a completion queue to be woken up, implying that an error (negative return code) from kernel_thread could lead to deadlock. Repaired by checking return code at call time, and setting saved return code to zero in the event of an error.
3) callers of kernel_thread never bothered to check the return code at all. This can lead to seemingly unrelated errors later in execution. Fixed by checking return code at call time and printing a warning message on failure.
Regards Neil
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
arch/ia64/sn/kernel/xpc_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/ia64/sn/kernel/xpc_main.c +++ b/arch/ia64/sn/kernel/xpc_main.c @@ -583,7 +583,7 @@ xpc_activate_partition(struct xpc_partit pid = kernel_thread(xpc_activating, (void *) ((u64) partid), 0); - if (unlikely(pid <= 0)) { + if (unlikely(pid < 0)) { spin_lock_irqsave(&part->act_lock, irq_flags); part->act_state = XPC_P_INACTIVE; XPC_SET_REASON(part, xpcCloneKThreadFailed, __LINE__); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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