Messages in this thread Patch in this message | | | Subject | Process Events: Fix biarch compatibility issue. use __u64 timestamp | From | Chandra Seetharaman <> | Date | Fri, 14 Jul 2006 09:45:13 -0700 |
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Linus, Andrew,
Events sent by Process Events Connector from a 64-bit kernel are not binary compatible with a 32-bit userspace program because the "timestamp" field (struct timespec) is not arch independent. This affects the fields that follow "timestamp" as they will be be off by 8 bytes.
This is a problem for 32-bit userspace programs running with 64-bit kernels on ppc64, s390, x86-64.. any "biarch" system.
Matt had submitted a different solution to lkml as an RFC earlier. We have since switched to a solution recommended by Evgeniy Polyakov.
This patch fixes the problem by changing the timestamp to be a __u64, which stores the number of nanoseconds.
Tested on a x86_64 system with both 32 bit application and 64 bit application and on a i386 system.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> --- Index: linux-2.6.18-rc1/include/linux/cn_proc.h =================================================================== --- linux-2.6.18-rc1.orig/include/linux/cn_proc.h 2006-07-13 15:14:25.000000000 -0700 +++ linux-2.6.18-rc1/include/linux/cn_proc.h 2006-07-13 15:14:38.000000000 -0700 @@ -57,7 +57,8 @@ struct proc_event { PROC_EVENT_EXIT = 0x80000000 } what; __u32 cpu; - struct timespec timestamp; + __u64 __attribute__((aligned(8))) timestamp_ns; + /* Number of nano seconds since system boot */ union { /* must be last field of proc_event struct */ struct { __u32 err; Index: linux-2.6.18-rc1/drivers/connector/cn_proc.c =================================================================== --- linux-2.6.18-rc1.orig/drivers/connector/cn_proc.c 2006-07-13 15:14:25.000000000 -0700 +++ linux-2.6.18-rc1/drivers/connector/cn_proc.c 2006-07-13 15:16:36.000000000 -0700 @@ -51,6 +51,7 @@ void proc_fork_connector(struct task_str struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE]; + struct timespec ts; if (atomic_read(&proc_event_num_listeners) < 1) return; @@ -58,7 +59,8 @@ void proc_fork_connector(struct task_str msg = (struct cn_msg*)buffer; ev = (struct proc_event*)msg->data; get_seq(&msg->seq, &ev->cpu); - ktime_get_ts(&ev->timestamp); /* get high res monotonic timestamp */ + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + ev->timestamp_ns = timespec_to_ns(&ts); ev->what = PROC_EVENT_FORK; ev->event_data.fork.parent_pid = task->real_parent->pid; ev->event_data.fork.parent_tgid = task->real_parent->tgid; @@ -76,6 +78,7 @@ void proc_exec_connector(struct task_str { struct cn_msg *msg; struct proc_event *ev; + struct timespec ts; __u8 buffer[CN_PROC_MSG_SIZE]; if (atomic_read(&proc_event_num_listeners) < 1) @@ -84,7 +87,8 @@ void proc_exec_connector(struct task_str msg = (struct cn_msg*)buffer; ev = (struct proc_event*)msg->data; get_seq(&msg->seq, &ev->cpu); - ktime_get_ts(&ev->timestamp); + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + ev->timestamp_ns = timespec_to_ns(&ts); ev->what = PROC_EVENT_EXEC; ev->event_data.exec.process_pid = task->pid; ev->event_data.exec.process_tgid = task->tgid; @@ -100,6 +104,7 @@ void proc_id_connector(struct task_struc struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE]; + struct timespec ts; if (atomic_read(&proc_event_num_listeners) < 1) return; @@ -118,7 +123,8 @@ void proc_id_connector(struct task_struc } else return; get_seq(&msg->seq, &ev->cpu); - ktime_get_ts(&ev->timestamp); + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + ev->timestamp_ns = timespec_to_ns(&ts); memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); msg->ack = 0; /* not used */ @@ -131,6 +137,7 @@ void proc_exit_connector(struct task_str struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE]; + struct timespec ts; if (atomic_read(&proc_event_num_listeners) < 1) return; @@ -138,7 +145,8 @@ void proc_exit_connector(struct task_str msg = (struct cn_msg*)buffer; ev = (struct proc_event*)msg->data; get_seq(&msg->seq, &ev->cpu); - ktime_get_ts(&ev->timestamp); + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + ev->timestamp_ns = timespec_to_ns(&ts); ev->what = PROC_EVENT_EXIT; ev->event_data.exit.process_pid = task->pid; ev->event_data.exit.process_tgid = task->tgid; @@ -164,6 +172,7 @@ static void cn_proc_ack(int err, int rcv struct cn_msg *msg; struct proc_event *ev; __u8 buffer[CN_PROC_MSG_SIZE]; + struct timespec ts; if (atomic_read(&proc_event_num_listeners) < 1) return; @@ -171,7 +180,8 @@ static void cn_proc_ack(int err, int rcv msg = (struct cn_msg*)buffer; ev = (struct proc_event*)msg->data; msg->seq = rcvd_seq; - ktime_get_ts(&ev->timestamp); + ktime_get_ts(&ts); /* get high res monotonic timestamp */ + ev->timestamp_ns = timespec_to_ns(&ts); ev->cpu = -1; ev->what = PROC_EVENT_NONE; ev->event_data.ack.err = err; --
---------------------------------------------------------------------- Chandra Seetharaman | Be careful what you choose.... - sekharan@us.ibm.com | .......you may get it. ----------------------------------------------------------------------
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