Messages in this thread Patch in this message | | | Date | Fri, 28 Jul 2006 16:07:13 -0400 | From | nhorman@tuxdrive ... | Subject | [KJ] audit return code handling for kernel_thread [2/11] |
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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/s390/mm/cmm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -161,7 +161,10 @@ cmm_thread(void *dummy) static void cmm_start_thread(void) { - kernel_thread(cmm_thread, NULL, 0); + if (kernel_thread(cmm_thread, NULL, 0) < 0) { + printk(KERN_WARNING "Could not start cmm thread\n"); + clear_bit(0,&cmm_thread_active); + } } static void - 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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