From fe40f016c667f247b8e81c318cafa173de745fdd Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 14 Apr 2016 15:29:01 -0400 Subject: [PATCH] Add comment describing ioctl number duplication Signed-off-by: Mathieu Desnoyers --- lttng-abi.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/lttng-abi.h b/lttng-abi.h index e23393ff..9b9a2323 100644 --- a/lttng-abi.h +++ b/lttng-abi.h @@ -197,6 +197,11 @@ struct lttng_kernel_filter_bytecode { _IOR(0xF6, 0x58, int32_t) #define LTTNG_KERNEL_SESSION_UNTRACK_PID \ _IOR(0xF6, 0x59, int32_t) +/* + * ioctl 0x58 and 0x59 are duplicated here. It works, since _IOR vs _IO + * are generating two different ioctl numbers, but this was not done on + * purpose. We should generally try to avoid those duplications. + */ #define LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS _IO(0xF6, 0x58) #define LTTNG_KERNEL_SESSION_METADATA_REGEN _IO(0xF6, 0x59) -- 2.34.1