On Wed, 2010-06-23 at 20:02 +1000, Ian Munsie wrote:
> From: Jason Baron <jba...@redhat.com>
>
> Add core support to event tracing for compat syscalls. The basic idea is that
> we
> check if we have a compat task via 'is_compat_task()'. If so, we lookup in the
> new compat_syscalls_metadata table, the corresponding struct
> syscall_metadata, to
> check syscall arguments and whether or not we are enabled.
>
> Signed-off-by: Jason Baron <jba...@redhat.com>
> Signed-off-by: Ian Munsie <imun...@au1.ibm.com>
> ---
> include/linux/compat.h | 2 +
> include/trace/syscall.h | 4 ++
> kernel/trace/trace.h | 2 +
> kernel/trace/trace_syscalls.c | 86
> +++++++++++++++++++++++++++++++++++++----
> 4 files changed, 86 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/compat.h b/include/linux/compat.h
> index ab638e9..a94f13d 100644
> --- a/include/linux/compat.h
> +++ b/include/linux/compat.h
> @@ -363,6 +363,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
>
> #else /* CONFIG_COMPAT */
>
> +#define NR_syscalls_compat 0
> +
> static inline int is_compat_task(void)
> {
> return 0;
> diff --git a/include/trace/syscall.h b/include/trace/syscall.h
> index 75f3dce..67d4e64 100644
> --- a/include/trace/syscall.h
> +++ b/include/trace/syscall.h
> @@ -22,6 +22,7 @@
> struct syscall_metadata {
> const char *name;
> int syscall_nr;
> + int compat_syscall_nr;
This is also bloating the kernel. I don't like to add fields to the
syscall_metadata lightly.
You're adding 4 more bytes to this structure to handle a few items. Find
a better way to do this.
> int nb_args;
> const char **types;
> const char **args;
> @@ -38,6 +39,9 @@ struct syscall_metadata {
>
> #ifdef CONFIG_FTRACE_SYSCALLS
> extern unsigned long arch_syscall_addr(int nr);
> +#ifdef CONFIG_COMPAT
> +extern unsigned long arch_compat_syscall_addr(int nr);
> +#endif
> extern int init_syscall_trace(struct ftrace_event_call *call);
>
> extern int reg_event_syscall_enter(struct ftrace_event_call *call);
> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
> index 01ce088..53ace4b 100644
> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -79,12 +79,14 @@ enum trace_type {
> struct syscall_trace_enter {
> struct trace_entry ent;
> int nr;
> + int compat;
You're adding 4 bytes to a trace (taking up precious buffer space) for a
single flag. If anything, set the 31st bit of nr if it is compat.
-- Steve
> unsigned long args[];
> };
>
> struct syscall_trace_exit {
> struct trace_entry ent;
> int nr;
> + int compat;
> long ret;
> };
>
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
