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author | Oleg Nesterov <oleg@redhat.com> | 2013-11-08 21:52:21 +0400 |
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committer | Oleg Nesterov <oleg@redhat.com> | 2013-11-20 19:30:57 +0400 |
commit | 3247343118daa73f2b94b7fa565425d1d9f9ac84 (patch) | |
tree | db1b65941295431fbbb5cc8d822c0ebe0e0b6757 /include/linux/uprobes.h | |
parent | caea6cf52139116e43e615d87fcbf9823e197fdf (diff) | |
download | linux-3247343118daa73f2b94b7fa565425d1d9f9ac84.tar.xz |
uprobes: Add uprobe_task->dup_xol_work/dup_xol_addr
uprobe_task->vaddr is a bit strange. The generic code uses it only
to pass the additional argument to arch_uprobe_pre_xol(), and since
it is always equal to instruction_pointer() this looks even more
strange.
And both utask->vaddr and and utask->autask have the same scope,
they only have the meaning when the task executes the probed insn
out-of-line, so it is safe to reuse both in UTASK_RUNNING state.
This all means that logically ->vaddr belongs to arch_uprobe_task
and we should probably move it there, arch_uprobe_pre_xol() can
record instruction_pointer() itself.
OTOH, it is also used by uprobe_copy_process() and dup_xol_work()
for another purpose, this doesn't look clean and doesn't allow to
move this member into arch_uprobe_task.
This patch adds the union with 2 anonymous structs into uprobe_task.
The first struct is autask + vaddr, this way we "almost" move vaddr
into autask.
The second struct has 2 new members for uprobe_copy_process() paths:
->dup_xol_addr which can be used instead ->vaddr, and ->dup_xol_work
which can be used to avoid kmalloc() and simplify the code.
Note that this union will likely have another member(s), we need
something like "private_data_for_handlers" so that the tracing
handlers could use it to communicate with call_fetch() methods.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'include/linux/uprobes.h')
-rw-r--r-- | include/linux/uprobes.h | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 319eae70fe84..2225542624de 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -26,6 +26,7 @@ #include <linux/errno.h> #include <linux/rbtree.h> +#include <linux/types.h> struct vm_area_struct; struct mm_struct; @@ -72,14 +73,24 @@ enum uprobe_task_state { */ struct uprobe_task { enum uprobe_task_state state; - struct arch_uprobe_task autask; - struct return_instance *return_instances; - unsigned int depth; - struct uprobe *active_uprobe; + union { + struct { + struct arch_uprobe_task autask; + unsigned long vaddr; + }; + + struct { + struct callback_head dup_xol_work; + unsigned long dup_xol_addr; + }; + }; + struct uprobe *active_uprobe; unsigned long xol_vaddr; - unsigned long vaddr; + + struct return_instance *return_instances; + unsigned int depth; }; /* |