From: Chandra Seetharaman Date: Sun, 30 Jul 2006 10:03:04 +0000 (-0700) Subject: [PATCH] Process Events: Fix biarch compatibility issue. use __u64 timestamp X-Git-Tag: v2.6.18-rc4~149 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=822cfbff2ef49a08d1b9618d50f81b475d4f936c;p=linux-2.6 [PATCH] Process Events: Fix biarch compatibility issue. use __u64 timestamp 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 Signed-off-by: Matt Helsley Cc: Evgeniy Polyakov Cc: Guillaume Thouvenin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index 498aa37bca..3ece692313 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -51,6 +51,7 @@ void proc_fork_connector(struct task_struct *task) 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_struct *task) 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_struct *task) { 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_struct *task) 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_struct *task, int which_id) 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_struct *task, int which_id) } 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_struct *task) 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_struct *task) 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 rcvd_seq, int rcvd_ack) 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 rcvd_seq, int rcvd_ack) 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; diff --git a/include/linux/cn_proc.h b/include/linux/cn_proc.h index dbb7769009..1c86d65bc4 100644 --- a/include/linux/cn_proc.h +++ b/include/linux/cn_proc.h @@ -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;