From dcad1a204f72624796ae83359403898d10393b9c Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 3 Jul 2013 16:40:28 +0900 Subject: [PATCH] tracing/uprobes: Fetch args before reserving a ring buffer Fetching from user space should be done in a non-atomic context. So use a per-cpu buffer and copy its content to the ring buffer atomically. Note that we can migrate during accessing user memory thus use a per-cpu mutex to protect concurrent accesses. This is needed since we'll be able to fetch args from an user memory which can be swapped out. Before that uprobes could fetch args from registers only which saved in a kernel space. While at it, use __get_data_size() and store_trace_args() to reduce code duplication. And add struct uprobe_cpu_buffer and its helpers as suggested by Oleg. Reviewed-by: Masami Hiramatsu Acked-by: Oleg Nesterov Cc: Srikar Dronamraju Cc: zhangwei(Jovi) Cc: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim --- Reading git-format-patch failed