From: "Bruno Prémont" <bonbons@linux-vserver.org> To: Jiri Kosina <jkosina@suse.cz> Cc: <linux-input@vger.kernel.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH] hid: avoid '\0' in hid debugfs events file Date: Mon, 15 Mar 2010 19:00:27 +0100 [thread overview] Message-ID: <20100315190027.752c82ea@neptune.home> (raw) When dumping /sys/kernel/debug/hid/$device/events '\0' characters show up (invisible if cat to console but shown by less or while looking at a dump file). These are due to hid_debug_event() adding strlen()+1 bytes to the ring buffer (e.g. including the trailing '\0'). Any roll-over causes a '\0' as well as hid_debug_event() handles the ring buffers with HID_DEBUG_BUFSIZE-1 size while hid_debug_events_read() handles it with full HID_DEBUG_BUFSIZE size. Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org> --- Note: The ring buffer overflow case (when tail crosses head) seems to be suboptimal at best. Would there be a good way to mark those cases so reader can know where data got lost. (though this might not be easy keeping the lockless design) diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c index 6abd036..2602695 100644 --- a/drivers/hid/hid-debug.c +++ b/drivers/hid/hid-debug.c @@ -564,10 +564,10 @@ void hid_debug_event(struct hid_device *hdev, char *buf) struct hid_debug_list *list; list_for_each_entry(list, &hdev->debug_list, node) { - for (i = 0; i <= strlen(buf); i++) - list->hid_debug_buf[(list->tail + i) % (HID_DEBUG_BUFSIZE - 1)] = + for (i = 0; i < strlen(buf); i++) + list->hid_debug_buf[(list->tail + i) % HID_DEBUG_BUFSIZE] = buf[i]; - list->tail = (list->tail + i) % (HID_DEBUG_BUFSIZE - 1); + list->tail = (list->tail + i) % HID_DEBUG_BUFSIZE; } } EXPORT_SYMBOL_GPL(hid_debug_event);
WARNING: multiple messages have this Message-ID (diff)
From: "Bruno Prémont" <bonbons@linux-vserver.org> To: Jiri Kosina <jkosina@suse.cz> Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] hid: avoid '\0' in hid debugfs events file Date: Mon, 15 Mar 2010 19:00:27 +0100 [thread overview] Message-ID: <20100315190027.752c82ea@neptune.home> (raw) When dumping /sys/kernel/debug/hid/$device/events '\0' characters show up (invisible if cat to console but shown by less or while looking at a dump file). These are due to hid_debug_event() adding strlen()+1 bytes to the ring buffer (e.g. including the trailing '\0'). Any roll-over causes a '\0' as well as hid_debug_event() handles the ring buffers with HID_DEBUG_BUFSIZE-1 size while hid_debug_events_read() handles it with full HID_DEBUG_BUFSIZE size. Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org> --- Note: The ring buffer overflow case (when tail crosses head) seems to be suboptimal at best. Would there be a good way to mark those cases so reader can know where data got lost. (though this might not be easy keeping the lockless design) diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c index 6abd036..2602695 100644 --- a/drivers/hid/hid-debug.c +++ b/drivers/hid/hid-debug.c @@ -564,10 +564,10 @@ void hid_debug_event(struct hid_device *hdev, char *buf) struct hid_debug_list *list; list_for_each_entry(list, &hdev->debug_list, node) { - for (i = 0; i <= strlen(buf); i++) - list->hid_debug_buf[(list->tail + i) % (HID_DEBUG_BUFSIZE - 1)] = + for (i = 0; i < strlen(buf); i++) + list->hid_debug_buf[(list->tail + i) % HID_DEBUG_BUFSIZE] = buf[i]; - list->tail = (list->tail + i) % (HID_DEBUG_BUFSIZE - 1); + list->tail = (list->tail + i) % HID_DEBUG_BUFSIZE; } } EXPORT_SYMBOL_GPL(hid_debug_event); -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next reply other threads:[~2010-03-15 18:01 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-03-15 18:00 Bruno Prémont [this message] 2010-03-15 18:00 ` [PATCH] hid: avoid '\0' in hid debugfs events file Bruno Prémont 2010-03-16 12:58 ` Jiri Kosina 2010-03-16 12:58 ` Jiri Kosina 2010-03-16 17:35 ` Bruno Prémont 2010-03-16 17:35 ` Bruno Prémont
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